/* ===== MODERN PORTFOLIO STYLES ===== */

/* Reset & Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Color Palette */
    --primary: #00d4ff;
    --secondary: #7c3aed;
    --accent: #ff6b6b;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    
    /* Neutral Colors */
    --dark: #0f172a;
    --gray-900: #1e293b;
    --gray-800: #334155;
    --gray-700: #475569;
    --gray-600: #64748b;
    --gray-500: #94a3b8;
    --gray-400: #cbd5e1;
    --gray-300: #e2e8f0;
    --gray-200: #f1f5f9;
    --gray-100: #f8fafc;
    --white: #ffffff;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    --gradient-accent: linear-gradient(135deg, var(--accent) 0%, var(--warning) 100%);
    --gradient-dark: linear-gradient(135deg, var(--dark) 0%, var(--gray-900) 100%);
    
    /* Typography */
    --font-primary: 'Poppins', sans-serif;
    --font-code: 'Fira Code', monospace;
    
    /* Spacing */
    --section-padding: 120px 0;
    --border-radius: 12px;
    --border-radius-lg: 20px;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 15px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.15);
    --shadow-xl: 0 20px 50px rgba(0, 0, 0, 0.2);
    
    /* Transitions */
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: var(--font-primary);
    font-weight: 400;
    line-height: 1.6;
    color: var(--gray-700);
    background: var(--dark);
    overflow-x: hidden;
}

/* ===== UTILITY CLASSES ===== */
.section-padding {
    padding: var(--section-padding);
}

.highlight {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
}

.title-highlight {
    position: relative;
    color: var(--white);
}

.title-highlight::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 50px;
    height: 3px;
    background: var(--gradient-primary);
    border-radius: 2px;
}

/* ===== MATRIX BACKGROUND ===== */
.matrix-background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -2;
    background: var(--dark);
    overflow: hidden;
}

.matrix-background::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 20% 80%, rgba(0, 212, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(124, 58, 237, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(255, 107, 107, 0.05) 0%, transparent 50%);
    animation: matrixMove 20s ease-in-out infinite;
}

@keyframes matrixMove {
    0%, 100% { transform: translate(0, 0); }
    25% { transform: translate(-20px, -10px); }
    50% { transform: translate(20px, -20px); }
    75% { transform: translate(-10px, 10px); }
}

/* ===== PAGE LOADER ===== */
.page-loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--dark);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

.page-loader.hidden {
    opacity: 0;
    visibility: hidden;
}

.terminal-loader {
    background: var(--gray-900);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    width: 400px;
    max-width: 90vw;
}

.terminal-header {
    background: var(--gray-800);
    padding: 12px 16px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.terminal-controls {
    display: flex;
    gap: 6px;
}

.control {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.control.red { background: #ff5f56; }
.control.yellow { background: #ffbd2e; }
.control.green { background: #27ca3f; }

.terminal-title {
    color: var(--gray-400);
    font-family: var(--font-code);
    font-size: 12px;
}

.terminal-body {
    padding: 20px;
    background: var(--gray-900);
    font-family: var(--font-code);
}

.typing-text {
    color: var(--primary);
    font-size: 14px;
}

.cursor {
    animation: blink 1s infinite;
    color: var(--primary);
}

@keyframes blink {
    0%, 50% { opacity: 1; }
    51%, 100% { opacity: 0; }
}

/* ===== NAVIGATION ===== */
.navbar {
    background: rgba(15, 23, 42, 0.95) !important;
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    padding: 1rem 0;
    transition: var(--transition);
}

.navbar.scrolled {
    background: rgba(15, 23, 42, 0.98) !important;
    box-shadow: var(--shadow-lg);
}

.navbar-brand {
    font-family: var(--font-code);
    font-weight: 600;
    font-size: 1.5rem;
    color: var(--white) !important;
    text-decoration: none;
}

.brand-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.navbar-toggler {
    border: none;
    padding: 0;
    width: 30px;
    height: 20px;
    position: relative;
}

.navbar-toggler span {
    display: block;
    width: 100%;
    height: 2px;
    background: var(--white);
    margin: 4px 0;
    transition: var(--transition);
    border-radius: 2px;
}

.navbar-toggler:focus {
    box-shadow: none;
}

.nav-link {
    color: var(--gray-300) !important;
    font-weight: 500;
    padding: 0.8rem 1.2rem !important;
    position: relative;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link i {
    font-size: 14px;
    width: 16px;
}

.nav-link::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: var(--transition);
    transform: translateX(-50%);
}

.nav-link:hover,
.nav-link.active {
    color: var(--white) !important;
    transform: translateY(-2px);
}

.nav-link:hover::before,
.nav-link.active::before {
    width: 80%;
}

/* ===== HERO SECTION ===== */
.hero-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
}

.hero-particles {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

.hero-content {
    color: var(--white);
    z-index: 2;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(0, 212, 255, 0.1);
    border: 1px solid rgba(0, 212, 255, 0.3);
    padding: 8px 16px;
    border-radius: 25px;
    font-size: 14px;
    font-weight: 500;
    color: var(--primary);
    margin-bottom: 1.5rem;
    backdrop-filter: blur(10px);
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 1rem;
    color: var(--white);
}

.hero-subtitle {
    font-size: 1.5rem;
    font-weight: 500;
    margin-bottom: 1.5rem;
    min-height: 2.5rem;
    display: flex;
    align-items: center;
}

.cursor-blink {
    animation: blink 1s infinite;
    color: var(--primary);
    font-weight: 300;
}

.hero-description {
    font-size: 1.1rem;
    color: #e2e8f0; /* Sáng hơn cho dễ đọc */
    margin-bottom: 2rem;
    max-width: 500px;
    line-height: 1.8;
}

.hero-stats {
    display: flex;
    gap: 2rem;
    margin-bottom: 2.5rem;
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
    display: block;
}

.stat-label {
    font-size: 0.9rem;
    color: #cbd5e1; /* Sáng hơn cho dễ đọc */
    margin-top: 4px;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.hero-actions .btn {
    flex: 1; /* Cả 2 buttons có width bằng nhau */
    min-width: 200px; /* Tăng min-width */
}

.btn {
    padding: 14px 30px; /* Tăng size cho đồng đều */
    border-radius: 30px; /* Bo tròn hơn */
    font-weight: 600;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    transition: var(--transition);
    border: 2px solid transparent; /* Border transparent để size đều nhau */
    cursor: pointer;
    font-size: 1rem;
    box-sizing: border-box; /* Đảm bảo border không làm thay đổi kích thước */
}

