/* ========================================
   福建省青少年人工智能创新赛 - 现代化样式
   ======================================== */

/* CSS Variables */
:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --secondary-color: #7c3aed;
    --accent-color: #06b6d4;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f8fafc;
    --bg-white: #ffffff;
    --gradient-primary: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
    --gradient-hero: linear-gradient(135deg, #0f172a 0%, #1e3a5f 50%, #2563eb 100%);
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Microsoft YaHei", sans-serif;
    color: var(--text-dark);
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

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

/* ========================================
   Header / Navigation
   ======================================== */
.competition-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 1rem 0;
    transition: var(--transition);
}

.competition-header.scrolled {
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
    padding: 0.5rem 0;
}

.header-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.header-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.header-logo img {
    height: 48px;
    width: auto;
}

.header-logo .logo-text {
    font-size: 1.25rem;
    font-weight: 700;
    color: #fff;
    transition: var(--transition);
}

.competition-header.scrolled .header-logo .logo-text {
    color: var(--text-dark);
}

.header-nav {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.header-nav a {
    color: rgba(255, 255, 255, 0.9);
    font-weight: 500;
    font-size: 0.95rem;
    position: relative;
    padding: 0.5rem 0;
}

.competition-header.scrolled .header-nav a {
    color: var(--text-dark);
}

.header-nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition);
}

.header-nav a:hover::after {
    width: 100%;
}

.header-nav a:hover {
    color: var(--primary-light);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    background: var(--gradient-primary);
    color: #fff;
    font-weight: 600;
    font-size: 0.9rem;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    transition: var(--transition);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px -5px rgba(37, 99, 235, 0.4);
    color: #fff;
}

.btn-outline {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    background: transparent;
    color: #fff;
    font-weight: 600;
    font-size: 0.9rem;
    border-radius: var(--radius-md);
    border: 2px solid rgba(255, 255, 255, 0.3);
    cursor: pointer;
    transition: var(--transition);
}

/* 移动端菜单专用操作按钮：桌面端隐藏 */
.header-nav .nav-login,
.header-nav .nav-register {
    display: none;
}

.competition-header.scrolled .btn-outline {
    color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: #fff;
    color: #fff;
}

.competition-header.scrolled .btn-outline:hover {
    background: var(--primary-color);
    color: #fff;
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    color: #fff;
    font-size: 1.5rem;
    cursor: pointer;
}

.competition-header.scrolled .mobile-menu-toggle {
    color: var(--text-dark);
}

/* ========================================
   用户中心下拉菜单（头像 + 用户名）
   ======================================== */
.user-dropdown {
    position: relative;
}

.user-dropdown-toggle {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(255, 255, 255, 0.12);
    border: 1px solid rgba(255, 255, 255, 0.25);
    border-radius: var(--radius-lg);
    padding: 0.4rem 0.9rem 0.4rem 0.4rem;
    color: #fff;
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
    transition: var(--transition);
}

.competition-header.scrolled .user-dropdown-toggle {
    background: rgba(255, 255, 255, 0.8);
    border-color: var(--primary-color);
    color: var(--text-dark);
}

.user-dropdown-toggle:hover {
    box-shadow: var(--shadow-sm);
}

.user-avatar {
    width: 30px;
    height: 30px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid #fff;
    flex: 0 0 auto;
}

.competition-header.scrolled .user-avatar {
    border-color: var(--primary-color);
}

.user-avatar-default {
    width: 30px;
    height: 30px;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    color: #fff;
    font-size: 0.9rem;
    flex: 0 0 auto;
}

.user-name {
    max-width: 120px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.user-caret {
    font-size: 0.8rem;
    opacity: 0.8;
    transition: var(--transition);
}

.user-dropdown.open .user-caret {
    transform: rotate(180deg);
}

.user-dropdown-menu {
    position: absolute;
    right: 0;
    top: calc(100% + 8px);
    min-width: 190px;
    background: #fff;
    border-radius: var(--radius-lg);
    box-shadow: 0 15px 40px -10px rgba(0, 0, 0, 0.25);
    padding: 0.5rem;
    opacity: 0;
    visibility: hidden;
    transform: translateY(8px);
    transition: all 0.22s ease;
    z-index: 1001;
}

