/* ============================================
   fanshichuang.com - 范士闯数学
   v3 版式：极简 · 厚重 · 大气
   配色：全白底 + 深绿色点缀
   ============================================ */

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

:root {
  --green: #1B5E20;
  --green-light: #2E7D32;
  --text-dark: #1a1a1a;
  --text-mid: #4a4a4a;
  --text-light: #787878;
  --white: #ffffff;
  --border: #e8e8e8;
  --radius: 4px;
}

html { font-size: 16px; }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Microsoft YaHei', 'PingFang SC', sans-serif;
  color: var(--text-dark);
  background: var(--white);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-family: 'Noto Serif SC', 'SimSun', 'Songti SC', serif;
  font-weight: 700;
  line-height: 1.3;
}

a { color: var(--green); text-decoration: none; }
img { max-width: 100%; height: auto; display: block; }

/* ---------- Layout ---------- */
.container { max-width: 1080px; margin: 0 auto; padding: 0 40px; }
.section { padding: 100px 0; }

.section-label {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--green);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin-bottom: 16px;
}

.section-title {
  font-size: 2rem;
  color: var(--text-dark);
  margin-bottom: 48px;
  letter-spacing: 0.04em;
}

/* ---------- Nav ---------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 100;
  padding: 18px 0;
}

.nav-inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 40px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: 'Noto Serif SC', serif;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--green);
}

.nav-logo { height: 32px; width: auto; border-radius: 4px; }

/* ---------- Hero ---------- */
.hero {
  padding: 120px 0 0;
  display: flex;
  min-height: 85vh;
  align-items: center;
}

.hero-left {
  flex: 1;
  padding: 0 60px 0 40px;
}

.hero-right {
  flex: 1;
  height: 85vh;
  overflow: hidden;
}

.hero-right img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center top;
}

.hero-name {
  font-size: 4rem;
  font-weight: 700;
  color: var(--green);
  letter-spacing: 0.06em;
  line-height: 1.15;
  margin-bottom: 4px;
}

.hero-name-sub {
  font-size: 0.42em;
  font-weight: 500;
  color: var(--text-mid);
  margin-left: 0.35em;
  letter-spacing: 0.04em;
  vertical-align: baseline;
}

.hero-sub {
  font-size: 1.15rem;
  color: var(--text-mid);
  font-weight: 400;
  margin-top: 12px;
  line-height: 1.7;
}

.hero-stats {
  display: flex;
  gap: 48px;
  margin-top: 40px;
}

.hero-stat-num {
  font-family: 'Noto Serif SC', serif;
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--green);
  line-height: 1;
}

.hero-stat-label { font-size: 0.85rem; color: var(--text-light); margin-top: 4px; }

.hero-cta {
  display: inline-block;
  margin-top: 36px;
  background: var(--green);
  color: var(--white);
  padding: 14px 36px;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius);
  letter-spacing: 0.04em;
  transition: background 0.2s;
}
.hero-cta:hover { background: var(--green-light); color: var(--white); }

/* ---------- Motto ---------- */
.motto {
  background: var(--green);
  color: var(--white);
  text-align: center;
  padding: 100px 0;
}

.motto-text {
  font-family: 'Noto Serif SC', serif;
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: 0.12em;
}

.motto-sub {
  margin-top: 18px;
  font-size: 0.95rem;
  opacity: 0.75;
  font-weight: 400;
}

/* ---------- Features (01-04) ---------- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 40px;
}

.feature-item {
  position: relative;
  padding-top: 10px;
}

.feature-num {
  font-family: 'Noto Serif SC', serif;
  font-size: 2rem;
  font-weight: 700;
  color: #d0e8d0;
  line-height: 1;
  margin-bottom: 12px;
}

.feature-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 8px;
}

.feature-desc {
  font-size: 0.9rem;
  color: var(--text-light);
  line-height: 1.6;
}

/* ---------- Do Cards ---------- */
.do-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 48px;
}

.do-card {
  border-top: 3px solid var(--green);
  padding-top: 24px;
}

.do-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--green);
  margin-bottom: 12px;
}

.do-card p {
  font-size: 0.93rem;
  color: var(--text-mid);
  line-height: 1.8;
}

/* ---------- Books ---------- */
.books-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 28px;
}

.books-grid img {
  border-radius: 6px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.08);
}

.book-label {
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-light);
  margin-top: 10px;
}

/* ---------- Timeline ---------- */
.timeline {
  max-width: 720px;
  margin: 0 auto;
}

.tl-item {
  display: flex;
  gap: 28px;
  padding-bottom: 32px;
  position: relative;
}

