/* ===========================
   CSS Variables & Reset
   =========================== */

/* Light Theme (Default) */
:root {
    --bg-primary: #f8f7fc;
    --bg-secondary: #f0eef8;
    --bg-card: #ffffff;
    --bg-card-hover: #f5f3fa;
    --surface: #ede9f7;
    --border: rgba(95, 73, 247, 0.1);
    --border-hover: rgba(95, 73, 247, 0.3);

    --text-primary: #1a1525;
    --text-secondary: #5a5266;
    --text-tertiary: #8b8595;

    --accent: #5F49F7;
    --accent-dark: #4a35d4;
    --accent-glow: rgba(95, 73, 247, 0.12);
    --accent-secondary: #B948CB;
    --accent-tertiary: #7c3aed;

    --navbar-scrolled-bg: rgba(248, 247, 252, 0.85);
    --badge-bg: rgba(255, 255, 255, 0.85);
    --hero-title-grad: linear-gradient(135deg, #1a1525 0%, #5a5266 100%);
    --shadow-card: 0 4px 20px rgba(95, 73, 247, 0.06);
    --shadow-hover: 0 20px 40px rgba(95, 73, 247, 0.12);

    --gradient-1: linear-gradient(135deg, #5F49F7 0%, #B948CB 100%);
    --gradient-2: linear-gradient(135deg, #B948CB 0%, #7c3aed 100%);
    --gradient-3: linear-gradient(135deg, #5F49F7 0%, #7c3aed 100%);
    --gradient-4: linear-gradient(135deg, #B948CB 0%, #5F49F7 100%);
    --gradient-5: linear-gradient(135deg, #8b5cf6 0%, #B948CB 100%);
    --gradient-6: linear-gradient(135deg, #7c3aed 0%, #B948CB 100%);

    /* Typography */
    --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', 'Courier New', monospace;

    /* Spacing */
    --container-max: 1280px;
    --section-padding: 100px 0;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 28px;

    /* 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);
}

/* Dark Theme */
[data-theme="dark"] {
    --bg-primary: #0a0e1a;
    --bg-secondary: #0f1525;
    --bg-card: #141b2d;
    --bg-card-hover: #1a2238;
    --surface: #1e293b;
    --border: rgba(148, 163, 184, 0.12);
    --border-hover: rgba(95, 73, 247, 0.3);

    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-tertiary: #64748b;

    --navbar-scrolled-bg: rgba(10, 14, 26, 0.85);
    --badge-bg: rgba(10, 14, 26, 0.8);
    --hero-title-grad: linear-gradient(135deg, #f1f5f9 0%, #94a3b8 100%);
    --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.2);
    --shadow-hover: 0 20px 40px rgba(0, 0, 0, 0.3);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

ul {
    list-style: none;
}

img, svg {
    display: block;
    max-width: 100%;
}

::selection {
    background: var(--accent);
    color: var(--bg-primary);
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 10px;
}
::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}
::-webkit-scrollbar-thumb {
    background: var(--surface);
    border-radius: 5px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--accent-dark);
}

/* ===========================
   Loader
   =========================== */
.loader {
    position: fixed;
    inset: 0;
    background: var(--bg-primary);
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}
.loader.hidden {
    opacity: 0;
    visibility: hidden;
}
.loader-content {
    text-align: center;
}
.loader-ring {
    width: 60px;
    height: 60px;
    border: 3px solid var(--surface);
    border-top-color: var(--accent);
    border-radius: 50%;
    margin: 0 auto 20px;
    animation: spin 1s linear infinite;
}
.loader-text {
    font-family: var(--font-mono);
    font-size: 14px;
    color: var(--accent);
    letter-spacing: 3px;
    text-transform: uppercase;
}
@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ===========================
   Container
   =========================== */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
}

/* ===========================
   Buttons
   =========================== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: var(--radius-md);
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    outline: none;
    font-family: var(--font-sans);
    white-space: nowrap;
}
.btn-primary {
    background: var(--accent);
    color: var(--bg-primary);
    box-shadow: 0 4px 20px var(--accent-glow);
}
.btn-primary:hover {
    background: var(--accent-dark);
    transform: translateY(-2px);
    box-shadow: 0 6px 30px var(--accent-glow);
}
.btn-primary:active {
    transform: scale(0.98);
}
.btn-outline {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border);
}
.btn-outline:hover {
    border-color: var(--accent);
    color: var(--accent);
    transform: translateY(-2px);
}
.btn-full {
    width: 100%;
    justify-content: center;
}