.btn-primary {
    background: rgba(0, 212, 255, 0.1); /* Nền mờ giống outline */
    color: var(--white);
    border-color: rgba(0, 212, 255, 0.5); /* Thêm border như outline */
    box-shadow: none; /* Không có shadow */
}

.btn-primary:hover {
    background: var(--gradient-primary); /* Hover mới có gradient */
    transform: translateY(-3px);
    box-shadow: 0 6px 25px rgba(0, 212, 255, 0.5);
    color: var(--white);
    border-color: transparent;
}

.btn-outline {
    background: rgba(0, 212, 255, 0.1); /* Nền mờ giống primary */
    color: var(--white);
    border-color: rgba(0, 212, 255, 0.5);
    backdrop-filter: blur(10px);
    box-shadow: none; /* Không có shadow */
}

.btn-outline:hover {
    background: var(--gradient-primary); /* Hover mới có gradient */
    color: var(--white);
    border-color: transparent;
    transform: translateY(-3px);
    box-shadow: 0 6px 25px rgba(0, 212, 255, 0.5);
}

/* ===== HERO VISUAL ===== */
.hero-visual {
    position: relative;
    z-index: 1;
}

.code-window {
    background: var(--gray-900);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    transform: perspective(1000px) rotateY(-5deg) rotateX(5deg);
    transition: var(--transition-slow);
}

.code-window:hover {
    transform: perspective(1000px) rotateY(0deg) rotateX(0deg);
}

.window-header {
    background: var(--gray-800);
    padding: 12px 16px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.window-controls {
    display: flex;
    gap: 6px;
}

.window-title {
    color: var(--gray-400);
    font-family: var(--font-code);
    font-size: 12px;
}

.code-content {
    padding: 20px;
    font-family: var(--font-code);
    font-size: 14px;
    line-height: 1.8;
}

.code-line {
    display: flex;
    align-items: center;
    margin-bottom: 4px;
    opacity: 0;
    animation: codeReveal 0.5s ease forwards;
}

.code-line:nth-child(1) { animation-delay: 0.5s; }
.code-line:nth-child(2) { animation-delay: 0.7s; }
.code-line:nth-child(3) { animation-delay: 0.9s; }
.code-line:nth-child(4) { animation-delay: 1.1s; }
.code-line:nth-child(5) { animation-delay: 1.3s; }
.code-line:nth-child(6) { animation-delay: 1.5s; }

@keyframes codeReveal {
    to {
        opacity: 1;
    }
}

.line-number {
    color: var(--gray-500);
    width: 20px;
    text-align: right;
    margin-right: 16px;
    user-select: none;
}

.code-text {
    color: var(--gray-300);
}

.keyword { color: #c678dd; }
.class-name { color: #e5c07b; }
.function { color: #61afef; }
.string { color: #98c379; }

.floating-elements {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

.floating-icon {
    position: absolute;
    width: 50px;
    height: 50px;
    background: rgba(0, 212, 255, 0.1);
    border: 1px solid rgba(0, 212, 255, 0.3);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    font-size: 20px;
    backdrop-filter: blur(10px);
    animation: float 6s ease-in-out infinite;
    animation-delay: var(--delay);
}

.floating-icon:nth-child(1) { top: 10%; left: 10%; }
.floating-icon:nth-child(2) { top: 20%; right: 15%; }
.floating-icon:nth-child(3) { bottom: 30%; left: 5%; }
.floating-icon:nth-child(4) { bottom: 15%; right: 10%; }
.floating-icon:nth-child(5) { top: 50%; left: -10%; }

@keyframes float {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    25% { transform: translateY(-10px) rotate(5deg); }
    50% { transform: translateY(-20px) rotate(0deg); }
    75% { transform: translateY(-10px) rotate(-5deg); }
}

.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    color: var(--gray-400);
    text-align: center;
    animation: bounce 2s infinite;
}

.scroll-text {
    font-size: 14px;
    margin-bottom: 8px;
}

.scroll-arrow {
    font-size: 16px;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
    40% { transform: translateX(-50%) translateY(-10px); }
    60% { transform: translateX(-50%) translateY(-5px); }
}

/* ===== ABOUT SECTION ===== */
.about-section {
    background: var(--gray-900);
    position: relative;
}

.section-header {
    margin-bottom: 4rem;
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--white);
}

.section-subtitle {
    font-size: 1.1rem;
    color: #cbd5e1; /* Sáng hơn cho dễ đọc */
    max-width: 600px;
    margin: 0 auto;
}

.about-image {
    position: relative;
    z-index: 2;
}

.image-frame {
    position: relative;
    width: 100%;
    max-width: 400px;
    margin: 0 auto;
}

.profile-pic {
    width: 300px;
    height: 300px;
    border-radius: 50%;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 8rem;
    color: var(--white);
    box-shadow: var(--shadow-xl);
    position: relative;
    overflow: hidden;
    margin: 0 auto;
}

.profile-pic::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--gradient-primary);
    opacity: 0.1;
    transition: var(--transition);
}

.profile-pic:hover::before {
    opacity: 0.2;
}

.experience-badge {
    position: absolute;
    top: 20px;
    right: 20px;
    width: 80px;
    height: 80px;
    background: var(--gray-800);
    border: 3px solid var(--primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
}

.badge-content {
    text-align: center;
}

.badge-number {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    line-height: 1;
}

.badge-text {
    font-size: 0.7rem;
    color: var(--gray-400);
    line-height: 1.2;
}

.achievement-badges {
    margin-top: 3rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.achievement-item {
    display: flex;
    align-items: center;
    gap: 12px;
    background: rgba(0, 212, 255, 0.1);
    border: 1px solid rgba(0, 212, 255, 0.3);
    padding: 12px 16px;
    border-radius: var(--border-radius);
    color: var(--primary);
    font-size: 14px;
    font-weight: 500;
    backdrop-filter: blur(10px);
    transition: var(--transition);
}

.achievement-item:hover {
    background: rgba(0, 212, 255, 0.2);
    transform: translateX(5px);
}

.about-content {
    color: var(--white);
}

.about-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--white);
}

.about-description {
    font-size: 1.1rem;
    color: #e2e8f0; /* Sáng hơn cho dễ đọc */
    line-height: 1.8;
    margin-bottom: 2rem;
}

