/* ===== 全局重置 & 变量 ===== */
:root {
    --primary: #07c160;
    --primary-dark: #06ad56;
    --primary-light: #e8f8ee;
    --bg: #f7f7f7;
    --card-bg: #ffffff;
    --text: #191919;
    --text-light: #888;
    --text-lighter: #b2b2b2;
    --shadow: 0 8px 30px rgba(0,0,0,0.06);
    --shadow-hover: 0 16px 48px rgba(7,193,96,0.15);
    --radius: 20px;
    --radius-sm: 12px;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --font: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

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

body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    scroll-behavior: smooth;
}

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

img {
    max-width: 100%;
    display: block;
    border-radius: var(--radius-sm);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== 导航栏 ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255,255,255,0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0,0,0,0.04);
    transition: var(--transition);
}

.navbar.scrolled {
    box-shadow: 0 4px 20px rgba(0,0,0,0.04);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 22px;
    font-weight: 700;
    color: var(--primary);
}

.logo i {
    font-size: 30px;
}

.nav-links {
    display: flex;
    gap: 8px;
}

.nav-links a {
    padding: 8px 18px;
    border-radius: 40px;
    font-weight: 500;
    font-size: 15px;
    color: var(--text-light);
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 6px;
}

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

.hamburger {
    display: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--text);
    padding: 8px;
}

/* ===== Hero 区域 ===== */
.hero {
    padding: 140px 0 80px;
    background: linear-gradient(160deg, #ffffff 0%, #f0faf4 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -40%;
    right: -20%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(7,193,96,0.06) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.hero-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 60px;
    position: relative;
    z-index: 2;
}

.hero-text {
    flex: 1;
}

.hero-text h1 {
    font-size: 52px;
    font-weight: 900;
    line-height: 1.15;
    margin-bottom: 20px;
    background: linear-gradient(135deg, #191919 30%, #07c160 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-text p {
    font-size: 18px;
    color: var(--text-light);
    max-width: 480px;
    margin-bottom: 32px;
}

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

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    border-radius: 40px;
    font-weight: 600;
    font-size: 16px;
    border: none;
    cursor: pointer;
    transition: var(--transition);
}

.btn-primary {
    background: var(--primary);
    color: white;
    box-shadow: 0 4px 16px rgba(7,193,96,0.3);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 8px 28px rgba(7,193,96,0.4);
}

.btn-secondary {
    background: white;
    color: var(--text);
    border: 2px solid #e0e0e0;
}

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

.hero-stats {
    display: flex;
    gap: 32px;
    margin-top: 40px;
    padding-top: 28px;
    border-top: 1px solid rgba(0,0,0,0.06);
}

.hero-stats div {
    font-size: 14px;
    color: var(--text-light);
}

.hero-stats span {
    font-size: 24px;
    font-weight: 700;
    color: var(--text);
    display: block;
}

/* 手机模拟 */
.hero-visual {
    flex: 1;
    display: flex;
    justify-content: center;
}

.phone-mockup {
    width: 260px;
    background: #1a1a1a;
    border-radius: 36px;
    padding: 12px;
    box-shadow: 0 30px 60px rgba(0,0,0,0.15);
}

.phone-screen {
    background: white;
    border-radius: 28px;
    overflow: hidden;
    min-height: 460px;
}

.chat-header {
    background: var(--primary);
    color: white;
    padding: 16px 20px;
    font-weight: 600;
    font-size: 18px;
}

.chat-list {
    padding: 8px 0;
}

.chat-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    border-bottom: 1px solid #f0f0f0;
    transition: var(--transition);
}

.chat-item:hover {
    background: #f9f9f9;
}

.chat-item img {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    flex-shrink: 0;
}

.chat-item div strong {
    font-size: 15px;
    display: block;
}

.chat-item div p {
    font-size: 13px;
    color: var(--text-light);
    margin: 0;
}

/* ===== 功能卡片 ===== */
.features {
    padding: 80px 0;
}

.section-title {
    text-align: center;
    margin-bottom: 56px;
}

.section-title h2 {
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 12px;
}

.section-title h2 span {
    color: var(--primary);
}

.section-title p {
    color: var(--text-light);
    font-size: 16px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 28px;
}

