/* ========================================
   撤三答辩知识库 - 主样式表
   设计方向：专业法律科技感，极简无框架
   ======================================== */

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

:root {
  --primary: #1a56db;
  --primary-dark: #1e40af;
  --primary-light: #dbeafe;
  --green: #059669;
  --green-light: #d1fae5;
  --amber: #d97706;
  --amber-light: #fef3c7;
  --red: #dc2626;
  --red-light: #fee2e2;
  --dark: #111827;
  --body: #374151;
  --muted: #6b7280;
  --light: #f9fafb;
  --white: #ffffff;
  --border: #e5e7eb;
  --radius: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.06);
  --shadow-md: 0 4px 6px rgba(0,0,0,.07), 0 2px 4px rgba(0,0,0,.06);
  --shadow-lg: 0 10px 15px rgba(0,0,0,.07), 0 4px 6px rgba(0,0,0,.05);
  --max-width: 960px;
}

html { font-size: 16px; scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--body);
  background: var(--light);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--primary); text-decoration: none; transition: color .2s; }
a:hover { color: var(--primary-dark); text-decoration: underline; }

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

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 20px; }

/* === Header === */
.site-header {
  background: var(--white);
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 100;
  backdrop-filter: blur(8px);
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  max-width: var(--max-width); margin: 0 auto; padding: 0 20px; height: 60px;
}
.site-logo {
  font-size: 1.1rem; font-weight: 700; color: var(--dark);
  display: flex; align-items: center; gap: 8px;
}
.site-logo .logo-icon { font-size: 1.4rem; }
.site-logo:hover { text-decoration: none; color: var(--primary); }

.nav-links { display: flex; gap: 24px; list-style: none; }
.nav-links a { font-size: .9rem; color: var(--muted); font-weight: 500; padding: 4px 0; border-bottom: 2px solid transparent; }
.nav-links a:hover, .nav-links a.active { color: var(--primary); text-decoration: none; border-bottom-color: var(--primary); }

/* Mobile nav */
.nav-toggle { display: none; background: none; border: none; font-size: 1.5rem; cursor: pointer; color: var(--dark); padding: 8px; }
@media (max-width: 768px) {
  .nav-links { display: none; position: absolute; top: 60px; left: 0; right: 0; background: var(--white); flex-direction: column; padding: 16px 20px; gap: 12px; border-bottom: 1px solid var(--border); box-shadow: var(--shadow-md); }
  .nav-links.open { display: flex; }
  .nav-toggle { display: block; }
}

/* === Hero === */
.hero {
  background: linear-gradient(135deg, #1e40af 0%, #1a56db 50%, #2563eb 100%);
  color: var(--white); padding: 80px 20px 64px; text-align: center;
  position: relative; overflow: hidden;
}
.hero::after {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(circle at 20% 50%, rgba(255,255,255,.08) 0%, transparent 60%);
}
.hero .container { position: relative; z-index: 1; }
.hero h1 { font-size: 2.2rem; font-weight: 800; margin-bottom: 16px; line-height: 1.3; letter-spacing: -.02em; }
.hero p { font-size: 1.1rem; opacity: .9; max-width: 640px; margin: 0 auto 32px; line-height: 1.8; }

.hero-cta {
  display: inline-flex; align-items: center; gap: 10px;
  background: var(--white); color: var(--primary);
  padding: 14px 32px; border-radius: 50px; font-size: 1rem; font-weight: 700;
  box-shadow: 0 8px 24px rgba(0,0,0,.25); transition: all .3s;
}
.hero-cta:hover { transform: translateY(-2px); box-shadow: 0 12px 32px rgba(0,0,0,.3); text-decoration: none; color: var(--primary-dark); }

.hero-stats { display: flex; justify-content: center; gap: 48px; margin-top: 48px; flex-wrap: wrap; }
.hero-stat { text-align: center; }
.hero-stat .num { font-size: 1.8rem; font-weight: 800; }
.hero-stat .label { font-size: .85rem; opacity: .75; margin-top: 4px; }

@media (max-width: 640px) {
  .hero { padding: 48px 20px 40px; }
  .hero h1 { font-size: 1.6rem; }
  .hero p { font-size: .95rem; }
  .hero-stats { gap: 24px; }
}

