/* ============================================
   CSS Variables & Base Styles - Klein Blue Theme
   ============================================ */
:root {
    /* Colors - Black Klein Blue Palette */
    --bg-primary: #0a0a0a;
    --bg-secondary: #111111;
    --bg-card: #151515;
    --bg-card-hover: #1a1a1a;
    --bg-white: #ffffff;
    
    /* Primary - Klein Blue */
    --primary: #002FA7;
    --primary-light: #003BB5;
    
    /* Accent - Klein Blue Gradient */
    --gold-100: #E6ECFF;
    --gold-200: #B3C6FF;
    --gold-300: #80A0FF;
    --gold-400: #4D7AFF;
    --gold-500: #002FA7;
    --gold-600: #0022B7;
    
    /* Gradient Blue - Klein Blue Theme */
    --gold-gradient: linear-gradient(135deg, #4D9FFF 0%, #0066FF 50%, #0044CC 100%);
    --gold-text: linear-gradient(135deg, #80C0FF 0%, #4D9FFF 50%, #0066FF 100%);
    --gold-glow: linear-gradient(135deg, rgba(0, 102, 255, 0.25) 0%, rgba(0, 68, 204, 0.25) 100%);
    --gold-highlight: linear-gradient(135deg, #99CCFF 0%, #66AAFF 100%);
    --text-glow: 0 0 20px rgba(77, 159, 255, 0.3);
    
    /* Text */
    --text-primary: #ffffff;
    --text-secondary: #b0b0b0;
    --text-muted: #666666;
    --text-light: #444444;
    
    /* Borders */
    --border-light: rgba(0, 47, 167, 0.1);
    --border-medium: rgba(0, 47, 167, 0.2);
    --border-gold: rgba(0, 47, 167, 0.3);
    
    /* Effects */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.5);
    --shadow-gold: 0 0 30px rgba(0, 47, 167, 0.15);
    
    /* Typography */
    --font-heading: "Noto Serif SC", "Source Han Serif CN", serif;
    --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
    --font-mono: "DM Sans", sans-serif;

    /* Spacing */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-2xl: 48px;
    --space-3xl: 64px;
    --space-4xl: 80px;
    --space-5xl: 100px;

    /* Layout */
    --container-max: 1200px;
    --navbar-height: 80px;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 20px;

    /* Transitions */
    --transition-fast: 200ms ease;
    --transition-normal: 400ms ease;
    --transition-slow: 600ms ease;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-body);
    font-size: 1rem;
    line-height: 1.8;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    text-decoration: none;
    color: inherit;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

ul, ol {
    list-style: none;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 600;
    line-height: 1.3;
}

/* Container */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--space-xl);
}

/* ============================================
   Navigation - Clean & Professional
   ============================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--navbar-height);
    z-index: 1000;
    background: rgba(10, 10, 10, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-light);
}

.navbar-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: var(--gold-gradient);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-heading);
    font-size: 1.125rem;
    font-weight: 700;
    color: #ffffff;
}

.logo-text {
    font-family: var(--font-heading);
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--space-xl);
}

.nav-link {
    font-size: 0.875rem;
    color: var(--text-secondary);
    position: relative;
    padding: var(--space-sm) 0;
    transition: all var(--transition-fast);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--gold-gradient);
    transition: width var(--transition-normal);
}

.nav-link:hover,
.nav-link.active {
    color: var(--gold-300);
}

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

.cta-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: 8px 20px;
    background: var(--gold-gradient);
    color: #ffffff;
    font-size: 0.8125rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.cta-btn:hover {
    box-shadow: 0 4px 20px rgba(0, 47, 167, 0.35);
}

.nav-cta {
    padding: 8px 16px;
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: var(--space-sm);
}

.mobile-menu-btn span {
    width: 20px;
    height: 2px;
    background: var(--gold-500);
    transition: all var(--transition-fast);
}

.mobile-menu-btn.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-btn.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* Mobile Menu */
.mobile-menu {
    position: fixed;
    top: var(--navbar-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--bg-primary);
    z-index: 999;
    transform: translateX(100%);
    transition: transform var(--transition-normal);
    padding: var(--space-lg);
}

.mobile-menu.active {
    transform: translateX(0);
}

.mobile-nav {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.mobile-nav-link {
    font-size: 1rem;
    color: var(--text-primary);
    padding: var(--space-md) 0;
    border-bottom: 1px solid var(--border-light);
}

.mobile-cta {
    margin-top: var(--space-md);
    justify-content: center;
}

/* ============================================
   Banner Carousel
   ============================================ */
.banner-carousel {
    position: relative;
    width: 100%;
    overflow: hidden;
    background: linear-gradient(135deg, #0a0a0a 0%, #1a1a1a 50%, #0d0d0d 100%);
    min-height: 300px;
}

/* Tech Background Grid */
.banner-carousel::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        linear-gradient(rgba(0, 47, 167, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 47, 167, 0.03) 1px, transparent 1px);
    background-size: 50px 50px;
    z-index: 0;
    pointer-events: none;
}

/* Glowing Orbs */
.banner-carousel::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -20%;
    width: 60%;
    height: 100%;
    background: radial-gradient(ellipse at center, rgba(0, 47, 167, 0.12) 0%, transparent 70%);
    z-index: 0;
    pointer-events: none;
    animation: pulse-glow 8s ease-in-out infinite;
}

@keyframes pulse-glow {
    0%, 100% { opacity: 0.5; transform: scale(1); }
    50% { opacity: 1; transform: scale(1.1); }
}

/* Tech Circuit Lines */
.tech-circuit {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    overflow: hidden;
    z-index: 0;
    pointer-events: none;
}

.tech-line {
    position: absolute;
    background: linear-gradient(90deg, transparent, rgba(77, 159, 255, 0.4), transparent);
    height: 1px;
    animation: tech-scan 4s linear infinite;
}

