/* ========================================
   RESET VÀ BASE STYLES - Thiết lập cơ bản
   ======================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Màu sắc chủ đạo - Neon/Holo Theme */
    --primary-neon: #00ffff;
    --secondary-neon: #ff00ff;
    --accent-neon: #ffff00;
    --success-neon: #00ff00;
    --warning-neon: #ff8000;
    
    /* Màu nền chính */
    --bg-dark: #0a0a0a;
    --bg-darker: #050505;
    --bg-card: rgba(255, 255, 255, 0.05);
    --bg-glass: rgba(255, 255, 255, 0.1);
    
    /* Màu chữ */
    --text-primary: #ffffff;
    --text-secondary: #cccccc;
    --text-muted: #888888;
    
    /* Hiệu ứng */
    --shadow-neon: 0 0 20px rgba(0, 255, 255, 0.3);
    --shadow-pink: 0 0 20px rgba(255, 0, 255, 0.3);
    --shadow-yellow: 0 0 20px rgba(255, 255, 0, 0.3);
    --shadow-green: 0 0 20px rgba(0, 255, 0, 0.3);
    
    /* Gradient backgrounds */
    --gradient-primary: linear-gradient(135deg, #00ffff 0%, #ff00ff 100%);
    --gradient-secondary: linear-gradient(135deg, #ff00ff 0%, #ffff00 100%);
    --gradient-accent: linear-gradient(135deg, #ffff00 0%, #00ff00 100%);
    --gradient-holo: linear-gradient(45deg, #00ffff, #ff00ff, #ffff00, #00ff00);
}

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-dark);
    overflow-x: hidden;
    /* Hiệu ứng holo background */
    background-image: 
        radial-gradient(circle at 20% 80%, rgba(0, 255, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(255, 0, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(255, 255, 0, 0.05) 0%, transparent 50%);
}

body.loaded {
    opacity: 1;
}

/* ========================================
   NAVIGATION - Thanh điều hướng với hiệu ứng neon
   ======================================== */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(10, 10, 10, 0.9);
    backdrop-filter: blur(20px);
    z-index: 1000;
    transition: all 0.3s ease;
    border-bottom: 1px solid rgba(0, 255, 255, 0.2);
    /* Hiệu ứng neon border */
    box-shadow: 0 0 30px rgba(0, 255, 255, 0.1);
}

.navbar.scrolled {
    background: rgba(5, 5, 5, 0.95);
    box-shadow: var(--shadow-neon);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo .logo-text {
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-family: 'JetBrains Mono', monospace;
    /* Hiệu ứng glow */
    text-shadow: 0 0 10px rgba(0, 255, 255, 0.5);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
    padding: 0.5rem 1rem;
    border-radius: 25px;
}

.nav-link:hover {
    color: var(--primary-neon);
    background: rgba(0, 255, 255, 0.1);
    box-shadow: 0 0 15px rgba(0, 255, 255, 0.3);
    transform: translateY(-2px);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: all 0.3s ease;
    transform: translateX(-50%);
}

.nav-link:hover::after {
    width: 80%;
    box-shadow: 0 0 10px rgba(0, 255, 255, 0.8);
}

/* Hamburger menu với hiệu ứng neon */
.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.hamburger:hover {
    background: rgba(0, 255, 255, 0.1);
    box-shadow: 0 0 15px rgba(0, 255, 255, 0.3);
}

.hamburger .bar {
    width: 25px;
    height: 3px;
    background: var(--primary-neon);
    margin: 3px 0;
    transition: all 0.3s ease;
    border-radius: 2px;
    box-shadow: 0 0 5px rgba(0, 255, 255, 0.5);
}

.hamburger.active .bar:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

.hamburger.active .bar:nth-child(2) {
    opacity: 0;
}

.hamburger.active .bar:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* ========================================
   HERO SECTION - Phần giới thiệu chính với hiệu ứng holo
   ======================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: var(--bg-darker);
    position: relative;
    overflow: hidden;
}

