/* 全局样式 */
:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --secondary: #8b5cf6;
    --accent: #a855f7;
    --bg-dark: #0f0f23;
    --bg-darker: #0a0a1a;
    --bg-card: #1a1a2e;
    --bg-card-hover: #1f1f38;
    --text-primary: #ffffff;
    --text-secondary: #a0aec0;
    --text-muted: #718096;
    --border-color: #2d2d44;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(99, 102, 241, 0.2), 0 4px 6px -2px rgba(99, 102, 241, 0.1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 1rem 0;
    transition: all 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
    background: transparent;
}

.navbar.scrolled {
    background: rgba(15, 15, 35, 0.4);
    backdrop-filter: blur(30px) saturate(180%);
    -webkit-backdrop-filter: blur(30px) saturate(180%);
    border-bottom: 1px solid rgba(255, 255, 255, 0.15);
    padding: 0.75rem 0;
}

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

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.5rem;
    font-weight: 700;
}

.logo-bracket {
    color: var(--secondary);
}

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

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

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--text-primary);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--gradient);
    border-radius: 1px;
}

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* 英雄区 */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    padding-top: 80px;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 0;
    background: radial-gradient(ellipse at center, rgba(99, 102, 241, 0.15) 0%, rgba(15, 15, 35, 0) 70%);
}

.code-rain {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    overflow: hidden;
    opacity: 0.1;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 800px;
    padding: 2rem;
}

.hero-badge {
    display: inline-block;
    padding: 0.5rem 1.25rem;
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.3);
    border-radius: 50px;
    color: var(--secondary);
    font-size: 0.9rem;
    font-weight: 500;
    margin-bottom: 1.5rem;
}

.hero-title {
    font-size: 4rem;
    font-weight: 800;
    margin-bottom: 1rem;
    line-height: 1.1;
}

.title-line {
    display: block;
}

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

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    min-height: 2em;
}

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

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

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

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 3rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.875rem 2rem;
    border-radius: 12px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background: var(--gradient);
    color: white;
    box-shadow: var(--shadow-lg);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 20px 25px -5px rgba(99, 102, 241, 0.3), 0 10px 10px -5px rgba(99, 102, 241, 0.2);
}

.btn-secondary {
    background: rgba(26, 26, 46, 0.5);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    color: var(--text-primary);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.btn-secondary:hover {
    background: rgba(31, 31, 56, 0.6);
    border-color: rgba(99, 102, 241, 0.5);
    transform: translateY(-2px);
}

.btn-full {
    width: 100%;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
    max-width: 600px;
    margin: 0 auto;
}

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

.stat-number {
    font-size: 2.5rem;
    font-weight: 800;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-family: 'JetBrains Mono', monospace;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: 0.25rem;
}

.scroll-indicator {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1;
}

.scroll-indicator span {
    display: block;
    width: 30px;
    height: 50px;
    border: 2px solid var(--text-secondary);
    border-radius: 25px;
    position: relative;
}

.scroll-indicator span::before {
    content: '';
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 6px;
    height: 6px;
    background: var(--text-secondary);
    border-radius: 50%;
    animation: scroll 2s infinite;
}

@keyframes scroll {
    0% { top: 8px; opacity: 1; }
    100% { top: 32px; opacity: 0; }
}

/* 区块通用样式 */
section {
    padding: 6rem 0;
}

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

.section-tag {
    display: inline-block;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.875rem;
    color: var(--secondary);
    letter-spacing: 2px;
    margin-bottom: 0.75rem;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.section-line {
    width: 60px;
    height: 4px;
    background: var(--gradient);
    border-radius: 2px;
    margin: 0 auto;
}

/* 关于我们 */
.about {
    background: var(--bg-darker);
}

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

.about-text h3 {
    font-size: 1.75rem;
    margin-bottom: 1.5rem;
}

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

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

.feature-item {
    background: rgba(26, 26, 46, 0.5);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    padding: 1.5rem;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: all 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.feature-item:hover {
    border-color: rgba(99, 102, 241, 0.5);
    transform: translateY(-4px) scale(1.02);
    box-shadow: 0 12px 40px rgba(99, 102, 241, 0.2);
}

.feature-icon {
    font-size: 2rem;
    margin-bottom: 0.75rem;
}

.feature-item h4 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.feature-item p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin: 0;
}

/* 代码窗口 */
.code-window {
    background: rgba(26, 26, 46, 0.5);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-radius: 12px;
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
}

.code-header {
    display: flex;
    align-items: center;
    padding: 0.75rem 1rem;
    background: rgba(0, 0, 0, 0.3);
    border-bottom: 1px solid var(--border-color);
}

.code-dots {
    display: flex;
    gap: 0.5rem;
    margin-right: 1rem;
}

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

.dot.red { background: #ff5f56; }
.dot.yellow { background: #ffbd2e; }
.dot.green { background: #27c93f; }