.motto-card {
    background: rgba(0, 212, 255, 0.1);
    border: 1px solid rgba(0, 212, 255, 0.3);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin-bottom: 2rem;
    position: relative;
    backdrop-filter: blur(10px);
}

.motto-icon {
    position: absolute;
    top: -10px;
    left: 20px;
    width: 20px;
    height: 20px;
    background: var(--primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 10px;
    color: var(--white);
}

.motto-text {
    font-style: italic;
    font-size: 1rem;
    color: #e2e8f0; /* Sáng hơn cho dễ đọc */
    margin: 0;
    line-height: 1.6;
}

.personal-info {
    margin-bottom: 2rem;
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
}

.info-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.info-label {
    font-weight: 500;
    color: var(--gray-400);
}

.info-value {
    font-weight: 600;
    color: var(--white);
}

.soft-skills {
    margin-top: 2rem;
}

.skills-title {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--white);
}

.skills-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem;
}

.skill-tag {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(124, 58, 237, 0.1);
    border: 1px solid rgba(124, 58, 237, 0.3);
    padding: 8px 16px;
    border-radius: 25px;
    font-size: 14px;
    font-weight: 500;
    color: var(--secondary);
    backdrop-filter: blur(10px);
    transition: var(--transition);
}

.skill-tag:hover {
    background: rgba(124, 58, 237, 0.2);
    transform: translateY(-2px);
}

/* ===== RESPONSIVE DESIGN ===== */
@media (max-width: 768px) {
    .hero-stats {
        gap: 1rem;
    }
    
    .stat-number {
        font-size: 1.5rem;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .code-window {
        transform: none;
    }
    
    .floating-icon {
        display: none;
    }
    
    .achievement-badges {
        margin-top: 2rem;
    }
    
    .info-grid {
        grid-template-columns: 1fr;
    }
}

/* Animated Background */
.animated-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background: linear-gradient(-45deg, #667eea, #764ba2, #f093fb, #f5576c);
    background-size: 400% 400%;
    animation: gradientShift 15s ease infinite;
}

.animated-bg::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(45deg, #667eea, #764ba2, #f093fb, #f5576c);
    background-size: 400% 400%;
    animation: gradientShift 20s ease infinite reverse;
    opacity: 0.8;
}

@keyframes gradientShift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

/* Navbar */
.navbar {
    background: rgba(255, 255, 255, 0.95) !important;
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    box-shadow: 0 4px 30px rgba(0,0,0,0.1);
    transition: all 0.3s ease;
    border-bottom: 1px solid rgba(255,255,255,0.2);
}

.navbar-brand {
    font-weight: 700;
    font-size: 1.8rem;
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    transition: all 0.3s ease;
}

.navbar-brand:hover {
    transform: scale(1.05);
}

.nav-link {
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
    color: var(--text-dark) !important;
    margin: 0 10px;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color) !important;
    transform: translateY(-2px);
}

.nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 3px;
    bottom: -5px;
    left: 50%;
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
    transition: all 0.3s ease;
    border-radius: 3px;
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
    left: 0;
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    color: white;
    text-align: center;
    overflow: hidden;
}

.hero-content {
    animation: fadeInUp 1.2s ease;
    z-index: 10;
    position: relative;
}

.hero h1 {
    font-size: 4rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 8px rgba(0,0,0,0.3);
    animation: titleGlow 2s ease-in-out infinite alternate;
}

.hero h2 {
    font-size: 2rem;
    font-weight: 300;
    margin-bottom: 2rem;
    opacity: 0.95;
}

@keyframes titleGlow {
    from { text-shadow: 2px 2px 8px rgba(0,0,0,0.3), 0 0 20px rgba(255,255,255,0.1); }
    to { text-shadow: 2px 2px 8px rgba(0,0,0,0.3), 0 0 30px rgba(255,255,255,0.3); }
}

.typing-animation {
    display: inline-block;
    border-right: 3px solid white;
    animation: blink 1.2s infinite;
    min-width: 20px;
}

@keyframes blink {
    0%, 50% { border-color: white; }
    51%, 100% { border-color: transparent; }
}

.btn-hero {
    background: rgba(255,255,255,0.15);
    border: 2px solid rgba(255,255,255,0.3);
    color: white;
    padding: 15px 35px;
    border-radius: 50px;
    font-weight: 600;
    text-decoration: none;
    display: inline-block;
    margin: 15px;
    transition: all 0.4s ease;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    position: relative;
    overflow: hidden;
}

.btn-hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s ease;
}

.btn-hero:hover::before {
    left: 100%;
}

.btn-hero:hover {
    background: rgba(255,255,255,0.25);
    border-color: rgba(255,255,255,0.6);
    transform: translateY(-5px) scale(1.05);
    box-shadow: 0 15px 35px rgba(0,0,0,0.3);
    color: white;
}

.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    color: white;
    animation: bounce 2s infinite;
    cursor: pointer;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
    40% { transform: translateX(-50%) translateY(-10px); }
    60% { transform: translateX(-50%) translateY(-5px); }
}

/* Floating Shapes */
.floating-shapes {
    position: absolute;
    width: 100%;
    height: 100%;
    overflow: hidden;
    z-index: 1;
}

.shape {
    position: absolute;
    background: rgba(255,255,255,0.08);
    border-radius: 50%;
    animation: float 25s infinite linear;
    backdrop-filter: blur(2px);
}

.shape:nth-child(1) {
    width: 100px;
    height: 100px;
    left: 10%;
    animation-delay: 0s;
}

.shape:nth-child(2) {
    width: 80px;
    height: 80px;
    left: 70%;
    animation-delay: 7s;
}

.shape:nth-child(3) {
    width: 120px;
    height: 120px;
    left: 40%;
    animation-delay: 14s;
}

.shape:nth-child(4) {
    width: 60px;
    height: 60px;
    left: 90%;
    animation-delay: 21s;
}

.shape:nth-child(5) {
    width: 90px;
    height: 90px;
    left: 20%;
    animation-delay: 3s;
}

@keyframes float {
    0% {
        transform: translateY(100vh) rotate(0deg) scale(0);
        opacity: 0;
    }
    10% {
        opacity: 1;
        transform: translateY(90vh) rotate(36deg) scale(1);
    }
    90% {
        opacity: 1;
        transform: translateY(-10vh) rotate(324deg) scale(1);
    }
    100% {
        transform: translateY(-20vh) rotate(360deg) scale(0);
        opacity: 0;
    }
}

