:root {
  --bg: #f5f7f4;
  --surface: #ffffff;
  --surface-soft: #edf5ee;
  --ink: #18211a;
  --muted: #637064;
  --line: #dce7dc;
  --brand: #17894d;
  --brand-dark: #0d5f35;
  --warning: #f2b84b;
  --shadow: 0 14px 34px rgba(28, 89, 54, 0.1);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background:
    linear-gradient(180deg, rgba(23, 137, 77, 0.13), transparent 280px),
    var(--bg);
  color: var(--ink);
  font-family: "Microsoft YaHei", "Noto Sans SC", sans-serif;
  line-height: 1.72;
}

img {
  max-width: 100%;
}

a {
  color: inherit;
  text-decoration: none;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

.page-shell {
  width: min(100%, 540px);
  min-height: 100vh;
  margin: 0 auto;
  padding: 18px 14px 44px;
}

.guide-header {
  padding: 22px 2px 12px;
}

.eyebrow {
  width: fit-content;
  margin: 0 0 12px;
  padding: 4px 10px;
  border: 1px solid rgba(23, 137, 77, 0.22);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.72);
  color: var(--brand-dark);
  font-size: 13px;
  font-weight: 700;
}

h1 {
  margin-bottom: 10px;
  font-size: 30px;
  line-height: 1.18;
  letter-spacing: 0;
}

.intro {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 15px;
}

.quick-nav {
  position: sticky;
  top: 0;
  z-index: 5;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  margin: 10px -4px 16px;
  padding: 10px 4px;
  background: rgba(245, 247, 244, 0.94);
  backdrop-filter: blur(12px);
}

.quick-nav a {
  min-height: 38px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  color: var(--brand-dark);
  font-size: 13px;
  font-weight: 800;
  box-shadow: 0 8px 18px rgba(20, 54, 33, 0.06);
}

.notice,
.tutorial-step {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.notice {
  margin-bottom: 14px;
  padding: 16px 14px;
  scroll-margin-top: 72px;
}

.notice h2,
.step-heading h3,
.case-heading h2 {
  margin-bottom: 0;
  font-size: 20px;
  line-height: 1.3;
  letter-spacing: 0;
}

.notice p,
.tutorial-step > p,
details p {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 15px;
}

.flow-list {
  display: grid;
  gap: 8px;
  margin: 14px 0 0;
  padding-left: 22px;
  color: var(--ink);
  font-size: 15px;
}

.flow-list li::marker {
  color: var(--brand);
  font-weight: 900;
}

.case-section {
  display: grid;
  gap: 16px;
  margin-bottom: 18px;
  scroll-margin-top: 72px;
}

.case-heading {
  padding: 18px 2px 0;
}

.case-heading p {
  width: fit-content;
  margin-bottom: 8px;
  padding: 4px 10px;
  border-radius: 999px;
  background: var(--surface-soft);
  color: var(--brand-dark);
  font-size: 13px;
  font-weight: 800;
}

.case-heading h2 {
  font-size: 24px;
}

.case-heading span {
  display: block;
  margin-top: 6px;
  color: var(--muted);
  font-size: 14px;
}

.tutorial-step {
  overflow: hidden;
}

.step-heading {
  display: grid;
  grid-template-columns: 42px 1fr;
  align-items: center;
  gap: 10px;
  padding: 16px 14px 0;
}

.step-heading span {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  border-radius: 8px;
  background: var(--brand);
  color: #fff;
  font-size: 13px;
  font-weight: 900;
}

.tutorial-step > p {
  padding: 0 14px;
}

figure {
  margin: 14px 0 0;
  background: #f8faf8;
}

figure img {
  display: block;
  width: 100%;
  height: auto;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

figcaption {
  padding: 9px 14px 12px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
}

details {
  padding: 12px 0;
  border-top: 1px solid var(--line);
}

details:first-of-type {
  margin-top: 12px;
}

summary {
  color: var(--ink);
  cursor: pointer;
  font-size: 15px;
  font-weight: 800;
}

summary::marker {
  color: var(--brand);
}

@media (min-width: 760px) {
  body {
    background:
      linear-gradient(90deg, rgba(23, 137, 77, 0.08), transparent 38%, transparent 62%, rgba(242, 184, 75, 0.1)),
      var(--bg);
  }

  .page-shell {
    padding-top: 30px;
  }
}