.tl-item::after {
  content: '';
  position: absolute;
  left: 11px;
  top: 48px;
  bottom: 0;
  width: 1px;
  background: var(--border);
}

.tl-item:last-child::after { display: none; }

.tl-dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--green);
  margin-top: 7px;
  flex-shrink: 0;
}

.tl-year {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--green);
  min-width: 80px;
  flex-shrink: 0;
}

.tl-content h4 { font-size: 1rem; font-weight: 600; margin-bottom: 2px; }
.tl-content p { font-size: 0.88rem; color: var(--text-light); line-height: 1.6; }

/* ---------- Awards ---------- */
.awards-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  text-align: center;
}

.award-card img {
  max-height: 220px;
  margin: 0 auto 16px;
  border-radius: 6px;
}

.award-card h4 { font-size: 0.95rem; margin-bottom: 4px; }
.award-card p { font-size: 0.83rem; color: var(--text-light); }

/* ---------- Reach ---------- */
.reach {
  text-align: center;
}

.reach-text {
  font-family: 'Noto Serif SC', serif;
  font-size: 1.5rem;
  color: var(--text-dark);
  line-height: 1.8;
  letter-spacing: 0.04em;
}

.reach-text strong { color: var(--green); }

.reach-cities {
  margin-top: 20px;
  font-size: 0.9rem;
  color: var(--text-light);
}

/* ---------- QR Codes ---------- */
.qr-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  text-align: center;
}

.qr-item img {
  width: 140px;
  height: 140px;
  margin: 0 auto 14px;
  border-radius: 6px;
}

.qr-item h4 { font-size: 1rem; margin-bottom: 4px; }
.qr-item p { font-size: 0.83rem; color: var(--text-light); }

/* ---------- CTA ---------- */
.cta-section {
  text-align: center;
}

.cta-qr {
  width: 200px;
  height: 200px;
  margin: 0 auto 16px;
  border-radius: 6px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.08);
}

.cta-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.cta-desc { color: var(--text-light); margin-bottom: 32px; }

/* ---------- Footer ---------- */
.footer {
  background: #111;
  color: #777;
  padding: 40px 0 32px;
  text-align: center;
  font-size: 0.85rem;
}

.footer a { color: #999; }
.footer a:hover { color: var(--white); }

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  .hero {
    flex-direction: column-reverse;
    min-height: auto;
    padding-top: 80px;
  }

  .hero-left { padding: 40px 24px; text-align: center; }
  .hero-right { height: 55vh; width: 100%; }
  .hero-name { font-size: 2.5rem; }
  .hero-stats { gap: 28px; flex-wrap: wrap; justify-content: center; }
  .hero-stat-num { font-size: 1.8rem; }

  .section-title { font-size: 1.5rem; }
  .motto-text { font-size: 1.35rem; }
  .reach-text { font-size: 1.2rem; }
  .cta-title { font-size: 1.3rem; }

  .features-grid, .do-grid, .books-grid, .awards-grid, .qr-grid {
    grid-template-columns: 1fr 1fr;
  }
  .qr-item img { width: 120px; height: 120px; }
  .cta-qr { width: 180px; height: 180px; }

  .section { padding: 64px 0; }
  .container { padding: 0 24px; }
  .nav-inner { padding: 0 24px; }

  .do-grid { gap: 32px; }
  .features-grid { gap: 24px; }
}

@media (max-width: 480px) {
  .hero { padding-top: 72px; }
  .hero-left { padding: 32px 20px; }
  .hero-right { height: 45vh; }
  .hero-name { font-size: 2rem; }
  .hero-stat-num { font-size: 1.5rem; }
  .hero-stats { gap: 20px; }

  .section-title { font-size: 1.3rem; }
  .motto-text { font-size: 1.15rem; letter-spacing: 0.08em; }
  .reach-text { font-size: 1.05rem; }
  .cta-title { font-size: 1.15rem; }

  .features-grid, .books-grid, .awards-grid, .qr-grid {
    grid-template-columns: 1fr;
  }
  .do-grid { grid-template-columns: 1fr; }

  .tl-item { gap: 14px; }
  .tl-year { min-width: 50px; font-size: 0.78rem; }
  .tl-content h4 { font-size: 0.93rem; }

  .container { padding: 0 20px; }
  .nav-inner { padding: 0 20px; }
  .section { padding: 48px 0; }

  .qr-item img { width: 100px; height: 100px; }
  .cta-qr { width: 160px; height: 160px; }

  .motto { padding: 64px 0; }
}