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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
}

/* Header Styles */
header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 1rem 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

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

.logo {
    font-size: 1.8rem;
    font-weight: bold;
    text-decoration: none;
    color: white;
}

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

.nav-links a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
}

.nav-links a:hover {
    color: #ffd700;
}

.nav-links a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -5px;
    left: 0;
    background-color: #ffd700;
    transition: width 0.3s ease;
}

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

.user-actions {
    display: flex;
    gap: 1rem;
}

.btn {
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.3s ease;
    display: inline-block;
    text-align: center;
}

.btn-primary {
    background-color: #ffd700;
    color: #333;
}

.btn-primary:hover {
    background-color: #ffed4e;
    transform: translateY(-2px);
}

.btn-secondary {
    background-color: transparent;
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background-color: white;
    color: #667eea;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 4rem 0;
    text-align: center;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

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

/* Section Styles */
.section {
    margin-bottom: 3rem;
}

.section-title {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: #333;
    text-align: center;
    position: relative;
    padding-bottom: 0.5rem;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 2px;
}

/* Card Styles */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.card {
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    cursor: pointer;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15);
}

.card-img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.card-content {
    padding: 1.5rem;
}

.card-title {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
    color: #333;
}

.card-subtitle {
    color: #666;
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.card-text {
    color: #555;
    margin-bottom: 1rem;
    font-size: 0.95rem;
}

.card-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1rem;
    border-top: 1px solid #eee;
}

.card-tag {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
}

/* Form Styles */
.form-container {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    max-width: 600px;
    margin: 0 auto;
}

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

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: #333;
}

.form-input,
.form-textarea,
.form-select {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 2px rgba(102, 126, 234, 0.2);
}

.form-textarea {
    resize: vertical;
    min-height: 120px;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.form-check {
    display: flex;
    align-items: center;
    margin-bottom: 0.5rem;
}

.form-check-input {
    margin-right: 0.5rem;
}

.form-actions {
    display: flex;
    gap: 1rem;
    justify-content: flex-end;
    margin-top: 2rem;
}

/* Tab Navigation */
.tabs {
    display: flex;
    background: white;
    padding: 0.5rem;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    margin-bottom: 2rem;
    gap: 0.5rem;
    overflow-x: auto;
    scrollbar-width: thin;
    scrollbar-color: #667eea #f0f0f0;
}

/* 滚动条样式 */
.tabs::-webkit-scrollbar {
    height: 6px;
}

.tabs::-webkit-scrollbar-track {
    background: #f0f0f0;
    border-radius: 3px;
}

.tabs::-webkit-scrollbar-thumb {
    background: #667eea;
    border-radius: 3px;
}

.tabs::-webkit-scrollbar-thumb:hover {
    background: #764ba2;
}

.tab-btn {
    background: #f8f9fa;
    border: none;
    padding: 0.8rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    color: #666;
    cursor: pointer;
    transition: all 0.3s ease;
    border-radius: 8px;
    white-space: nowrap;
    position: relative;
    overflow: hidden;
    z-index: 1;
}

/* 按钮悬停效果 */
.tab-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    opacity: 0;
    transition: opacity 0.3s ease;
    z-index: -1;
    border-radius: 8px;
}

.tab-btn:hover {
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
}

.tab-btn:hover::before {
    opacity: 1;
}

/* 激活状态样式 */
.tab-btn.active {
    color: white;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
    transform: translateY(-2px);
}

.tab-btn.active::before {
    opacity: 1;
}

/* 移除旧的下划线样式 */
.tab-btn.active::after {
    display: none;
}

.tab-content {
    display: none;
    animation: fadeIn 0.3s ease-in;
}

/* 淡入动画 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 确保激活的内容显示 */
.tab-content.active {
    display: block;
}

/* 移动端优化 */
@media (max-width: 768px) {
    .tabs {
        padding: 0.3rem;
        gap: 0.3rem;
    }
    
