/* =============================================================
   Czkawka 中文官网 - 主样式表
   配色：基于 logo 的蓝紫渐变（#4480e1 → #926dd3）
   风格：扁平 / 现代 / 专业
   ============================================================= */

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

:root {
  --c-primary: #4480e1;
  --c-primary-dark: #356ac4;
  --c-primary-light: #e8f0fd;
  --c-secondary: #926dd3;
  --c-secondary-dark: #7a4ec0;
  --c-gradient: linear-gradient(135deg, #4480e1 0%, #926dd3 100%);
  --c-gradient-soft: linear-gradient(135deg, rgba(68,128,225,.12) 0%, rgba(146,109,211,.12) 100%);

  --c-text: #1a1f36;
  --c-text-soft: #4a5568;
  --c-text-muted: #718096;
  --c-bg: #ffffff;
  --c-bg-soft: #f7f8fc;
  --c-bg-card: #ffffff;
  --c-border: #e2e8f0;
  --c-border-soft: #edf2f7;
  --c-success: #2bb673;
  --c-warning: #f6ad55;
  --c-danger: #e53e3e;

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-xl: 28px;

  --shadow-sm: 0 1px 3px rgba(26,31,54,.06), 0 1px 2px rgba(26,31,54,.04);
  --shadow-md: 0 4px 16px rgba(26,31,54,.08), 0 2px 6px rgba(26,31,54,.04);
  --shadow-lg: 0 12px 40px rgba(26,31,54,.10), 0 4px 12px rgba(26,31,54,.06);
  --shadow-xl: 0 24px 60px rgba(26,31,54,.14);

  --container: 1200px;
  --transition: all .25s cubic-bezier(.4,0,.2,1);

  --font: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SF Mono", "JetBrains Mono", Consolas, "Liberation Mono", Menlo, monospace;
}

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.7;
  color: var(--c-text);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--c-primary); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--c-primary-dark); }
ul, ol { list-style: none; }

h1, h2, h3, h4, h5, h6 { font-weight: 700; line-height: 1.3; color: var(--c-text); }
h1 { font-size: clamp(2rem, 5vw, 3.4rem); letter-spacing: -.02em; }
h2 { font-size: clamp(1.6rem, 3.5vw, 2.4rem); letter-spacing: -.01em; }
h3 { font-size: 1.3rem; }
h4 { font-size: 1.1rem; }

p { color: var(--c-text-soft); }
code, pre { font-family: var(--font-mono); font-size: .92em; }

/* ---------- Layout helpers ---------- */
.container { width: 100%; max-width: var(--container); margin: 0 auto; padding: 0 24px; }
.section { padding: 96px 0; }
.section-sm { padding: 64px 0; }
.section-soft { background: var(--c-bg-soft); }
.text-center { text-align: center; }
.gradient-text {
  background: var(--c-gradient);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
}

.section-head { max-width: 720px; margin: 0 auto 56px; text-align: center; }
.section-head .eyebrow {
  display: inline-block; padding: 6px 14px; margin-bottom: 16px;
  background: var(--c-primary-light); color: var(--c-primary-dark);
  font-size: .82rem; font-weight: 600; border-radius: 999px; letter-spacing: .04em;
}
.section-head h2 { margin-bottom: 16px; }
.section-head p { font-size: 1.08rem; color: var(--c-text-muted); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 13px 26px; font-size: 1rem; font-weight: 600; line-height: 1;
  border: none; border-radius: var(--radius-md); cursor: pointer;
  transition: var(--transition); white-space: nowrap; text-decoration: none;
  font-family: inherit;
}
.btn-primary {
  background: var(--c-gradient); color: #fff;
  box-shadow: 0 6px 18px rgba(68,128,225,.32);
}
.btn-primary:hover { color: #fff; transform: translateY(-2px); box-shadow: 0 10px 28px rgba(68,128,225,.42); }
.btn-secondary {
  background: #fff; color: var(--c-text);
  border: 1.5px solid var(--c-border);
}
.btn-secondary:hover { border-color: var(--c-primary); color: var(--c-primary); transform: translateY(-2px); }
.btn-ghost { background: transparent; color: var(--c-primary); padding: 10px 18px; }
.btn-ghost:hover { background: var(--c-primary-light); }
.btn-lg { padding: 16px 32px; font-size: 1.08rem; }
.btn-block { display: flex; width: 100%; }