.user-dropdown.open .user-dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.user-dropdown-head {
    padding: 0.6rem 0.75rem;
    font-size: 0.75rem;
    font-weight: 700;
    color: #9aa5b1;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.user-dropdown-menu a {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.55rem 0.75rem;
    border-radius: var(--radius-sm);
    color: var(--text-dark);
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition);
}

.user-dropdown-menu a i {
    width: 18px;
    text-align: center;
    color: var(--primary-color);
}

.user-dropdown-menu a:hover {
    background: #f1f5f9;
    color: var(--primary-color);
}

.user-dropdown-divider {
    height: 1px;
    background: #eef2f6;
    margin: 0.35rem 0;
}

.user-dropdown-menu .user-dropdown-signout {
    color: #dc2626;
}

.user-dropdown-menu .user-dropdown-signout i {
    color: #dc2626;
}

.user-dropdown-menu .user-dropdown-signout:hover {
    background: #fef2f2;
    color: #dc2626;
}

/* 移动端 NAV 内的用户菜单 */
.nav-user-menu {
    display: none;
    flex-direction: column;
    width: 100%;
}

.nav-user-head {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.5rem 0.75rem 0.9rem;
    margin-bottom: 0.25rem;
    border-bottom: 1px solid #eef2f6;
    font-weight: 600;
    color: var(--text-dark);
}

.nav-user-menu a {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.75rem 1rem;
    width: 100%;
    color: var(--text-dark);
    font-weight: 500;
}

.nav-user-menu a::after {
    display: none;
}

.nav-user-menu a i {
    width: 18px;
    text-align: center;
    color: var(--primary-color);
}

/* ========================================
   Hero Section
   ======================================== */
.hero-section {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: var(--gradient-hero);
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 1;
}

.hero-bg img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0.3;
}

.hero-bg::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(15, 23, 42, 0.9) 0%, rgba(37, 99, 235, 0.7) 100%);
}

.hero-particles {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 2;
    overflow: hidden;
}

.particle {
    position: absolute;
    width: 4px;
    height: 4px;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    animation: float 15s infinite ease-in-out;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0) translateX(0);
        opacity: 0;
    }
    10% {
        opacity: 1;
    }
    90% {
        opacity: 1;
    }
    100% {
        transform: translateY(-100vh) translateX(100px);
        opacity: 0;
    }
}

.hero-content {
    position: relative;
    z-index: 10;
    max-width: 1280px;
    margin: 0 auto;
    padding: 8rem 1.5rem 4rem;
    text-align: center;
    color: #fff;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 9999px;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 1.5rem;
    border: 1px solid rgba(255, 255, 255, 0.2);
    animation: fadeInDown 0.8s ease;
}

.hero-badge .dot {
    width: 8px;
    height: 8px;
    background: #22c55e;
    border-radius: 50%;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    animation: fadeInUp 0.8s ease 0.2s both;
}

.hero-title .highlight {
    background: linear-gradient(135deg, #60a5fa 0%, #a78bfa 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: clamp(1rem, 2vw, 1.5rem);
    color: rgba(255, 255, 255, 0.8);
    max-width: 600px;
    margin: 0 auto 2rem;
    animation: fadeInUp 0.8s ease 0.4s both;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease 0.6s both;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 3rem;
    margin-top: 4rem;
    animation: fadeInUp 0.8s ease 0.8s both;
}

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

.hero-stat-value {
    font-size: 2.5rem;
    font-weight: 800;
    color: #fff;
}

.hero-stat-label {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.7);
    margin-top: 0.25rem;
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ========================================
   Section Common
   ======================================== */
.section {
    padding: 5rem 0;
}

.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 3rem;
}

.section-tag {
    display: inline-block;
    padding: 0.375rem 1rem;
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary-color);
    font-size: 0.875rem;
    font-weight: 600;
    border-radius: 9999px;
    margin-bottom: 1rem;
}

.section-title {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 800;
    color: var(--text-dark);
    margin-bottom: 1rem;
    line-height: 1.2;
}

