/* ========================================
   百家哭 - WeChat Style Design System
   ======================================== */

/* Reset & Base */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --green: #07C160;
    --green-dark: #06AD56;
    --green-light: #E8F8EF;
    --text-primary: #191919;
    --text-secondary: #576B95;
    --text-tertiary: #999;
    --bg: #FFFFFF;
    --bg-light: #F7F8FA;
    --bg-green: #07C160;
    --border: #EDEDED;
    --radius: 12px;
    --radius-lg: 16px;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
    --shadow-lg: 0 8px 32px rgba(0,0,0,0.12);
    --max-width: 1200px;
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-family);
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg);
    overflow-x: hidden;
}

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

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

/* Utility */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

.container-narrow {
    max-width: 800px;
}

.text-green {
    color: var(--green);
}

.link-light {
    color: rgba(255,255,255,0.8);
    text-decoration: underline;
}
.link-light:hover {
    color: #fff;
}

/* ========================================
   Header
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    transition: box-shadow 0.3s;
}

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

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

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 700;
    color: var(--text-primary);
}

.logo-icon {
    flex-shrink: 0;
}

.nav {
    display: flex;
    gap: 4px;
}

.nav-link {
    padding: 8px 16px;
    font-size: 15px;
    color: var(--text-secondary);
    border-radius: 6px;
    transition: all 0.2s;
}

.nav-link:hover,
.nav-link.active {
    color: var(--green);
    background: var(--green-light);
}

/* Mobile menu button */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.mobile-menu-btn span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all 0.3s;
}

.mobile-menu-btn.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}
.mobile-menu-btn.active span:nth-child(2) {
    opacity: 0;
}
.mobile-menu-btn.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* ========================================
   Buttons
   ======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 28px;
    font-size: 16px;
    font-weight: 500;
    border-radius: 8px;
    border: none;
    cursor: pointer;
    transition: all 0.25s;
    text-decoration: none;
    line-height: 1;
}

.btn-lg {
    padding: 16px 36px;
    font-size: 18px;
    border-radius: 10px;
}

.btn-primary {
    background: var(--green);
    color: #fff;
}

.btn-primary:hover {
    background: var(--green-dark);
    box-shadow: 0 4px 16px rgba(7,193,96,0.35);
    transform: translateY(-1px);
}

.btn-outline {
    background: transparent;
    color: var(--text-primary);
    border: 1.5px solid var(--border);
}

.btn-outline:hover {
    border-color: var(--green);
    color: var(--green);
    background: var(--green-light);
}

.btn-white {
    background: #fff;
    color: var(--green);
    font-weight: 600;
}

.btn-white:hover {
    background: rgba(255,255,255,0.9);
    box-shadow: 0 4px 16px rgba(0,0,0,0.15);
}

/* ========================================
   Hero Section
   ======================================== */
.hero {
    position: relative;
    padding: 120px 0 100px;
    overflow: hidden;
}

.hero .container {
    display: flex;
    align-items: center;
    gap: 60px;
}

.hero-content {
    flex: 1;
    max-width: 560px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 16px;
    background: var(--green-light);
    border-radius: 20px;
    font-size: 14px;
    color: var(--green);
    margin-bottom: 24px;
    font-weight: 500;
}

.hero-title {
    font-size: 48px;
    font-weight: 700;
    line-height: 1.25;
    letter-spacing: -0.5px;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.hero-desc {
    font-size: 18px;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 36px;
    max-width: 480px;
}

.hero-actions {
    display: flex;
    gap: 16px;
    margin-bottom: 48px;
}

.hero-stats {
    display: flex;
    gap: 40px;
    padding-top: 32px;
    border-top: 1px solid var(--border);
}

.stat-item {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.stat-number {
    font-size: 32px;
    font-weight: 700;
    color: var(--green);
    letter-spacing: -1px;
}

.stat-label {
    font-size: 14px;
    color: var(--text-tertiary);
}

/* Hero Visual - Screenshot */
.hero-visual {
    flex-shrink: 0;
    width: 320px;
}