/* Sections */
.section {
    padding: 120px 0;
    position: relative;
}

.section-title {
    text-align: center;
    margin-bottom: 5rem;
    position: relative;
}

.section-title h2 {
    font-size: 3rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 1rem;
    position: relative;
}

.section-title p {
    font-size: 1.2rem;
    color: #666;
    margin-bottom: 2rem;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -20px;
    left: 50%;
    transform: translateX(-50%);
    width: 100px;
    height: 4px;
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
    border-radius: 3px;
}

/* Glass Effect Sections */
.glass-section {
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255,255,255,0.2);
}

/* About Section */
.about-avatar {
    width: 350px;
    height: 350px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color), var(--accent-color));
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto;
    box-shadow: 0 30px 60px rgba(0,0,0,0.15);
    transition: all 0.5s ease;
    position: relative;
    overflow: hidden;
}

.about-avatar::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(45deg, transparent, rgba(255,255,255,0.1), transparent);
    transform: translateX(-100%);
    transition: transform 0.8s ease;
}

.about-avatar:hover::before {
    transform: translateX(100%);
}

.about-avatar:hover {
    transform: scale(1.08) rotate(5deg);
    box-shadow: 0 40px 80px rgba(0,0,0,0.2);
}

.about-avatar i {
    font-size: 10rem;
    color: white;
    z-index: 2;
}

/* Skills Category Styles */
.category-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.category-icon {
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--white);
}

.category-title {
    font-size: 1.4rem;
    font-weight: 700;
    color: #f1f5f9; /* Sáng hơn cho dark mode */
    margin: 0;
}

.skill-item {
    margin-bottom: 2rem;
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}

.skill-item.animate {
    opacity: 1;
    transform: translateY(0);
}

.skill-name {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.8rem;
    font-weight: 700; /* Đậm hơn */
    font-size: 1.1rem;
    color: #f1f5f9; /* Sáng hơn cho dark mode */
}

.skill-level {
    color: #cbd5e1;
    font-weight: 600;
}

.skill-progress {
    height: 12px;
    background: rgba(0,0,0,0.05);
    border-radius: 8px;
    overflow: hidden;
    position: relative;
}

.skill-progress::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    width: 100%;
    background: linear-gradient(90deg, 
        rgba(255,255,255,0.1) 0%, 
        rgba(255,255,255,0.3) 50%, 
        rgba(255,255,255,0.1) 100%);
    animation: shimmer 2s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.skill-progress-bar {
    height: 100%;
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
    border-radius: 8px;
    transition: width 2s ease;
    position: relative;
    width: 0;
}

/* ===== TIMELINE (EXPERIENCE) SECTION ===== */
.timeline {
    position: relative;
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem 0;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    width: 2px;
    height: 100%;
    background: linear-gradient(180deg, var(--primary) 0%, var(--secondary) 100%);
}

.timeline-item {
    margin-bottom: 3rem;
    position: relative;
}

.timeline-dot {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    width: 20px;
    height: 20px;
    background: var(--primary);
    border: 4px solid var(--dark);
    border-radius: 50%;
    z-index: 2;
    box-shadow: 0 0 0 4px rgba(0, 212, 255, 0.2);
}

.timeline-content {
    background: var(--gray-800);
    border: 1px solid rgba(0, 212, 255, 0.3);
    border-radius: var(--border-radius);
    padding: 2rem;
    margin-left: calc(50% + 30px);
    position: relative;
    backdrop-filter: blur(10px);
    transition: var(--transition);
}

.timeline-item:nth-child(even) .timeline-content {
    margin-left: 0;
    margin-right: calc(50% + 30px);
}

.timeline-content:hover {
    transform: translateY(-5px);
    border-color: var(--primary);
    box-shadow: var(--shadow-lg);
}

.timeline-badge {
    display: inline-block;
    background: rgba(0, 212, 255, 0.1);
    color: var(--primary);
    padding: 0.4rem 1rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 1rem;
    border: 1px solid rgba(0, 212, 255, 0.3);
}

.timeline-title {
    color: var(--white);
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.timeline-company {
    color: var(--gray-400);
    font-size: 1rem;
    font-weight: 500;
    margin-bottom: 1rem;
}

.timeline-description {
    color: #e2e8f0; /* Sáng hơn cho dễ đọc */
    line-height: 1.8;
    margin-bottom: 1.5rem;
    padding-left: 1.5rem;
}

.timeline-description li {
    margin-bottom: 0.5rem;
    position: relative;
}

.timeline-description li::before {
    content: '▹';
    position: absolute;
    left: -1.5rem;
    color: var(--primary);
    font-weight: bold;
}

.timeline-skills {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.timeline-skills span {
    background: rgba(124, 58, 237, 0.1);
    color: var(--secondary);
    padding: 0.4rem 0.8rem;
    border-radius: 15px;
    font-size: 0.75rem;
    font-weight: 500;
    border: 1px solid rgba(124, 58, 237, 0.3);
}

/* ===== CONTACT SECTION ===== */
.contact-card {
    background: var(--gray-800);
    border: 1px solid rgba(0, 212, 255, 0.3);
    border-radius: var(--border-radius-lg);
    padding: 2rem;
    text-align: center;
    transition: var(--transition);
    height: 100%;
    backdrop-filter: blur(10px);
}

.contact-card:hover {
    transform: translateY(-10px);
    border-color: var(--primary);
    box-shadow: var(--shadow-xl);
}

.contact-icon {
    width: 80px;
    height: 80px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    font-size: 2rem;
    color: var(--white);
    transition: var(--transition);
}

.contact-card:hover .contact-icon {
    transform: scale(1.1) rotate(10deg);
}

.contact-title {
    color: var(--white);
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.contact-info {
    color: #e2e8f0; /* Sáng hơn cho dễ đọc */
    font-size: 1rem;
    margin-bottom: 1.5rem;
}

.contact-link {
    display: inline-block;
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
}

.contact-link:hover {
    color: var(--white);
    transform: translateX(5px);
}

.social-section {
    margin-top: 3rem;
}

.social-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.social-link {
    width: 60px;
    height: 60px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 1.5rem;
    text-decoration: none;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.social-link::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--gradient-accent);
    opacity: 0;
    transition: var(--transition);
}

.social-link:hover {
    transform: translateY(-5px) scale(1.1);
    box-shadow: var(--shadow-lg);
    color: var(--white);
}