.section-desc {
    font-size: 1.1rem;
    color: var(--text-light);
}

/* ========================================
   Event Categories Section
   ======================================== */
.events-section {
    background: var(--bg-light);
}

.events-grid {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.event-card {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    position: relative;
}

.event-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.event-card-image {
    position: relative;
    height: 200px;
    overflow: hidden;
}

.event-card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.event-card:hover .event-card-image img {
    transform: scale(1.05);
}

.event-card-badge {
    position: absolute;
    top: 1rem;
    left: 1rem;
    padding: 0.375rem 0.75rem;
    background: var(--gradient-primary);
    color: #fff;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
}

.event-card-content {
    padding: 1.5rem;
}

.event-card-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.event-card-desc {
    font-size: 0.9rem;
    color: var(--text-light);
    margin-bottom: 1rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.event-card-meta {
    display: flex;
    align-items: center;
    gap: 1rem;
    font-size: 0.8rem;
    color: var(--text-light);
    margin-bottom: 1rem;
}

.event-card-meta i {
    color: var(--primary-color);
}

.event-card-actions {
    display: flex;
    gap: 0.75rem;
}

.event-card-actions a {
    flex: 1;
    text-align: center;
    padding: 0.625rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 600;
    transition: var(--transition);
}

.event-card-actions .btn-detail {
    background: var(--bg-light);
    color: var(--text-dark);
}

.event-card-actions .btn-detail:hover {
    background: var(--primary-color);
    color: #fff;
}

.event-card-actions .btn-register {
    background: var(--primary-color);
    color: #fff;
}

.event-card-actions .btn-register:hover {
    background: var(--primary-dark);
}

/* ========================================
   News Section
   ======================================== */
.news-section {
    background: var(--bg-white);
}

.news-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.news-tabs {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: 2rem;
}

.news-tab {
    padding: 0.625rem 1.5rem;
    background: var(--bg-light);
    color: var(--text-dark);
    font-weight: 600;
    font-size: 0.9rem;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    transition: var(--transition);
}

.news-tab.active,
.news-tab:hover {
    background: var(--primary-color);
    color: #fff;
}

.news-list {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.news-item {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid #e5e7eb;
}

.news-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.news-item-image {
    display: block;
    height: 180px;
    overflow: hidden;
}

.news-item-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.news-item:hover .news-item-image img {
    transform: scale(1.05);
}

.news-item-content {
    padding: 1.25rem;
}

.news-item-date {
    font-size: 0.8rem;
    color: var(--text-light);
    margin-bottom: 0.5rem;
}

.news-item-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    line-height: 1.4;
}

.news-item-title:hover {
    color: var(--primary-color);
}

.news-item-excerpt {
    font-size: 0.875rem;
    color: var(--text-light);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.news-more {
    text-align: center;
    margin-top: 2.5rem;
}

/* ========================================
   Statistics Section
   ======================================== */
.stats-section {
    background: var(--gradient-hero);
    position: relative;
    overflow: hidden;
}

.stats-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="2" fill="rgba(255,255,255,0.05)"/></svg>');
    background-size: 50px 50px;
}

.stats-grid {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
    position: relative;
    z-index: 1;
}

.stat-item {
    text-align: center;
    color: #fff;
}

.stat-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 1rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.stat-value {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 0.25rem;
}

.stat-label {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.7);
}

/* ========================================
   About / Organizers Section
   ======================================== */
.about-section {
    background: var(--bg-light);
}

.about-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about-content h3 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 1.5rem;
}

.about-content p {
    color: var(--text-light);
    margin-bottom: 1rem;
    line-height: 1.8;
}

.about-features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-top: 2rem;
}

.about-feature {
    display: flex;
    gap: 1rem;
}

.about-feature-icon {
    width: 48px;
    height: 48px;
    background: rgba(37, 99, 235, 0.1);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    font-size: 1.25rem;
    flex-shrink: 0;
}

.about-feature-text h4 {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 0.25rem;
}

.about-feature-text p {
    font-size: 0.8rem;
    color: var(--text-light);
    margin: 0;
}