/* Hiệu ứng holo background */
.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 30% 20%, rgba(0, 255, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 70% 80%, rgba(255, 0, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 50% 50%, rgba(255, 255, 0, 0.05) 0%, transparent 70%);
    animation: holoFloat 8s ease-in-out infinite;
}

@keyframes holoFloat {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    50% { transform: translateY(-20px) rotate(1deg); }
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    position: relative;
    z-index: 2;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 4rem;
    align-items: center;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
    background: var(--gradient-holo);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: textGlow 3s ease-in-out infinite alternate;
}

@keyframes textGlow {
    0% { filter: drop-shadow(0 0 10px rgba(0, 255, 255, 0.5)); }
    100% { filter: drop-shadow(0 0 20px rgba(255, 0, 255, 0.5)); }
}

.highlight {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 0 20px rgba(0, 255, 255, 0.8);
}

.hero-subtitle {
    font-size: 1.5rem;
    font-weight: 400;
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
    text-shadow: 0 0 10px rgba(255, 255, 255, 0.3);
}

.hero-description {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    color: var(--text-secondary);
    max-width: 600px;
    line-height: 1.8;
}

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

.btn {
    padding: 0.75rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-block;
    border: 2px solid transparent;
    position: relative;
    overflow: hidden;
}

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

.btn-primary {
    background: var(--gradient-primary);
    color: var(--bg-dark);
    box-shadow: var(--shadow-neon);
}

.btn-primary:hover {
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 0 30px rgba(0, 255, 255, 0.6);
}

.btn-secondary {
    background: transparent;
    color: var(--primary-neon);
    border-color: var(--primary-neon);
    box-shadow: 0 0 15px rgba(0, 255, 255, 0.3);
}

.btn-secondary:hover {
    background: var(--primary-neon);
    color: var(--bg-dark);
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 0 30px rgba(0, 255, 255, 0.8);
}

/* ========================================
   HERO IMAGE GALLERY - Gallery hình ảnh với hiệu ứng neon
   ======================================== */
.hero-image {
    display: flex;
    justify-content: center;
}

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

.image-container {
    position: relative;
    border-radius: 50%;
    overflow: hidden;
    border: 4px solid rgba(0, 255, 255, 0.3);
    box-shadow: var(--shadow-neon);
    transition: all 0.3s ease;
}

.image-container:hover {
    transform: scale(1.05);
    border-color: var(--primary-neon);
    box-shadow: 0 0 30px rgba(0, 255, 255, 0.6);
}

.main-image {
    width: 200px;
    height: 200px;
}

.secondary-image {
    width: 120px;
    height: 120px;
    opacity: 0.8;
}

.secondary-image:hover {
    opacity: 1;
}

.image-container img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: all 0.3s ease;
    display: block;
    opacity: 0;
}

.image-container:hover img {
    transform: scale(1.1);
}

/* Fallback cho hình ảnh bị lỗi */
.image-container img:not([src]),
.image-container img[src=""],
.image-container img[src*="error"] {
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--bg-dark);
    font-size: 2rem;
}

.image-container img:not([src])::before,
.image-container img[src=""]::before,
.image-container img[src*="error"]::before {
    content: "📷";
    font-size: 3rem;
}

.image-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(45deg, rgba(0, 255, 255, 0.3), rgba(255, 0, 255, 0.3));
    opacity: 0;
    transition: opacity 0.3s ease;
}

.image-container:hover .image-overlay {
    opacity: 1;
}

/* ========================================
   PORTFOLIO BANNER - Banner giới thiệu với grid layout
   ======================================== */
.portfolio-banner {
    padding: 4rem 0;
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    border-top: 1px solid rgba(0, 255, 255, 0.2);
    border-bottom: 1px solid rgba(255, 0, 255, 0.2);
}

.banner-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

.banner-card {
    background: var(--bg-glass);
    padding: 2rem;
    border-radius: 20px;
    text-align: center;
    transition: all 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    position: relative;
    overflow: hidden;
}