/* ===========================
   Navbar
   =========================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 20px 0;
    transition: var(--transition);
    background: transparent;
}
.navbar.scrolled {
    background: var(--navbar-scrolled-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    padding: 14px 0;
}
.nav-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-primary);
    font-weight: 700;
    font-size: 18px;
}
.logo-icon {
    width: 36px;
    height: 36px;
    flex-shrink: 0;
}
.logo-text {
    transition: var(--transition);
}
.nav-menu {
    display: flex;
    align-items: center;
    gap: 4px;
}
.nav-link {
    padding: 8px 16px;
    color: var(--text-secondary);
    font-size: 15px;
    font-weight: 500;
    border-radius: var(--radius-sm);
    transition: var(--transition);
    position: relative;
}
.nav-link:hover {
    color: var(--text-primary);
    background: var(--surface);
}
.nav-link.active {
    color: var(--accent);
}
.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 20px;
    height: 2px;
    background: var(--accent);
    border-radius: 1px;
}
.nav-actions {
    display: flex;
    align-items: center;
    gap: 10px;
}
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}
.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: var(--transition);
}
.nav-toggle.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}
.nav-toggle.active span:nth-child(2) {
    opacity: 0;
}
.nav-toggle.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* Theme Toggle Button */
.theme-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    color: var(--text-secondary);
    flex-shrink: 0;
}
.theme-toggle:hover {
    border-color: var(--accent);
    color: var(--accent);
}
.theme-toggle svg {
    width: 20px;
    height: 20px;
    transition: var(--transition);
}
.theme-toggle .icon-sun {
    display: none;
}
.theme-toggle .icon-moon {
    display: block;
}
[data-theme="dark"] .theme-toggle .icon-sun {
    display: block;
}
[data-theme="dark"] .theme-toggle .icon-moon {
    display: none;
}

/* Theme Transition */
body, .navbar, .section, .footer, .loader,
.stat-card, .research-card, .project-card, .news-featured,
.news-item, .timeline-content, .team-card, .contact-item,
.contact-form-wrapper, .value-item, .team-stats {
    transition: background-color 0.3s ease, border-color 0.3s ease, color 0.3s ease;
}

/* ===========================
   Hero Section
   =========================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    background: var(--bg-primary);
}
.particle-canvas {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}
.hero-overlay {
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at center, transparent 0%, var(--bg-primary) 80%);
    z-index: 2;
}
.hero-content {
    position: relative;
    z-index: 3;
    text-align: center;
    max-width: 800px;
    padding: 0 24px;
}
.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 18px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 100px;
    font-size: 13px;
    font-family: var(--font-mono);
    color: var(--accent);
    margin-bottom: 24px;
}
.badge-dot {
    width: 8px;
    height: 8px;
    background: var(--accent);
    border-radius: 50%;
    animation: pulse-dot 2s ease-in-out infinite;
}
@keyframes pulse-dot {
    0%, 100% { opacity: 1; box-shadow: 0 0 0 0 var(--accent-glow); }
    50% { opacity: 0.6; box-shadow: 0 0 0 8px transparent; }
}
.hero-title {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 900;
    letter-spacing: -0.02em;
    line-height: 1.1;
    margin-bottom: 20px;
    background: var(--hero-title-grad);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}
.hero-subtitle {
    font-size: clamp(1.1rem, 3vw, 1.5rem);
    color: var(--accent);
    font-weight: 500;
    margin-bottom: 24px;
    letter-spacing: 0.05em;
}
.hero-desc {
    font-size: 16px;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 36px;
}
.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}
.hero-scroll {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 3;
    text-align: center;
    color: var(--text-tertiary);
    font-size: 12px;
    letter-spacing: 2px;
    text-transform: uppercase;
}
.scroll-line {
    width: 1px;
    height: 40px;
    background: linear-gradient(to bottom, var(--accent), transparent);
    margin: 12px auto 0;
    animation: scroll-line 2s ease-in-out infinite;
}
@keyframes scroll-line {
    0% { transform: scaleY(0); transform-origin: top; }
    50% { transform: scaleY(1); transform-origin: top; }
    50.01% { transform-origin: bottom; }
    100% { transform: scaleY(0); transform-origin: bottom; }
}

