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

:root {
    --primary: #07c160;
    --primary-dark: #06ad56;
    --primary-light: #e8f8ef;
    --secondary: #f5f5f5;
    --text: #1a1a1a;
    --text-light: #8c8c8c;
    --bg: #ffffff;
    --card-bg: #ffffff;
    --shadow: 0 8px 30px rgba(0,0,0,0.08);
    --shadow-hover: 0 12px 40px rgba(0,0,0,0.14);
    --radius: 16px;
    --radius-sm: 8px;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --max-width: 1200px;
    --nav-height: 64px;
    --gradient: linear-gradient(135deg, #07c160 0%, #06ad56 100%);
    --gradient-bg: linear-gradient(135deg, #e8f8ef 0%, #d4edda 100%);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    scroll-behavior: smooth;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

a {
    text-decoration: none;
    color: inherit;
}

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

/* ===== 导航栏 ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: rgba(255,255,255,0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0,0,0,0.05);
    z-index: 1000;
    transition: var(--transition);
}

.navbar.scrolled {
    box-shadow: 0 2px 20px rgba(0,0,0,0.06);
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-icon {
    width: 32px;
    height: 32px;
}

.logo-text {
    font-size: 20px;
    font-weight: 700;
    color: var(--primary);
    letter-spacing: -0.5px;
}

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-links a {
    font-size: 15px;
    font-weight: 500;
    color: var(--text-light);
    transition: var(--transition);
    position: relative;
    padding: 4px 0;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient);
    border-radius: 2px;
    transition: var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--primary);
}

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

.nav-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.hamburger span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text);
    border-radius: 2px;
    transition: var(--transition);
}

/* ===== 按钮 ===== */
.btn-primary {
    background: var(--gradient);
    color: white;
    border: none;
    padding: 10px 24px;
    border-radius: 50px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 4px 14px rgba(7, 193, 96, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(7, 193, 96, 0.4);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-secondary {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
    padding: 10px 24px;
    border-radius: 50px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.btn-secondary:hover {
    background: var(--primary-light);
    transform: translateY(-2px);
}

.btn-lg {
    padding: 14px 36px;
    font-size: 16px;
}

/* ===== Hero ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    padding-top: var(--nav-height);
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--gradient-bg);
    z-index: -1;
}

.hero-bg::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -30%;
    width: 80%;
    height: 80%;
    background: radial-gradient(circle, rgba(7,193,96,0.12) 0%, transparent 70%);
    border-radius: 50%;
}

.hero-bg::after {
    content: '';
    position: absolute;
    bottom: -40%;
    left: -20%;
    width: 60%;
    height: 60%;
    background: radial-gradient(circle, rgba(7,193,96,0.08) 0%, transparent 70%);
    border-radius: 50%;
}

.hero-content {
    text-align: center;
    max-width: 600px;
    padding: 40px 24px;
    animation: fadeUp 1s ease-out;
}

.hero-logo {
    width: 200px;
    margin: 0 auto 24px;
}

.hero-content h1 {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 16px;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-content p {
    font-size: 18px;
    color: var(--text-light);
    margin-bottom: 32px;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.hero-scroll {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    color: var(--text-light);
    font-size: 13px;
    animation: bounce 2s infinite;
}

.scroll-arrow {
    width: 20px;
    height: 20px;
    border-right: 2px solid var(--text-light);
    border-bottom: 2px solid var(--text-light);
    transform: rotate(45deg);
    margin: 8px auto 0;
}

/* ===== 通用section ===== */
section {
    padding: 80px 0;
}

.section-title {
    font-size: 32px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 8px;
    color: var(--text);
}

.section-subtitle {
    text-align: center;
    color: var(--text-light);
    margin-bottom: 48px;
    font-size: 16px;
}

/* ===== 朋友圈卡片 ===== */
.moment-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 24px;
}

.moment-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: var(--transition);
    cursor: pointer;
}

.moment-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
}

.moment-card-header {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px 20px;
}

.moment-avatar {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    object-fit: cover;
    background: var(--primary-light);
}