.social-link:hover::before {
    opacity: 1;
}

.social-link i {
    position: relative;
    z-index: 1;
}

/* ===== FOOTER ===== */
.footer {
    background: var(--dark);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding: 2rem 0;
    text-align: center;
}

.footer-content {
    color: var(--gray-400);
}

.footer-content p {
    margin-bottom: 0.5rem;
}

.footer-tagline {
    font-size: 0.9rem;
    color: var(--gray-500);
}

/* ===== RESPONSIVE: TIMELINE ===== */
@media (max-width: 768px) {
    .timeline::before {
        left: 20px;
    }
    
    .timeline-dot {
        left: 20px;
    }
    
    .timeline-content {
        margin-left: 60px !important;
        margin-right: 0 !important;
    }
}

/* Projects Section */
.project-card {
    background: white;
    border-radius: 20px;
    padding: 2.5rem;
    margin-bottom: 2rem;
    box-shadow: 0 15px 35px rgba(0,0,0,0.08);
    transition: all 0.5s ease;
    border: 1px solid rgba(255,255,255,0.2);
    position: relative;
    overflow: hidden;
    opacity: 0;
    transform: translateY(50px);
}

.project-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
}

.project-card.animate {
    opacity: 1;
    transform: translateY(0);
}

.project-card:hover {
    transform: translateY(-15px) scale(1.02);
    box-shadow: 0 25px 50px rgba(0,0,0,0.15);
}

.project-icon {
    width: 90px;
    height: 90px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    color: white;
    font-size: 2.5rem;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.project-icon::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(45deg, transparent, rgba(255,255,255,0.2), transparent);
    transform: translateX(-100%);
    transition: transform 0.5s ease;
}

.project-card:hover .project-icon {
    transform: rotate(10deg) scale(1.1);
}

.project-card:hover .project-icon::after {
    transform: translateX(100%);
}

.project-title {
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.project-desc {
    color: #666;
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.project-tag {
    background: linear-gradient(45deg, rgba(102, 126, 234, 0.1), rgba(116, 75, 162, 0.1));
    color: var(--primary-color);
    padding: 6px 15px;
    border-radius: 25px;
    font-size: 0.9rem;
    font-weight: 500;
    border: 1px solid rgba(102, 126, 234, 0.2);
    transition: all 0.3s ease;
}

.project-tag:hover {
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
    color: white;
    transform: translateY(-2px);
}

/* Contact Section */
.contact-card {
    background: white;
    padding: 2.5rem;
    border-radius: 20px;
    box-shadow: 0 15px 35px rgba(0,0,0,0.08);
    margin-bottom: 2rem;
    text-align: center;
    transition: all 0.4s ease;
    border: 1px solid rgba(255,255,255,0.2);
    opacity: 0;
    transform: translateY(30px);
}

.contact-card.animate {
    opacity: 1;
    transform: translateY(0);
}

.contact-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 25px 50px rgba(0,0,0,0.12);
}

.contact-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    color: white;
    font-size: 2rem;
    transition: all 0.4s ease;
}

.contact-card:hover .contact-icon {
    transform: scale(1.15) rotate(10deg);
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-top: 3rem;
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-radius: 50%;
    text-decoration: none;
    transition: all 0.4s ease;
    position: relative;
    overflow: hidden;
}

.social-link::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(45deg, transparent, rgba(255,255,255,0.2), transparent);
    transform: scale(0);
    transition: transform 0.3s ease;
}

.social-link:hover::before {
    transform: scale(1);
}

.social-link:hover {
    transform: translateY(-8px) scale(1.1);
    box-shadow: 0 15px 30px rgba(0,0,0,0.2);
    color: white;
}

/* Footer */
.footer {
    background: var(--bg-dark);
    color: var(--text-light);
    text-align: center;
    padding: 3rem 0;
    position: relative;
}

.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(60px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-on-scroll {
    opacity: 0;
    transform: translateY(50px);
    transition: all 0.8s ease;
}

.animate-on-scroll.animated {
    opacity: 1;
    transform: translateY(0);
}

/* Parallax Effect */
.parallax {
    transform: translateZ(0);
    transition: transform 0.1s ease-out;
}

/* Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.8rem;
    }
    
    .hero h2 {
        font-size: 1.5rem;
    }
    
    .section-title h2 {
        font-size: 2.2rem;
    }
    
    .about-avatar {
        width: 280px;
        height: 280px;
    }
    
    .about-avatar i {
        font-size: 7rem;
    }

    .btn-hero {
        padding: 12px 25px;
        font-size: 0.9rem;
    }

    .section {
        padding: 80px 0;
    }
}

/* Loading Animation */
.page-loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10000;
    transition: opacity 0.5s ease;
}

.loader-content {
    text-align: center;
    color: white;
}

.loader-spinner {
    width: 60px;
    height: 60px;
    border: 4px solid rgba(255,255,255,0.2);
    border-top: 4px solid white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* === PROJECTS SECTION STYLES === */
.projects-section {
    background: var(--background);
    position: relative;
    overflow: hidden;
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
    margin-top: 4rem;
}

.project-card {
    background: var(--card-bg);
    border-radius: 20px;
    padding: 2rem;
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
    opacity: 0;
    transform: translateY(30px);
}

.project-card.animate {
    opacity: 1;
    transform: translateY(0);
}

.project-card.featured {
    border: 2px solid var(--accent-color);
    box-shadow: 0 20px 40px rgba(64, 224, 208, 0.1);
}

.project-card.research {
    border: 2px solid #ff6b6b;
    box-shadow: 0 20px 40px rgba(255, 107, 107, 0.1);
}

.project-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 30px 60px rgba(0, 0, 0, 0.2);
}

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1.5rem;
}

.project-icon {
    width: 60px;
    height: 60px;
    border-radius: 15px;
    background: var(--gradient);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    color: white;
    box-shadow: 0 10px 20px rgba(64, 224, 208, 0.3);
}

.project-badge {
    background: rgba(64, 224, 208, 0.1);
    color: var(--accent-color);
    padding: 0.4rem 0.8rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    border: 1px solid var(--accent-color);
}

.project-title {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    line-height: 1.3;
}

.project-period {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: 1rem;
    font-weight: 500;
}

.project-description {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

/* Technical Architecture */
.tech-architecture {
    background: rgba(0, 0, 0, 0.3);
    border-radius: 12px;
    padding: 1.5rem;
    margin: 1.5rem 0;
    border: 1px solid rgba(64, 224, 208, 0.2);
}