/* ===========================
   Section Common
   =========================== */
.section {
    padding: var(--section-padding);
    position: relative;
}
.section-header {
    text-align: center;
    margin-bottom: 60px;
}
.section-tag {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 13px;
    color: var(--accent);
    letter-spacing: 3px;
    text-transform: uppercase;
    margin-bottom: 12px;
    padding: 4px 14px;
    background: var(--accent-glow);
    border-radius: 100px;
}
.section-title {
    font-size: clamp(2rem, 4vw, 2.8rem);
    font-weight: 800;
    letter-spacing: -0.02em;
    margin-bottom: 12px;
}
.section-desc {
    font-size: 16px;
    color: var(--text-secondary);
}

/* ===========================
   About Section
   =========================== */
.about {
    background: var(--bg-secondary);
}
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: start;
}
.about-text h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--text-primary);
}
.about-text p {
    color: var(--text-secondary);
    line-height: 1.9;
    margin-bottom: 16px;
}
.about-values {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-top: 40px;
}
.value-item {
    display: flex;
    gap: 16px;
    align-items: flex-start;
    padding: 24px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    transition: var(--transition);
}
.value-item:hover {
    border-color: var(--border-hover);
    transform: translateX(4px);
}
.value-icon {
    width: 44px;
    height: 44px;
    flex-shrink: 0;
    background: var(--accent-glow);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent);
}
.value-icon svg {
    width: 22px;
    height: 22px;
}
.value-content {
    min-width: 0;
}
.value-item h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 4px;
    color: var(--text-primary);
    white-space: nowrap;
}
.value-item p {
    font-size: 14px;
    color: var(--text-secondary);
    margin: 0;
    line-height: 1.6;
}
.about-stats {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    position: sticky;
    top: 100px;
}
.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 32px 24px;
    text-align: center;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}
.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--accent);
    transform: scaleX(0);
    transform-origin: left;
    transition: var(--transition-slow);
}
.stat-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-4px);
}
.stat-card:hover::before {
    transform: scaleX(1);
}
.stat-number {
    font-size: 3rem;
    font-weight: 900;
    font-family: var(--font-mono);
    color: var(--accent);
    line-height: 1;
    margin-bottom: 8px;
}
.stat-label {
    font-size: 15px;
    color: var(--text-secondary);
    font-weight: 500;
}
.stat-suffix {
    font-size: 14px;
    color: var(--text-tertiary);
    margin-top: 4px;
}

/* ===========================
   Research Section
   =========================== */
.research-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}
.research-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 32px 28px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}
.research-card::after {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200px;
    height: 200px;
    background: radial-gradient(circle, var(--accent-glow), transparent 70%);
    opacity: 0;
    transition: var(--transition-slow);
}
.research-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-4px);
    background: var(--bg-card-hover);
}
.research-card:hover::after {
    opacity: 1;
}
.research-icon {
    width: 56px;
    height: 56px;
    background: var(--accent-glow);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent);
    margin-bottom: 20px;
    transition: var(--transition);
}
.research-card:hover .research-icon {
    background: var(--accent);
    color: var(--bg-primary);
    transform: scale(1.1);
}
.research-icon svg {
    width: 28px;
    height: 28px;
}
.research-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-primary);
}
.research-card p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 20px;
}
.research-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}
.research-tags li {
    font-size: 12px;
    padding: 4px 12px;
    background: var(--surface);
    border-radius: 100px;
    color: var(--text-tertiary);
    font-family: var(--font-mono);
}