.tech-line:nth-child(1) { top: 20%; width: 60%; left: -10%; animation-delay: 0s; }
.tech-line:nth-child(2) { top: 40%; width: 80%; right: -20%; animation-delay: 1s; animation-direction: reverse; }
.tech-line:nth-child(3) { top: 60%; width: 50%; left: 20%; animation-delay: 2s; }
.tech-line:nth-child(4) { top: 80%; width: 70%; right: -10%; animation-delay: 0.5s; animation-direction: reverse; }

@keyframes tech-scan {
    0% { transform: translateX(-100%); opacity: 0; }
    50% { opacity: 1; }
    100% { transform: translateX(200%); opacity: 0; }
}

/* Floating Particles */
.tech-particle {
    position: absolute;
    width: 4px;
    height: 4px;
    background: var(--gold-400);
    border-radius: 50%;
    box-shadow: 0 0 10px rgba(255, 215, 0, 0.8), 0 0 20px rgba(255, 215, 0, 0.4);
    animation: float-particle 6s ease-in-out infinite;
    z-index: 1;
}

.tech-particle:nth-child(1) { top: 15%; left: 10%; animation-delay: 0s; }
.tech-particle:nth-child(2) { top: 30%; right: 15%; animation-delay: 1s; }
.tech-particle:nth-child(3) { top: 50%; left: 5%; animation-delay: 2s; }
.tech-particle:nth-child(4) { top: 70%; right: 8%; animation-delay: 3s; }
.tech-particle:nth-child(5) { top: 85%; left: 20%; animation-delay: 4s; }
.tech-particle:nth-child(6) { top: 25%; right: 25%; animation-delay: 5s; }
.tech-particle:nth-child(7) { top: 60%; right: 5%; animation-delay: 1.5s; }
.tech-particle:nth-child(8) { top: 40%; left: 15%; animation-delay: 2.5s; }

@keyframes float-particle {
    0%, 100% { transform: translateY(0) scale(1); opacity: 0.6; }
    50% { transform: translateY(-20px) scale(1.2); opacity: 1; }
}

/* Hexagon Pattern */
.tech-hexagon {
    position: absolute;
    width: 100px;
    height: 100px;
    border: 1px solid rgba(255, 215, 0, 0.1);
    clip-path: polygon(50% 0%, 100% 25%, 100% 75%, 50% 100%, 0% 75%, 0% 25%);
    animation: rotate-hexagon 20s linear infinite;
    z-index: 0;
}

.tech-hexagon:nth-child(1) { top: 10%; right: 5%; }
.tech-hexagon:nth-child(2) { bottom: 20%; left: 3%; animation-direction: reverse; animation-duration: 25s; }

@keyframes rotate-hexagon {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.carousel-track {
    position: relative;
    width: 100%;
    z-index: 5;
}

.carousel-slide {
    position: relative;
    display: none;
    width: 100%;
    background: transparent;
}

.carousel-slide.active {
    display: block;
}

.carousel-slide img {
    width: 100%;
    height: auto;
    max-height: 500px;
    object-fit: contain;
    display: block;
}

/* Overlay gradient for better text readability */
.carousel-slide::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(
        to bottom,
        rgba(10, 10, 10, 0.3) 0%,
        rgba(10, 10, 10, 0.1) 50%,
        rgba(10, 10, 10, 0.5) 100%
    );
    pointer-events: none;
}

/* Carousel Controls */
.carousel-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 44px;
    height: 44px;
    background: rgba(10, 10, 10, 0.7);
    backdrop-filter: blur(8px);
    border: 1px solid var(--border-light);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--gold-400);
    cursor: pointer;
    transition: all var(--transition-fast);
    z-index: 10;
}

.carousel-btn:hover {
    background: rgba(77, 159, 255, 0.15);
    border-color: var(--border-medium);
}

.carousel-prev {
    left: var(--space-lg);
}

.carousel-next {
    right: var(--space-lg);
}

/* Carousel Indicators */
.carousel-indicators {
    position: absolute;
    bottom: var(--space-xl);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: var(--space-sm);
    z-index: 10;
}

.indicator {
    width: 10px;
    height: 10px;
    background: rgba(255, 255, 255, 0.4);
    border-radius: 50%;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.indicator:hover {
    background: rgba(255, 255, 255, 0.7);
}

.indicator.active {
    background: var(--gold-400);
    box-shadow: 0 0 10px rgba(255, 215, 0, 0.5);
    transform: scale(1.2);
}

/* ============================================
   Hero Section - Professional & Clean
   ============================================ */
.hero {
    min-height: 85vh;
    display: flex;
    align-items: center;
    position: relative;
    background: var(--bg-primary);
    overflow: hidden;
    padding-top: var(--navbar-height);
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 50%;
    height: 100%;
    background: radial-gradient(ellipse at top right, rgba(255, 215, 0, 0.04) 0%, transparent 60%);
    pointer-events: none;
}

/* Subtle bottom border */
.hero::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--border-light), transparent);
}

.hero-content {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: var(--space-4xl);
    align-items: center;
    width: 100%;
    padding: var(--space-3xl) 0;
}

.hero-text {
    position: relative;
    z-index: 1;
}

.hero-eyebrow {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 0.75rem;
    background: rgba(255, 215, 0, 0.1);
    color: var(--gold-400);
    padding: 6px 14px;
    border-radius: 20px;
    letter-spacing: 1.5px;
    text-transform: uppercase;
    margin-bottom: var(--space-lg);
    border: 1px solid rgba(255, 215, 0, 0.2);
    font-weight: 500;
}

.hero-title {
    font-size: clamp(2.25rem, 4.5vw, 3.25rem);
    color: var(--text-primary);
    margin-bottom: var(--space-lg);
    letter-spacing: -0.02em;
    line-height: 1.2;
    font-weight: 700;
}

.hero-title .accent {
    background: var(--gold-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: block;
    font-size: clamp(1.25rem, 2.5vw, 1.75rem);
    margin-top: var(--space-sm);
    font-weight: 600;
}