.arch-flow {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.arch-step {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem;
    background: rgba(64, 224, 208, 0.1);
    border-radius: 10px;
    border: 1px solid var(--accent-color);
    min-width: 120px;
}

.arch-step i {
    font-size: 1.5rem;
    color: var(--accent-color);
}

.arch-step span {
    font-size: 0.875rem;
    text-align: center;
    color: var(--text-primary);
    font-weight: 500;
}

.arch-arrow {
    font-size: 1.5rem;
    color: var(--accent-color);
    font-weight: bold;
}

/* Network Topology */
.network-topology {
    background: rgba(0, 0, 0, 0.3);
    border-radius: 12px;
    padding: 1.5rem;
    margin: 1.5rem 0;
    border: 1px solid rgba(64, 224, 208, 0.2);
}

.topology-diagram {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.network-connections {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.network-node {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem;
    background: rgba(64, 224, 208, 0.1);
    border-radius: 10px;
    border: 1px solid var(--accent-color);
    min-width: 120px;
}

.network-node.controller {
    background: rgba(255, 107, 107, 0.1);
    border-color: #ff6b6b;
}

.network-node i {
    font-size: 1.5rem;
    color: var(--accent-color);
}

.network-node.controller i {
    color: #ff6b6b;
}

.load-balance-flow {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    justify-content: center;
}

.server-node {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    padding: 0.8rem;
    background: rgba(64, 224, 208, 0.1);
    border-radius: 8px;
    border: 1px solid var(--accent-color);
    min-width: 80px;
    font-size: 0.8rem;
}

/* Research Flow */
.research-flow {
    display: flex;
    gap: 1rem;
    margin: 1.5rem 0;
    flex-wrap: wrap;
    justify-content: center;
}

.research-step {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: rgba(0, 0, 0, 0.3);
    border-radius: 12px;
    border: 1px solid rgba(255, 107, 107, 0.2);
    flex: 1;
    min-width: 200px;
}

.step-number {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: #ff6b6b;
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    flex-shrink: 0;
}

.step-content h5 {
    margin: 0 0 0.5rem 0;
    color: var(--text-primary);
    font-size: 0.9rem;
}

.step-content p {
    margin: 0;
    color: var(--text-secondary);
    font-size: 0.8rem;
}

/* Project Highlights */
.project-highlights {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 0.75rem;
    margin: 1.5rem 0;
}

.highlight-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem;
    background: rgba(64, 224, 208, 0.1);
    border-radius: 8px;
    font-size: 0.875rem;
    color: var(--text-primary);
}

.highlight-item i {
    color: var(--accent-color);
    width: 16px;
}

/* Tech Tags */
.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin: 1.5rem 0;
}

.tech-tag {
    background: rgba(64, 224, 208, 0.1);
    color: var(--accent-color);
    padding: 0.3rem 0.8rem;
    border-radius: 15px;
    font-size: 0.75rem;
    font-weight: 500;
    border: 1px solid rgba(64, 224, 208, 0.3);
    transition: all 0.3s ease;
}

.tech-tag:hover {
    background: var(--accent-color);
    color: var(--background);
    transform: translateY(-2px);
}

/* Project Results */
.project-results {
    background: rgba(0, 0, 0, 0.3);
    border-radius: 12px;
    padding: 1.5rem;
    margin: 1.5rem 0;
    border-left: 4px solid var(--accent-color);
}

.project-results h4 {
    margin: 0 0 1rem 0;
    color: var(--text-primary);
    font-size: 1rem;
}

.project-results ul {
    margin: 0;
    padding-left: 1rem;
}

.project-results li {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    line-height: 1.5;
}

/* Demo Preview */
.demo-preview {
    background: rgba(64, 224, 208, 0.1);
    border-radius: 10px;
    padding: 1rem;
    margin: 1.5rem 0;
    border: 1px solid var(--accent-color);
    text-align: center;
}

.demo-thumbnail {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    color: var(--accent-color);
    font-weight: 600;
}

.demo-thumbnail i {
    font-size: 1.5rem;
}

/* Project Actions */
.project-actions {
    display: flex;
    gap: 1rem;
    margin-top: 1.5rem;
    flex-wrap: wrap;
}

.btn {
    padding: 0.75rem 1.5rem;
    border-radius: 25px;
    font-weight: 600;
    font-size: 0.875rem;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}

/* Buttons - đã được định nghĩa ở trên (dòng ~417), xóa duplicate này */

/* Skills Demonstration */
.skills-demonstration {
    margin-top: 4rem;
    padding: 2rem;
    background: rgba(0, 0, 0, 0.3);
    border-radius: 20px;
    border: 1px solid var(--border-color);
}

.demo-title {
    text-align: center;
    color: var(--text-primary);
    margin-bottom: 2rem;
    font-size: 1.5rem;
}

.demo-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.demo-item {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 15px;
    text-align: center;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.demo-item:hover {
    transform: translateY(-5px);
    border-color: var(--accent-color);
}

.demo-icon {
    width: 60px;
    height: 60px;
    margin: 0 auto 1rem;
    background: var(--gradient);
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: white;
}

.demo-item h4 {
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.demo-item p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: 1rem;
    line-height: 1.5;
}

.demo-badges {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    justify-content: center;
}

.badge-item {
    background: rgba(64, 224, 208, 0.1);
    color: var(--accent-color);
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.75rem;
    border: 1px solid rgba(64, 224, 208, 0.3);
}

/* Responsive Design for Projects */
@media (max-width: 768px) {
    .projects-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .project-card {
        padding: 1.5rem;
    }
    
    .arch-flow,
    .load-balance-flow,
    .research-flow {
        flex-direction: column;
        align-items: center;
    }
    
    .arch-arrow {
        transform: rotate(90deg);
    }
    
    .project-actions {
        flex-direction: column;
    }
    
    .btn {
        text-align: center;
        justify-content: center;
    }
    
    .demo-grid {
        grid-template-columns: 1fr;
    }
}

/* ===== STATUS BAR ===== */
.status-bar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 30px;
    background: var(--gray-900);
    border-bottom: 1px solid rgba(0, 212, 255, 0.3);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 1.5rem;
    font-family: var(--font-code);
    font-size: 0.75rem;
    color: var(--gray-400);
    z-index: 10000;
    transition: var(--transition);
}