.feature-card {
    background: var(--card-bg);
    padding: 32px 24px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transition: var(--transition);
    text-align: center;
    border: 1px solid rgba(0,0,0,0.02);
}

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

.icon-wrapper {
    width: 64px;
    height: 64px;
    background: var(--primary-light);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    font-size: 28px;
    color: var(--primary);
    transition: var(--transition);
}

.feature-card:hover .icon-wrapper {
    background: var(--primary);
    color: white;
}

.feature-card h3 {
    font-size: 20px;
    margin-bottom: 12px;
}

.feature-card p {
    color: var(--text-light);
    font-size: 15px;
}

/* ===== 统计区 ===== */
.stats-section {
    background: linear-gradient(135deg, #07c160 0%, #06ad56 100%);
    padding: 60px 0;
    color: white;
}

.stats-container {
    display: flex;
    justify-content: space-around;
    text-align: center;
    gap: 20px;
    flex-wrap: wrap;
}

.stat-item i {
    font-size: 36px;
    margin-bottom: 12px;
    opacity: 0.9;
}

.stat-item div {
    font-size: 42px;
    font-weight: 800;
    line-height: 1.2;
}

.stat-item p {
    margin-top: 6px;
    opacity: 0.85;
    font-size: 16px;
}

/* ===== 通用页面Banner ===== */
.page-banner {
    padding: 120px 0 60px;
    background: linear-gradient(135deg, #e8f8ee 0%, #f0faf4 100%);
    text-align: center;
}

.page-banner h1 {
    font-size: 40px;
    font-weight: 800;
    margin-bottom: 12px;
}

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

/* ===== 功能详情页 ===== */
.features-detail {
    padding: 60px 0;
}

.feature-block {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 36px 32px;
    margin-bottom: 24px;
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.feature-block-icon {
    font-size: 36px;
    color: var(--primary);
}

.feature-block h2 {
    font-size: 24px;
}

.feature-block p {
    color: var(--text-light);
    max-width: 600px;
}

/* ===== 朋友圈 ===== */
.moments-feed {
    padding: 60px 0;
}

.moment-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 24px;
    margin-bottom: 28px;
    box-shadow: var(--shadow);
}

.moment-header {
    display: flex;
    align-items: center;
    gap: 14px;
    margin-bottom: 14px;
}

.moment-header img {
    width: 48px;
    height: 48px;
    border-radius: 50%;
}

.moment-header strong {
    font-size: 16px;
}

.moment-header span {
    font-size: 13px;
    color: var(--text-lighter);
}

.moment-card p {
    margin-bottom: 16px;
    font-size: 15px;
}

.moment-images {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    margin-bottom: 16px;
}

.moment-images.single {
    grid-template-columns: 1fr;
    max-width: 400px;
}

.moment-images img {
    border-radius: var(--radius-sm);
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.moment-actions {
    display: flex;
    gap: 24px;
    padding-top: 14px;
    border-top: 1px solid #f0f0f0;
    color: var(--text-light);
    font-size: 14px;
}

.moment-actions i {
    margin-right: 4px;
}

/* ===== 管理后台 ===== */
.admin-page {
    background: #f0f2f5;
}

.admin-form-container {
    min-height: 70vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 120px 0 60px;
}

.admin-card {
    background: white;
    border-radius: var(--radius);
    padding: 48px 40px;
    box-shadow: var(--shadow);
    width: 100%;
    max-width: 420px;
    text-align: center;
}

.admin-card i.fa-lock {
    font-size: 48px;
    color: var(--primary);
    margin-bottom: 16px;
}

.admin-card h2 {
    margin-bottom: 24px;
}

.form-group {
    margin-bottom: 20px;
    text-align: left;
}

.form-group label {
    display: block;
    font-weight: 500;
    margin-bottom: 6px;
    font-size: 14px;
}

.form-group input {
    width: 100%;
    padding: 14px 16px;
    border: 2px solid #e0e0e0;
    border-radius: var(--radius-sm);
    font-size: 16px;
    transition: var(--transition);
    font-family: var(--font);
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(7,193,96,0.1);
}

