/* 降AI率 — 站点样式（2025 版面） */
:root {
  --paper: #faf7f2;
  --paper-2: #f0ebe3;
  --ink: #1a1814;
  --ink-muted: #4a453c;
  --ink-faint: #6b655a;
  --line: #e4ddd2;
  --accent: #0f766e;
  --accent-hover: #0d5c56;
  --accent-soft: rgba(15, 118, 110, 0.12);
  --warn: #b45309;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 2px rgba(26, 24, 20, 0.06), 0 8px 24px rgba(26, 24, 20, 0.06);
  --font-sans: "Noto Sans SC", ui-sans-serif, system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-serif: "Noto Serif SC", ui-serif, "Songti SC", "SimSun", serif;
  --max: 72rem;
  --article: 42rem;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1.0625rem;
  line-height: 1.65;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
  text-underline-offset: 3px;
}

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

.site-wrap {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* 顶栏 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(250, 247, 242, 0.88);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}

.site-header__inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0.875rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  color: var(--ink);
  font-weight: 700;
  font-size: 1.125rem;
  letter-spacing: -0.02em;
  text-decoration: none;
}
.brand:hover {
  text-decoration: none;
  color: var(--accent);
}

.brand-mark {
  width: 2.25rem;
  height: 2.25rem;
  border-radius: var(--radius-sm);
  background: none;
  display: grid;
  place-items: center;
  overflow: hidden;
}

.brand-mark img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: contain;
}

/* 导航 */
.nav-main {
  display: none;
  align-items: center;
  gap: 1.5rem;
}
@media (min-width: 900px) {
  .nav-main {
    display: flex;
  }
}

.nav-main a {
  color: var(--ink-muted);
  font-size: 0.9375rem;
  font-weight: 500;
  text-decoration: none;
}
.nav-main a:hover,
.nav-main a[aria-current="page"] {
  color: var(--accent);
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.5rem 0.9rem;
  border-radius: 999px;
  background: var(--ink);
  color: #fff !important;
  font-size: 0.875rem;
  font-weight: 600;
}
.nav-cta:hover {
  background: #2d2924;
  text-decoration: none;
}

/* 移动端菜单 */
.nav-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: #fff;
  cursor: pointer;
}
@media (min-width: 900px) {
  .nav-toggle {
    display: none;
  }
}

.nav-drawer {
  display: none;
  border-top: 1px solid var(--line);
  background: var(--paper);
}
.nav-drawer.is-open {
  display: block;
}
.nav-drawer__inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 1rem 1.25rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.nav-drawer a {
  color: var(--ink-muted);
  font-weight: 500;
  padding: 0.35rem 0;
}

/* Hero */
.hero {
  padding: 3.5rem 1.25rem 4rem;
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(ellipse 80% 60% at 50% -20%, rgba(15, 118, 110, 0.15), transparent),
    var(--paper);
}

.hero__inner {
  max-width: var(--max);
  margin: 0 auto;
  display: grid;
  gap: 2rem;
  align-items: start;
}
@media (min-width: 960px) {
  .hero__inner {
    grid-template-columns: 1.15fr 0.85fr;
    gap: 3rem;
  }
}

.hero-kicker {
  display: inline-block;
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.75rem;
}

.hero h1 {
  font-family: var(--font-serif);
  font-size: clamp(1.85rem, 4vw, 2.75rem);
  font-weight: 700;
  line-height: 1.2;
  margin: 0 0 1rem;
  color: var(--ink);
}

.hero-lead {
  font-size: 1.125rem;
  color: var(--ink-muted);
  max-width: 38rem;
  margin: 0 0 1.5rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.65rem 1.15rem;
  border-radius: 999px;
  font-size: 0.9375rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.15s, color 0.15s, box-shadow 0.15s;
}
.btn-primary {
  background: var(--accent);
  color: #fff;
}
.btn-primary:hover {
  background: var(--accent-hover);
  text-decoration: none;
  box-shadow: var(--shadow);
}
.btn-ghost {
  background: #fff;
  color: var(--ink);
  border: 1px solid var(--line);
}
.btn-ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
  text-decoration: none;
}