.banner-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--gradient-primary);
    opacity: 0;
    transition: opacity 0.3s ease;
    z-index: -1;
}

.banner-card:hover {
    transform: translateY(-10px) scale(1.02);
    box-shadow: var(--shadow-neon);
    border-color: var(--primary-neon);
}

.banner-card:hover::before {
    opacity: 0.1;
}

.banner-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1rem;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: var(--bg-dark);
    transition: all 0.3s ease;
    box-shadow: var(--shadow-neon);
}

.banner-card:hover .banner-icon {
    transform: rotate(360deg) scale(1.1);
    box-shadow: 0 0 30px rgba(0, 255, 255, 0.8);
}

.banner-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.banner-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.6;
}

/* ========================================
   CONTAINER VÀ SECTION STYLES
   ======================================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

section {
    padding: 5rem 0;
}

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

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 1rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-divider {
    width: 80px;
    height: 4px;
    background: var(--gradient-primary);
    margin: 0 auto;
    border-radius: 2px;
    box-shadow: var(--shadow-neon);
}

/* ========================================
   ABOUT SECTION - Phần giới thiệu với flex layout
   ======================================== */
.about {
    background: var(--bg-card);
    backdrop-filter: blur(20px);
}

.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 4rem;
    align-items: start;
}

.about-text p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-top: 3rem;
}

.stat-item {
    text-align: center;
    padding: 1.5rem;
    background: var(--bg-glass);
    border-radius: 12px;
    transition: all 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
}

.stat-item:hover {
    transform: translateY(-5px) scale(1.02);
    box-shadow: var(--shadow-neon);
    border-color: var(--primary-neon);
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.5rem;
    text-shadow: 0 0 20px rgba(0, 255, 255, 0.5);
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.contact-card {
    background: var(--bg-glass);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: var(--shadow-neon);
    border: 1px solid rgba(0, 255, 255, 0.2);
    backdrop-filter: blur(10px);
}

.contact-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
    font-size: 0.95rem;
    transition: all 0.3s ease;
    padding: 0.5rem;
    border-radius: 8px;
}

.contact-item:hover {
    background: rgba(0, 255, 255, 0.1);
    transform: translateX(5px);
}

.contact-item i {
    width: 20px;
    color: var(--primary-neon);
    font-size: 1.1rem;
    text-shadow: 0 0 10px rgba(0, 255, 255, 0.5);
}

.contact-item a {
    color: var(--primary-neon);
    text-decoration: none;
    transition: color 0.3s ease;
}

.contact-item a:hover {
    color: var(--secondary-neon);
    text-shadow: 0 0 10px rgba(255, 0, 255, 0.5);
}

/* ========================================
   SKILLS SECTION - Phần kỹ năng với animation
   ======================================== */
.skills {
    background: var(--bg-dark);
}


.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 3rem;
}

.skill-category {
    background: var(--bg-glass);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: var(--shadow-neon);
    border: 1px solid rgba(0, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    transition: all 0.3s ease;
}

.skill-category:hover {
    transform: translateY(-5px);
    box-shadow: 0 0 40px rgba(0, 255, 255, 0.4);
}

.skill-category h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    text-align: center;
}

.skill-item {
    margin-bottom: 1.5rem;
}

.skill-name {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    display: block;
}

.skill-bar {
    height: 8px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 4px;
    overflow: hidden;
    position: relative;
}

.skill-progress {
    height: 100%;
    background: var(--gradient-primary);
    border-radius: 4px;
    transition: width 1.5s ease-in-out;
    position: relative;
    box-shadow: 0 0 10px rgba(0, 255, 255, 0.5);
}

.skill-progress::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    animation: shimmer 2s infinite;
}

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

/* ========================================
   PROJECTS SECTION - Dự án với hiệu ứng neon
   ======================================== */
.projects {
    background: var(--bg-card);
    backdrop-filter: blur(20px);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.project-card {
    background: var(--bg-glass);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow-neon);
    transition: all 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
}