.hero-desc {
    font-size: 1rem;
    color: var(--text-secondary);
    max-width: 520px;
    margin-bottom: var(--space-xl);
    line-height: 1.8;
}

.hero-actions {
    display: flex;
    gap: var(--space-md);
    align-items: center;
}

/* Buttons - Clean & Professional */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: 12px 24px;
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
    letter-spacing: 0.3px;
}

.btn-primary {
    background: var(--gold-gradient);
    color: #0a0a0a;
    font-weight: 600;
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 20px rgba(77, 159, 255, 0.35);
}

.btn-secondary {
    background: transparent;
    color: var(--gold-400);
    border: 1px solid rgba(77, 159, 255, 0.3);
}

.btn-secondary:hover {
    background: rgba(77, 159, 255, 0.08);
    border-color: var(--gold-500);
}

.btn-full {
    width: 100%;
}

/* Hero Visual */
.hero-visual {
    position: relative;
    z-index: 1;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-md);
}

.stat-card {
    background: var(--bg-card);
    padding: var(--space-lg);
    border-radius: var(--radius-md);
    text-align: center;
    border: 1px solid var(--border-light);
    transition: all var(--transition-normal);
    position: relative;
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60%;
    height: 2px;
    background: var(--gold-gradient);
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.stat-card:hover {
    border-color: var(--border-medium);
    background: var(--bg-card-hover);
}

.stat-card:hover::before {
    opacity: 1;
}

.stat-card:first-child {
    grid-column: span 2;
}

.stat-number {
    font-family: var(--font-mono);
    font-size: 2.5rem;
    font-weight: 700;
    background: var(--gold-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
}

.stat-suffix {
    font-size: 1.25rem;
    background: var(--gold-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 0.8125rem;
    color: var(--text-muted);
    margin-top: var(--space-xs);
    letter-spacing: 0.5px;
}

/* Remove old decorative elements */
.hero-decoration {
    display: none;
}

/* ============================================
   Section Styles - Clean & Professional
   ============================================ */
.section {
    padding: var(--space-4xl) 0;
    position: relative;
}

.section-alt {
    background: var(--bg-secondary);
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-3xl);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.section-eyebrow {
    display: inline-block;
    font-size: 0.6875rem;
    color: var(--gold-400);
    padding: 5px 12px;
    border-radius: 20px;
    letter-spacing: 2px;
    text-transform: uppercase;
    margin-bottom: var(--space-md);
    border: 1px solid rgba(255, 215, 0, 0.25);
    font-weight: 500;
}

.section-title {
    font-size: clamp(1.5rem, 3.5vw, 2.25rem);
    background: var(--gold-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--space-md);
    letter-spacing: -0.01em;
    font-weight: 700;
}

.section-subtitle {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ============================================
   About Section - Clean Layout
   ============================================ */
.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: start;
}

.about-text {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.about-text p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    line-height: 1.85;
}

.about-text p strong {
    background: var(--gold-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* 企业文化 */
.culture-section {
    margin-top: 8px;
    padding-top: 24px;
    border-top: 1px solid var(--border-light);
}

.culture-title {
    font-size: 1rem;
    color: var(--gold-400);
    margin-bottom: 16px;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.culture-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}

.culture-item {
    background: rgba(255, 215, 0, 0.03);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-md);
    padding: 14px 16px;
    transition: all var(--transition-fast);
}

.culture-item:hover {
    border-color: var(--border-medium);
    background: rgba(255, 215, 0, 0.05);
}

.culture-item h4 {
    font-size: 0.6875rem;
    color: var(--gold-400);
    margin-bottom: 6px;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 600;
}

.culture-item p {
    font-size: 0.8125rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.about-visual {
    position: sticky;
    top: 100px;
}

.about-image-grid {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.about-img-card {
    background: rgba(77, 159, 255, 0.02);
    border-radius: var(--radius-md);
    padding: 20px;
    border: 1px solid var(--border-light);
    display: flex;
    align-items: center;
    gap: 16px;
    transition: all var(--transition-fast);
}

.about-img-card:hover {
    border-color: var(--border-medium);
    background: rgba(77, 159, 255, 0.05);
}

.about-img-card:first-child {
    background: linear-gradient(135deg, rgba(77, 159, 255, 0.08) 0%, rgba(0, 102, 255, 0.03) 100%);
    border-color: var(--border-gold);
}

.about-card-icon {
    flex-shrink: 0;
    width: 44px;
    height: 44px;
    background: rgba(255, 215, 0, 0.1);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
}

.about-card-icon svg {
    width: 22px;
    height: 22px;
    color: var(--gold-400);
}

.about-img-card-content {
    flex: 1;
    min-width: 0;
}

.about-img-card h4 {
    font-size: 0.9375rem;
    color: var(--text-primary);
    margin-bottom: 2px;
    font-weight: 600;
}

.about-img-card p {
    font-size: 0.8125rem;
    color: var(--text-muted);
}

/* 移除旧的about-feature样式 */
.about-feature {
    display: flex;
    align-items: flex-start;
    gap: var(--space-md);
}

.feature-icon {
    width: 48px;
    height: 48px;
    background: var(--gold-glow);
    border: 1px solid var(--border-medium);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--gold-400);
    flex-shrink: 0;
}

.feature-text {
    font-size: 0.9375rem;
    color: var(--text-primary);
    font-weight: 500;
}

/* ============================================
   Teachers Section - Clean Professional Layout
   ============================================ */
.featured-teachers {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 24px;
    margin-bottom: 32px;
}

.teacher-card-horizontal {
    background: rgba(255, 215, 0, 0.02);
    border-radius: var(--radius-md);
    padding: 24px;
    border: 1px solid var(--border-light);
    display: flex;
    gap: 24px;
    transition: all var(--transition-fast);
}

.teacher-card-horizontal:hover {
    border-color: var(--border-medium);
    background: rgba(255, 215, 0, 0.04);
}

.teacher-card-horizontal.main {
    background: linear-gradient(135deg, rgba(255, 215, 0, 0.06) 0%, rgba(255, 179, 0, 0.02) 100%);
    border-color: var(--border-gold);
}

