/* 全局样式与教程·FAQ 页专属样式合并 */
:root {
    --canvas-bg: #0b0e14;
    --surface-bg: rgba(18, 22, 28, 0.82);
    --surface-border: rgba(255, 255, 255, 0.08);
    --stroke-color: rgba(255, 255, 255, 0.06);
    --accent-glow: linear-gradient(135deg, rgba(99, 102, 241, 0.25) 0%, rgba(6, 182, 212, 0.18) 100%);
    --text-main: #eef2f6;
    --text-muted: #94a3b8;
    --text-accent: #38bdf8;
    --brand-gradient: linear-gradient(135deg, #6366f1 0%, #06b6d4 50%, #a855f7 100%);
    --card-radius: 20px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--canvas-bg);
    color: var(--text-main);
    line-height: 1.7;
    overflow-x: hidden;
    position: relative;
}

body::before, body::after {
    content: "";
    position: fixed;
    z-index: -1;
    pointer-events: none;
    border-radius: 50%;
}
body::before { top: -10%; left: -6%; width: 58vw; height: 58vw; background: radial-gradient(circle, rgba(99,102,241,0.18) 0%, rgba(11,14,20,0) 70%); }
body::after { bottom: -6%; right: -6%; width: 48vw; height: 48vw; background: radial-gradient(circle, rgba(6,182,212,0.13) 0%, rgba(11,14,20,0) 70%); }

.navbar { position: sticky; top: 0; z-index: 1000; background: rgba(11,14,20,0.82); backdrop-filter: blur(24px); -webkit-backdrop-filter: blur(24px); border-bottom: 1px solid rgba(255,255,255,0.06); height: 72px; animation: fadeIn 0.7s ease both; }
.navbar-container { max-width: 1400px; margin: 0 auto; height: 100%; display: flex; align-items: center; justify-content: space-between; padding: 0 48px; }
.nav-brand a { text-decoration: none; color: var(--text-main); font-size: 19px; font-weight: 800; display: flex; align-items: center; gap: 10px; letter-spacing: -0.4px; }
.nav-brand img { width: 30px; height: 30px; object-fit: contain; }
.nav-right-zone { display: flex; align-items: center; gap: 20px; }
.nav-menu { display: flex; gap: 4px; }
.nav-item { text-decoration: none; color: var(--text-muted); font-size: 13.5px; font-weight: 600; padding: 7px 16px; border-radius: 9px; transition: all 0.25s; }
.nav-item:hover { color: var(--text-accent); background: rgba(56,189,248,0.08); }
.nav-item.active { color: #fff; background: #1e293b; box-shadow: 0 3px 10px rgba(0,0,0,0.3); }
.btn-github { display: inline-flex; align-items: center; gap: 7px; padding: 7px 15px; border-radius: 9px; background: #1e293b; border: 1px solid rgba(255,255,255,0.1); color: var(--text-main); text-decoration: none; font-size: 13px; font-weight: 600; box-shadow: 0 2px 6px rgba(0,0,0,0.3); transition: all 0.25s; }
.btn-github:hover { background: #334155; border-color: rgba(255,255,255,0.18); transform: translateY(-1px); }
.btn-github svg { width: 15px; height: 15px; fill: currentColor; }

.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 13px 28px; border-radius: 11px; font-size: 14.5px; font-weight: 600; text-decoration: none; transition: all 0.3s; white-space: nowrap; }
.btn-primary { background: var(--brand-gradient); color: #fff; box-shadow: 0 7px 26px rgba(99,102,241,0.4); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 11px 32px rgba(99,102,241,0.55); }
.btn-secondary { background: #1e293b; color: var(--text-main); border: 1px solid rgba(255,255,255,0.1); box-shadow: 0 3px 16px rgba(0,0,0,0.3); }
.btn-secondary:hover { background: #334155; transform: translateY(-2px); }

.section-header { text-align: center; margin-bottom: 48px; }
.section-eyebrow { font-size: 12px; font-weight: 700; text-transform: uppercase; letter-spacing: 1.6px; color: var(--text-accent); margin-bottom: 10px; display: block; }
.section-title { font-size: 34px; font-weight: 900; letter-spacing: -1px; color: var(--text-main); margin-bottom: 14px; }
.section-desc { font-size: 15px; color: var(--text-muted); max-width: 680px; margin: 0 auto; line-height: 1.7; }

/* 教程 Hero */
.faq-hero { padding: 48px 48px 0; text-align: center; max-width: 1400px; margin: 0 auto; }
.faq-hero .hero-title { font-size: 42px; background: linear-gradient(135deg, #eef2f6 20%, #6366f1 50%, #06b6d4 100%); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; margin-bottom: 12px; }
.faq-hero .hero-subtitle { font-size: 16px; max-width: 700px; margin: 0 auto 32px; color: var(--text-muted); line-height: 1.7; }