/* === Section === */
.section { padding: 64px 20px; }
.section-alt { background: var(--white); }
.section-title { font-size: 1.5rem; font-weight: 700; color: var(--dark); margin-bottom: 12px; text-align: center; }
.section-desc { color: var(--muted); text-align: center; max-width: 560px; margin: 0 auto 40px; font-size: .95rem; }

/* === Feature Cards === */
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 24px; }
.card {
  background: var(--white); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 28px 24px; transition: all .3s; box-shadow: var(--shadow);
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); border-color: var(--primary-light); }
.card-icon { font-size: 2rem; margin-bottom: 16px; display: block; }
.card h3 { font-size: 1.1rem; color: var(--dark); margin-bottom: 8px; }
.card p { font-size: .9rem; color: var(--muted); line-height: 1.7; }
.card-link { display: inline-block; margin-top: 12px; font-size: .9rem; font-weight: 600; }

/* === FAQ Preview === */
.faq-list { max-width: 720px; margin: 0 auto; }
.faq-item { background: var(--white); border: 1px solid var(--border); border-radius: var(--radius); margin-bottom: 12px; overflow: hidden; }
.faq-question {
  width: 100%; background: none; border: none; text-align: left;
  padding: 18px 20px; font-size: .95rem; font-weight: 600; color: var(--dark);
  cursor: pointer; display: flex; justify-content: space-between; align-items: center; gap: 12px;
}
.faq-question::after { content: '+'; font-size: 1.2rem; color: var(--muted); flex-shrink: 0; transition: transform .2s; }
.faq-item.open .faq-question::after { transform: rotate(45deg); }
.faq-answer { padding: 0 20px 18px; font-size: .9rem; color: var(--body); line-height: 1.8; display: none; }
.faq-item.open .faq-answer { display: block; }
.faq-more { text-align: center; margin-top: 24px; }

/* === Knowledge Page === */
.knowledge-page { max-width: 760px; margin: 0 auto; }
.knowledge-page article { background: var(--white); border: 1px solid var(--border); border-radius: var(--radius); padding: 40px; box-shadow: var(--shadow); }
.knowledge-page h1 { font-size: 1.8rem; color: var(--dark); margin-bottom: 8px; }
.knowledge-page .meta { color: var(--muted); font-size: .85rem; margin-bottom: 32px; }
.knowledge-page h2 { font-size: 1.25rem; color: var(--dark); margin: 36px 0 12px; padding-top: 20px; border-top: 1px solid var(--border); }
.knowledge-page h3 { font-size: 1.05rem; color: var(--dark); margin: 24px 0 8px; }
.knowledge-page p { margin-bottom: 14px; }
.knowledge-page ul, .knowledge-page ol { margin: 0 0 14px 20px; }
.knowledge-page li { margin-bottom: 6px; }

/* Info boxes */
.info-box {
  padding: 16px 20px; border-radius: var(--radius); margin: 20px 0; font-size: .9rem; line-height: 1.7;
}
.info-box.warning { background: var(--amber-light); border-left: 4px solid var(--amber); }
.info-box.danger { background: var(--red-light); border-left: 4px solid var(--red); }
.info-box.success { background: var(--green-light); border-left: 4px solid var(--green); }
.info-box.info { background: var(--primary-light); border-left: 4px solid var(--primary); }
.info-box strong { display: block; margin-bottom: 4px; color: var(--dark); }

/* Timeline */
.timeline { position: relative; padding: 20px 0; margin: 24px 0; }
.timeline::before { content: ''; position: absolute; left: 16px; top: 0; bottom: 0; width: 2px; background: var(--border); }
.timeline-item { position: relative; padding-left: 48px; margin-bottom: 28px; }
.timeline-item:last-child { margin-bottom: 0; }
.timeline-dot { position: absolute; left: 8px; top: 4px; width: 18px; height: 18px; border-radius: 50%; background: var(--primary); border: 3px solid var(--primary-light); }
.timeline-item h3 { margin: 0 0 4px; font-size: 1rem; color: var(--dark); }
.timeline-item p { font-size: .9rem; color: var(--muted); margin: 0; }

@media (max-width: 640px) {
  .knowledge-page article { padding: 24px 16px; }
  .knowledge-page h1 { font-size: 1.4rem; }
}