.hero-visual img {
    width: 100%;
    height: auto;
    border-radius: 12px;
}

/* Hero background decoration */
.hero-bg-dots {
    position: absolute;
    top: -100px;
    right: -100px;
    width: 500px;
    height: 500px;
    background-image: radial-gradient(circle, rgba(7,193,96,0.08) 1px, transparent 1px);
    background-size: 30px 30px;
    pointer-events: none;
    z-index: -1;
}

/* ========================================
   Section Common
   ======================================== */
.section {
    padding: 80px 0;
}

.section-bg {
    background: var(--bg-light);
}

.section-green {
    background: linear-gradient(135deg, #07C160 0%, #06AD56 100%);
    color: #fff;
}

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

.section-header-light .section-title,
.section-header-light .section-desc {
    color: #fff;
}

.section-tag {
    display: inline-block;
    padding: 4px 16px;
    background: var(--green-light);
    color: var(--green);
    border-radius: 20px;
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 16px;
}

.section-title {
    font-size: 36px;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.5px;
    margin-bottom: 12px;
}

.section-desc {
    font-size: 17px;
    color: var(--text-secondary);
}

/* ========================================
   Features Grid
   ======================================== */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.feature-card {
    padding: 32px 28px;
    background: #fff;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    transition: all 0.3s;
    cursor: default;
}

.feature-card:hover {
    box-shadow: var(--shadow-md);
    border-color: transparent;
    transform: translateY(-2px);
}

.feature-icon {
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--green-light);
    border-radius: 12px;
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 10px;
    color: var(--text-primary);
}

.feature-card p {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ========================================
   Strategies Grid
   ======================================== */
.strategies-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.strategy-card {
    padding: 24px 20px;
    background: #fff;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    text-align: center;
    transition: all 0.3s;
}

.strategy-card:hover {
    border-color: var(--green);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.strategy-card h4 {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.strategy-card p {
    font-size: 13px;
    color: var(--text-tertiary);
    line-height: 1.5;
}

/* ========================================
   Why Choose Us
   ======================================== */
.why-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
}

.why-item {
    display: flex;
    gap: 24px;
    align-items: flex-start;
}

.why-number {
    font-size: 48px;
    font-weight: 800;
    color: var(--green-light);
    line-height: 1;
    flex-shrink: 0;
    font-variant-numeric: tabular-nums;
}

.why-content h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.why-content p {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ========================================
   Download Section
   ======================================== */
.download-single {
    display: flex;
    justify-content: center;
    margin-bottom: 40px;
}

.download-card-single {
    max-width: 420px;
    width: 100%;
}

.download-card {
    text-align: center;
    padding: 48px 32px;
    background: rgba(255,255,255,0.12);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255,255,255,0.2);
    transition: all 0.3s;
}

.download-card:hover {
    background: rgba(255,255,255,0.2);
    transform: translateY(-2px);
}

.download-card-icon {
    margin-bottom: 20px;
}

.download-card-icon svg {
    border-radius: 18px;
    box-shadow: 0 4px 16px rgba(0,0,0,0.2);
}

.download-card h3 {
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 8px;
}

.download-card p {
    font-size: 15px;
    color: rgba(255,255,255,0.7);
    margin-bottom: 28px;
}

.download-card .btn {
    margin-bottom: 12px;
}

.download-meta {
    display: block;
    font-size: 13px;
    color: rgba(255,255,255,0.5);
}

.download-other {
    text-align: center;
    font-size: 14px;
    color: rgba(255,255,255,0.6);
}

.download-other a {
    margin: 0 4px;
    transition: color 0.2s;
}

/* ========================================
   FAQ
   ======================================== */
.faq-list {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.faq-item {
    border-bottom: 1px solid var(--border);
}

.faq-question {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 0;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 17px;
    font-weight: 500;
    color: var(--text-primary);
    text-align: left;
    font-family: var(--font-family);
    transition: color 0.2s;
}

.faq-question:hover {
    color: var(--green);
}

.faq-arrow {
    flex-shrink: 0;
    transition: transform 0.3s;
}

.faq-item.active .faq-arrow {
    transform: rotate(180deg);
}

.faq-item.active .faq-question {
    color: var(--green);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s ease, padding 0.35s ease;
}

.faq-item.active .faq-answer {
    max-height: 200px;
    padding-bottom: 20px;
}

