/* 智学伴营销页 · 深墨青绿 + 翡翠 + 暖金 — CSS Variables + BEM,区块前缀隔离 */
:root {
  --bg: #0a1712;
  --bg-soft: #0f1f19;
  --card: #142a22;
  --line: #20402f;
  --text: #eaf6ef;
  --muted: #93b3a4;
  --accent: #35d0a5;
  --accent-soft: #35d0a522;
  --accent-warm: #f0b429;
  --radius: 16px;
  --gap: 24px;
  --font: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background:
    radial-gradient(ellipse 80% 50% at 50% -10%, #122a1f66, transparent),
    var(--bg);
  color: var(--text);
  line-height: 1.75;
  font-size: 1rem;
  -webkit-font-smoothing: antialiased;
}

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

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── 区块骨架 ─────────────────────────────── */
.sec {
  max-width: 1080px;
  margin: 0 auto;
  padding: 96px 24px;
}

.sec__title {
  font-size: clamp(1.5rem, 3.2vw, 2.25rem);
  line-height: 1.3;
  margin-bottom: 48px;
  text-align: center;
}

/* ── 入场动效(渐进增强,无 JS 直显) ────────── */
.js .reveal { opacity: 0; transform: translateY(12px); transition: opacity .5s, transform .5s; }
.reveal.is-in { opacity: 1; transform: none; }

/* ── 截图放大 ─────────────────────────────── */
.zoomable { cursor: zoom-in; }

.img-zoom-mask {
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: rgba(4, 12, 9, .92);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 32px;
  cursor: zoom-out;
}
.img-zoom-mask img { max-width: 100%; max-height: 100%; border-radius: var(--radius); }
.img-zoom-mask[hidden] { display: none; }

/* ── 导航 ─────────────────────────────────── */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--gap);
  max-width: 1080px;
  margin: 0 auto;
  padding: 14px 24px;
  background: rgba(10, 23, 18, .85);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}

.nav__brand {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text);
}
.nav__brand:hover { text-decoration: none; color: var(--accent); }

.nav__links { display: flex; gap: 24px; }
.nav__links a { color: var(--muted); font-size: .9375rem; }
.nav__links a:hover { color: var(--text); text-decoration: none; }

.nav__cta {
  background: var(--accent);
  color: #06231a;
  font-weight: 600;
  font-size: .9375rem;
  padding: 8px 18px;
  border-radius: 999px;
  white-space: nowrap;
}
.nav__cta:hover { text-decoration: none; filter: brightness(1.08); }

/* ── 1 · Hero ─────────────────────────────── */
.sec--hero {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
  gap: 48px;
  align-items: center;
  padding-top: 72px;
  padding-bottom: 72px;
}

.sec--hero h1 {
  font-size: clamp(2.25rem, 5.5vw, 4rem);
  line-height: 1.18;
  margin-bottom: 20px;
  letter-spacing: .01em;
}

.hero-key {
  font-style: normal;
  background: linear-gradient(120deg, #35d0a5, #6ee7c5);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-sub { color: var(--muted); font-size: 1.125rem; margin-bottom: 24px; }

.hero-tags { display: flex; flex-wrap: wrap; gap: 12px; list-style: none; margin-bottom: 32px; }

.tag {
  border: 1px solid var(--line);
  background: var(--bg-soft);
  color: var(--text);
  font-size: .875rem;
  padding: 6px 14px;
  border-radius: 999px;
  white-space: nowrap;
}

.hero-cta { font-size: 1.0625rem; }

.cta-wechat { color: var(--accent); font-weight: 700; }

.hero-shot img {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--card);
  box-shadow: 0 24px 64px #00000066;
}

/* ── 2 · 痛点 ─────────────────────────────── */
.sec--pain .pain-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--gap);
}

.pain-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 32px;
}

.pain-card h3 { font-size: 1.25rem; margin-bottom: 12px; }
.pain-card p { color: var(--muted); }

/* ── 3 · 三步流程 ─────────────────────────── */
.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--gap);
  list-style: none;
  counter-reset: step;
  margin-bottom: 48px;
}

.step {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px;
}

.step__no {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 700;
  margin-bottom: 16px;
}

.step h3 { font-size: 1.125rem; margin-bottom: 8px; }
.step p { color: var(--muted); font-size: .9375rem; }

.how-shot img {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--card);
}

/* ── 4 · Bento 功能矩阵 ───────────────────── */
.bento {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--gap);
}

.bento__cell {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px;
}

.bento__cell--wide { grid-column: span 2; }

.bento__cell h3 { font-size: 1.0625rem; margin-bottom: 8px; }
.bento__cell p { color: var(--muted); font-size: .9375rem; }

/* ── 5 · 场景人群 ─────────────────────────── */
.scene-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--gap);
}

.scene-card {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px;
}

.scene-card h3 { font-size: 1.125rem; margin-bottom: 8px; color: var(--accent); }
.scene-card p { color: var(--muted); font-size: .9375rem; }