/* ===========================
   Projects Section
   =========================== */
.projects {
    background: var(--bg-secondary);
}
.project-filters {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 40px;
}
.filter-btn {
    padding: 8px 20px;
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-secondary);
    border-radius: 100px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    font-family: var(--font-sans);
}
.filter-btn:hover {
    border-color: var(--accent);
    color: var(--text-primary);
}
.filter-btn.active {
    background: var(--accent);
    color: var(--bg-primary);
    border-color: var(--accent);
}
.project-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}
.project-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: var(--transition);
    cursor: pointer;
}
.project-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
}
.project-card.hidden {
    display: none;
}
.project-image {
    height: 180px;
    position: relative;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}
.project-gradient {
    position: absolute;
    inset: 0;
    opacity: 0.15;
    transition: var(--transition-slow);
}
.project-card:hover .project-gradient {
    opacity: 0.25;
}
.grad-1 { background: var(--gradient-1); }
.grad-2 { background: var(--gradient-2); }
.grad-3 { background: var(--gradient-3); }
.grad-4 { background: var(--gradient-4); }
.grad-5 { background: var(--gradient-5); }
.grad-6 { background: var(--gradient-6); }
.project-pattern {
    position: relative;
    z-index: 2;
    color: var(--text-primary);
    opacity: 0.7;
    transition: var(--transition-slow);
}
.project-card:hover .project-pattern {
    opacity: 1;
    transform: scale(1.05);
}
.project-pattern svg {
    width: 200px;
    height: 120px;
}
.project-info {
    padding: 24px;
}
.project-category {
    display: inline-block;
    font-size: 12px;
    color: var(--accent);
    font-family: var(--font-mono);
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 1px;
}
.project-info h3 {
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--text-primary);
    line-height: 1.4;
}
.project-info p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 16px;
}
.project-meta {
    display: flex;
    gap: 16px;
}
.meta-item {
    display: flex;
    align-items: center;
    gap: 5px;
    font-size: 13px;
    color: var(--text-tertiary);
}
.meta-item svg {
    color: var(--text-tertiary);
}

/* ===========================
   Video Showcase Section
   =========================== */
.video-showcase {
    background: var(--bg-secondary);
}

.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

.video-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow-card);
    transition: all 0.4s ease;
}

.video-card:hover {
    border-color: var(--border-hover);
    box-shadow: var(--shadow-hover);
    transform: translateY(-4px);
}

.video-wrapper {
    position: relative;
    width: 100%;
    aspect-ratio: 16 / 9;
    background: #000;
    overflow: hidden;
}

.video-wrapper video {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.video-info {
    padding: 1.5rem;
}

.video-tag {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: var(--accent-glow);
    color: var(--accent);
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.video-info h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

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

/* ===========================
   News Section
   =========================== */
.news-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: start;
}
.news-featured {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: var(--transition);
}
.news-featured:hover {
    border-color: var(--border-hover);
    transform: translateY(-4px);
}
.news-featured-image {
    height: 240px;
    position: relative;
    overflow: hidden;
}
.news-gradient {
    position: absolute;
    inset: 0;
    background: var(--gradient-1);
    opacity: 0.2;
}
.news-date-badge {
    position: absolute;
    top: 20px;
    left: 20px;
    background: var(--badge-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 12px 16px;
    text-align: center;
}
.date-day {
    display: block;
    font-size: 1.8rem;
    font-weight: 800;
    color: var(--accent);
    line-height: 1;
}
.date-month {
    display: block;
    font-size: 12px;
    color: var(--text-secondary);
    margin-top: 4px;
    font-family: var(--font-mono);
}
.news-featured-content {
    padding: 28px;
}
.news-tag {
    display: inline-block;
    font-size: 12px;
    padding: 4px 12px;
    background: var(--accent-glow);
    color: var(--accent);
    border-radius: 100px;
    margin-bottom: 12px;
    font-weight: 500;
}
.news-featured-content h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 12px;
    line-height: 1.4;
    color: var(--text-primary);
}
.news-featured-content p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 20px;
}
.news-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: var(--accent);
    font-size: 14px;
    font-weight: 500;
    transition: var(--transition);
}
.news-link:hover {
    gap: 10px;
}
.news-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}
.news-item {
    display: flex;
    gap: 20px;
    padding: 20px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    transition: var(--transition);
    cursor: pointer;
}
.news-item:hover {
    border-color: var(--border-hover);
    transform: translateX(4px);
    background: var(--bg-card-hover);
}
.news-item-date {
    flex-shrink: 0;
    text-align: center;
    min-width: 50px;
    padding-top: 4px;
}
.news-item-date .day {
    display: block;
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--accent);
    line-height: 1;
}
.news-item-date .month {
    display: block;
    font-size: 12px;
    color: var(--text-tertiary);
    margin-top: 4px;
}
.news-item-content {
    flex: 1;
}
.news-tag-small {
    display: inline-block;
    font-size: 11px;
    padding: 2px 10px;
    background: var(--surface);
    color: var(--text-tertiary);
    border-radius: 100px;
    margin-bottom: 8px;
    font-weight: 500;
}
.news-item-content h4 {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 6px;
    line-height: 1.4;
    color: var(--text-primary);
}
.news-item-content p {
    font-size: 13px;
    color: var(--text-tertiary);
    line-height: 1.5;
}
.news-item-content h4 a {
    color: inherit;
    text-decoration: none;
    transition: color 0.2s;
}
.news-item-content h4 a:hover {
    color: var(--color-primary);
}
.news-item-link {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 12px;
    font-weight: 500;
    color: var(--color-primary);
    text-decoration: none;
    margin-top: 8px;
    transition: gap 0.2s;
}
.news-item-link:hover {
    gap: 8px;
}
.news-more {
    text-align: center;
    margin-top: 48px;
}