/* ---------- Navbar ---------- */
.navbar {
  position: sticky; top: 0; z-index: 1000;
  background: rgba(255,255,255,.85);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--c-border-soft);
}
.navbar .container { display: flex; align-items: center; justify-content: space-between; height: 70px; }
.brand { display: flex; align-items: center; gap: 10px; font-size: 1.25rem; font-weight: 800; color: var(--c-text); }
.brand:hover { color: var(--c-text); }
.brand img { height: 36px; width: auto; }
.brand-text { background: var(--c-gradient); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.nav-menu { display: flex; align-items: center; gap: 4px; }
.nav-menu a {
  padding: 9px 14px; color: var(--c-text-soft); font-weight: 500; font-size: .96rem;
  border-radius: var(--radius-sm); transition: var(--transition);
}
.nav-menu a:hover, .nav-menu a.active { color: var(--c-primary); background: var(--c-primary-light); }
.nav-actions { display: flex; align-items: center; gap: 12px; }
.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
.nav-toggle span { display: block; width: 22px; height: 2px; background: var(--c-text); margin: 5px 0; transition: var(--transition); }

@media (max-width: 900px) {
  .nav-menu {
    position: fixed; top: 70px; left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 0;
    background: #fff; border-bottom: 1px solid var(--c-border);
    padding: 12px 24px 20px; max-height: 0; overflow: hidden;
    transition: max-height .3s ease;
  }
  .nav-menu.open { max-height: 480px; }
  .nav-menu a { padding: 12px 14px; border-radius: var(--radius-sm); }
  .nav-toggle { display: block; }
  .nav-actions .btn-secondary { display: none; }
}

/* ---------- Hero ---------- */
.hero {
  position: relative; overflow: hidden;
  padding: 80px 0 100px;
  background: var(--c-bg-soft);
}
.hero::before {
  content: ''; position: absolute; top: -200px; right: -200px;
  width: 600px; height: 600px;
  background: radial-gradient(circle, rgba(68,128,225,.15) 0%, transparent 70%);
  pointer-events: none;
}
.hero::after {
  content: ''; position: absolute; bottom: -200px; left: -200px;
  width: 500px; height: 500px;
  background: radial-gradient(circle, rgba(146,109,211,.15) 0%, transparent 70%);
  pointer-events: none;
}
.hero .container { position: relative; display: grid; grid-template-columns: 1.05fr 1fr; gap: 60px; align-items: center; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 7px 14px; margin-bottom: 24px;
  background: #fff; border: 1px solid var(--c-border);
  border-radius: 999px; font-size: .86rem; font-weight: 500; color: var(--c-text-soft);
  box-shadow: var(--shadow-sm);
}
.hero-badge .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--c-success); box-shadow: 0 0 0 4px rgba(43,182,115,.18); }
.hero h1 { margin-bottom: 22px; }
.hero h1 .accent { background: var(--c-gradient); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.hero-lead { font-size: 1.18rem; color: var(--c-text-soft); margin-bottom: 32px; max-width: 560px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 36px; }
.hero-stats { display: flex; flex-wrap: wrap; gap: 36px; }
.hero-stat .num { font-size: 1.9rem; font-weight: 800; background: var(--c-gradient); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; line-height: 1; }
.hero-stat .label { font-size: .88rem; color: var(--c-text-muted); margin-top: 6px; }