/* === Process Steps === */
.process-steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 16px; margin: 24px 0; }
.process-step {
  background: var(--white); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 20px; text-align: center; position: relative;
}
.process-step .step-num {
  width: 36px; height: 36px; border-radius: 50%; background: var(--primary);
  color: var(--white); display: inline-flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: .9rem; margin-bottom: 10px;
}
.process-step h4 { font-size: .9rem; color: var(--dark); margin-bottom: 4px; }
.process-step p { font-size: .8rem; color: var(--muted); margin: 0; }

/* === Calculator === */
.calculator { max-width: 480px; margin: 0 auto; }
.calc-card { background: var(--white); border: 1px solid var(--border); border-radius: var(--radius); padding: 32px; box-shadow: var(--shadow); }
.calc-field { margin-bottom: 20px; }
.calc-field label { display: block; font-size: .9rem; font-weight: 600; color: var(--dark); margin-bottom: 8px; }
.calc-field input { width: 100%; padding: 12px 16px; border: 1px solid var(--border); border-radius: var(--radius); font-size: .95rem; color: var(--dark); transition: border-color .2s; }
.calc-field input:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-light); }
.calc-result { background: var(--light); border-radius: var(--radius); padding: 20px; margin-top: 20px; }
.calc-result .deadline-date { font-size: 1.3rem; font-weight: 700; color: var(--dark); }
.calc-result .remaining { margin-top: 8px; font-size: .9rem; }
.calc-result .remaining.urgent { color: var(--red); font-weight: 600; }
.calc-result .remaining.warning { color: var(--amber); font-weight: 600; }
.calc-result .remaining.safe { color: var(--green); }
.btn { display: inline-block; padding: 12px 24px; background: var(--primary); color: var(--white); border: none; border-radius: var(--radius); font-size: .95rem; font-weight: 600; cursor: pointer; transition: all .2s; }
.btn:hover { background: var(--primary-dark); transform: translateY(-1px); }
.btn-block { display: block; width: 100%; text-align: center; }

/* === Breadcrumb === */
.breadcrumb { padding: 16px 0; font-size: .85rem; color: var(--muted); }
.breadcrumb a { color: var(--muted); }
.breadcrumb span { color: var(--dark); }

/* === Footer === */
.site-footer {
  background: var(--dark); color: #9ca3af; padding: 48px 20px 32px;
  font-size: .85rem; line-height: 1.8;
}
.footer-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 32px; margin-bottom: 32px; }
.footer-col h4 { color: var(--white); font-size: .95rem; margin-bottom: 12px; }
.footer-col a { color: #9ca3af; display: block; padding: 2px 0; }
.footer-col a:hover { color: var(--white); text-decoration: none; }
.footer-bottom { border-top: 1px solid #374151; padding-top: 20px; text-align: center; font-size: .8rem; }
.footer-bottom a { color: #9ca3af; margin: 0 8px; }

/* === WeChat CTA Banner === */
.wechat-cta {
  background: linear-gradient(135deg, #07c160 0%, #06ad56 100%);
  color: var(--white); padding: 28px 24px; border-radius: var(--radius);
  text-align: center; margin: 40px 0;
}
.wechat-cta h3 { font-size: 1.1rem; margin-bottom: 8px; }
.wechat-cta p { font-size: .9rem; opacity: .9; margin-bottom: 16px; }
.wechat-cta .search-hint {
  display: inline-block; background: rgba(255,255,255,.2); padding: 10px 24px;
  border-radius: 50px; font-size: 1rem; font-weight: 700; letter-spacing: .05em;
}

/* === Back to top === */
.back-to-top {
  position: fixed; bottom: 24px; right: 24px; z-index: 99;
  background: var(--primary); color: var(--white); border: none;
  width: 44px; height: 44px; border-radius: 50%; font-size: 1.2rem;
  cursor: pointer; box-shadow: var(--shadow-md); transition: all .3s;
  display: none; align-items: center; justify-content: center;
}
.back-to-top.visible { display: flex; }
.back-to-top:hover { background: var(--primary-dark); transform: translateY(-2px); }

/* === Breadcrumb Schema (hidden) === */
.schema-hidden { display: none; }

/* === Print === */
@media print {
  .site-header, .site-footer, .wechat-cta, .back-to-top, .hero { display: none; }
  .knowledge-page article { box-shadow: none; border: none; padding: 0; }
}