/* ============================================================
   大字白板 落地页样式
   风格：温暖关怀 · 落地朴实 · 大字易读 · 移动优先响应式
   ============================================================ */

:root {
  --bg: #fbf6ef;
  --bg-soft: #f5ebdd;
  --surface: #ffffff;
  --ink: #2c2419;         /* 正文深棕，比纯黑柔和 */
  --ink-soft: #6b5f4e;
  --brand: #e8894a;       /* 暖橙 */
  --brand-dark: #cf6f30;
  --brand-tint: #fbe7d2;
  --line: #ece0cf;
  --radius: 18px;
  --radius-lg: 28px;
  --shadow: 0 10px 30px rgba(120, 84, 40, 0.08);
  --shadow-soft: 0 4px 16px rgba(120, 84, 40, 0.06);
  --maxw: 1120px;
  --step: clamp(1rem, 0.6rem + 1.4vw, 1.375rem); /* 基准正文，偏大 */
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  font-size: var(--step);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

h1, h2, h3 { line-height: 1.25; color: var(--ink); margin: 0 0 .5em; }
h1 { font-size: clamp(2.25rem, 1.3rem + 4.4vw, 4rem); font-weight: 900; letter-spacing: -0.01em; }
h2 { font-size: clamp(1.7rem, 1.1rem + 2.6vw, 2.6rem); font-weight: 800; }
h3 { font-size: clamp(1.2rem, 1rem + 1vw, 1.5rem); font-weight: 700; }
p { margin: 0 0 1rem; }

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

.container { width: 100%; max-width: var(--maxw); margin-inline: auto; padding-inline: clamp(1.1rem, 4vw, 2.5rem); }

.skip-link {
  position: absolute; left: -9999px; top: 0;
  background: var(--brand); color: #fff; padding: .75rem 1.2rem; border-radius: 0 0 12px 0; z-index: 100;
}
.skip-link:focus { left: 0; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: .85rem 1.6rem; border-radius: 999px; font-weight: 700;
  font-size: 1.05rem; line-height: 1; cursor: pointer;
  transition: transform .15s ease, box-shadow .2s ease, background .2s ease;
  text-decoration: none; min-height: 52px;
}
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--brand); color: #fff; box-shadow: var(--shadow-soft); }
.btn-primary:hover { background: var(--brand-dark); transform: translateY(-2px); }
.btn-ghost { background: transparent; color: var(--brand-dark); border: 2px solid var(--brand); }
.btn-ghost:hover { background: var(--brand-tint); }
.btn-small { background: var(--brand); color: #fff; padding: .6rem 1.15rem; min-height: 44px; font-size: 1rem; }
.btn-small:hover { background: var(--brand-dark); }

/* ---------- 头部 ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(251, 246, 239, 0.9);
  backdrop-filter: saturate(1.2) blur(8px);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; gap: 1rem; min-height: 68px; }
.brand { display: inline-flex; align-items: center; gap: .5rem; font-weight: 900; font-size: 1.25rem; color: var(--ink); }
.brand:hover { text-decoration: none; }
.site-nav { display: none; gap: 1.6rem; margin-left: auto; }
.site-nav a { color: var(--ink-soft); font-weight: 600; }
.site-nav a:hover { color: var(--brand-dark); text-decoration: none; }
.header-inner .btn-small { margin-left: auto; }
.site-nav + .btn-small { margin-left: 0; }

/* ---------- Hero ---------- */
.hero { padding: clamp(2.5rem, 6vw, 5rem) 0 clamp(2rem, 5vw, 4rem); }
.hero-inner { display: grid; gap: clamp(2rem, 5vw, 3.5rem); align-items: center; }
.eyebrow {
  display: inline-block; background: var(--brand-tint); color: var(--brand-dark);
  font-weight: 700; font-size: .95rem; padding: .35rem .9rem; border-radius: 999px; margin-bottom: 1rem;
}
.hero-copy .lead { font-size: clamp(1.1rem, .9rem + .8vw, 1.4rem); color: var(--ink-soft); max-width: 34ch; }
.hero-scan {
  display: flex; align-items: center; gap: 1.2rem; flex-wrap: wrap;
  margin: 1.8rem 0 0; padding: 1.1rem 1.3rem;
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); box-shadow: var(--shadow-soft);
}
.hero-scan-qr {
  width: 140px; height: 140px; flex: none;
  border-radius: 12px; background: #fff; padding: .4rem; border: 1px solid var(--line);
}
.hero-scan-text { min-width: 12rem; flex: 1; }
.hero-scan-text strong { display: block; font-size: 1.2rem; color: var(--ink); }
.hero-scan-text p { margin: .35rem 0 .8rem; color: var(--ink-soft); font-size: 1rem; }
.hero-media img {
  width: 100%; border-radius: var(--radius-lg);
  box-shadow: var(--shadow); border: 1px solid var(--line);
}

/* ---------- 通用区块 ---------- */
.section { padding: clamp(3rem, 7vw, 5.5rem) 0; }
.section-soft { background: var(--bg-soft); }
.section-head { max-width: 52ch; margin-bottom: clamp(1.8rem, 4vw, 2.8rem); }
.section-sub { color: var(--ink-soft); font-size: clamp(1.05rem, .95rem + .5vw, 1.25rem); margin: 0; }