.teacher-image {
    flex-shrink: 0;
}

.teacher-avatar {
    width: 100px;
    height: 100px;
    background: var(--gold-gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-heading);
    font-size: 2.25rem;
    font-weight: 600;
    color: #0a0a0a;
}

.teacher-avatar-lg {
    width: 120px;
    height: 120px;
    font-size: 2.75rem;
}

/* Teacher Photo Styles */
.teacher-photo {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    object-fit: cover;
    transition: all var(--transition-fast);
}

.teacher-photo:hover {
    transform: scale(1.03);
    opacity: 0.9;
}

.teacher-photo-lg {
    width: 120px;
    height: 120px;
    border-width: 3px;
}

@media (max-width: 768px) {
    .teacher-photo {
        width: 80px;
        height: 80px;
    }

    .teacher-photo-lg {
        width: 100px;
        height: 100px;
    }
}

.teacher-info {
    flex: 1;
    min-width: 0;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.teacher-name {
    font-size: 1.25rem;
    color: var(--text-primary);
    font-weight: 600;
    letter-spacing: 0.3px;
}

.teacher-title {
    font-size: 0.8125rem;
    background: var(--gold-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 500;
}

.teacher-divider {
    width: 40px;
    height: 2px;
    background: var(--gold-gradient);
}

.teacher-achievements {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.teacher-achievements li {
    font-size: 0.75rem;
    color: var(--text-secondary);
    background: rgba(77, 159, 255, 0.06);
    padding: 4px 10px;
    border-radius: var(--radius-sm);
    border: 1px solid rgba(77, 159, 255, 0.15);
    line-height: 1.4;
}

.teacher-achievements li strong {
    background: var(--gold-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.teacher-desc {
    font-size: 0.8125rem;
    color: var(--text-muted);
    line-height: 1.7;
}

.teacher-record {
    padding-top: 12px;
    border-top: 1px dashed var(--border-light);
}

.teacher-record strong {
    font-size: 0.6875rem;
    color: var(--gold-400);
    display: block;
    margin-bottom: 4px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.teacher-record p {
    font-size: 0.8125rem;
    color: var(--text-muted);
    line-height: 1.65;
}

/* Full Teacher Grid */
.teacher-grid-full {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.teacher-grid-full .teacher-card-horizontal {
    padding: 20px;
    gap: 18px;
}

.teacher-grid-full .teacher-photo {
    width: 90px;
    height: 90px;
}

.teacher-grid-full .teacher-name {
    font-size: 1.125rem;
}

.teacher-grid-full .teacher-achievements li {
    font-size: 0.6875rem;
    padding: 3px 8px;
}

/* Teacher Grid */
.teacher-team-header {
    text-align: center;
    margin-bottom: var(--space-xl);
}

.teacher-team-header h3 {
    font-size: 1.25rem;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
}

.teacher-team-header p {
    font-size: 0.9375rem;
    color: var(--text-muted);
}

.teacher-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.teacher-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    text-align: center;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-light);
    transition: all var(--transition-normal);
}

.teacher-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-gold);
    border-color: var(--border-medium);
}

.teacher-card-icon {
    font-size: 2.5rem;
    margin-bottom: var(--space-md);
}

.teacher-card-icon svg {
    color: var(--gold-400);
}

.teacher-card h4 {
    font-size: 1.0625rem;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
}

.teacher-card p {
    font-size: 0.875rem;
    color: var(--text-muted);
    line-height: 1.7;
}

.teacher-card strong {
    background: var(--gold-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ============================================
   Cases Section
   ============================================ */
.cases {
    background: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    position: relative;
    overflow: hidden;
}

.cases::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23FFD700' fill-opacity='0.02'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    opacity: 0.5;
}

.cases .section-header {
    position: relative;
}

.case-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
    margin-bottom: var(--space-3xl);
    position: relative;
}

.case-stat {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    text-align: center;
    transition: all var(--transition-normal);
}

.case-stat:hover {
    border-color: var(--border-gold);
    box-shadow: var(--shadow-gold);
}

.case-stat-number {
    font-family: var(--font-mono);
    font-size: 2.75rem;
    font-weight: 700;
    line-height: 1;
}

.case-stat-number span {
    background: var(--gold-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.case-stat-label {
    font-size: 0.8125rem;
    color: var(--text-muted);
    margin-top: var(--space-sm);
}

/* Case Tabs */
.case-tabs {
    display: flex;
    justify-content: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-xl);
    position: relative;
}

.case-tab {
    padding: var(--space-md) var(--space-xl);
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-sm);
    font-size: 0.9375rem;
    font-weight: 500;
    transition: all var(--transition-fast);
}

.case-tab:hover {
    background: var(--gold-glow);
    color: var(--gold-400);
    border-color: var(--border-medium);
}

.case-tab.active {
    background: var(--gold-gradient);
    color: #0a0a0a;
    border-color: var(--gold-500);
    font-weight: 600;
}

/* Case Content */
.case-panel {
    display: none;
    position: relative;
}

.case-panel.active {
    display: block;
}

.case-highlight {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    margin-bottom: var(--space-xl);
}

.case-highlight-icon {
    font-size: 2.5rem;
    flex-shrink: 0;
}

.case-highlight-icon svg {
    color: var(--gold-400);
}

.case-highlight h4 {
    font-size: 1.125rem;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
}

.case-highlight p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

.case-highlight strong {
    background: var(--gold-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.case-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.case-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all var(--transition-normal);
    border: 1px solid var(--border-light);
}

.case-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-gold);
    border-color: var(--border-medium);
}

.case-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-md) var(--space-lg);
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-light);
}

.case-type {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.9375rem;
}

.case-result {
    font-size: 0.6875rem;
    font-weight: 600;
    background: var(--gold-gradient);
    color: #0a0a0a;
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
    letter-spacing: 0.5px;
}