.hero-visual { position: relative; }
.hero-mockup {
  background: #fff; border: 1px solid var(--c-border);
  border-radius: var(--radius-lg); box-shadow: var(--shadow-xl);
  overflow: hidden;
}
.hero-mockup-bar { display: flex; gap: 6px; padding: 12px 16px; background: var(--c-bg-soft); border-bottom: 1px solid var(--c-border-soft); }
.hero-mockup-bar span { width: 11px; height: 11px; border-radius: 50%; background: #cbd5e0; }
.hero-mockup-bar span:nth-child(1) { background: #fc8181; }
.hero-mockup-bar span:nth-child(2) { background: #f6c344; }
.hero-mockup-bar span:nth-child(3) { background: #4ade80; }
.hero-mockup-body { padding: 22px 24px 26px; }
.hero-mockup h4 { font-size: .92rem; color: var(--c-text-muted); margin-bottom: 14px; font-weight: 500; }
.scan-list { display: flex; flex-direction: column; gap: 10px; }
.scan-item { display: flex; align-items: center; gap: 12px; padding: 12px 14px; background: var(--c-bg-soft); border-radius: var(--radius-sm); }
.scan-icon { width: 34px; height: 34px; border-radius: 9px; display: flex; align-items: center; justify-content: center; flex-shrink: 0; font-size: 18px; }
.scan-icon.dupe { background: rgba(68,128,225,.14); }
.scan-icon.img  { background: rgba(146,109,211,.14); }
.scan-icon.empty{ background: rgba(43,182,115,.14); }
.scan-icon.big  { background: rgba(246,173,85,.16); }
.scan-text { flex: 1; }
.scan-text strong { display: block; font-size: .92rem; color: var(--c-text); font-weight: 600; }
.scan-text small { color: var(--c-text-muted); font-size: .78rem; }
.scan-size { font-family: var(--font-mono); font-size: .82rem; font-weight: 700; color: var(--c-primary); }

@media (max-width: 900px) {
  .hero .container { grid-template-columns: 1fr; gap: 40px; }
  .hero { padding: 56px 0 72px; }
}

/* ---------- Feature grid ---------- */
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.feature-card {
  background: var(--c-bg-card); border: 1px solid var(--c-border-soft);
  border-radius: var(--radius-lg); padding: 30px 26px;
  transition: var(--transition); position: relative; overflow: hidden;
}
.feature-card::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
  background: var(--c-gradient); transform: scaleX(0); transform-origin: left; transition: transform .3s ease;
}
.feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: transparent; }
.feature-card:hover::before { transform: scaleX(1); }
.feature-icon {
  width: 52px; height: 52px; border-radius: var(--radius-md);
  background: var(--c-gradient-soft); display: flex; align-items: center; justify-content: center;
  margin-bottom: 18px;
}
.feature-icon svg { width: 26px; height: 26px; }
.feature-card h3 { margin-bottom: 10px; font-size: 1.14rem; }
.feature-card p { color: var(--c-text-muted); font-size: .94rem; margin-bottom: 0; }

@media (max-width: 900px) { .feature-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 600px) { .feature-grid { grid-template-columns: 1fr; } }

/* ---------- Use cases ---------- */
.usecase-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.usecase-card {
  border-radius: var(--radius-lg); padding: 32px 26px;
  background: #fff; border: 1px solid var(--c-border-soft);
  transition: var(--transition);
}
.usecase-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.usecase-emoji { font-size: 2.2rem; line-height: 1; margin-bottom: 14px; display: block; }
.usecase-card h3 { font-size: 1.12rem; margin-bottom: 8px; }
.usecase-card p { font-size: .94rem; color: var(--c-text-muted); }
@media (max-width: 900px) { .usecase-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 600px) { .usecase-grid { grid-template-columns: 1fr; } }

/* ---------- Testimonials ---------- */
.testimonial-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.testimonial-card {
  background: #fff; border: 1px solid var(--c-border-soft);
  border-radius: var(--radius-lg); padding: 28px 26px;
  display: flex; flex-direction: column; gap: 18px;
  position: relative;
}
.testimonial-card::before {
  content: '"'; position: absolute; top: 8px; right: 22px;
  font-size: 4rem; line-height: 1; font-family: Georgia, serif;
  color: var(--c-primary); opacity: .15;
}
.stars { display: flex; gap: 3px; color: #f6c344; font-size: 1.05rem; }
.testimonial-text { color: var(--c-text-soft); font-size: .98rem; line-height: 1.7; flex: 1; }
.testimonial-author { display: flex; align-items: center; gap: 12px; padding-top: 12px; border-top: 1px solid var(--c-border-soft); }
.testimonial-avatar {
  width: 42px; height: 42px; border-radius: 50%;
  background: var(--c-gradient); color: #fff;
  display: flex; align-items: center; justify-content: center; font-weight: 700; font-size: 1rem;
}
.testimonial-author strong { display: block; font-size: .95rem; color: var(--c-text); }
.testimonial-author small { color: var(--c-text-muted); font-size: .82rem; }
@media (max-width: 900px) { .testimonial-grid { grid-template-columns: 1fr; } }