.code-filename {
    color: var(--text-muted);
    font-size: 0.875rem;
    font-family: 'JetBrains Mono', monospace;
}

.code-body {
    padding: 1.5rem;
    overflow-x: auto;
}

.code-body pre {
    margin: 0;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.875rem;
    line-height: 1.6;
}

.code-body code {
    color: var(--text-primary);
}

.keyword {
    color: #c792ea;
}

.string {
    color: #c3e88d;
}

.class-name {
    color: #ffcb6b;
}

.function-name {
    color: #82aaff;
}

.number {
    color: #f78c6c;
}

/* 团队题库 */
.problems-table-container {
    overflow-x: auto;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    background: rgba(26, 26, 46, 0.5);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
}

.problems-table {
    width: 100%;
    border-collapse: collapse;
    min-width: 1000px;
}

.problems-table th {
    background: rgba(0, 0, 0, 0.3);
    padding: 1rem;
    text-align: left;
    font-weight: 600;
    color: var(--text-secondary);
    font-size: 0.9rem;
    border-bottom: 1px solid var(--border-color);
    white-space: nowrap;
}

.problems-table td {
    padding: 1rem;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.problems-table tbody tr {
    transition: background 0.2s ease;
}

.problems-table tbody tr:hover {
    background: var(--bg-card-hover);
}

.problem-title {
    color: var(--text-primary) !important;
    font-weight: 500;
    white-space: nowrap;
}

.problem-title a {
    color: var(--text-primary);
    text-decoration: none;
    transition: color 0.3s ease;
}

.problem-title a:hover {
    color: var(--primary);
    text-decoration: underline;
}

.problem-type {
    color: var(--text-primary) !important;
}

.problem-tag {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: rgba(99, 102, 241, 0.1);
    color: var(--secondary);
    border-radius: 6px;
    font-size: 0.8rem;
    white-space: nowrap;
}

.difficulty {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 6px;
    font-size: 0.8rem;
    font-weight: 500;
    white-space: nowrap;
}

.difficulty.easy {
    background: rgba(16, 185, 129, 0.1);
    color: #10b981;
}

.difficulty.medium {
    background: rgba(245, 158, 11, 0.1);
    color: #f59e0b;
}

.difficulty.hard {
    background: rgba(239, 68, 68, 0.1);
    color: #ef4444;
}

.problem-source {
    color: var(--text-primary) !important;
    white-space: nowrap;
}

.problem-pass-rate {
    color: var(--text-primary) !important;
    font-family: 'JetBrains Mono', monospace;
    white-space: nowrap;
}

/* 状态样式 */
.status {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 6px;
    font-size: 0.8rem;
    font-weight: 500;
    white-space: nowrap;
}

.status.passed {
    background: rgba(16, 185, 129, 0.1);
    color: #10b981;
}

.status.unsubmitted {
    background: rgba(148, 163, 184, 0.1);
    color: #94a3b8;
}

/* 团队竞赛 */
.contests {
    background: var(--bg-darker);
}

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

.contest-card {
    background: rgba(26, 26, 46, 0.5);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-radius: 16px;
    padding: 2rem;
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: all 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
    position: relative;
    overflow: hidden;
}

.contest-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.contest-card:hover {
    transform: translateY(-8px) scale(1.02);
    border-color: rgba(99, 102, 241, 0.5);
    box-shadow: 0 12px 40px rgba(99, 102, 241, 0.2);
}

.contest-card:hover::before {
    transform: scaleX(1);
}

.contest-badge {
    display: inline-block;
    padding: 0.375rem 0.875rem;
    background: rgba(139, 92, 246, 0.1);
    color: var(--secondary);
    border-radius: 6px;
    font-size: 0.8rem;
    font-weight: 500;
    margin-bottom: 1rem;
}

.contest-badge.official {
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary);
}

.contest-title {
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
    line-height: 1.4;
}

.contest-info {
    margin-bottom: 1.5rem;
}

.contest-info-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.75rem;
}

.contest-info-item svg {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
    color: var(--secondary);
}

.contest-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.contest-participants {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.contest-btn {
    padding: 0.5rem 1.25rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background: transparent;
    color: var(--text-secondary);
    font-size: 0.875rem;
    cursor: pointer;
    transition: all 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.contest-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}

/* 团队成员 */
.members-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 900px;
    margin: 0 auto;
    justify-content: center;
}

.member-card {
    background: rgba(26, 26, 46, 0.5);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-radius: 16px;
    padding: 2rem;
    text-align: center;
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: all 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.member-card:hover {
    transform: translateY(-8px) scale(1.02);
    border-color: rgba(99, 102, 241, 0.5);
    box-shadow: 0 12px 40px rgba(99, 102, 241, 0.2);
}

.member-avatar {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    border-radius: 50%;
    overflow: hidden;
    border: 3px solid var(--primary);
}

