/* ============================================================
   漫蛙漫画 · 官网样式
   风格：清新绿 / 青蛙 Logo 主题
   ============================================================ */

:root {
    --bg: #F0FDF4;
    --bg-card: #FFFFFF;
    --line: #BBF7D0;
    --text: #1A2E1A;
    --text-soft: #556B55;
    --text-faint: #8FA88F;
    --accent: #16A34A;
    --accent-bright: #22C55E;
    --accent-deep: #15803D;
    --gradient: linear-gradient(135deg, #16A34A 0%, #22C55E 100%);
    --radius: 16px;
    --shadow: 0 4px 20px rgba(22,163,74,0.1);
    --shadow-lg: 0 20px 50px rgba(22,163,74,0.2);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    font-family: "PingFang SC", "Microsoft YaHei", sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
    padding-bottom: 70px;
}
img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; }

.container { max-width: 1140px; margin: 0 auto; padding: 0 24px; }

/* ============ 导航 ============ */
.navbar {
    position: sticky; top: 0; z-index: 100;
    background: rgba(255,255,255,0.92);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--line);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; }
.brand-logo { height: 40px; width: 40px; object-fit: contain; }
.brand-name { font-size: 18px; font-weight: 700; color: var(--accent-deep); }
.nav-links { display: flex; gap: 28px; }
.nav-links a { font-size: 14px; color: var(--text-soft); transition: color .2s; }
.nav-links a:hover { color: var(--accent-deep); }

/* ============ 按钮 ============ */
.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: 8px;
    padding: 12px 26px; border-radius: 12px;
    font-size: 14px; font-weight: 600; transition: all .25s;
}
.btn-small { padding: 8px 18px; font-size: 13px; border-radius: 10px; }
.btn-lg { padding: 16px 36px; font-size: 16px; }
.btn-primary {
    background: var(--gradient); color: #fff;
    box-shadow: 0 4px 14px rgba(22,163,74,0.3);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(22,163,74,0.4); }

/* ============ Hero ============ */
.hero {
    padding: 80px 0;
    background:
        radial-gradient(circle at 85% 20%, rgba(34,197,94,0.12), transparent 50%),
        var(--bg);
}
.hero-inner {
    display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 50px; align-items: center;
}
.hero-tag {
    display: inline-block; padding: 6px 16px;
    background: rgba(22,163,74,0.1); color: var(--accent-deep);
    border-radius: 20px; font-size: 13px; font-weight: 500; margin-bottom: 22px;
}
.hero-text h1 { font-size: 44px; font-weight: 800; line-height: 1.25; margin-bottom: 20px; }
.hero-desc { font-size: 16px; color: var(--text-soft); line-height: 1.9; margin-bottom: 32px; max-width: 480px; }
.hero-actions { margin-bottom: 28px; }
.hero-badges { display: flex; gap: 10px; flex-wrap: wrap; }
.badge {
    padding: 6px 16px; background: #fff; color: var(--accent-deep);
    border-radius: 20px; font-size: 13px; font-weight: 500;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
.hero-art { display: flex; justify-content: center; }
.hero-frog {
    max-width: 280px;
    animation: float 3s ease-in-out infinite;
}
@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-15px); }
}

/* ============ Section ============ */
section { padding: 80px 0; }
.section-title { font-size: 30px; font-weight: 800; text-align: center; margin-bottom: 44px; }

/* ============ 分类展示 ============ */
.categories { background: #fff; }
.cat-grid {
    display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px;
}
.cat-card {
    position: relative; border-radius: var(--radius); overflow: hidden;
    aspect-ratio: 3/4; cursor: pointer;
    box-shadow: var(--shadow); transition: transform .3s;
}
.cat-card:hover { transform: translateY(-6px); }
.cat-card img {
    width: 100%; height: 100%; object-fit: cover;
    transition: transform .4s;
}
.cat-card:hover img { transform: scale(1.05); }
.cat-overlay {
    position: absolute; bottom: 0; left: 0; right: 0;
    padding: 20px 16px;
    background: linear-gradient(transparent, rgba(0,0,0,0.7));
    color: #fff;
}
.cat-name { display: block; font-size: 18px; font-weight: 700; }
.cat-count { font-size: 12px; opacity: 0.9; }

/* ============ 功能特色 ============ */
.features-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.feature-card {
    padding: 30px 24px; background: var(--bg-card); border-radius: var(--radius);
    transition: all .3s; border: 1px solid var(--line); text-align: center;
}
.feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.feature-icon { font-size: 36px; margin-bottom: 14px; }
.feature-card h3 { font-size: 17px; margin-bottom: 8px; }
.feature-card p { font-size: 14px; color: var(--text-soft); line-height: 1.8; }

/* ============ FAQ ============ */
.faq-list { max-width: 720px; margin: 0 auto; }
.faq-list details {
    border: 1px solid var(--line); border-radius: 12px;
    padding: 18px 24px; margin-bottom: 10px; background: #fff;
}
.faq-list details[open] { border-color: var(--accent-bright); }
.faq-list summary {
    font-size: 15px; font-weight: 600; cursor: pointer;
    list-style: none; position: relative; padding-right: 28px;
}
.faq-list summary::after {
    content: "+"; position: absolute; right: 0; top: 50%;
    transform: translateY(-50%); font-size: 20px; color: var(--accent);
}
.faq-list details[open] summary::after { content: "−"; }
.faq-list details p { font-size: 14px; color: var(--text-soft); padding-top: 10px; }

/* ============ 页脚 ============ */
.footer {
    background: #14532D; color: rgba(255,255,255,0.6); padding: 32px 0;
}
.footer-inner { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px; }
.footer-brand { display: flex; align-items: center; gap: 10px; font-size: 14px; }
.footer-logo { height: 36px; width: 36px; object-fit: contain; }
.footer-copy { font-size: 13px; }

/* ============ 底部悬浮下载栏 ============ */
.sticky-bar {
    position: fixed; bottom: 0; left: 0; right: 0; z-index: 99;
    background: rgba(255,255,255,0.95); backdrop-filter: blur(12px);
    border-top: 1px solid var(--line); padding: 10px 0;
}
.sticky-inner { display: flex; align-items: center; gap: 12px; }
.sticky-logo { height: 36px; width: 36px; object-fit: contain; }
.sticky-text { flex: 1; display: flex; flex-direction: column; }
.sticky-text strong { font-size: 14px; }
.sticky-text span { font-size: 12px; color: var(--text-soft); }

/* ============ 滚动渐入 ============ */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .7s, transform .7s; }
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ============ 响应式 ============ */
@media (max-width: 900px) {
    .nav-links { display: none; }
    .hero-inner { grid-template-columns: 1fr; gap: 36px; }
    .hero-text h1 { font-size: 32px; }
    .features-grid { grid-template-columns: repeat(2, 1fr); }
    .cat-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-inner { flex-direction: column; text-align: center; }
}