.faq-answer p {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ========================================
   Footer
   ======================================== */
.footer {
    background: #1A1A1A;
    color: #999;
    padding: 60px 0 30px;
}

.footer-top {
    display: flex;
    justify-content: space-between;
    gap: 60px;
    margin-bottom: 40px;
    padding-bottom: 40px;
    border-bottom: 1px solid #333;
}

.footer-brand h3 {
    font-size: 22px;
    font-weight: 700;
    color: #fff;
    margin-bottom: 8px;
}

.footer-brand p {
    font-size: 14px;
    color: #888;
}

.footer-links {
    display: flex;
    gap: 60px;
}

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

.footer-col a {
    display: block;
    font-size: 14px;
    color: #999;
    margin-bottom: 10px;
    transition: color 0.2s;
}

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

.footer-bottom {
    text-align: center;
    font-size: 13px;
    color: #666;
    line-height: 2;
}

.footer-bottom a {
    color: #888;
    transition: color 0.2s;
}

.footer-bottom a:hover {
    color: var(--green);
}

.footer-divider {
    margin: 0 8px;
    color: #444;
}

.footer-icp {
    margin-top: 8px;
    color: #555;
    font-size: 12px;
}

/* ========================================
   About Page
   ======================================== */
.page-hero {
    background: var(--bg-light);
    padding: 120px 0 60px;
    text-align: center;
}

.page-hero h1 {
    font-size: 40px;
    font-weight: 700;
    margin-bottom: 12px;
}

.page-hero p {
    font-size: 17px;
    color: var(--text-secondary);
}

.page-content {
    padding: 60px 0;
}

.page-content .container {
    max-width: 800px;
}

.content-section {
    margin-bottom: 48px;
}

.content-section h2 {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--green-light);
}

.content-section p {
    font-size: 16px;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 12px;
}

.content-section ul {
    list-style: none;
    padding: 0;
}

.content-section ul li {
    position: relative;
    padding-left: 24px;
    font-size: 16px;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 8px;
}

.content-section ul li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 11px;
    width: 8px;
    height: 8px;
    background: var(--green);
    border-radius: 50%;
}

/* ========================================
   Responsive
   ======================================== */
@media (max-width: 1024px) {
    .hero .container {
        flex-direction: column;
        text-align: center;
    }
    .hero-content {
        max-width: 100%;
    }
    .hero-desc {
        max-width: 100%;
    }
    .hero-actions {
        justify-content: center;
    }
    .hero-stats {
        justify-content: center;
    }
    .hero-visual {
        width: 100%;
    }
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .strategies-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .why-grid {
        grid-template-columns: 1fr;
    }
    .footer-top {
        flex-direction: column;
        gap: 32px;
    }
    .footer-links {
        gap: 32px;
        flex-wrap: wrap;
    }
}

@media (max-width: 768px) {
    .header-inner {
        height: 56px;
    }
    .nav {
        position: fixed;
        top: 56px;
        left: 0;
        right: 0;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 16px 24px;
        gap: 4px;
        border-bottom: 1px solid var(--border);
        transform: translateY(-110%);
        opacity: 0;
        transition: all 0.3s;
        box-shadow: var(--shadow-md);
    }
    .nav.open {
        transform: translateY(0);
        opacity: 1;
    }
    .mobile-menu-btn {
        display: flex;
    }
    .hero {
        padding: 96px 0 60px;
    }
    .hero-title {
        font-size: 32px;
    }
    .hero-desc {
        font-size: 16px;
    }
    .hero-actions {
        flex-direction: column;
        align-items: center;
    }
    .hero-stats {
        gap: 24px;
        flex-wrap: wrap;
    }
    .stat-number {
        font-size: 24px;
    }
    .section {
        padding: 48px 0;
    }
    .section-title {
        font-size: 28px;
    }
    .features-grid {
        grid-template-columns: 1fr;
    }
    .strategies-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .download-card-single {
        max-width: 100%;
    }
    .page-hero h1 {
        font-size: 32px;
    }
}

@media (max-width: 480px) {
    .strategies-grid {
        grid-template-columns: 1fr;
    }
    .mockup-screen {
        width: 220px;
        height: 380px;
    }
}