.case-card-body {
    padding: var(--space-lg);
}

.case-score {
    display: flex;
    gap: var(--space-xl);
    margin-bottom: var(--space-md);
}

.score-item {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.score-label {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.score-change {
    font-family: var(--font-mono);
    font-size: 0.9375rem;
    font-weight: 600;
}

.score-change.improvement {
    background: var(--gold-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.case-position {
    font-size: 0.9375rem;
    color: var(--text-secondary);
}

.case-position strong {
    background: var(--gold-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.case-detail {
    font-size: 0.875rem;
    color: var(--text-muted);
    line-height: 1.8;
}

.case-detail strong {
    background: var(--gold-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ============================================
   Advantages Section - Clean Grid Layout
   ============================================ */
.advantages-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.advantage-card {
    background: rgba(77, 159, 255, 0.02);
    border-radius: var(--radius-md);
    padding: 20px;
    border: 1px solid var(--border-light);
    position: relative;
    transition: all var(--transition-fast);
    display: flex;
    flex-direction: column;
}

.advantage-card:hover {
    border-color: var(--border-medium);
    background: rgba(77, 159, 255, 0.05);
}

.advantage-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--gold-gradient);
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.advantage-card:hover::before {
    opacity: 1;
}

.advantage-number {
    position: absolute;
    top: 16px;
    right: 16px;
    font-family: var(--font-mono);
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--gold-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    opacity: 0.15;
    line-height: 1;
}

.advantage-icon {
    width: 44px;
    height: 44px;
    background: rgba(255, 215, 0, 0.08);
    border: 1px solid rgba(255, 215, 0, 0.15);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--gold-400);
    margin-bottom: 14px;
    flex-shrink: 0;
}

.advantage-title {
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 10px;
    font-weight: 600;
    letter-spacing: 0.3px;
}

.advantage-desc {
    font-size: 0.8125rem;
    color: var(--text-muted);
    line-height: 1.7;
    flex: 1;
}

.advantage-highlight {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid var(--border-light);
    line-height: 1.5;
}

.advantage-highlight span {
    background: var(--gold-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 600;
}

/* 第5个优势 - 全宽卡片 */
.advantage-card-full {
    grid-column: span 4;
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 24px;
    align-items: center;
    padding: 24px;
    margin-top: 4px;
    background: linear-gradient(135deg, rgba(77, 159, 255, 0.06) 0%, rgba(0, 102, 255, 0.02) 100%);
    border-color: var(--border-gold);
}

.advantage-card-full .advantage-icon {
    width: 52px;
    height: 52px;
    margin-bottom: 0;
}

.advantage-card-full .advantage-content {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 24px;
    align-items: center;
}

.advantage-card-full .advantage-text {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.advantage-card-full .advantage-number {
    position: static;
    font-size: 1.25rem;
    opacity: 1;
    background: var(--gold-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 4px;
}

.advantage-card-full .advantage-title {
    margin-bottom: 0;
}

.advantage-card-full .advantage-desc {
    margin-top: 6px;
}

.advantage-card-full .advantage-highlight {
    margin-top: 0;
    padding-top: 0;
    border-top: none;
    background: rgba(255, 215, 0, 0.05);
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-light);
}

/* ============================================
   Credentials Section - Clean Grid
   ============================================ */
.credentials {
    background: var(--bg-primary);
}

.credentials-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-md);
}

.credential-card {
    background: rgba(77, 159, 255, 0.02);
    border-radius: var(--radius-md);
    padding: var(--space-lg);
    text-align: center;
    border: 1px solid var(--border-light);
    transition: all var(--transition-normal);
}

.credential-card:hover {
    border-color: var(--border-medium);
    background: rgba(77, 159, 255, 0.05);
}

.credential-icon {
    width: 52px;
    height: 52px;
    background: var(--gold-gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--space-md);
    font-size: 1.25rem;
    color: #0a0a0a;
}

.credential-icon svg {
    color: #0a0a0a;
}

.credential-card h3 {
    font-size: 0.9375rem;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
    font-weight: 600;
}

.credential-card p {
    font-size: 0.8125rem;
    color: var(--text-muted);
    line-height: 1.6;
}

.credential-card strong {
    background: var(--gold-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ============================================
   Contact Section - Professional Layout
   ============================================ */
.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-3xl);
    align-items: center;
}

.contact-info {
    max-width: 480px;
}

.contact-title {
    font-size: clamp(1.375rem, 2.5vw, 1.75rem);
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
    font-weight: 700;
}

.contact-desc {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-xl);
    line-height: 1.7;
}

.contact-items {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.contact-item {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.contact-icon {
    width: 44px;
    height: 44px;
    background: rgba(255, 215, 0, 0.08);
    border: 1px solid rgba(255, 215, 0, 0.15);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--gold-400);
    flex-shrink: 0;
}

.contact-label {
    font-size: 0.6875rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 2px;
}

.contact-value {
    font-size: 0.9375rem;
    color: var(--text-primary);
    font-weight: 500;
}

/* Contact Form */
.contact-form-wrapper {
    background: rgba(77, 159, 255, 0.02);
    border-radius: var(--radius-md);
    padding: var(--space-xl);
    border: 1px solid var(--border-light);
}

.contact-form h3 {
    font-size: 1.125rem;
    color: var(--text-primary);
    margin-bottom: var(--space-lg);
    text-align: center;
    font-weight: 600;
}

.form-group {
    margin-bottom: var(--space-md);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: var(--space-sm) var(--space-md);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-sm);
    font-family: inherit;
    font-size: 0.9375rem;
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.03);
    transition: all var(--transition-fast);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--gold-500);
    background: rgba(255, 255, 255, 0.05);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--text-light);
}

.form-group select {
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='%23FFD700' stroke-width='2'%3E%3Cpolyline points='6,9 12,15 18,9'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    background-size: 16px;
}