/* ===========================
   Honors Section
   =========================== */
.honors {
    background: var(--bg-secondary);
}
.honors-timeline {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
}
.timeline-line {
    position: absolute;
    left: 20px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(to bottom, var(--accent), var(--accent-dark), transparent);
}
.timeline-item {
    position: relative;
    padding-left: 60px;
    padding-bottom: 40px;
}
.timeline-item:last-child {
    padding-bottom: 0;
}
.timeline-dot {
    position: absolute;
    left: 13px;
    top: 6px;
    width: 16px;
    height: 16px;
    background: var(--bg-secondary);
    border: 3px solid var(--accent);
    border-radius: 50%;
    z-index: 2;
    transition: var(--transition);
}
.timeline-item:hover .timeline-dot {
    background: var(--accent);
    box-shadow: 0 0 0 6px var(--accent-glow);
}
.timeline-content {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 24px;
    transition: var(--transition);
}
.timeline-content:hover {
    border-color: var(--border-hover);
    transform: translateX(4px);
}
.timeline-year {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 14px;
    color: var(--accent);
    font-weight: 700;
    margin-bottom: 8px;
}
.timeline-content h4 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--text-primary);
}
.timeline-content p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ===========================
   Team Section
   =========================== */
.team-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    margin-bottom: 60px;
}
.team-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 32px 24px;
    text-align: center;
    transition: var(--transition);
}
.team-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-6px);
    background: var(--bg-card-hover);
}
.team-avatar {
    width: 100px;
    height: 100px;
    margin: 0 auto 20px;
    color: var(--accent);
    position: relative;
}
.team-avatar svg {
    width: 100%;
    height: 100%;
}
.team-info h3 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 4px;
    color: var(--text-primary);
}
.team-role {
    display: block;
    font-size: 13px;
    color: var(--accent);
    margin-bottom: 12px;
    font-weight: 500;
}
.team-info p {
    font-size: 13px;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 16px;
    text-align: left;
}
.team-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    justify-content: center;
}
.team-tags span {
    font-size: 11px;
    padding: 3px 10px;
    background: var(--surface);
    border-radius: 100px;
    color: var(--text-tertiary);
    font-family: var(--font-mono);
}
.team-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    padding: 40px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
}
.team-stat-item {
    text-align: center;
}
.team-stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--accent);
    font-family: var(--font-mono);
    margin-bottom: 4px;
}
.team-stat-label {
    font-size: 14px;
    color: var(--text-secondary);
}

/* ===========================
   Contact Section
   =========================== */
.contact {
    background: var(--bg-secondary);
}
.contact-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 40px;
    max-width: 700px;
    margin: 0 auto;
}
.contact-info h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 16px;
}
.contact-info > p {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 32px;
}
.contact-items {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}
.contact-item {
    display: flex;
    gap: 16px;
    align-items: flex-start;
    padding: 20px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    transition: var(--transition);
}
.contact-item:hover {
    border-color: var(--border-hover);
    transform: translateX(4px);
}
.contact-icon {
    width: 44px;
    height: 44px;
    flex-shrink: 0;
    background: var(--accent-glow);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent);
}
.contact-icon svg {
    width: 22px;
    height: 22px;
}
.contact-label {
    display: block;
    font-size: 13px;
    color: var(--text-tertiary);
    margin-bottom: 2px;
}
.contact-value {
    display: block;
    font-size: 15px;
    color: var(--text-primary);
    font-weight: 500;
}
.contact-form-wrapper {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 40px;
}
.contact-form h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 24px;
}
.form-group {
    margin-bottom: 20px;
}
.form-group label {
    display: block;
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 8px;
    font-weight: 500;
}
.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 14px;
    font-family: var(--font-sans);
    transition: var(--transition);
    resize: vertical;
}
.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}
.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--text-tertiary);
}
.form-message {
    margin-top: 16px;
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    font-size: 14px;
    text-align: center;
    display: none;
}
.form-message.success {
    display: block;
    background: rgba(52, 211, 153, 0.1);
    color: #34d399;
    border: 1px solid rgba(52, 211, 153, 0.3);
}
.form-message.error {
    display: block;
    background: rgba(248, 113, 113, 0.1);
    color: #f87171;
    border: 1px solid rgba(248, 113, 113, 0.3);
}