/* 步骤卡片 */
.tutorial-grid { max-width: 1200px; margin: 0 auto 80px; padding: 0 48px; display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 24px; }
.tutorial-card { background: #1e293b; border: 1px solid rgba(255,255,255,0.06); border-radius: var(--card-radius); padding: 32px 24px; box-shadow: 0 8px 24px rgba(0,0,0,0.4); transition: transform 0.3s; }
.tutorial-card:hover { transform: translateY(-5px); }
.tutorial-num { width: 48px; height: 48px; background: var(--brand-gradient); border-radius: 14px; display: flex; align-items: center; justify-content: center; font-weight: 900; font-size: 22px; color: #fff; margin-bottom: 16px; }
.tutorial-card h3 { font-size: 20px; font-weight: 800; color: var(--text-main); margin-bottom: 10px; }
.tutorial-card p { font-size: 13.5px; color: var(--text-muted); line-height: 1.7; }
.tutorial-card code { background: #334155; padding: 2px 8px; border-radius: 5px; font-size: 12.5px; color: var(--text-accent); }

/* FAQ 折叠 */
.faq-accordion { max-width: 900px; margin: 0 auto 80px; padding: 0 48px; }
.faq-item { background: #1e293b; border: 1px solid rgba(255,255,255,0.05); border-radius: 16px; margin-bottom: 16px; overflow: hidden; }
.faq-question { width: 100%; background: transparent; border: none; color: var(--text-main); font-size: 16px; font-weight: 700; padding: 22px 24px; text-align: left; cursor: pointer; display: flex; justify-content: space-between; align-items: center; transition: background 0.2s; }
.faq-question:hover { background: rgba(99,102,241,0.05); }
.faq-question::after { content: "+"; font-size: 22px; color: var(--text-accent); font-weight: 400; transition: transform 0.3s; }
.faq-item.open .faq-question::after { content: "−"; transform: rotate(180deg); }
.faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.4s, padding 0.4s; padding: 0 24px; color: var(--text-muted); font-size: 14px; line-height: 1.7; }
.faq-item.open .faq-answer { max-height: 500px; padding: 0 24px 22px; }

/* 视频 */
.video-tutorial { max-width: 860px; margin: 0 auto 80px; border-radius: 18px; overflow: hidden; background: #1e293b; border: 1px solid rgba(255,255,255,0.06); box-shadow: 0 16px 40px rgba(0,0,0,0.5); }
.video-container { position: relative; width: 100%; padding-bottom: 56.25%; height: 0; }
.video-container iframe { position: absolute; top: 0; left: 0; width: 100%; height: 100%; border: 0; }

.bottom-cta { max-width: 1400px; margin: 0 auto 100px; padding: 0 48px; text-align: center; }
.cta-bottom-title { font-size: 30px; font-weight: 900; letter-spacing: -0.8px; color: var(--text-main); margin-bottom: 12px; }
.cta-bottom-text { font-size: 15px; color: var(--text-muted); margin-bottom: 28px; }
.cta-group { display: flex; align-items: center; justify-content: center; gap: 14px; flex-wrap: wrap; }

.footer { background-color: #0f172a; color: var(--text-muted); padding: 64px 48px; border-top: 1px solid rgba(255,255,255,0.05); }
.footer-container { max-width: 1400px; margin: 0 auto; display: grid; grid-template-columns: 1.6fr 1fr 1fr; gap: 52px; }
.footer-brand-side { display: flex; flex-direction: column; gap: 14px; }
.footer-brand-title { font-size: 15px; font-weight: 800; color: var(--text-main); }
.footer-text { font-size: 12.5px; color: var(--text-muted); line-height: 1.6; }
.footer-nav-col { display: flex; flex-direction: column; gap: 14px; }
.footer-col-title { font-size: 13px; font-weight: 700; color: var(--text-main); letter-spacing: 0.4px; }
.footer-links-list { display: flex; flex-direction: column; gap: 10px; list-style: none; }
.footer-links-list a { color: var(--text-muted); text-decoration: none; font-size: 12.5px; font-weight: 500; transition: color 0.2s; }
.footer-links-list a:hover { color: var(--text-accent); }

@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }

@media (max-width: 1024px) {
    .section-title { font-size: 28px; }
    .footer-container { grid-template-columns: 1fr 1fr; gap: 36px; }
}
@media (max-width: 768px) {
    .navbar-container { padding: 0 20px; }
    .nav-menu { display: none; }
    .faq-hero { padding: 32px 20px 0; }
    .faq-hero .hero-title { font-size: 30px; }
    .tutorial-grid { padding: 0 20px; grid-template-columns: 1fr; }
    .faq-accordion { padding: 0 20px; }
    .bottom-cta { padding: 0 20px; margin-bottom: 60px; }
    .footer-container { grid-template-columns: 1fr; gap: 28px; }
    .footer { padding: 48px 24px; }
}