.about-image {
    position: relative;
}

.about-image img {
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
}

.about-image-badge {
    position: absolute;
    bottom: -1rem;
    left: -1rem;
    background: var(--gradient-primary);
    color: #fff;
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-lg);
}

.about-image-badge .number {
    font-size: 2rem;
    font-weight: 800;
    line-height: 1;
}

.about-image-badge .label {
    font-size: 0.8rem;
    opacity: 0.9;
}

/* ========================================
   Footer
   ======================================== */
.competition-footer {
    background: #0f172a;
    color: #fff;
    padding: 4rem 0 2rem;
}

.footer-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-brand img {
    height: 40px;
    margin-bottom: 1rem;
}

.footer-brand p {
    color: #94a3b8;
    font-size: 0.9rem;
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

.footer-social {
    display: flex;
    gap: 0.75rem;
}

.footer-social a {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    transition: var(--transition);
}

.footer-social a:hover {
    background: var(--primary-color);
    transform: translateY(-2px);
}

.footer-links h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1.25rem;
}

.footer-links ul {
    list-style: none;
}

.footer-links li {
    margin-bottom: 0.75rem;
}

.footer-links a {
    color: #94a3b8;
    font-size: 0.9rem;
    transition: var(--transition);
}

.footer-links a:hover {
    color: #fff;
    padding-left: 4px;
}

.footer-contact-item {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    margin-bottom: 1rem;
    color: #94a3b8;
    font-size: 0.9rem;
}

.footer-contact-item i {
    color: var(--primary-color);
    margin-top: 0.25rem;
}

.footer-bottom {
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: #64748b;
    font-size: 0.85rem;
}

.footer-bottom a {
    color: #94a3b8;
}

.footer-bottom a:hover {
    color: #fff;
}

/* ========================================
   Responsive Design
   ======================================== */
@media (max-width: 1024px) {
    .about-container {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .events-grid,
    .news-list {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .header-nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: #fff;
        flex-direction: column;
        padding: 1rem;
        box-shadow: var(--shadow-lg);
    }
    
    .header-nav.active {
        display: flex;
    }

    .nav-user-menu {
        display: flex;
    }
    
    .header-nav a {
        color: var(--text-dark) !important;
        padding: 0.75rem 1rem;
        width: 100%;
    }
    
    .mobile-menu-toggle {
        display: block;
    }
    
    /* 移动端隐藏 header-actions 里的操作按钮，只保留菜单按钮 */
    .header-actions .btn-outline,
    .header-actions .btn-primary,
    .header-actions .user-dropdown {
        display: none;
    }
    
    /* 移动端 NAV 中的登录/报名按钮：成整行显示 */
    .header-nav .nav-login,
    .header-nav .nav-register {
        margin-top: 0.5rem;
        display: flex;
        align-items: center;
        justify-content: center;
        text-align: center;
        padding: 0.75rem 1.5rem !important;
        border-radius: var(--radius-md);
        font-weight: 600;
        width: 100%;
        white-space: nowrap;
    }
    
    .header-nav .nav-login {
        margin-top: 0.75rem;
        border: 2px solid var(--primary-color);
        color: var(--primary-color) !important;
    }
    
    .header-nav .nav-register {
        background: var(--gradient-primary);
        color: #fff !important;
    }
    
    /* 移动端 LOGO 文字隐藏，避免换行挤压 */
    .header-logo .logo-text {
        display: none;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 1.5rem;
    }
    
    .events-grid {
        grid-template-columns: 1fr;
    }
    
    .news-list {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .about-features {
        grid-template-columns: 1fr;
    }
    
    .news-tabs {
        flex-wrap: wrap;
    }
}

@media (max-width: 480px) {
    .stats-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .section {
        padding: 3rem 0;
    }
}

/* ========================================
   Animations
   ======================================== */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

.slide-in-left {
    opacity: 0;
    transform: translateX(-30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.slide-in-left.visible {
    opacity: 1;
    transform: translateX(0);
}

.slide-in-right {
    opacity: 0;
    transform: translateX(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.slide-in-right.visible {
    opacity: 1;
    transform: translateX(0);
}