/* ---------- CTA Banner ---------- */
.cta-banner {
  background: var(--c-gradient); border-radius: var(--radius-xl);
  padding: 64px 48px; text-align: center; color: #fff;
  position: relative; overflow: hidden;
}
.cta-banner::before, .cta-banner::after {
  content: ''; position: absolute; border-radius: 50%;
  background: rgba(255,255,255,.08);
}
.cta-banner::before { top: -120px; right: -80px; width: 320px; height: 320px; }
.cta-banner::after { bottom: -160px; left: -60px; width: 280px; height: 280px; }
.cta-banner h2 { color: #fff; margin-bottom: 14px; position: relative; }
.cta-banner p { color: rgba(255,255,255,.9); font-size: 1.1rem; margin-bottom: 28px; position: relative; }
.cta-banner .hero-actions { justify-content: center; margin-bottom: 0; position: relative; }
.cta-banner .btn-secondary { background: rgba(255,255,255,.15); color: #fff; border-color: rgba(255,255,255,.3); }
.cta-banner .btn-secondary:hover { background: rgba(255,255,255,.25); color: #fff; }
@media (max-width: 600px) { .cta-banner { padding: 44px 24px; } }

/* ---------- Footer ---------- */
.footer { background: #0f1424; color: #cbd5e0; padding: 64px 0 28px; }
.footer-grid { display: grid; grid-template-columns: 1.4fr repeat(3, 1fr); gap: 40px; margin-bottom: 44px; }
.footer-brand img { height: 36px; margin-bottom: 16px; }
.footer-brand p { color: #94a3b8; font-size: .92rem; max-width: 320px; }
.footer h4 { color: #fff; font-size: .98rem; margin-bottom: 18px; font-weight: 600; }
.footer ul li { margin-bottom: 10px; }
.footer ul li a { color: #94a3b8; font-size: .92rem; }
.footer ul li a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.08); padding-top: 24px;
  display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px;
  font-size: .86rem; color: #64748b;
}
.footer-bottom a { color: #64748b; }
.footer-bottom a:hover { color: #cbd5e0; }
@media (max-width: 800px) { .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; } }

/* ---------- Page header (subpages) ---------- */
.page-header {
  background: var(--c-bg-soft); padding: 64px 0 56px;
  position: relative; overflow: hidden; text-align: center;
}
.page-header::before {
  content: ''; position: absolute; top: -150px; left: 50%; transform: translateX(-50%);
  width: 700px; height: 400px;
  background: radial-gradient(ellipse, rgba(68,128,225,.12) 0%, transparent 60%);
}
.page-header .container { position: relative; }
.page-header .breadcrumb {
  font-size: .88rem; color: var(--c-text-muted); margin-bottom: 16px;
}
.page-header .breadcrumb a { color: var(--c-text-muted); }
.page-header .breadcrumb a:hover { color: var(--c-primary); }
.page-header h1 { margin-bottom: 14px; }
.page-header p { font-size: 1.12rem; color: var(--c-text-soft); max-width: 720px; margin: 0 auto; }