.project-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 0 50px rgba(0, 255, 255, 0.6);
}

.project-image {
    height: 200px;
    background: var(--gradient-primary);
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* AquaLife - Dark theme như yêu cầu */
.aqualife-bg {
    background: #1a1a1a;
    position: relative;
    overflow: hidden;
    border-radius: 20px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.3);
}

.aqualife-bg::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        /* App icon area */
        linear-gradient(135deg, #4a90e2 0%, #f5a623 100%),
        /* Title area */
        linear-gradient(90deg, transparent 0%, #666 0%, #666 100%, transparent 100%);
    background-size: 
        15% 20%,
        60% 15%;
    background-position: 
        10% 10%,
        20% 10%;
    opacity: 0.8;
}

.aqualife-bg::after {
    content: 'AquaLife';
    position: absolute;
    top: 12%;
    left: 30%;
    color: #ccc;
    font-size: 1rem;
    font-weight: 600;
    z-index: 3;
}

.aqualife-bg .fish-emoji {
    position: absolute;
    font-size: 1.5rem;
    z-index: 2;
    top: 60%;
}

.aqualife-bg .fish-emoji:nth-child(1) {
    left: 15%;
}

.aqualife-bg .fish-emoji:nth-child(2) {
    left: 50%;
    transform: translateX(-50%);
}

.aqualife-bg .fish-emoji:nth-child(3) {
    right: 15%;
}

/* QLDA - Cooking Platform với gradient neon */
.qlda-bg {
    background: var(--gradient-secondary);
    position: relative;
    overflow: hidden;
    border-radius: 20px;
    box-shadow: var(--shadow-pink);
}

.qlda-bg::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        /* Kitchen icon */
        linear-gradient(135deg, #ff6b6b 0%, #feca57 100%),
        /* Title area */
        linear-gradient(90deg, transparent 0%, rgba(255,255,255,0.2) 0%, rgba(255,255,255,0.2) 100%, transparent 100%);
    background-size: 
        15% 20%,
        60% 15%;
    background-position: 
        10% 10%,
        20% 10%;
    opacity: 0.8;
}

.qlda-bg::after {
    content: 'QLDA';
    position: absolute;
    top: 12%;
    left: 30%;
    color: white;
    font-size: 1rem;
    font-weight: 600;
    z-index: 3;
}

.qlda-bg .food-emoji {
    position: absolute;
    font-size: 1.5rem;
    z-index: 2;
    top: 60%;
}

.qlda-bg .food-emoji:nth-child(1) {
    left: 15%;
}

.qlda-bg .food-emoji:nth-child(2) {
    left: 50%;
    transform: translateX(-50%);
}

.qlda-bg .food-emoji:nth-child(3) {
    right: 15%;
}

/* Pickleball - Sports booking với gradient neon */
.pickleball-bg {
    background: var(--gradient-accent);
    position: relative;
    overflow: hidden;
    border-radius: 20px;
    box-shadow: var(--shadow-green);
}

.pickleball-bg::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        /* Sports icon */
        linear-gradient(135deg, #2ecc71 0%, #3498db 100%),
        /* Title area */
        linear-gradient(90deg, transparent 0%, rgba(255,255,255,0.2) 0%, rgba(255,255,255,0.2) 100%, transparent 100%);
    background-size: 
        15% 20%,
        60% 15%;
    background-position: 
        10% 10%,
        20% 10%;
    opacity: 0.8;
}

.pickleball-bg::after {
    content: 'Pickleball';
    position: absolute;
    top: 12%;
    left: 30%;
    color: white;
    font-size: 1rem;
    font-weight: 600;
    z-index: 3;
}

.pickleball-bg .sport-emoji {
    position: absolute;
    font-size: 1.5rem;
    z-index: 2;
    top: 60%;
}

.pickleball-bg .sport-emoji:nth-child(1) {
    left: 15%;
}

.pickleball-bg .sport-emoji:nth-child(2) {
    left: 50%;
    transform: translateX(-50%);
}