.form-group select option {
    background: var(--bg-card);
}

.form-group textarea {
    resize: vertical;
    min-height: 80px;
}

/* ============================================
   Footer - Clean & Professional
   ============================================ */
.footer {
    background: var(--bg-secondary);
    color: var(--text-primary);
    padding: var(--space-2xl) 0 var(--space-lg);
    border-top: 1px solid var(--border-light);
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--space-3xl);
    margin-bottom: var(--space-2xl);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-sm);
}

.footer-logo .logo-icon {
    background: var(--gold-gradient);
}

.footer-logo .logo-text {
    color: var(--text-primary);
}

.footer-slogan {
    font-family: var(--font-heading);
    font-size: 1rem;
    background: var(--gold-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 4px;
}

.footer-desc {
    font-size: 0.8125rem;
    color: var(--text-muted);
    line-height: 1.6;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.footer-link-group h4 {
    font-size: 0.75rem;
    color: var(--text-primary);
    margin-bottom: var(--space-md);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-weight: 600;
}

.footer-link-group a {
    display: block;
    font-size: 0.8125rem;
    color: var(--text-muted);
    padding: 4px 0;
    transition: all var(--transition-fast);
}

.footer-link-group a:hover {
    color: var(--gold-400);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--space-lg);
    border-top: 1px solid var(--border-light);
}

.footer-bottom p {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-bottom: 4px;
}

/* ============================================
   Modal - Clean Design
   ============================================ */
.modal {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.85);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.modal.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: var(--bg-card);
    border-radius: var(--radius-md);
    padding: var(--space-xl);
    text-align: center;
    max-width: 380px;
    width: 90%;
    transform: scale(0.95);
    transition: transform var(--transition-normal);
    border: 1px solid var(--border-light);
}

.modal.active .modal-content {
    transform: scale(1);
}

.modal-icon {
    width: 56px;
    height: 56px;
    background: var(--gold-gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #0a0a0a;
    font-size: 1.5rem;
    margin: 0 auto var(--space-md);
}

.modal-content h3 {
    font-size: 1.125rem;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
}

.modal-content p {
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
    font-size: 0.875rem;
}

/* ============================================
   Animations
   ============================================ */
.animate-item {
    opacity: 0;
    transform: translateY(30px);
}

.animate-item.animated {
    opacity: 1;
    transform: translateY(0);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

/* ============================================
   Responsive Design - Tablet (768px - 1024px)
   ============================================ */
@media (max-width: 1024px) {
    :root {
        --container-max: 960px;
        --navbar-height: 70px;
    }

    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: var(--space-3xl);
    }

    .hero::before {
        display: none;
    }

    .hero-desc {
        margin: 0 auto var(--space-2xl);
    }

    .hero-actions {
        justify-content: center;
    }

    .hero-stats {
        max-width: 400px;
        margin: 0 auto;
    }

    .about-content {
        grid-template-columns: 1fr;
        gap: 48px;
    }

    .about-visual {
        order: -1;
    }

    .culture-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .featured-teachers {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .teacher-card-horizontal {
        flex-direction: column;
        text-align: center;
    }

    .teacher-image {
        margin: 0 auto;
    }

    .teacher-divider {
        margin: var(--space-md) auto;
    }

    .teacher-achievements {
        justify-content: center;
    }

    .teacher-grid-full {
        grid-template-columns: repeat(2, 1fr);
    }

    .case-stats {
        grid-template-columns: repeat(3, 1fr);
    }

    .case-cards {
        grid-template-columns: repeat(2, 1fr);
    }

    .advantages-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
    }

    .advantage-card-full {
        grid-column: span 2;
        grid-template-columns: auto 1fr;
    }

    .advantage-card-full .advantage-content {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .advantage-card-full .advantage-highlight {
        margin-top: 12px;
    }

    .advantage-card-full .advantage-desc {
        margin-top: 8px;
    }

    .credentials-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .contact-wrapper {
        grid-template-columns: 1fr;
        gap: var(--space-3xl);
    }

    .contact-info {
        max-width: 100%;
        text-align: center;
    }

    .contact-items {
        align-items: center;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: var(--space-3xl);
    }

    /* Banner adjustments */
    .tech-hexagon {
        display: none;
    }
}

/* ============================================
   Responsive Design - Mobile (< 768px)
   ============================================ */
@media (max-width: 768px) {
    :root {
        --space-5xl: 60px;
        --space-4xl: 48px;
        --space-3xl: 40px;
        --navbar-height: 60px;
        --container-max: 100%;
    }

    body {
        font-size: 15px;
        line-height: 1.7;
    }

    .container {
        padding: 0 var(--space-md);
    }

    /* Navigation Mobile */
    .nav-links,
    .nav-cta {
        display: none;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .logo-icon {
        width: 36px;
        height: 36px;
        font-size: 1rem;
    }

    .logo-text {
        font-size: 1.1rem;
    }

    /* Banner Carousel Mobile */
    .banner-carousel {
        min-height: 250px;
    }

    .carousel-btn {
        width: 38px;
        height: 38px;
        opacity: 0.8;
    }

    .carousel-prev {
        left: var(--space-sm);
    }

    .carousel-next {
        right: var(--space-sm);
    }

    .carousel-indicators {
        gap: 6px;
    }

    .indicator {
        width: 8px;
        height: 8px;
    }

    .carousel-slide img {
        max-height: 280px;
    }

    /* Tech elements hide on mobile for better performance */
    .tech-circuit,
    .tech-particle {
        display: none;
    }

    /* Hero Section Mobile */
    .hero {
        min-height: auto;
        padding: calc(var(--navbar-height) + var(--space-xl)) 0 var(--space-3xl);
    }

    .hero-eyebrow {
        font-size: 0.6875rem;
        padding: 4px 12px;
    }

    .hero-title {
        font-size: 1.75rem;
        line-height: 1.2;
    }

    .hero-title .accent {
        font-size: 1.25rem;
    }

    .hero-desc {
        font-size: 0.9375rem;
        line-height: 1.8;
    }

    .hero-actions {
        flex-direction: column;
        gap: var(--space-sm);
    }