.card {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: clamp(1.4rem, 3vw, 2rem);
  box-shadow: var(--shadow-soft);
}

/* 痛点 */
.pain-grid, .feature-grid, .mode-grid { display: grid; gap: 1.2rem; list-style: none; padding: 0; margin: 0; }
.pain-grid h3, .feature h3 { margin-bottom: .3rem; }
.pain-grid p, .feature p { color: var(--ink-soft); margin: 0; }

/* 功能 */
.feature-icon {
  width: 60px; height: 60px; border-radius: 16px; background: var(--brand-tint);
  color: var(--brand-dark); display: grid; place-items: center;
  font-size: 1.8rem; font-weight: 900; margin-bottom: 1rem;
}

/* 模式 */
.mode { padding: 0; overflow: hidden; }
.mode img { width: 100%; background: var(--bg-soft); padding: 1.4rem; object-fit: contain; max-height: 300px; }
.mode figcaption { padding: 1.2rem clamp(1.2rem, 3vw, 1.6rem) 1.6rem; }
.mode h3 { margin-bottom: .3rem; }
.mode p { color: var(--ink-soft); margin: 0; }

/* 步骤 */
.steps { list-style: none; padding: 0; margin: 0; display: grid; gap: 1.2rem; counter-reset: step; }
.steps li { display: flex; gap: 1.1rem; align-items: flex-start; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.3rem 1.5rem; box-shadow: var(--shadow-soft); }
.step-num {
  flex: none; width: 46px; height: 46px; border-radius: 50%;
  background: var(--brand); color: #fff; font-weight: 900; font-size: 1.3rem;
  display: grid; place-items: center;
}
.steps h3 { margin: 0 0 .2rem; }
.steps p { margin: 0; color: var(--ink-soft); }

/* CTA */
.section-cta { background: linear-gradient(135deg, var(--brand-tint), #f7dcbc); }
.cta-inner { display: grid; gap: 2rem; align-items: center; }
.cta-copy h2 { margin-bottom: .5rem; }
.cta-copy p { color: var(--ink-soft); margin: 0; font-size: 1.15rem; }
.cta-qr { justify-self: start; text-align: center; }
.cta-qr img { width: min(260px, 70vw); border-radius: var(--radius); background: #fff; padding: .8rem; box-shadow: var(--shadow); }
.cta-qr p { margin: .8rem 0 0; font-weight: 700; color: var(--brand-dark); }

/* FAQ */
.faq-list { display: grid; gap: .9rem; max-width: 60ch; }
.faq-item { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 0 1.4rem; box-shadow: var(--shadow-soft); }
.faq-item summary {
  cursor: pointer; font-weight: 700; font-size: 1.15rem; padding: 1.1rem 0;
  list-style: none; display: flex; justify-content: space-between; align-items: center; gap: 1rem;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: "+"; color: var(--brand); font-size: 1.6rem; font-weight: 400; line-height: 1; transition: transform .2s ease; }
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item p { margin: 0 0 1.1rem; color: var(--ink-soft); }

/* 页脚 */
.site-footer { background: #2c2419; color: #e9ddca; padding: clamp(2.2rem, 5vw, 3rem) 0 1.5rem; }
.footer-inner { display: flex; flex-wrap: wrap; gap: 1.5rem 2rem; align-items: center; justify-content: space-between; }
.footer-brand { display: flex; align-items: center; gap: .9rem; }
.footer-brand strong { font-size: 1.2rem; color: #fff; }
.footer-brand p { margin: .2rem 0 0; color: #bcae97; }
.footer-qr { width: 96px; border-radius: 12px; background: #fff; padding: .4rem; }
.footer-meta { border-top: 1px solid rgba(255,255,255,.12); margin-top: 1.5rem; padding-top: 1.2rem; }
.footer-meta p { margin: 0; color: #9c8f79; font-size: .95rem; }

/* ---------- 滚动进入动效（克制） ---------- */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .6s ease, transform .6s ease; }
.reveal.is-visible { opacity: 1; transform: none; }
/* 同组元素轻微错峰 */
.pain-grid .reveal:nth-child(2), .feature-grid .reveal:nth-child(2), .mode-grid .reveal:nth-child(2), .steps .reveal:nth-child(2) { transition-delay: .08s; }
.pain-grid .reveal:nth-child(3), .feature-grid .reveal:nth-child(3), .mode-grid .reveal:nth-child(3), .steps .reveal:nth-child(3) { transition-delay: .16s; }

/* ---------- 响应式断点 ---------- */
@media (min-width: 640px) {
  .pain-grid { grid-template-columns: repeat(3, 1fr); }
  .steps { grid-template-columns: repeat(3, 1fr); }
}
@media (min-width: 768px) {
  .site-nav { display: flex; }
  .header-inner .btn-small { margin-left: 0; }
  .feature-grid { grid-template-columns: repeat(3, 1fr); }
  .mode-grid { grid-template-columns: repeat(3, 1fr); }
  .cta-inner { grid-template-columns: 1.4fr 1fr; }
  .cta-qr { justify-self: end; }
}
@media (min-width: 1024px) {
  .hero-inner { grid-template-columns: 1.05fr 1fr; }
}

/* ---------- 尊重减少动态效果 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .btn { transition: none; }
}