/* Counter Animation */
.counter {
    display: inline-block;
}

/* ========================================
   News Modal
   ======================================== */
.news-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 2000;
    align-items: center;
    justify-content: center;
}

.news-modal.open {
    display: flex;
}

.news-modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(15, 23, 42, 0.6);
    backdrop-filter: blur(4px);
    animation: fadeIn 0.3s ease;
}

.news-modal-dialog {
    position: relative;
    z-index: 1;
    width: 90%;
    max-width: 560px;
    max-height: 80vh;
    overflow-y: auto;
    background: #fff;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    animation: modalIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes modalIn {
    from {
        opacity: 0;
        transform: translateY(30px) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.news-modal-close {
    position: absolute;
    top: 0.75rem;
    right: 0.75rem;
    width: 32px;
    height: 32px;
    border: none;
    background: var(--bg-light);
    color: var(--text-light);
    border-radius: 50%;
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.9rem;
}

.news-modal-close:hover {
    background: var(--primary-color);
    color: #fff;
}

.news-modal-content {
    padding: 2rem;
}

.news-modal-date {
    font-size: 0.9rem;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.news-modal-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-dark);
    line-height: 1.4;
    margin-bottom: 1rem;
}

.news-modal-excerpt {
    font-size: 1rem;
    color: var(--text-light);
    line-height: 1.8;
    border-left: 4px solid var(--primary-color);
    padding-left: 1rem;
}

@media (max-width: 768px) {
    .news-modal-content {
        padding: 1.5rem;
    }
}

/* ===== 左侧悬浮工具条 ===== */
.float-toolbar {
    position: fixed;
    right: 16px;
    bottom: 28px;
    z-index: 999;
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.float-toolbar .ft-item {
    position: relative;
    width: 46px;
    height: 46px;
    border-radius: 12px;
    background: #fff;
    color: var(--primary-color);
    box-shadow: 0 6px 16px -6px rgba(15,23,42,.18);
    border: 1px solid rgba(37,99,235,.16);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    text-decoration: none;
    transition: all .25s ease;
    cursor: pointer;
    box-sizing: border-box;
}
.float-toolbar .ft-item:hover {
    background: var(--primary-color);
    color: #fff;
    transform: translateY(-3px);
}
.float-toolbar .ft-top {
    display: none;
}
.float-toolbar.show-top .ft-top {
    display: flex;
}
.float-toolbar .ft-tip {
    position: absolute;
    right: calc(100% + 14px);
    top: 50%;
    transform: translateY(-50%) translateX(8px);
    background: #fff;
    color: var(--text-dark);
    border: 1px solid rgba(37,99,235,.16);
    box-shadow: 0 10px 24px -8px rgba(15,23,42,.25);
    border-radius: 10px;
    padding: 8px 14px;
    font-size: 14px;
    font-weight: 600;
    white-space: nowrap;
    opacity: 0;
    visibility: hidden;
    transition: opacity .25s ease, transform .25s ease;
    pointer-events: none;
}
.float-toolbar .ft-item:hover .ft-tip {
    opacity: 1;
    visibility: visible;
    transform: translateY(-50%) translateX(0);
}
.float-toolbar .ft-tip.ft-qr-tip {
    width: 134px;
    padding: 6px;
}
.float-toolbar .ft-tip.ft-qr-tip img {
    display: block;
    width: 120px;
    height: 120px;
    max-width: none;
    object-fit: contain;
    border-radius: 6px;
}
.float-toolbar .ft-tip::before {
    content: '';
    position: absolute;
    left: 100%;
    top: 50%;
    transform: translateY(-50%);
    border: 6px solid transparent;
    border-left-color: #fff;
}
@media (max-width: 768px) {
    .float-toolbar {
        right: 12px;
        bottom: 20px;
        gap: 8px;
    }
    .float-toolbar .ft-item {
        width: 40px;
        height: 40px;
        font-size: 17px;
        border-radius: 10px;
    }
    .float-toolbar .ft-tip.ft-qr-tip {
        width: 110px;
    }
    .float-toolbar .ft-tip.ft-qr-tip img {
        width: 96px;
        height: 96px;
        max-width: none;
    }
}