    .hero-actions .btn {
        width: 100%;
    }

    .hero-stats {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--space-sm);
    }

    .stat-card {
        padding: var(--space-md);
    }

    .stat-card:first-child {
        grid-column: span 2;
    }

    .stat-number {
        font-size: 2rem;
    }

    .stat-suffix {
        font-size: 1.25rem;
    }

    .stat-label {
        font-size: 0.75rem;
    }

    .hero-decoration {
        display: none;
    }

    /* Section Mobile */
    .section {
        padding: var(--space-2xl) 0;
    }

    .section-header {
        margin-bottom: var(--space-2xl);
    }

    .section-title {
        font-size: 1.5rem;
    }

    .section-subtitle {
        font-size: 0.9375rem;
    }

    /* About Mobile */
    .about-text p {
        font-size: 0.9375rem;
    }

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

    .about-visual {
        position: static;
    }

    .about-image-grid {
        gap: 10px;
    }

    .about-img-card {
        padding: 14px;
        gap: 12px;
    }

    .about-card-icon {
        width: 40px;
        height: 40px;
    }

    .about-card-icon svg {
        width: 20px;
        height: 20px;
    }

    /* Teachers Mobile */
    .featured-teachers {
        gap: 16px;
        margin-bottom: 24px;
    }

    .teacher-card-horizontal {
        padding: 16px;
        gap: 16px;
    }

    .teacher-card-horizontal.main {
        padding: 20px;
    }

    .teacher-name {
        font-size: 1.125rem;
    }

    .teacher-title {
        font-size: 0.75rem;
    }

    .teacher-divider {
        width: 32px;
    }

    .teacher-achievements {
        font-size: 0.75rem;
        gap: 6px;
    }

    .teacher-achievements li {
        font-size: 0.6875rem;
        padding: 3px 8px;
    }

    .teacher-desc,
    .teacher-record p {
        font-size: 0.8125rem;
        line-height: 1.65;
    }

    .teacher-record {
        padding-top: 10px;
    }

    .teacher-record strong {
        font-size: 0.6875rem;
    }

    .teacher-grid-full {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .teacher-grid-full .teacher-card-horizontal {
        padding: 16px;
        gap: 14px;
    }

    .teacher-grid-full .teacher-photo {
        width: 80px;
        height: 80px;
    }

    .teacher-grid-full .teacher-name {
        font-size: 1.0625rem;
    }

    /* Advantages Mobile */
    .advantages-grid {
        grid-template-columns: 1fr;
    }

    .advantage-card-full {
        grid-column: span 1;
        grid-template-columns: 1fr;
    }

    .advantage-number {
        font-size: 2rem;
        top: var(--space-md);
        right: var(--space-md);
    }

    .advantage-title {
        font-size: 1rem;
    }

    .advantage-desc,
    .advantage-highlight {
        font-size: 0.8125rem;
    }

    /* Credentials Mobile */
    .credentials-grid {
        grid-template-columns: 1fr;
    }

    .credential-card {
        padding: var(--space-lg);
    }

    .credential-icon {
        width: 56px;
        height: 56px;
    }

    /* Contact Mobile */
    .contact-wrapper {
        gap: var(--space-2xl);
    }

    .contact-title {
        font-size: 1.5rem;
    }

    .contact-desc {
        font-size: 0.9375rem;
    }

    .contact-item {
        flex-direction: column;
        text-align: center;
        gap: var(--space-sm);
    }

    .contact-icon {
        width: 48px;
        height: 48px;
    }

    .contact-form-wrapper {
        padding: var(--space-lg);
    }

    /* Case Tabs Mobile */
    .case-tabs {
        flex-direction: column;
    }

    .case-tab {
        text-align: center;
    }

    .case-highlight {
        flex-direction: column;
        text-align: center;
    }

    .case-score {
        justify-content: center;
    }

    .case-cards {
        grid-template-columns: 1fr;
    }

    /* Footer Mobile */
    .footer-links {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .footer-link-group a {
        padding: var(--space-sm) 0;
    }

    .footer-bottom p {
        font-size: 0.75rem;
    }

    /* Modal Mobile */
    .modal-content {
        padding: var(--space-xl);
        margin: var(--space-md);
    }

    /* Scroll Animations - reduce motion on mobile */
    .animate-item {
        opacity: 1;
        transform: none;
        transition: none;
    }

    .animate-item.animated {
        opacity: 1;
        transform: none;
    }

    /* Improve touch targets */
    .btn {
        min-height: 44px;
        min-width: 44px;
    }

    .nav-link {
        min-height: 44px;
        display: flex;
        align-items: center;
    }

    .carousel-btn {
        min-width: 44px;
        min-height: 44px;
    }

    /* Prevent text selection on UI elements */
    .navbar,
    .carousel-btn,
    .mobile-menu-btn {
        -webkit-user-select: none;
        user-select: none;
    }

    /* Better scrolling */
    html {
        -webkit-overflow-scrolling: touch;
    }

    /* Hide decorative elements on mobile */
    .hero-decoration {
        display: none;
    }
}

/* ============================================
   Responsive Design - Small Mobile (< 480px)
   ============================================ */
@media (max-width: 480px) {
    :root {
        --space-5xl: 50px;
        --space-4xl: 40px;
        --space-3xl: 32px;
        --space-2xl: 24px;
    }

    body {
        font-size: 14px;
    }

    .container {
        padding: 0 var(--space-sm);
    }

    /* Banner Carousel Small Mobile */
    .banner-carousel {
        min-height: 200px;
    }

    .carousel-btn {
        width: 34px;
        height: 34px;
        opacity: 0.7;
    }

    .carousel-indicators {
        bottom: var(--space-sm);
    }

    .carousel-slide img {
        max-height: 200px;
    }

    /* Hero Small Mobile */
    .hero-title {
        font-size: 1.5rem;
    }

    .hero-title .accent {
        font-size: 1.1rem;
    }

    .hero-desc {
        font-size: 0.875rem;
    }

    .btn {
        padding: var(--space-sm) var(--space-md);
        font-size: 0.875rem;
    }