.pickleball-bg .sport-emoji:nth-child(3) {
    right: 15%;
}

.project-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.project-card:hover .project-overlay {
    opacity: 1;
}

.project-links {
    display: flex;
    gap: 1rem;
}

.project-link {
    width: 50px;
    height: 50px;
    background: var(--bg-glass);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-neon);
    text-decoration: none;
    font-size: 1.2rem;
    transition: all 0.3s ease;
    border: 1px solid rgba(0, 255, 255, 0.3);
    backdrop-filter: blur(10px);
}

.project-link:hover {
    transform: scale(1.1) rotate(360deg);
    background: var(--primary-neon);
    color: var(--bg-dark);
    box-shadow: var(--shadow-neon);
}

.project-content {
    padding: 2rem;
}

.project-content h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

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

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tech-tag {
    background: var(--bg-glass);
    color: var(--primary-neon);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
    border: 1px solid rgba(0, 255, 255, 0.3);
    backdrop-filter: blur(10px);
    transition: all 0.3s ease;
}

.tech-tag:hover {
    background: var(--primary-neon);
    color: var(--bg-dark);
    transform: scale(1.05);
    box-shadow: 0 0 15px rgba(0, 255, 255, 0.5);
}

/* ========================================
   EDUCATION SECTION - Học vấn với hiệu ứng neon
   ======================================== */
.education {
    background: var(--bg-dark);
}

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

.education-item {
    background: var(--bg-glass);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: var(--shadow-neon);
    display: flex;
    gap: 1.5rem;
    align-items: flex-start;
    border: 1px solid rgba(0, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    transition: all 0.3s ease;
}

.education-item:hover {
    transform: translateY(-5px) scale(1.02);
    box-shadow: 0 0 40px rgba(0, 255, 255, 0.4);
}

.education-icon {
    width: 60px;
    height: 60px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--bg-dark);
    font-size: 1.5rem;
    flex-shrink: 0;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-neon);
}

.education-item:hover .education-icon {
    transform: rotate(360deg) scale(1.1);
}

.education-details h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.education-school {
    color: var(--text-secondary);
    font-weight: 500;
    margin-bottom: 0.25rem;
}

.education-period {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: 0.25rem;
}

.education-gpa {
    color: var(--primary-neon);
    font-weight: 600;
    font-size: 0.9rem;
    text-shadow: 0 0 10px rgba(0, 255, 255, 0.5);
}

/* ========================================
   CONTACT SECTION - Liên hệ với hiệu ứng neon
   ======================================== */
.contact {
    background: var(--bg-card);
    backdrop-filter: blur(20px);
}

.contact-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.contact-info h3 {
    font-size: 2rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.contact-info p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 3rem;
}

.contact-methods {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    max-width: 1200px;
    margin: 0 auto;
}

.contact-method {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.5rem;
    background: var(--bg-glass);
    border-radius: 12px;
    transition: all 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    text-decoration: none;
    color: inherit;
}

.contact-method:hover {
    transform: translateY(-5px) scale(1.02);
    box-shadow: var(--shadow-neon);
    border-color: var(--primary-neon);
}

.contact-method i {
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--bg-dark);
    font-size: 1.2rem;
    flex-shrink: 0;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-neon);
}

.contact-method:hover i {
    transform: rotate(360deg) scale(1.1);
}

.contact-method h4 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.contact-method p {
    color: var(--text-secondary);
    margin: 0;
    transition: color 0.3s ease;
    word-wrap: break-word;
    overflow-wrap: break-word;
    hyphens: auto;
}

.contact-method:hover p {
    color: var(--primary-neon);
    text-shadow: 0 0 10px rgba(0, 255, 255, 0.5);
}

/* ========================================
   FOOTER - Chân trang với flexbox layout
   ======================================== */
.footer {
    background: var(--bg-darker);
    color: var(--text-primary);
    padding: 2rem 0;
    border-top: 1px solid rgba(0, 255, 255, 0.2);
    box-shadow: 0 -5px 20px rgba(0, 0, 0, 0.3);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 2rem;
    min-height: 60px;
}