.status-left,
.status-right {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.status-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.status-item i {
    color: var(--primary);
    font-size: 0.7rem;
}

/* Adjust navbar for status bar */
.navbar.fixed-top {
    top: 30px;
}

.hero-section {
    padding-top: 30px;
}

/* ===== THEME TOGGLE ===== */
.theme-toggle {
    background: transparent;
    border: 2px solid rgba(0, 212, 255, 0.3);
    color: var(--primary);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition);
    margin-right: 1rem;
}

.theme-toggle:hover {
    background: rgba(0, 212, 255, 0.1);
    border-color: var(--primary);
    transform: rotate(180deg);
}

.theme-toggle i {
    font-size: 1rem;
}

/* ===== LIGHT MODE STYLES ===== */
[data-theme="light"] {
    /* Light mode color overrides - Đảm bảo contrast tốt */
    --dark: #ffffff;
    --gray-900: #f8f9fa;
    --gray-800: #ffffff;
    --gray-700: #212529;
    --gray-600: #343a40;
    --gray-500: #495057;
    --gray-400: #6c757d;
    --gray-300: #212529;
    --gray-200: #343a40;
    --gray-100: #495057;
    --white: #1a1a1a;
    
    /* Text colors for better readability */
    --text-primary: #1a1a1a;
    --text-secondary: #4a5568;
    --text-light: #718096;
    
    /* Background colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f7fafc;
    --bg-tertiary: #edf2f7;
    
    /* Shadows for light mode */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 15px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.15);
    --shadow-xl: 0 20px 50px rgba(0, 0, 0, 0.2);
}

/* Background */
[data-theme="light"] body {
    background: #ffffff;
    color: #1a1a1a;
}

[data-theme="light"] .matrix-background {
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
}

[data-theme="light"] .matrix-background::before {
    background: 
        radial-gradient(circle at 20% 80%, rgba(0, 212, 255, 0.08) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(124, 58, 237, 0.08) 0%, transparent 50%);
}

/* Status Bar */
[data-theme="light"] .status-bar {
    background: #ffffff;
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    color: #4a5568;
}

[data-theme="light"] .status-item i {
    color: var(--primary);
}

/* Navbar */
[data-theme="light"] .navbar {
    background: rgba(255, 255, 255, 0.98) !important;
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
}

[data-theme="light"] .navbar-brand .brand-text {
    color: #1a1a1a;
}

[data-theme="light"] .nav-link {
    color: #4a5568 !important;
}

[data-theme="light"] .nav-link:hover,
[data-theme="light"] .nav-link.active {
    color: #1a1a1a !important;
}

/* Hero Section */
[data-theme="light"] .hero-section {
    color: #1a1a1a;
}

[data-theme="light"] .hero-badge {
    background: rgba(0, 212, 255, 0.15);
    border-color: rgba(0, 212, 255, 0.4);
}

[data-theme="light"] .hero-title {
    color: #1a1a1a;
}

[data-theme="light"] .hero-description {
    color: #4a5568;
}

[data-theme="light"] .stat-label {
    color: #718096;
}

[data-theme="light"] .code-window {
    background: #2d3748;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

[data-theme="light"] .window-header {
    background: #1a202c;
}

[data-theme="light"] .floating-icon {
    background: rgba(0, 212, 255, 0.12);
    border-color: rgba(0, 212, 255, 0.4);
}

[data-theme="light"] .scroll-indicator {
    color: #718096;
}

/* About Section */
[data-theme="light"] .about-section {
    background: #f7fafc;
}

[data-theme="light"] .section-title {
    color: #1a1a1a;
}

[data-theme="light"] .section-subtitle {
    color: #718096;
}

[data-theme="light"] .about-title {
    color: #1a1a1a;
}

[data-theme="light"] .about-description {
    color: #4a5568;
}

[data-theme="light"] .motto-card {
    background: rgba(0, 212, 255, 0.08);
    border-color: rgba(0, 212, 255, 0.3);
}

[data-theme="light"] .motto-text {
    color: #2d3748;
}

[data-theme="light"] .info-label {
    color: #718096;
}

[data-theme="light"] .info-value {
    color: #1a1a1a;
}

[data-theme="light"] .achievement-item {
    background: rgba(0, 212, 255, 0.12);
    border-color: rgba(0, 212, 255, 0.4);
}

[data-theme="light"] .skill-tag {
    background: rgba(124, 58, 237, 0.12);
    border-color: rgba(124, 58, 237, 0.4);
}

/* Skills Section */
[data-theme="light"] .skills-section {
    background: #ffffff;
}

[data-theme="light"] .skill-category {
    background: #ffffff;
    border: 1px solid #e2e8f0;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
}

[data-theme="light"] .category-title {
    color: #1a1a1a;
}

[data-theme="light"] .skill-name {
    color: #2d3748;
}

[data-theme="light"] .skill-level {
    color: #718096;
}

[data-theme="light"] .skill-bar {
    background: #e2e8f0;
}

/* Projects Section */
[data-theme="light"] .projects-section {
    background: #f7fafc;
}

[data-theme="light"] .project-card-simple {
    background: #ffffff;
    border: 1px solid #e2e8f0;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
}

[data-theme="light"] .project-card-simple:hover {
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

[data-theme="light"] .project-title-simple {
    color: #1a1a1a;
}

[data-theme="light"] .project-desc-simple {
    color: #4a5568;
}

[data-theme="light"] .project-tech-simple span {
    background: rgba(0, 212, 255, 0.12);
    border-color: rgba(0, 212, 255, 0.4);
}

/* Experience Section */
[data-theme="light"] #experience {
    background: #ffffff !important;
}

[data-theme="light"] .timeline::before {
    background: linear-gradient(180deg, var(--primary) 0%, var(--secondary) 100%);
}

[data-theme="light"] .timeline-content {
    background: #ffffff;
    border: 1px solid #e2e8f0;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
}

[data-theme="light"] .timeline-title {
    color: #1a1a1a;
}

[data-theme="light"] .timeline-company {
    color: #718096;
}

[data-theme="light"] .timeline-description {
    color: #4a5568;
}

[data-theme="light"] .timeline-skills span {
    background: rgba(124, 58, 237, 0.12);
    border-color: rgba(124, 58, 237, 0.4);
}

/* Contact Section */
[data-theme="light"] #contact {
    background: #f7fafc !important;
}