/* ---------- Download page ---------- */
.dl-platform-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; margin-bottom: 56px; }
.dl-card {
  background: #fff; border: 1px solid var(--c-border-soft);
  border-radius: var(--radius-lg); padding: 32px 28px;
  transition: var(--transition); position: relative;
}
.dl-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-3px); border-color: transparent; }
.dl-card-icon {
  width: 56px; height: 56px; border-radius: var(--radius-md);
  background: var(--c-gradient-soft); display: flex; align-items: center; justify-content: center;
  margin-bottom: 18px;
}
.dl-card-icon svg { width: 30px; height: 30px; }
.dl-card h3 { font-size: 1.22rem; margin-bottom: 6px; }
.dl-card .version { color: var(--c-text-muted); font-size: .86rem; margin-bottom: 16px; }
.dl-card ul { margin-bottom: 22px; }
.dl-card ul li { font-size: .9rem; color: var(--c-text-soft); padding: 5px 0; padding-left: 22px; position: relative; }
.dl-card ul li::before { content: '✓'; position: absolute; left: 0; color: var(--c-success); font-weight: 700; }
@media (max-width: 900px) { .dl-platform-grid { grid-template-columns: 1fr; } }

.dl-cli-block {
  background: #1a1f36; border-radius: var(--radius-lg); padding: 32px 36px;
  color: #e2e8f0; margin-bottom: 48px;
}
.dl-cli-block h3 { color: #fff; margin-bottom: 6px; }
.dl-cli-block .version { color: #94a3b8; font-size: .86rem; margin-bottom: 18px; }
.dl-cli-tabs { display: flex; gap: 8px; margin-bottom: 14px; flex-wrap: wrap; }
.dl-cli-tab {
  padding: 8px 16px; background: rgba(255,255,255,.06); color: #cbd5e0;
  border-radius: var(--radius-sm); font-size: .88rem; cursor: pointer; transition: var(--transition);
  border: 1px solid transparent;
}
.dl-cli-tab.active { background: rgba(68,128,225,.25); color: #fff; border-color: rgba(68,128,225,.4); }
.dl-cli-code {
  background: rgba(0,0,0,.3); border: 1px solid rgba(255,255,255,.08);
  border-radius: var(--radius-sm); padding: 18px 20px;
  font-family: var(--font-mono); font-size: .9rem; color: #cbd5e0;
  overflow-x: auto; white-space: pre;
}
.dl-cli-code .prompt { color: #4480e1; user-select: none; }
.dl-cli-code .comment { color: #64748b; }

/* ---------- Download modal ---------- */
.modal-overlay {
  position: fixed; inset: 0; z-index: 2000;
  background: rgba(15,20,36,.65); backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px);
  display: flex; align-items: center; justify-content: center; padding: 20px;
  opacity: 0; visibility: hidden; transition: opacity .25s ease, visibility .25s ease;
}
.modal-overlay.open { opacity: 1; visibility: visible;  left: 0;
  right: 0;
  top: 0;
  bottom: 0; }
  button { outline: none } 
.modal {
  background: #fff; border-radius: var(--radius-xl); max-width: 560px; width: 100%;
  padding: 36px 32px 28px; position: relative;
  transform: scale(.95) translateY(10px); transition: transform .25s ease;
  box-shadow: var(--shadow-xl);
}
.modal-overlay.open .modal { transform: scale(1) translateY(0); }
.modal-close {
  position: absolute; top: 16px; right: 16px;
  width: 34px; height: 34px; border: none; background: var(--c-bg-soft);
  border-radius: 50%; cursor: pointer; font-size: 1.2rem; color: var(--c-text-muted);
  display: flex; align-items: center; justify-content: center; transition: var(--transition);
}
.modal-close:hover { background: var(--c-border); color: var(--c-text); }
.modal-eyebrow {
  display: inline-block; padding: 5px 12px; background: var(--c-primary-light);
  color: var(--c-primary-dark); border-radius: 999px; font-size: .76rem; font-weight: 600;
  margin-bottom: 12px;
}
.modal h3 { font-size: 1.4rem; margin-bottom: 8px; }
.modal-subtitle { color: var(--c-text-muted); font-size: .94rem; margin-bottom: 24px; }
.qr-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-bottom: 22px; }
.qr-item { text-align: center; padding: 18px 12px; background: var(--c-bg-soft); border-radius: var(--radius-md); transition: var(--transition); }
.qr-item:hover { background: var(--c-primary-light); }
.qr-item img { width: 150px; height: 150px; margin: 0 auto 10px; display: block; }
.qr-item .platform { font-weight: 700; color: var(--c-text); font-size: .96rem; margin-bottom: 2px; }
.qr-item .desc { font-size: .78rem; color: var(--c-text-muted); }
.modal-footer { text-align: center; padding-top: 16px; border-top: 1px solid var(--c-border-soft); }
.modal-footer small { color: var(--c-text-muted); font-size: .82rem; display: block; margin-bottom: 12px; }
.modal-footer a { font-size: .9rem; font-weight: 600; }