.footer-content p {
    margin: 0;
    font-size: 0.9rem;
    color: var(--text-secondary);
    flex: 1;
    min-width: 200px;
}

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

.footer-links a {
    color: var(--text-primary);
    text-decoration: none;
    transition: all 0.3s ease;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
    position: relative;
}

.footer-links a:hover {
    color: var(--primary-neon);
    background: rgba(0, 255, 255, 0.1);
    box-shadow: 0 0 15px rgba(0, 255, 255, 0.3);
    transform: translateY(-2px);
}

.footer-links a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: all 0.3s ease;
    transform: translateX(-50%);
}

.footer-links a:hover::after {
    width: 80%;
}

/* ========================================
   RESPONSIVE DESIGN - Thiết kế responsive
   ======================================== */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: rgba(10, 10, 10, 0.95);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow-neon);
        padding: 2rem 0;
        backdrop-filter: blur(20px);
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-menu li {
        margin: 1rem 0;
    }

    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.25rem;
    }

    .image-gallery {
        flex-direction: row;
        justify-content: center;
        gap: 0.5rem;
    }

    .main-image {
        width: 150px;
        height: 150px;
    }

    .secondary-image {
        width: 80px;
        height: 80px;
    }

    .banner-grid {
        grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
        gap: 1rem;
    }

    .about-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .stats {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .skills-grid {
        grid-template-columns: 1fr;
    }


    .projects-grid {
        grid-template-columns: 1fr;
    }

    .education-content {
        grid-template-columns: 1fr;
    }

    .education-item {
        flex-direction: column;
        text-align: center;
    }

    .contact-methods {
        grid-template-columns: 1fr;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
        gap: 1.5rem;
    }

    .footer-content p {
        order: 2;
        margin-top: 1rem;
    }

    .footer-links {
        order: 1;
        justify-content: center;
        gap: 1rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }

    .nav-container {
        padding: 0 1rem;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1.1rem;
    }
    
    .section-title {
        font-size: 2rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 100%;
        text-align: center;
    }

    .image-gallery {
        flex-direction: column;
        gap: 0.5rem;
    }

    .main-image {
        width: 120px;
        height: 120px;
    }

    .secondary-image {
        width: 60px;
        height: 60px;
    }

    .banner-grid {
        grid-template-columns: 1fr;
    }


    .contact-methods {
        grid-template-columns: 1fr;
    }

    .footer-links {
        gap: 0.5rem;
    }

    .footer-links a {
        padding: 0.4rem 0.8rem;
        font-size: 0.8rem;
    }
}

/* ========================================
   ANIMATION CLASSES - Các lớp animation
   ======================================== */
.animate {
    animation: fadeInUp 0.6s ease-out;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ========================================
   RIPPLE EFFECT - Hiệu ứng sóng khi click
   ======================================== */

/* ========================================
   CURSOR EFFECTS - Hiệu ứng cursor
   ======================================== */
.cursor {
    position: fixed;
    width: 20px;
    height: 20px;
    background: var(--gradient-primary);
    border-radius: 50%;
    pointer-events: none;
    z-index: 9999;
    transition: transform 0.1s ease;
    box-shadow: var(--shadow-neon);
}

.cursor.hover {
    transform: scale(1.5);
    background: var(--gradient-secondary);
}

/* ========================================
   LOADING ANIMATION - Animation khi load trang
   ======================================== */
body {
    opacity: 0;
    transition: opacity 0.5s ease;
}

body.loaded {
    opacity: 1;
}

/* ========================================
   PRINT STYLES - Styles cho in ấn
   ======================================== */
@media print {
    .navbar,
    .hero,
    .footer {
        display: none;
    }

    body {
        background-color: white;
        color: black;
    }

    section {
        padding: 2rem 0;
        page-break-inside: avoid;
    }

    .container {
        max-width: none;
        padding: 0;
    }
}