/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #667eea;
    --primary-dark: #5a67d8;
    --secondary-color: #764ba2;
    --text-color: #333;
    --text-light: #666;
    --bg-color: #f8f9fa;
    --white: #fff;
    --border-color: #e0e0e0;
    --success: #27ae60;
    --danger: #e74c3c;
    --warning: #f39c12;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏 */
.navbar {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--white);
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 25px;
    align-items: center;
}

.nav-links a {
    color: var(--white);
    text-decoration: none;
    font-weight: 500;
    transition: opacity 0.3s;
}

.nav-links a:hover {
    opacity: 0.8;
}

.btn-register {
    background: rgba(255,255,255,0.2);
    padding: 8px 20px;
    border-radius: 20px;
    border: 1px solid rgba(255,255,255,0.3);
}

.btn-logout {
    background: rgba(0,0,0,0.1);
    padding: 8px 20px;
    border-radius: 20px;
}

/* 主内容区域 */
.main-content {
    min-height: calc(100vh - 200px);
    padding: 40px 0;
}

/* 卡片样式 */
.card {
    background: var(--white);
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    overflow: hidden;
    transition: transform 0.3s, box-shadow 0.3s;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.12);
}

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

.card-body {
    padding: 20px;
}

.card-title {
    font-size: 1.2rem;
    margin-bottom: 8px;
    color: var(--text-color);
}

.card-text {
    color: var(--text-light);
    font-size: 0.95rem;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 10px 25px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.3s;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--white);
}

.btn-primary:hover {
    opacity: 0.9;
    transform: translateY(-2px);
}

.btn-success {
    background: var(--success);
    color: var(--white);
}

.btn-danger {
    background: var(--danger);
    color: var(--white);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
}

.btn-small {
    padding: 6px 15px;
    font-size: 0.9rem;
}

/* 表单样式 */
.form-group {
    margin-bottom: 20px;
}

.form-label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-color);
}

.form-control {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* 网格布局 */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 25px;
}

.grid-3 {
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
}

/* 英雄区域 */
.hero {
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.1), rgba(118, 75, 162, 0.1));
    padding: 60px 0;
    text-align: center;
    margin-bottom: 40px;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 15px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 1.2rem;
    color: var(--text-light);
}

/* 页脚 */
.footer {
    background: var(--white);
    padding: 30px 0;
    text-align: center;
    color: var(--text-light);
    margin-top: 60px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .navbar .container {
        flex-direction: column;
        gap: 15px;
    }
    
    .nav-links {
        flex-wrap: wrap;
        justify-content: center;
        gap: 15px;
    }
    
    .hero h1 {
        font-size: 1.8rem;
    }
}

/* 播放器相关样式 */
.card:hover .play-btn {
    opacity: 1 !important;
}

.play-btn:hover {
    transform: translate(-50%, -50%) scale(1.1) !important;
}