:root {
  color-scheme: light;
  --bg: #f7fbfa;
  --surface: #ffffff;
  --ink: #182321;
  --muted: #5d6d69;
  --line: #d9e6e2;
  --green: #17b879;
  --cyan: #24b8c2;
  --coral: #ef6f5e;
  --gold: #c99a2e;
  --shadow: 0 18px 45px rgba(19, 52, 48, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.65;
}

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

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

/* ---- 无障碍：跳过导航链接 ---- */
.skip-link {
  position: absolute;
  top: -100%;
  left: 18px;
  z-index: 20;
  padding: 10px 16px;
  border-radius: 0 0 6px 6px;
  background: var(--ink);
  color: #fff;
  font-weight: 700;
  text-decoration: none;
}

.skip-link:focus {
  top: 0;
}

/* ---- 面包屑导航 ---- */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
  font-size: 14px;
  color: var(--muted);
}

.breadcrumb a {
  color: var(--green);
  font-weight: 600;
}

.breadcrumb a:hover {
  text-decoration: underline;
}

.breadcrumb span[aria-hidden] {
  color: var(--line);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 16px clamp(18px, 4vw, 56px);
  background: rgba(247, 251, 250, 0.92);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
}

.brand-mark {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  border-radius: 8px;
  background: var(--ink);
  color: #fff;
  font-size: 14px;
  letter-spacing: 0;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 22px;
  color: var(--muted);
  font-size: 15px;
}

.site-nav a:hover,
.article-card a:hover {
  color: var(--green);
}

.hero {
  min-height: min(680px, calc(100vh - 150px));
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(320px, 1.1fr);
  align-items: center;
  gap: clamp(28px, 5vw, 72px);
  padding: clamp(44px, 7vw, 96px) clamp(18px, 4vw, 56px) clamp(32px, 5vw, 64px);
  overflow: hidden;
}

.hero-copy {
  max-width: 660px;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--coral);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0;
}

h1,
h2,
h3,
p {
  overflow-wrap: anywhere;
}

h1 {
  margin: 0;
  font-size: clamp(42px, 7vw, 82px);
  line-height: 1.04;
  letter-spacing: 0;
}

h2 {
  margin: 0;
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1.2;
  letter-spacing: 0;
}

h3 {
  margin: 0;
  font-size: 20px;
  line-height: 1.35;
  letter-spacing: 0;
}

.hero-text {
  max-width: 590px;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 18px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.button {
  display: inline-flex;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  padding: 12px 18px;
  font-weight: 800;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button.primary {
  background: var(--green);
  color: #fff;
  box-shadow: 0 12px 28px rgba(23, 184, 121, 0.25);
}

.button.secondary {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
}

.hero-image {
  width: min(920px, 64vw);
  height: auto;
  justify-self: end;
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.section {
  padding: clamp(48px, 7vw, 88px) clamp(18px, 4vw, 56px);
}

.section-head {
  max-width: 760px;
  margin-bottom: 26px;
}

/* ---- FAQ 折叠面板 ---- */
.faq-list {
  max-width: 820px;
}

.faq-item {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: 0 6px 18px rgba(19, 52, 48, 0.05);
}

.faq-item + .faq-item {
  margin-top: 12px;
}

.faq-item summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  cursor: pointer;
  font-weight: 800;
  font-size: 17px;
  list-style: none;
  user-select: none;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  flex-shrink: 0;
  margin-left: 16px;
  font-size: 20px;
  color: var(--green);
  transition: transform 0.2s ease;
}

.faq-item[open] summary::after {
  content: "−";
  transform: rotate(0);
}

.faq-item p {
  margin: 0;
  padding: 0 24px 20px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.7;
}

.faq-item:hover {
  border-color: var(--green);
}

.faq-item[open] {
  border-color: var(--green);
}

.step-list,
.article-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.step-item,
.article-card,
.check-panel,
.content-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: 0 10px 28px rgba(19, 52, 48, 0.07);
}

.step-item,
.article-card {
  padding: 24px;
}

.step-number {
  display: inline-flex;
  margin-bottom: 18px;
  color: var(--gold);
  font-weight: 800;
}

.step-item p,
.article-card p {
  margin: 12px 0 0;
  color: var(--muted);
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(280px, 0.72fr);
  gap: clamp(24px, 5vw, 64px);
  align-items: center;
  background: #eef8f4;
}

.split p {
  color: var(--muted);
}

.check-panel {
  padding: 8px;
}

.check-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px;
  border-bottom: 1px solid var(--line);
}

.check-row:last-child {
  border-bottom: 0;
}

.check-row strong {
  color: var(--green);
  white-space: nowrap;
}

.article-card {
  min-height: 190px;
  display: flex;
  flex-direction: column;
}

.article-card p {
  margin: 0 0 14px;
  color: var(--coral);
  font-weight: 800;
  font-size: 13px;
}

.article-card span {
  margin-top: auto;
  color: var(--muted);
  font-size: 14px;
}

.site-footer {
  padding: 28px clamp(18px, 4vw, 56px);
  border-top: 1px solid var(--line);
  color: var(--muted);
  background: #fff;
}

.site-footer p {
  margin: 0;
}

.article-shell {
  width: min(960px, calc(100% - 36px));
  margin: 0 auto;
  padding: clamp(42px, 6vw, 76px) 0;
}

.article-hero {
  margin-bottom: 24px;
}

.article-hero h1 {
  font-size: clamp(36px, 6vw, 64px);
}

.content-card {
  padding: clamp(22px, 4vw, 42px);
}

.content-card h2 {
  margin-top: 34px;
  font-size: clamp(24px, 3vw, 34px);
}

.content-card h2:first-child {
  margin-top: 0;
}

.content-card p,
.content-card li {
  color: var(--muted);
}

.content-card ul {
  padding-left: 22px;
}

.back-link {
  display: inline-flex;
  margin-top: 26px;
  color: var(--green);
  font-weight: 800;
}

@media (max-width: 880px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
  }

  .site-nav {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 2px;
  }

  .hero,
  .split {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .hero-image {
    width: 100%;
    justify-self: stretch;
  }

  .step-list,
  .article-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 520px) {
  .hero-actions,
  .button {
    width: 100%;
  }

  .site-nav {
    gap: 16px;
    font-size: 14px;
  }

  h1 {
    font-size: 40px;
  }

  .breadcrumb {
    font-size: 13px;
    gap: 6px;
  }

  .faq-item summary {
    font-size: 15px;
    padding: 16px 18px;
  }

  .faq-item p {
    padding: 0 18px 16px;
    font-size: 14px;
  }
}

/* ---- 打印样式 ---- */
@media print {
  .site-header,
  .site-nav,
  .skip-link,
  .hero-actions,
  .back-link,
  .site-footer {
    display: none;
  }

  body {
    background: #fff;
    color: #000;
    font-size: 13px;
    line-height: 1.5;
  }

  .hero {
    min-height: auto;
    padding: 0;
  }

  .hero-image {
    max-width: 50%;
    box-shadow: none;
  }

  .content-card,
  .step-item,
  .article-card,
  .check-panel,
  .faq-item {
    border: 1px solid #ccc;
    box-shadow: none;
    break-inside: avoid;
  }

  a {
    color: #000;
    text-decoration: underline;
  }

  .breadcrumb {
    margin-bottom: 12px;
  }
}