/* ── 6 · 信任区 ───────────────────────────── */
.sec--trust .trust-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--gap);
  list-style: none;
  margin-bottom: 48px;
}

.trust-item {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px;
  text-align: center;
}

.trust-item h3 { font-size: 1.0625rem; margin-bottom: 8px; }
.trust-item p { color: var(--muted); font-size: .9375rem; }

.trust-shots {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--gap);
  align-items: start;
  margin-bottom: 48px;
}

.trust-shots figure:first-child { max-width: 300px; margin: 0 auto; }

.trust-shots img {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--card);
}

.trust-cta { text-align: center; font-size: 1.0625rem; }

/* ── 7 · 定价(sec--pricing 整块可删) ─────── */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--gap);
  align-items: stretch;
}

.price-card {
  position: relative;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
}

.price-card--free { opacity: .82; }

.price-card--hot {
  border-color: var(--accent);
  transform: translateY(-6px);
  box-shadow: 0 16px 48px #35d0a522;
}

.price-card__ribbon {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent-warm);
  color: #241703;
  font-size: .8125rem;
  font-weight: 700;
  padding: 2px 14px;
  border-radius: 999px;
  white-space: nowrap;
}

.price-card__name { font-size: 1.0625rem; color: var(--muted); margin-bottom: 8px; }

.price-card__price {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 4px;
}

.price-card__unit { font-size: .9375rem; font-weight: 400; color: var(--muted); }

.price-card__badge {
  display: inline-block;
  font-size: .8125rem;
  color: var(--accent);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 1px 12px;
  margin-bottom: 12px;
  align-self: flex-start;
}

.price-card__desc { color: var(--muted); font-size: .875rem; margin-bottom: 12px; }

.price-card__list {
  list-style: none;
  margin-top: 8px;
}

.price-card__list li {
  color: var(--muted);
  font-size: .9375rem;
  padding: 4px 0 4px 20px;
  position: relative;
}

.price-card__list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--accent);
}

.pricing-note {
  text-align: center;
  color: var(--muted);
  font-size: .9375rem;
  margin-top: 32px;
}

/* ── 8 · FAQ ──────────────────────────────── */
.faq-item {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px 28px;
  max-width: 760px;
  margin: 0 auto var(--gap);
}

.faq-item summary {
  cursor: pointer;
  font-weight: 600;
  list-style-position: inside;
}

.faq-item[open] summary { color: var(--accent); margin-bottom: 8px; }
.faq-item p { color: var(--muted); }

/* ── 9 · 尾 CTA ───────────────────────────── */
.sec--cta { text-align: center; }

.sec--cta h2 { font-size: clamp(1.5rem, 3.2vw, 2.25rem); margin-bottom: 12px; }

.cta-sub { color: var(--muted); margin-bottom: 32px; }

.cta-qr {
  display: inline-block;
  background: #fff;
  border-radius: var(--radius);
  padding: 12px;
  margin-bottom: 24px;
}
.cta-qr img { width: 200px; height: 200px; }

.cta-wechat-big { font-size: 1.25rem; }

/* ── 页脚 ─────────────────────────────────── */
.footer {
  border-top: 1px solid var(--line);
  background: var(--bg-soft);
  text-align: center;
  color: var(--muted);
  font-size: .875rem;
  padding: 28px 24px;
}
.footer a { color: var(--muted); }
.footer a:hover { color: var(--text); }

/* ── 响应式 ───────────────────────────────── */
@media (max-width: 900px) {
  .sec { padding: 64px 24px; }

  .bento { grid-template-columns: repeat(2, 1fr); }
  .bento__cell--wide { grid-column: span 2; }

  .scene-grid { grid-template-columns: repeat(2, 1fr); }

  .sec--pain .pain-grid { grid-template-columns: 1fr; }

  .pricing-grid { grid-template-columns: 1fr; }
  .price-card--hot { transform: none; }

  .trust-shots { grid-template-columns: repeat(2, 1fr); }
  .trust-shots figure:first-child { grid-column: span 2; max-width: 300px; }

  .sec--hero { grid-template-columns: 1fr; }
  .hero-shot { max-width: 340px; }
}

@media (max-width: 600px) {
  .sec { padding: 56px 16px; }

  .nav__links { display: none; }

  .sec--hero { padding-top: 40px; }
  .hero-shot { max-width: 260px; margin: 0 auto; }

  .steps { grid-template-columns: 1fr; }

  .bento { grid-template-columns: 1fr; }
  .bento__cell--wide { grid-column: span 1; }

  .scene-grid { grid-template-columns: 1fr; }

  .sec--trust .trust-grid { grid-template-columns: 1fr; }

  .trust-shots { grid-template-columns: 1fr; }
  .trust-shots figure:first-child { grid-column: span 1; }
}

/* ── 动效敏感用户:全部禁用 ────────────────── */
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
  .reveal { opacity: 1; transform: none; }
}