/* ================================================
   QingQia 公众号矩阵 - 前台官网样式
   ================================================ */

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
    font-family: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', 'Segoe UI', Helvetica, Arial, sans-serif;
    color: #1f2937;
    line-height: 1.6;
    background: #fff;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a { color: #2a7ae2; text-decoration: none; }
a:hover { color: #1b5fc1; }
ul { list-style: none; padding: 0; margin: 0; }

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ============== 按钮 ============== */
.btn {
    display: inline-block;
    padding: 10px 22px;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    border: 1px solid transparent;
    transition: all 0.2s ease;
}
.btn-primary {
    background: linear-gradient(135deg, #2a7ae2 0%, #1b5fc1 100%);
    color: #fff;
}
.btn-primary:hover { background: linear-gradient(135deg, #1b5fc1 0%, #144a99 100%); color: #fff; }
.btn-outline {
    background: transparent;
    color: #2a7ae2;
    border-color: #2a7ae2;
}
.btn-outline:hover { background: #2a7ae2; color: #fff; }
.btn-lg { padding: 14px 32px; font-size: 16px; }
.btn-block { display: block; width: 100%; text-align: center; }

/* ============== Header ============== */
.site-header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: saturate(180%) blur(12px);
    border-bottom: 1px solid #e5e7eb;
}
.site-header .container {
    display: flex;
    align-items: center;
    height: 64px;
}
.site-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 18px;
    font-weight: 700;
    color: #1f2937;
}
.site-logo:hover { color: #2a7ae2; }
.logo-icon { font-size: 24px; }

.site-nav {
    flex: 1;
    display: flex;
    gap: 32px;
    margin-left: 48px;
}
.site-nav a {
    color: #4b5563;
    font-weight: 500;
    transition: color 0.2s;
    padding: 4px 0;
    position: relative;
}
.site-nav a:hover { color: #2a7ae2; }
.site-nav a.active::after {
    content: '';
    position: absolute;
    left: 0;
    right: 0;
    bottom: -22px;
    height: 2px;
    background: #2a7ae2;
}

.site-actions {
    display: flex;
    gap: 12px;
}

/* ============== 移动端导航 (汉堡折叠菜单) ============== */
/* 汉堡按钮: 默认隐藏, 仅手机端显示 */
.nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 42px;
    height: 42px;
    margin-left: auto;
    padding: 0;
    background: transparent;
    border: none;
    cursor: pointer;
}
.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: #1f2937;
    border-radius: 2px;
    transition: transform 0.25s ease, opacity 0.25s ease;
}
/* 展开态: 汉堡变 X */
.mobile-menu.open ~ .nav-toggle span:nth-child(1),
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* 折叠菜单容器: 从顶栏下方滑出 */
.mobile-menu {
    display: none;
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    background: #fff;
    border-bottom: 1px solid #e5e7eb;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
    z-index: 999;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}
.mobile-menu.open { max-height: 480px; }
.mobile-menu nav {
    display: flex;
    flex-direction: column;
    padding: 8px 0;
}
.mobile-menu nav a {
    padding: 14px 24px;
    color: #374151;
    font-size: 16px;
    font-weight: 500;
    border-bottom: 1px solid #f3f4f6;
}
.mobile-menu nav a:hover,
.mobile-menu nav a.active { color: #2a7ae2; background: #f9fafb; }
.mobile-menu .mobile-actions {
    display: flex;
    flex-direction: column;
    gap: 12px;
    padding: 16px 24px;
}
.mobile-menu .mobile-actions .btn { width: 100%; text-align: center; }

/* ============== Hero (首页) ============== */
.hero {
    position: relative;
    padding: 120px 0 100px;
    background: linear-gradient(135deg, #f3f7fe 0%, #e8f0fe 50%, #f3f7fe 100%);
    overflow: hidden;
}
.hero::before, .hero::after {
    content: '';
    position: absolute;
    width: 400px;
    height: 400px;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.4;
}
.hero::before { background: #2a7ae2; top: -100px; left: -100px; }
.hero::after { background: #06b6d4; bottom: -100px; right: -100px; }
.hero .container {
    position: relative;
    text-align: center;
}
.hero h1 {
    font-size: 56px;
    font-weight: 800;
    line-height: 1.15;
    margin: 0 0 24px;
    color: #1f2937;
}
.hero h1 .highlight {
    background: linear-gradient(135deg, #2a7ae2, #06b6d4);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}
.hero p.lead {
    font-size: 20px;
    color: #4b5563;
    max-width: 720px;
    margin: 0 auto 40px;
}
.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
}
.hero-stats {
    display: flex;
    justify-content: center;
    gap: 64px;
    margin-top: 80px;
    flex-wrap: wrap;
}
.hero-stat {
    text-align: center;
}
.hero-stat-num {
    font-size: 36px;
    font-weight: 700;
    color: #2a7ae2;
}
.hero-stat-label {
    font-size: 14px;
    color: #6b7280;
}

/* ============== Section ============== */
.section {
    padding: 80px 0;
}
.section-alt {
    background: #f9fafb;
}
.section-title {
    text-align: center;
    margin-bottom: 60px;
}
.section-title h2 {
    font-size: 36px;
    font-weight: 700;
    margin: 0 0 12px;
    color: #1f2937;
}
.section-title p {
    font-size: 16px;
    color: #6b7280;
    max-width: 600px;
    margin: 0 auto;
}