.avatar-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    background: var(--bg-darker);
}

.member-name {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

.member-role {
    color: var(--secondary);
    font-size: 0.9rem;
    font-weight: 500;
    margin-bottom: 0.75rem;
}

.member-desc {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 1rem;
    line-height: 1.6;
}

.member-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    justify-content: center;
}

.member-tags span {
    padding: 0.25rem 0.75rem;
    background: rgba(99, 102, 241, 0.1);
    color: var(--secondary);
    border-radius: 6px;
    font-size: 0.8rem;
}

/* 加入我们 */
.contact {
    background: var(--bg-darker);
}

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

.contact-info h3 {
    font-size: 1.75rem;
    margin-bottom: 1.5rem;
}

.contact-info p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    line-height: 1.8;
}

.contact-list {
    margin-top: 2rem;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1rem;
    background: rgba(26, 26, 46, 0.5);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-radius: 12px;
    margin-bottom: 1rem;
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: all 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.contact-item:hover {
    border-color: rgba(99, 102, 241, 0.5);
    transform: translateX(4px) scale(1.02);
    box-shadow: 0 8px 32px rgba(99, 102, 241, 0.15);
}

.contact-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.contact-item h4 {
    font-size: 1rem;
    margin-bottom: 0.25rem;
}

.contact-item p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin: 0;
}

/* 表单 */
.form-card {
    background: rgba(26, 26, 46, 0.5);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-radius: 16px;
    padding: 2rem;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.form-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.875rem 1rem;
    background: var(--bg-darker);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 1rem;
    font-family: inherit;
    transition: all 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

/* 页脚 */
.footer {
    background: var(--bg-darker);
    border-top: 1px solid var(--border-color);
    padding: 4rem 0 2rem;
}

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

.footer-logo {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.footer-brand p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.footer-links h4 {
    font-size: 1rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

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

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

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: var(--primary);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* 回到顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--gradient);
    color: white;
    border: none;
    font-size: 1.25rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
    z-index: 999;
    box-shadow: var(--shadow-lg);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 20px rgba(99, 102, 241, 0.3);
}

/* 客服按钮 */
.service-btn {
    position: fixed;
    bottom: 5.5rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: rgba(26, 26, 46, 0.5);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 1.25rem;
    cursor: pointer;
    z-index: 999;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    transition: all 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.service-btn:hover {
    transform: translateY(-4px);
    border-color: rgba(99, 102, 241, 0.5);
    box-shadow: 0 8px 32px rgba(99, 102, 241, 0.15);
}

/* 响应式设计 */
@media (max-width: 968px) {
    .about-content,
    .contact-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .hero-stats {
        grid-template-columns: repeat(2, 1fr);
        gap: 1.5rem;
    }

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

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: rgba(15, 15, 35, 0.98);
        backdrop-filter: blur(10px);
        flex-direction: column;
        padding: 2rem;
        gap: 1.5rem;
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
        border-bottom: 1px solid var(--border-color);
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .hamburger {
        display: flex;
    }

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

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

    .hamburger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

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

    .hero-subtitle {
        font-size: 1rem;
    }

    .hero-buttons {
        flex-direction: column;
        width: 100%;
        max-width: 300px;
        margin: 0 auto 2rem;
    }

    .btn {
        width: 100%;
    }

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

    .about-features {
        grid-template-columns: 1fr;
    }

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

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

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

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

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

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

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

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

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

    .back-to-top {
        bottom: 1rem;
        right: 1rem;
        width: 44px;
        height: 44px;
    }
}
/* ========== 动画效果 ========== */

/* 代码雨下落动画（参考版） */
.code-rain span {
    position: absolute;
    font-family: 'JetBrains Mono', monospace;
    color: var(--primary);
    animation: fall linear infinite;
}

@keyframes fall {
    0% {
        transform: translateY(-100%);
        opacity: 0;
    }
    10% {
        opacity: 1;
    }
    90% {
        opacity: 1;
    }
    100% {
        transform: translateY(100vh);
        opacity: 0;
    }
}

/* 英雄区入场动画 */
.hero-badge {
    animation: fadeInUp 0.8s ease;
}

.hero-title {
    animation: fadeInUp 0.8s ease 0.1s both;
}

.hero-subtitle {
    animation: fadeInUp 0.8s ease 0.2s both;
}

.hero-buttons {
    animation: fadeInUp 0.8s ease 0.3s both;
}

.hero-stats {
    animation: fadeInUp 0.8s ease 0.4s both;
}

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

/* 标题渐变流动动画 */
.highlight {
    background-size: 200% 200%;
    animation: gradient 3s ease infinite;
}

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

/* 导航栏链接下划线动画 */
.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient);
    border-radius: 1px;
    transition: width 0.3s ease;
}

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

/* 滚动淡入动画 */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}

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

/* 技能条动画 */
.skill-progress {
    transition: width 1s ease;
}