/* ===========================
   Footer
   =========================== */
.footer {
    background: var(--bg-primary);
    border-top: 1px solid var(--border);
    padding: 60px 0 24px;
}
.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}
.footer-brand .nav-logo {
    margin-bottom: 16px;
}
.footer-brand p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
    max-width: 320px;
}
.footer-links h4 {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 16px;
    color: var(--text-primary);
}
.footer-links ul {
    display: grid;
    gap: 10px;
}
.footer-links a {
    font-size: 14px;
    color: var(--text-secondary);
    transition: var(--transition);
}
.footer-links a:hover {
    color: var(--accent);
    padding-left: 4px;
}
.footer-bottom {
    padding-top: 24px;
    border-top: 1px solid var(--border);
    text-align: center;
}
.footer-bottom p {
    font-size: 13px;
    color: var(--text-tertiary);
}

/* ===========================
   Back to Top
   =========================== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    background: var(--accent);
    color: var(--bg-primary);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: var(--transition);
    z-index: 999;
    box-shadow: 0 4px 20px var(--accent-glow);
}
.back-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.back-to-top:hover {
    background: var(--accent-dark);
    transform: translateY(-4px);
}

/* ===========================
   Reveal Animation
   =========================== */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1), transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
    transition-delay: var(--delay, 0s);
}
.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ===========================
   Responsive Design
   =========================== */
@media (max-width: 1024px) {
    .research-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .project-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .team-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
    .about-grid {
        gap: 40px;
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: 60px 0;
    }
    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 75%;
        max-width: 320px;
        height: 100vh;
        background: var(--bg-secondary);
        flex-direction: column;
        align-items: flex-start;
        padding: 80px 24px 24px;
        gap: 8px;
        transition: right 0.3s cubic-bezier(0.16, 1, 0.3, 1);
        border-left: 1px solid var(--border);
        z-index: 999;
    }
    .nav-menu.active {
        right: 0;
    }
    .nav-link {
        width: 100%;
        padding: 12px 16px;
    }
    .nav-link.active::after {
        display: none;
    }
    .nav-toggle {
        display: flex;
        z-index: 1000;
    }
    .logo-text {
        display: none;
    }
    .about-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    .about-stats {
        position: static;
    }
    .research-grid {
        grid-template-columns: 1fr;
    }
    .project-grid {
        grid-template-columns: 1fr;
    }
    .news-grid {
        grid-template-columns: 1fr;
    }
    .video-grid {
        grid-template-columns: 1fr;
    }
    .team-grid {
        grid-template-columns: 1fr;
    }
    .team-stats {
        grid-template-columns: repeat(2, 1fr);
        padding: 24px;
    }
    .contact-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    .contact-items {
        grid-template-columns: 1fr;
    }
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }
    .hero-actions {
        flex-direction: column;
        align-items: center;
    }
    .hero-actions .btn {
        width: 100%;
        max-width: 280px;
        justify-content: center;
    }
    .hero-desc br {
        display: none;
    }
    .project-filters {
        gap: 8px;
    }
    .filter-btn {
        padding: 6px 14px;
        font-size: 13px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }
    .nav-container {
        padding: 0 16px;
    }
    .section-header {
        margin-bottom: 40px;
    }
    .stat-card {
        padding: 24px 16px;
    }
    .stat-number {
        font-size: 2.2rem;
    }
    .hero-badge {
        font-size: 11px;
        padding: 6px 14px;
    }
    .team-stats {
        grid-template-columns: 1fr 1fr;
        gap: 16px;
    }
    .team-stat-number {
        font-size: 2rem;
    }
    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 42px;
        height: 42px;
    }
    .about-values {
        grid-template-columns: 1fr;
    }
}

/* ===========================
   Reduced Motion
   =========================== */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    .reveal {
        opacity: 1;
        transform: none;
    }
    html {
        scroll-behavior: auto;
    }
}