/* 海角社区网站全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2c5f8d;
    --secondary-color: #3d8fc7;
    --accent-color: #f39c12;
    --text-dark: #2c3e50;
    --text-light: #7f8c8d;
    --bg-light: #f8f9fa;
    --bg-white: #ffffff;
    --border-color: #e0e6ed;
    --shadow: 0 2px 15px rgba(0,0,0,0.08);
    --shadow-hover: 0 5px 25px rgba(0,0,0,0.12);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-light);
    opacity: 0;
    transition: opacity 0.3s ease;
}

body.loaded {
    opacity: 1;
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

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

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

/* 头部导航 */
header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

header.scrolled {
    box-shadow: var(--shadow-hover);
}

.header-top {
    background: rgba(0,0,0,0.1);
    padding: 10px 0;
    font-size: 14px;
}

.header-top .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-main {
    padding: 20px 0;
}

.header-main .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 28px;
    font-weight: 700;
}

.logo-icon {
    width: 45px;
    height: 45px;
    background: var(--accent-color);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
}

nav ul {
    display: flex;
    list-style: none;
    gap: 35px;
}

nav a {
    color: white;
    font-weight: 500;
    padding: 8px 0;
    border-bottom: 2px solid transparent;
}

nav a:hover {
    border-bottom-color: var(--accent-color);
}

/* 英雄区域 */
.hero-section {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 80px 0;
    text-align: center;
}

.hero-content h2 {
    font-size: 48px;
    margin-bottom: 20px;
    animation: fadeInUp 0.8s ease;
}

.hero-content p {
    font-size: 20px;
    margin-bottom: 30px;
    opacity: 0.95;
    animation: fadeInUp 0.8s ease 0.2s backwards;
}

.cta-button {
    display: inline-block;
    background: var(--accent-color);
    color: white;
    padding: 15px 40px;
    border-radius: 50px;
    font-size: 18px;
    font-weight: 600;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    animation: fadeInUp 0.8s ease 0.4s backwards;
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0,0,0,0.3);
}

/* 板块区域 */
.sections-area {
    padding: 60px 0;
    background: var(--bg-white);
}

.section-header {
    text-align: center;
    margin-bottom: 50px;
}

.section-header h2 {
    font-size: 36px;
    color: var(--text-dark);
    margin-bottom: 15px;
}

.section-header p {
    color: var(--text-light);
    font-size: 18px;
}

.sections-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.section-card {
    background: white;
    border-radius: 15px;
    padding: 30px;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
}

.section-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.section-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 30px;
    margin-bottom: 20px;
    color: white;
}

.section-card h3 {
    font-size: 22px;
    margin-bottom: 15px;
    color: var(--text-dark);
}

.section-card p {
    color: var(--text-light);
    line-height: 1.8;
}

/* 热门话题 */
.trending-topics {
    padding: 60px 0;
    background: var(--bg-light);
}

.topic-list {
    display: grid;
    gap: 20px;
}

.topic-item {
    background: white;
    border-radius: 12px;
    padding: 25px;
    display: flex;
    gap: 20px;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

.topic-item:hover {
    box-shadow: var(--shadow-hover);
    transform: translateX(5px);
}

.topic-image {
    width: 120px;
    height: 120px;
    border-radius: 10px;
    object-fit: cover;
    flex-shrink: 0;
}

.topic-content {
    flex: 1;
}

.topic-title {
    font-size: 20px;
    margin-bottom: 10px;
    color: var(--text-dark);
    font-weight: 600;
}

.topic-meta {
    display: flex;
    gap: 20px;
    color: var(--text-light);
    font-size: 14px;
    margin-top: 10px;
}

/* 社区活动 */
.community-events {
    padding: 60px 0;
    background: var(--bg-white);
}

.events-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
}

.event-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

.event-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.event-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.event-content {
    padding: 25px;
}

.event-date {
    display: inline-block;
    background: var(--accent-color);
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 13px;
    margin-bottom: 15px;
}

.event-title {
    font-size: 20px;
    margin-bottom: 10px;
    color: var(--text-dark);
}

/* 用户动态 */
.user-feed {
    padding: 60px 0;
    background: var(--bg-light);
}

.feed-item {
    background: white;
    border-radius: 12px;
    padding: 25px;
    margin-bottom: 20px;
    box-shadow: var(--shadow);
}

.feed-header {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 15px;
}

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

.feed-content {
    line-height: 1.8;
    margin-bottom: 15px;
}

.feed-actions {
    display: flex;
    gap: 20px;
    color: var(--text-light);
    font-size: 14px;
}

.feed-actions span:hover {
    color: var(--primary-color);
    cursor: pointer;
}

/* 底部 */
footer {
    background: var(--text-dark);
    color: white;
    padding: 50px 0 20px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 30px;
}

.footer-section h3 {
    margin-bottom: 20px;
    font-size: 20px;
}

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

.footer-section li {
    margin-bottom: 10px;
}

.footer-section a {
    color: rgba(255,255,255,0.8);
}

.footer-section a:hover {
    color: white;
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255,255,255,0.1);
    color: rgba(255,255,255,0.7);
}

/* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 24px;
    cursor: pointer;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    z-index: 999;
}

.back-to-top:hover {
    background: var(--secondary-color);
    transform: translateY(-3px);
}

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

/* 响应式设计 */
@media (max-width: 768px) {
    .header-main .container {
        flex-direction: column;
        gap: 20px;
    }

    nav ul {
        flex-wrap: wrap;
        justify-content: center;
        gap: 15px;
    }

    .hero-content h2 {
        font-size: 32px;
    }

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

    .topic-item {
        flex-direction: column;
    }

    .topic-image {
        width: 100%;
        height: 200px;
    }
}