    .tab-btn {
        padding: 0.6rem 1rem;
        font-size: 0.9rem;
    }
}

/* Profile Styles */
.profile-header {
    display: flex;
    align-items: center;
    gap: 2rem;
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    margin-bottom: 2rem;
}

.profile-avatar {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    object-fit: cover;
    border: 5px solid #667eea;
}

.profile-info h2 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.profile-title {
    color: #667eea;
    font-size: 1.2rem;
    margin-bottom: 1rem;
}

.profile-stats {
    display: flex;
    gap: 2rem;
    margin-top: 1rem;
}

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

.stat-number {
    font-size: 1.5rem;
    font-weight: bold;
    color: #333;
}

.stat-label {
    color: #666;
    font-size: 0.9rem;
}

/* Footer Styles */
footer {
    background: #333;
    color: white;
    padding: 2rem 0;
    margin-top: 4rem;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.footer-section h3 {
    margin-bottom: 1rem;
    color: #ffd700;
}

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

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: #ccc;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section ul li a:hover {
    color: #ffd700;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    margin-top: 2rem;
    border-top: 1px solid #444;
    color: #888;
}

/* Responsive Design */
@media (max-width: 768px) {
    nav {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
    }

    .nav-links {
        flex-wrap: wrap;
        justify-content: center;
        gap: 1rem;
    }

    .hero h1 {
        font-size: 2rem;
    }

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

    .container {
        padding: 1rem;
    }

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

    .form-row {
        grid-template-columns: 1fr;
    }

    .profile-header {
        flex-direction: column;
        text-align: center;
    }

    .profile-stats {
        justify-content: center;
    }

    .tabs {
        flex-wrap: wrap;
    }

    .tab-btn {
        padding: 0.8rem 1rem;
        font-size: 0.9rem;
    }
}

/* Animation Classes */
.fade-in {
    animation: fadeIn 0.5s ease-in;
}

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

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
}

/* Search Bar */
.search-bar {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    background: white;
    padding: 1rem;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.search-input {
    flex: 1;
    padding: 0.8rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 1rem;
}

.search-input:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 2px rgba(102, 126, 234, 0.2);
}

/* Filter Section */
.filter-section {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.filter-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.filter-label {
    font-weight: 500;
    color: #333;
}

/* Audio/Video Player */
.media-player {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    margin-bottom: 2rem;
}

.player-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-top: 1rem;
}

.player-btn {
    background: #667eea;
    color: white;
    border: none;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.player-btn:hover {
    background: #764ba2;
    transform: scale(1.1);
}

.progress-bar {
    flex: 1;
    height: 5px;
    background: #ddd;
    border-radius: 3px;
    cursor: pointer;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
    width: 0%;
    transition: width 0.1s ease;
}

/* Comment Section */
.comments-section {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    margin-top: 2rem;
}

.comment {
    display: flex;
    gap: 1rem;
    padding: 1rem 0;
    border-bottom: 1px solid #eee;
}

.comment:last-child {
    border-bottom: none;
}

.comment-avatar {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    object-fit: cover;
}

.comment-content {
    flex: 1;
}

.comment-author {
    font-weight: 500;
    color: #333;
    margin-bottom: 0.3rem;
}

.comment-date {
    color: #999;
    font-size: 0.8rem;
    margin-bottom: 0.5rem;
}

.comment-text {
    color: #555;
}

/* Pagination */
.pagination {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    margin-top: 2rem;
}

.pagination-btn {
    padding: 0.5rem 1rem;
    border: 1px solid #ddd;
    background: white;
    color: #333;
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.pagination-btn:hover {
    border-color: #667eea;
    color: #667eea;
}

.pagination-btn.active {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

 

/* Alert Styles */
.alert {
    padding: 1rem;
    border-radius: 5px;
    margin-bottom: 1rem;
    font-weight: 500;
}

.alert-success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.alert-error {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.alert-info {
    background: #d1ecf1;
    color: #0c5460;
    border: 1px solid #bee5eb;
}

.alert-warning {
    background: #fff3cd;
    color: #856404;
    border: 1px solid #ffeeba;
}