/* ---------- Tutorial / FAQ ---------- */
.toc-grid { display: grid; grid-template-columns: 1fr 2.4fr; gap: 48px; align-items: start; }
.toc {
  position: sticky; top: 90px; background: #fff; border: 1px solid var(--c-border-soft);
  border-radius: var(--radius-lg); padding: 24px 22px;
}
.toc h4 { font-size: .82rem; text-transform: uppercase; letter-spacing: .08em; color: var(--c-text-muted); margin-bottom: 14px; }
.toc ul li { margin-bottom: 8px; }
.toc ul li a { display: block; padding: 7px 12px; color: var(--c-text-soft); font-size: .92rem; border-radius: var(--radius-sm); transition: var(--transition); }
.toc ul li a:hover, .toc ul li a.active { background: var(--c-primary-light); color: var(--c-primary-dark); font-weight: 600; }

.tutorial-step {
  background: #fff; border: 1px solid var(--c-border-soft);
  border-radius: var(--radius-lg); padding: 32px 32px; margin-bottom: 24px;
}
.tutorial-step .step-no {
  display: inline-flex; align-items: center; justify-content: center;
  width: 38px; height: 38px; border-radius: 50%;
  background: var(--c-gradient); color: #fff; font-weight: 800; font-size: 1rem;
  margin-bottom: 14px;
}
.tutorial-step h3 { margin-bottom: 12px; }
.tutorial-step p { margin-bottom: 14px; }
.tutorial-step ul { margin: 12px 0; padding-left: 4px; }
.tutorial-step ul li { padding: 6px 0 6px 26px; position: relative; color: var(--c-text-soft); }
.tutorial-step ul li::before { content: '→'; position: absolute; left: 4px; color: var(--c-primary); font-weight: 700; }
.tutorial-step code {
  background: var(--c-bg-soft); padding: 2px 7px; border-radius: 5px;
  font-size: .88em; color: var(--c-primary-dark);
}
.tutorial-step pre {
  background: #1a1f36; color: #e2e8f0; padding: 16px 20px;
  border-radius: var(--radius-sm); overflow-x: auto; margin: 14px 0;
  font-size: .88rem;
}
.tutorial-step pre code { background: none; color: inherit; padding: 0; }

@media (max-width: 900px) { .toc-grid { grid-template-columns: 1fr; } .toc { position: static; } }

/* ---------- FAQ ---------- */
.faq-list { max-width: 860px; margin: 0 auto; }
.faq-item {
  background: #fff; border: 1px solid var(--c-border-soft);
  border-radius: var(--radius-md); margin-bottom: 14px; overflow: hidden;
  transition: var(--transition);
}
.faq-item:hover { border-color: var(--c-border); }
.faq-q {
  width: 100%; text-align: left; background: none; border: none; cursor: pointer;
  padding: 20px 24px; font-size: 1.02rem; font-weight: 600; color: var(--c-text);
  display: flex; justify-content: space-between; align-items: center; gap: 16px;
  font-family: inherit;
}
.faq-q .icon { flex-shrink: 0; width: 24px; height: 24px; display: flex; align-items: center; justify-content: center; color: var(--c-primary); font-size: 1.4rem; transition: transform .25s ease; }
.faq-item.open .faq-q .icon { transform: rotate(45deg); }
.faq-a {
  max-height: 0; overflow: hidden; transition: max-height .3s ease;
  padding: 0 24px;
}
.faq-item.open .faq-a { max-height: 600px; padding-bottom: 22px; }
.faq-a p { color: var(--c-text-soft); margin-bottom: 12px; }
.faq-a p:last-child { margin-bottom: 0; }
.faq-a code { background: var(--c-bg-soft); padding: 2px 7px; border-radius: 5px; font-size: .88em; color: var(--c-primary-dark); }