    .btn svg {
        display: none;
    }

    .hero-stats {
        gap: var(--space-sm);
    }

    .stat-card {
        padding: var(--space-sm);
    }

    .stat-number {
        font-size: 1.75rem;
    }

    .stat-suffix {
        font-size: 1rem;
    }

    /* Teachers Small Mobile */
    .featured-teachers {
        gap: 12px;
        margin-bottom: 20px;
    }

    .teacher-card-horizontal {
        padding: 14px;
        gap: 12px;
    }

    .teacher-photo {
        width: 70px;
        height: 70px;
    }

    .teacher-photo-lg {
        width: 80px;
        height: 80px;
    }

    .teacher-name {
        font-size: 1rem;
    }

    .teacher-title {
        font-size: 0.6875rem;
    }

    .teacher-achievements {
        gap: 4px;
    }

    .teacher-achievements li {
        font-size: 0.625rem;
        padding: 2px 6px;
    }

    .teacher-desc {
        font-size: 0.75rem;
        line-height: 1.6;
    }

    .teacher-record p {
        font-size: 0.75rem;
    }

    .teacher-grid-full {
        gap: 12px;
    }

    .teacher-grid-full .teacher-card-horizontal {
        padding: 14px;
        gap: 12px;
    }

    .teacher-grid-full .teacher-photo {
        width: 70px;
        height: 70px;
    }

    .teacher-grid-full .teacher-name {
        font-size: 1rem;
    }

    /* About Small Mobile */
    .culture-item {
        padding: 12px;
    }

    .culture-item h4 {
        font-size: 0.625rem;
    }

    .culture-item p {
        font-size: 0.75rem;
    }

    .about-img-card {
        padding: 12px;
    }

    .about-card-icon {
        width: 36px;
        height: 36px;
    }

    .about-card-icon svg {
        width: 18px;
        height: 18px;
    }

    .about-img-card h4 {
        font-size: 0.875rem;
    }

    .about-img-card p {
        font-size: 0.75rem;
    }

    /* Section Small Mobile */
    .section-title {
        font-size: 1.25rem;
    }

    .section-subtitle {
        font-size: 0.875rem;
    }

    /* Contact Small Mobile */
    .contact-form-wrapper {
        padding: var(--space-md);
        border-radius: var(--radius-lg);
    }

    .contact-form h3 {
        font-size: 1.125rem;
    }

    .form-group {
        margin-bottom: var(--space-md);
    }

    .form-group input,
    .form-group select,
    .form-group textarea {
        padding: var(--space-sm);
        font-size: 15px; /* Prevent iOS zoom on focus */
    }

    /* Advantage cards Small Mobile */
    .advantage-card {
        padding: var(--space-md);
    }

    .advantage-icon {
        width: 48px;
        height: 48px;
    }

    /* Credentials Small Mobile */
    .credential-card {
        padding: var(--space-md);
    }

    .credential-icon {
        width: 48px;
        height: 48px;
    }

    /* Footer Small Mobile */
    .footer {
        padding: var(--space-2xl) 0 var(--space-md);
    }

    .footer-brand {
        margin-bottom: var(--space-lg);
    }

    /* Culture items Small Mobile */
    .culture-item {
        padding: var(--space-md);
    }

    /* About cards Small Mobile */
    .about-img-card {
        padding: var(--space-md);
    }

    .about-card-icon svg {
        width: 32px;
        height: 32px;
    }

    /* Improve touch targets for small screens */
    .indicator {
        min-width: 10px;
        min-height: 10px;
    }

    .case-tab {
        padding: var(--space-sm) var(--space-md);
        font-size: 0.875rem;
    }
}

/* ============================================
   Safe Area Support for Modern Devices
   ============================================ */
@supports (padding-bottom: env(safe-area-inset-bottom)) {
    .footer {
        padding-bottom: calc(var(--space-xl) + env(safe-area-inset-bottom));
    }

    .mobile-menu {
        padding-bottom: calc(var(--space-xl) + env(safe-area-inset-bottom));
    }

    .modal {
        padding-bottom: env(safe-area-inset-bottom);
    }
}

/* ============================================
   Reduced Motion Preference
   ============================================ */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }

    .tech-line,
    .tech-particle,
    .tech-hexagon,
    .banner-carousel::after {
        animation: none;
    }
}

/* ============================================
   High Contrast Mode Support
   ============================================ */
@media (prefers-contrast: high) {
    :root {
        --border-light: rgba(255, 255, 255, 0.3);
        --border-medium: rgba(255, 255, 255, 0.5);
        --text-secondary: #ffffff;
        --text-muted: #cccccc;
    }

    .advantage-card,
    .credential-card,
    .teacher-card-horizontal {
        border-width: 2px;
    }
}

/* ============================================
   Dark Mode (already dark, but optimize for OLED)
   ============================================ */
@media (max-width: 768px) {
    /* Pure black for OLED screens saves battery */
    @media (forced-colors: none) {
        .banner-carousel {
            background: #000000;
        }

        body {
            background-color: #000000;
        }

        .section-alt {
            background: #0a0a0a;
        }
    }
}

/* ============================================
   Landscape Mobile Optimization
   ============================================ */
@media (max-height: 500px) and (orientation: landscape) {
    .hero {
        min-height: auto;
        padding: calc(var(--navbar-height) + var(--space-md)) 0 var(--space-md);
    }

    .hero-content {
        gap: var(--space-md);
    }

    .hero-title {
        font-size: 1.5rem;
    }

    .hero-desc {
        display: none;
    }

    .hero-stats {
        grid-template-columns: repeat(4, 1fr);
        max-width: 100%;
    }

    .stat-card:first-child {
        grid-column: span 1;
    }

    .stat-number {
        font-size: 1.5rem;
    }

    .banner-carousel {
        min-height: 150px;
    }

    .carousel-slide img {
        max-height: 150px;
    }
}