.moment-user {
    font-weight: 600;
    font-size: 15px;
}

.moment-time {
    font-size: 12px;
    color: var(--text-light);
}

.moment-content {
    padding: 0 20px 16px;
    font-size: 15px;
    line-height: 1.7;
    color: #333;
}

.moment-image {
    width: 100%;
    height: 220px;
    object-fit: cover;
    background: var(--secondary);
}

.moment-actions {
    display: flex;
    justify-content: space-around;
    padding: 12px 20px;
    border-top: 1px solid rgba(0,0,0,0.05);
}

.moment-action {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 13px;
    color: var(--text-light);
    background: none;
    border: none;
    cursor: pointer;
    transition: var(--transition);
}

.moment-action:hover {
    color: var(--primary);
}

.moment-action.liked {
    color: #e74c3c;
}

/* ===== 视频号卡片 ===== */
.channel-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
}

.channel-card {
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    cursor: pointer;
    background: var(--card-bg);
}

.channel-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
}

.channel-thumb {
    width: 100%;
    height: 200px;
    object-fit: cover;
    background: var(--secondary);
}

.channel-info {
    padding: 16px 20px;
}

.channel-title {
    font-weight: 600;
    font-size: 16px;
    margin-bottom: 6px;
}

.channel-author {
    font-size: 13px;
    color: var(--text-light);
}

/* ===== 发现卡片 ===== */
.discover-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 20px;
}

.discover-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 24px 20px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    text-align: center;
    cursor: pointer;
}

.discover-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.discover-icon {
    font-size: 36px;
    margin-bottom: 12px;
    display: block;
}

.discover-card h3 {
    font-size: 18px;
    margin-bottom: 8px;
}

.discover-card p {
    font-size: 14px;
    color: var(--text-light);
}

/* ===== 个人中心 ===== */
.profile-card {
    display: flex;
    align-items: center;
    gap: 24px;
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 32px;
    box-shadow: var(--shadow);
    margin-bottom: 24px;
    flex-wrap: wrap;
}

.profile-avatar img {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    object-fit: cover;
    border: 3px solid var(--primary-light);
}

.profile-info h3 {
    font-size: 22px;
    font-weight: 600;
}

.profile-info p {
    color: var(--text-light);
    font-size: 14px;
}

.profile-stats {
    display: flex;
    gap: 32px;
    justify-content: center;
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 24px;
    box-shadow: var(--shadow);
}

.stat {
    text-align: center;
}

.stat span {
    font-size: 28px;
    font-weight: 700;
    color: var(--primary);
    display: block;
}

.stat p {
    color: var(--text-light);
    font-size: 14px;
    margin-top: 4px;
}

/* ===== 底部 ===== */
.footer {
    background: #1a1a1a;
    color: #ccc;
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 48px;
    margin-bottom: 40px;
}

.footer-logo {
    width: 160px;
    margin-bottom: 16px;
    filter: brightness(0) invert(1);
}

.footer-brand p {
    font-size: 14px;
    color: #999;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.footer-col h4 {
    color: white;
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 16px;
}

.footer-col a {
    display: block;
    color: #999;
    font-size: 14px;
    margin-bottom: 8px;
    transition: var(--transition);
}

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

.footer-bottom {
    border-top: 1px solid #333;
    padding-top: 24px;
    text-align: center;
    font-size: 13px;
    color: #666;
}

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

@keyframes bounce {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(10px); }
}

/* ===== 响应式 ===== */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: var(--nav-height);
        left: 0;
        right: 0;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 16px 24px;
        gap: 16px;
        box-shadow: 0 8px 30px rgba(0,0,0,0.08);
    }

    .nav-links.open {
        display: flex;
    }

    .hamburger {
        display: flex;
    }

    .hero-content h1 {
        font-size: 32px;
    }

    .hero-logo {
        width: 140px;
    }

    .section-title {
        font-size: 26px;
    }

    .moment-grid,
    .channel-grid,
    .discover-grid {
        grid-template-columns: 1fr;
    }

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

    .footer-links {
        grid-template-columns: 1fr;
    }

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

    .profile-stats {
        flex-wrap: wrap;
        gap: 16px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .hero-content h1 {
        font-size: 28px;
    }

    .btn-lg {
        padding: 12px 28px;
        font-size: 14px;
    }
}