[data-theme="light"] .contact-card {
    background: #ffffff;
    border: 1px solid #e2e8f0;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
}

[data-theme="light"] .contact-card:hover {
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

[data-theme="light"] .contact-title {
    color: #1a1a1a;
}

[data-theme="light"] .contact-info {
    color: #4a5568;
}

[data-theme="light"] .social-title {
    color: #1a1a1a !important;
}

/* Footer */
[data-theme="light"] .footer {
    background: #ffffff;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
}

[data-theme="light"] .footer-content {
    color: #718096;
}

/* Theme Toggle Icon */
[data-theme="light"] .theme-toggle {
    border-color: rgba(0, 212, 255, 0.4);
}

[data-theme="light"] .theme-toggle:hover {
    background: rgba(0, 212, 255, 0.12);
}

[data-theme="light"] .theme-toggle i::before {
    content: "\f186"; /* moon icon */
}

[data-theme="dark"] .theme-toggle i::before {
    content: "\f185"; /* sun icon */
}

/* ===== SIMPLE PROJECT CARDS ===== */
.projects-grid-simple {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.project-card-simple {
    background: var(--gray-800);
    border: 1px solid rgba(0, 212, 255, 0.3);
    border-radius: var(--border-radius-lg);
    padding: 2rem;
    text-align: center;
    transition: var(--transition);
    backdrop-filter: blur(10px);
}

.project-card-simple:hover {
    transform: translateY(-10px);
    border-color: var(--primary);
    box-shadow: var(--shadow-xl);
}

.project-icon-simple {
    width: 80px;
    height: 80px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    font-size: 2rem;
    color: var(--white);
    transition: var(--transition);
}

.project-card-simple:hover .project-icon-simple {
    transform: scale(1.1) rotate(10deg);
}

.project-title-simple {
    color: var(--white);
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.project-desc-simple {
    color: #cbd5e1; /* Sáng hơn cho dễ đọc */
    font-size: 0.95rem;
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.project-tech-simple {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin-bottom: 1.5rem;
}

.project-tech-simple span {
    background: rgba(0, 212, 255, 0.1);
    color: var(--primary);
    padding: 0.4rem 0.8rem;
    border-radius: 15px;
    font-size: 0.75rem;
    font-weight: 500;
    border: 1px solid rgba(0, 212, 255, 0.3);
}

.project-link-simple {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--gradient-primary);
    color: var(--white);
    padding: 0.75rem 1.5rem;
    border-radius: 25px;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.9rem;
    transition: var(--transition);
    box-shadow: var(--shadow-md);
}

.project-link-simple:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    color: var(--white);
}

/* Responsive */
@media (max-width: 768px) {
    .status-bar {
        font-size: 0.65rem;
        padding: 0 1rem;
    }
    
    .status-left,
    .status-right {
        gap: 0.75rem;
    }
    
    .status-item span {
        display: none;
    }
    
    .theme-toggle {
        width: 35px;
        height: 35px;
        margin-right: 0.5rem;
    }
    
    .projects-grid-simple {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
}

/* Animation for copy email notification */
@keyframes slideIn {
    from {
        transform: translateX(400px);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

@keyframes slideOut {
    from {
        transform: translateX(0);
        opacity: 1;
    }
    to {
        transform: translateX(400px);
        opacity: 0;
    }
}

/* Custom Cursor */
.cursor-dot,
.cursor-outline {
    pointer-events: none;
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    border-radius: 50%;
    z-index: 10000;
    transition: opacity 0.3s, transform 0.3s;
}

.cursor-dot {
    width: 8px;
    height: 8px;
    background: var(--primary);
    box-shadow: 0 0 10px var(--primary);
}

.cursor-outline {
    width: 40px;
    height: 40px;
    border: 2px solid var(--primary);
    opacity: 0.5;
    transition: width 0.3s, height 0.3s, opacity 0.3s;
}

/* Hide custom cursor on mobile */
@media (max-width: 768px) {
    .cursor-dot,
    .cursor-outline {
        display: none;
    }
}

/* Contact Form Styles */
.contact-form-wrapper {
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(0, 212, 255, 0.2);
    border-radius: 20px;
    padding: 3rem;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
}

.form-title {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.form-title i {
    color: var(--primary);
}

.form-subtitle {
    color: #cbd5e1;
    margin-bottom: 2rem;
    font-size: 1rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    color: #f1f5f9;
    font-weight: 600;
    margin-bottom: 0.5rem;
    font-size: 0.95rem;
}

.form-group label i {
    color: var(--primary);
    margin-right: 0.3rem;
}

.form-input,
.form-textarea {
    width: 100%;
    padding: 12px 15px;
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid rgba(0, 212, 255, 0.2);
    border-radius: 10px;
    color: var(--white);
    font-size: 1rem;
    transition: all 0.3s;
}

.form-input:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--primary);
    background: rgba(0, 212, 255, 0.1);
    box-shadow: 0 0 0 3px rgba(0, 212, 255, 0.1);
}

.form-textarea {
    resize: vertical;
    min-height: 120px;
}

.btn-submit {
    width: 100%;
    padding: 15px;
    font-size: 1.1rem;
    margin-top: 1rem;
    position: relative;
    overflow: hidden;
}

.btn-submit:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-submit:disabled:hover {
    transform: none;
}

.form-status {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 10px;
    text-align: center;
    font-weight: 600;
    display: none;
}

.form-status.success {
    display: block;
    background: rgba(34, 197, 94, 0.2);
    border: 2px solid rgba(34, 197, 94, 0.5);
    color: #22c55e;
}

.form-status.error {
    display: block;
    background: rgba(239, 68, 68, 0.2);
    border: 2px solid rgba(239, 68, 68, 0.5);
    color: #ef4444;
}

/* Light Mode Form */
[data-theme="light"] .contact-form-wrapper {
    background: #ffffff;
    border-color: rgba(0, 212, 255, 0.3);
}

[data-theme="light"] .form-title,
[data-theme="light"] .form-group label {
    color: #1a1a1a;
}

[data-theme="light"] .form-subtitle {
    color: #4a5568;
}

[data-theme="light"] .form-input,
[data-theme="light"] .form-textarea {
    background: #f8fafc;
    border-color: rgba(0, 212, 255, 0.3);
    color: #1a1a1a;
}

[data-theme="light"] .form-input:focus,
[data-theme="light"] .form-textarea:focus {
    background: rgba(0, 212, 255, 0.05);
}