.btn-block {
    width: 100%;
    justify-content: center;
    padding: 16px;
}

.error-msg {
    color: #e74c3c;
    font-size: 14px;
    margin-top: 12px;
    min-height: 20px;
}

.hint {
    margin-top: 20px;
    color: var(--text-lighter);
    font-size: 13px;
}

/* 管理面板 */
.admin-panel {
    padding: 120px 0 60px;
}

.admin-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 40px;
    flex-wrap: wrap;
    gap: 16px;
}

.admin-header h2 i {
    color: var(--primary);
}

.admin-tools {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
}

.tool-card {
    background: white;
    border-radius: var(--radius);
    padding: 32px 24px;
    box-shadow: var(--shadow);
    text-align: center;
}

.tool-card i {
    font-size: 40px;
    color: var(--primary);
    margin-bottom: 16px;
}

.tool-card h3 {
    margin-bottom: 8px;
}

.tool-card p {
    color: var(--text-light);
    margin-bottom: 20px;
}

.admin-note {
    margin-top: 40px;
    background: #fffbe6;
    padding: 20px;
    border-radius: var(--radius-sm);
    border-left: 4px solid #fadb14;
    color: #8c7a00;
}

/* ===== 回到顶部 ===== */
#backToTop {
    position: fixed;
    bottom: 40px;
    right: 40px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--primary);
    color: white;
    border: none;
    font-size: 20px;
    cursor: pointer;
    box-shadow: 0 4px 16px rgba(7,193,96,0.3);
    transition: var(--transition);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    z-index: 999;
}

#backToTop.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

#backToTop:hover {
    background: var(--primary-dark);
    transform: translateY(-4px);
}

/* ===== Footer ===== */
.footer {
    background: #191919;
    color: rgba(255,255,255,0.8);
    padding: 48px 0 0;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 24px;
    padding-bottom: 32px;
}

.footer-brand {
    font-size: 20px;
    font-weight: 600;
}

.footer-brand i {
    color: var(--primary);
    margin-right: 8px;
}

.footer-brand p {
    font-size: 14px;
    font-weight: 300;
    opacity: 0.6;
    margin-top: 4px;
}

.footer-links a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: rgba(255,255,255,0.08);
    color: white;
    font-size: 20px;
    transition: var(--transition);
    margin-left: 8px;
}

.footer-links a:hover {
    background: var(--primary);
    transform: scale(1.1);
}

.footer-bottom {
    text-align: center;
    padding: 20px;
    border-top: 1px solid rgba(255,255,255,0.06);
    font-size: 14px;
    opacity: 0.5;
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
    .hero-text h1 {
        font-size: 40px;
    }
    .hero-content {
        gap: 40px;
    }
}

@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: 64px;
        left: 0;
        right: 0;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 16px 24px;
        gap: 4px;
        box-shadow: 0 20px 40px rgba(0,0,0,0.08);
        transform: translateY(-120%);
        transition: var(--transition);
        border-bottom: 1px solid rgba(0,0,0,0.04);
    }
    .nav-links.open {
        transform: translateY(0);
    }
    .hamburger {
        display: block;
    }
    .hero-content {
        flex-direction: column;
        text-align: center;
    }
    .hero-text h1 {
        font-size: 34px;
    }
    .hero-text p {
        margin: 0 auto 24px;
    }
    .hero-buttons {
        justify-content: center;
    }
    .hero-stats {
        justify-content: center;
    }
    .hero-visual {
        margin-top: 20px;
    }
    .phone-mockup {
        width: 200px;
    }
    .features-grid {
        grid-template-columns: 1fr;
    }
    .stats-container {
        flex-direction: column;
        gap: 32px;
    }
    .section-title h2 {
        font-size: 28px;
    }
    .page-banner h1 {
        font-size: 30px;
    }
    #backToTop {
        bottom: 20px;
        right: 20px;
        width: 44px;
        height: 44px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }
    .hero {
        padding: 120px 0 60px;
    }
    .hero-text h1 {
        font-size: 28px;
    }
    .hero-stats {
        gap: 16px;
        flex-wrap: wrap;
    }
    .hero-stats div {
        flex: 1;
        min-width: 80px;
    }
    .admin-card {
        padding: 32px 20px;
    }
}