/* ---------- About page ---------- */
.about-grid { display: grid; grid-template-columns: 1.2fr 1fr; gap: 56px; align-items: center; }
.about-text h2 { margin-bottom: 18px; }
.about-text p { margin-bottom: 16px; }
.about-stats { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.about-stat {
  background: #fff; border: 1px solid var(--c-border-soft);
  border-radius: var(--radius-lg); padding: 24px 22px; text-align: center;
}
.about-stat .num { font-size: 2rem; font-weight: 800; background: var(--c-gradient); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; line-height: 1; margin-bottom: 6px; }
.about-stat .label { font-size: .88rem; color: var(--c-text-muted); }
@media (max-width: 900px) { .about-grid { grid-template-columns: 1fr; } }

.timeline { max-width: 860px; margin: 0 auto; position: relative; padding-left: 32px; }
.timeline::before { content: ''; position: absolute; left: 9px; top: 6px; bottom: 6px; width: 2px; background: linear-gradient(180deg, var(--c-primary), var(--c-secondary)); }
.timeline-item { position: relative; margin-bottom: 28px; }
.timeline-item::before { content: ''; position: absolute; left: -32px; top: 6px; width: 20px; height: 20px; border-radius: 50%; background: #fff; border: 3px solid var(--c-primary); box-shadow: 0 0 0 4px rgba(68,128,225,.12); }
.timeline-item .date { font-size: .84rem; color: var(--c-primary); font-weight: 700; margin-bottom: 4px; }
.timeline-item h4 { font-size: 1.04rem; margin-bottom: 6px; }
.timeline-item p { font-size: .92rem; color: var(--c-text-muted); }

/* ---------- Comparison table ---------- */
.compare-wrap { overflow-x: auto; border-radius: var(--radius-lg); border: 1px solid var(--c-border-soft); }
.compare-table { width: 100%; border-collapse: collapse; background: #fff; min-width: 720px; }
.compare-table th, .compare-table td { padding: 14px 18px; text-align: left; border-bottom: 1px solid var(--c-border-soft); font-size: .94rem; }
.compare-table thead th { background: var(--c-bg-soft); font-weight: 700; color: var(--c-text); }
.compare-table tbody tr:hover { background: var(--c-bg-soft); }
.compare-table .yes { color: var(--c-success); font-weight: 700; }
.compare-table .no { color: var(--c-text-muted); }
.compare-table .highlight { background: rgba(68,128,225,.05); font-weight: 600; color: var(--c-primary-dark); }

/* ---------- Misc ---------- */
.tag { display: inline-block; padding: 3px 10px; background: var(--c-primary-light); color: var(--c-primary-dark); border-radius: 999px; font-size: .76rem; font-weight: 600; }
.tag-purple { background: rgba(146,109,211,.12); color: var(--c-secondary-dark); }
.tag-success { background: rgba(43,182,115,.12); color: var(--c-success); }
.tag-warning { background: rgba(246,173,85,.16); color: #c47a1a; }

.kbd { display: inline-block; padding: 2px 8px; background: var(--c-bg-soft); border: 1px solid var(--c-border); border-bottom-width: 2px; border-radius: 5px; font-family: var(--font-mono); font-size: .85em; color: var(--c-text); }

/* ---------- Back to top ---------- */
.back-top {
  position: fixed; right: 24px; bottom: 24px; z-index: 900;
  width: 46px; height: 46px; border-radius: 50%;
  background: var(--c-gradient); color: #fff; border: none; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  box-shadow: var(--shadow-lg); opacity: 0; visibility: hidden;
  transition: var(--transition); font-size: 1.2rem;
}
.back-top.show { opacity: 1; visibility: visible; }
.back-top:hover { transform: translateY(-3px); }

/* ---------- Animation on scroll ---------- */
.fade-up { opacity: 0; transform: translateY(20px); transition: opacity .6s ease, transform .6s ease; }
.fade-up.visible { opacity: 1; transform: translateY(0); }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
  html { scroll-behavior: auto; }
}