/* ============== Grid 卡片 ============== */
.grid {
    display: grid;
    gap: 24px;
}
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 768px) {
    .grid-3, .grid-4 { grid-template-columns: 1fr; }
}

.feature-card {
    padding: 32px;
    background: #fff;
    border-radius: 12px;
    border: 1px solid #e5e7eb;
    transition: all 0.3s ease;
}
.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.08);
    border-color: #2a7ae2;
}
.feature-icon {
    width: 56px;
    height: 56px;
    border-radius: 12px;
    background: linear-gradient(135deg, #e8f0fe, #d1e3fc);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    margin-bottom: 20px;
}
.feature-card h3 {
    font-size: 18px;
    font-weight: 600;
    margin: 0 0 8px;
    color: #1f2937;
}
.feature-card p {
    color: #6b7280;
    margin: 0;
    font-size: 14px;
}

/* ============== Pricing 套餐卡片 ============== */
.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
    align-items: stretch;
}
.pricing-card {
    padding: 32px 28px;
    background: #fff;
    border: 1px solid #e5e7eb;
    border-radius: 16px;
    display: flex;
    flex-direction: column;
    transition: all 0.3s ease;
    position: relative;
}
.pricing-card:hover { box-shadow: 0 16px 32px rgba(0, 0, 0, 0.08); transform: translateY(-4px); }
.pricing-card.recommended {
    border: 2px solid #2a7ae2;
    box-shadow: 0 12px 32px rgba(42, 122, 226, 0.15);
}
.pricing-badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: linear-gradient(135deg, #2a7ae2, #06b6d4);
    color: #fff;
    padding: 4px 14px;
    border-radius: 999px;
    font-size: 12px;
    font-weight: 600;
}
.pricing-name {
    font-size: 20px;
    font-weight: 700;
    margin: 0 0 8px;
}
.pricing-desc {
    font-size: 13px;
    color: #6b7280;
    min-height: 40px;
    margin-bottom: 16px;
}
.pricing-price {
    margin-bottom: 24px;
}
.pricing-price .num {
    font-size: 42px;
    font-weight: 800;
    color: #1f2937;
}
.pricing-price .unit {
    color: #6b7280;
    font-size: 14px;
}
.pricing-price .yearly {
    display: block;
    color: #6b7280;
    font-size: 12px;
    margin-top: 4px;
}
.pricing-features {
    flex: 1;
    margin: 0 0 24px;
}
.pricing-features li {
    padding: 8px 0;
    color: #4b5563;
    font-size: 14px;
    border-bottom: 1px dashed #f3f4f6;
}
.pricing-features li:last-child { border-bottom: none; }
.pricing-features li::before {
    content: '✓ ';
    color: #10b981;
    font-weight: 700;
    margin-right: 6px;
}

/* ============== CTA 行动呼吁 ============== */
.cta {
    padding: 80px 0;
    background: linear-gradient(135deg, #2a7ae2 0%, #06b6d4 100%);
    color: #fff;
    text-align: center;
}
.cta h2 {
    font-size: 36px;
    font-weight: 700;
    margin: 0 0 16px;
}
.cta p {
    font-size: 18px;
    opacity: 0.9;
    margin: 0 0 32px;
}
.cta .btn {
    background: #fff;
    color: #2a7ae2;
    border: none;
}
.cta .btn:hover { background: #f3f7fe; color: #1b5fc1; }

/* ============== Footer ============== */
.site-footer {
    background: #1f2937;
    color: #d1d5db;
    padding: 60px 0 24px;
}
.footer-cols {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 2fr;
    gap: 40px;
    padding-bottom: 40px;
    border-bottom: 1px solid #374151;
}
.footer-col h4 {
    color: #fff;
    font-size: 14px;
    font-weight: 600;
    margin: 0 0 16px;
}
.footer-col ul li {
    padding: 6px 0;
}
.footer-col a {
    color: #9ca3af;
    font-size: 14px;
}
.footer-col a:hover { color: #fff; }
.footer-cta p {
    color: #9ca3af;
    font-size: 14px;
    margin: 0 0 16px;
}
.footer-bottom {
    padding-top: 24px;
    text-align: center;
    color: #9ca3af;
    font-size: 13px;
}
@media (max-width: 768px) {
    .footer-cols { grid-template-columns: 1fr 1fr; }
    /* 桌面导航与右上角操作按钮在手机端隐藏, 改用汉堡折叠菜单 */
    .site-nav { display: none; }
    .site-actions { display: none; }
    .nav-toggle { display: flex; }
    .mobile-menu { display: block; }
    .hero h1 { font-size: 36px; }
    .section-title h2 { font-size: 28px; }
}

/* ============== 简单动画 ============== */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}
.fade-in-up { animation: fadeInUp 0.6s ease forwards; }

/* 表单 */
.form-group { margin-bottom: 16px; }
.form-group label { display: block; font-size: 14px; font-weight: 500; margin-bottom: 6px; color: #374151; }
.form-control {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid #d1d5db;
    border-radius: 6px;
    font-size: 14px;
    transition: border-color 0.2s;
}
.form-control:focus { outline: none; border-color: #2a7ae2; box-shadow: 0 0 0 3px rgba(42, 122, 226, 0.1); }
textarea.form-control { min-height: 100px; resize: vertical; }