.hero-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.35rem 1.35rem 1.25rem;
  box-shadow: var(--shadow);
}
.hero-card h2 {
  font-size: 1rem;
  font-weight: 700;
  margin: 0 0 0.75rem;
  color: var(--ink);
}
.hero-card ul {
  margin: 0;
  padding: 0;
  list-style: none;
}
.hero-card li {
  padding: 0.45rem 0;
  border-top: 1px solid var(--line);
  font-size: 0.9375rem;
}
.hero-card li:first-child {
  border-top: none;
  padding-top: 0;
}
.hero-card a {
  color: var(--ink-muted);
  font-weight: 500;
}
.hero-card a:hover {
  color: var(--accent);
}

/* 区块 */
.section {
  padding: 3.25rem 1.25rem;
}
.section--alt {
  background: var(--paper-2);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.section__head {
  max-width: var(--max);
  margin: 0 auto 2rem;
}
.section__head h2 {
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 2.5vw, 2rem);
  margin: 0 0 0.5rem;
}
.section__head p {
  margin: 0;
  color: var(--ink-muted);
  max-width: 40rem;
}

.grid-cards {
  max-width: var(--max);
  margin: 0 auto;
  display: grid;
  gap: 1rem;
  grid-template-columns: 1fr;
}
@media (min-width: 640px) {
  .grid-cards {
    grid-template-columns: repeat(2, 1fr);
  }
}
@media (min-width: 1024px) {
  .grid-cards--3 {
    grid-template-columns: repeat(3, 1fr);
  }
}

.card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.35rem 1.25rem;
  box-shadow: 0 1px 0 rgba(26, 24, 20, 0.04);
  transition: border-color 0.15s, box-shadow 0.15s;
}
.card:hover {
  border-color: #c9c0b0;
  box-shadow: var(--shadow);
}

.card h3 {
  font-size: 1.0625rem;
  margin: 0 0 0.5rem;
}
.card p {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--ink-muted);
  line-height: 1.55;
}
.card__link {
  display: inline-block;
  margin-top: 0.85rem;
  font-size: 0.875rem;
  font-weight: 600;
}

/* 方法条 */
.method-grid {
  max-width: var(--max);
  margin: 0 auto;
  display: grid;
  gap: 1rem;
}
@media (min-width: 768px) {
  .method-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.method {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.25rem 1.2rem;
}
.method h3 {
  font-size: 1.05rem;
  margin: 0 0 0.35rem;
}
.method > p {
  margin: 0 0 0.75rem;
  color: var(--ink-muted);
  font-size: 0.9375rem;
}
.method ul {
  margin: 0;
  padding-left: 1.1rem;
  color: var(--ink-muted);
  font-size: 0.9rem;
}

/* 提示词 */
.prompt-grid {
  max-width: var(--max);
  margin: 0 auto;
  display: grid;
  gap: 1rem;
}
@media (min-width: 900px) {
  .prompt-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.prompt {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.15rem 1.1rem;
}
.prompt__top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 0.75rem;
  margin-bottom: 0.65rem;
}
.prompt__top h3 {
  margin: 0;
  font-size: 1rem;
}
.tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2rem 0.5rem;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-hover);
}
.prompt__body {
  font-size: 0.875rem;
  color: var(--ink-muted);
  line-height: 1.55;
  padding: 0.75rem 0.85rem;
  background: var(--paper);
  border-radius: var(--radius-sm);
  border: 1px dashed var(--line);
}
.prompt__actions {
  margin-top: 0.65rem;
}
.btn-copy {
  font-size: 0.8125rem;
  font-weight: 600;
  padding: 0.35rem 0.65rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  background: #fff;
  cursor: pointer;
  color: var(--ink);
}
.btn-copy:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.btn-copy.is-done {
  border-color: var(--accent);
  color: var(--accent);
}

/* 案例 */
.case-grid {
  max-width: var(--max);
  margin: 0 auto;
  display: grid;
  gap: 1rem;
}
@media (min-width: 900px) {
  .case-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.case {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.2rem;
}
.case h3 {
  margin: 0 0 0.35rem;
  font-size: 1.05rem;
}
.case .muted {
  font-size: 0.875rem;
  color: var(--ink-muted);
  margin: 0 0 0.85rem;
}
.case-block {
  font-size: 0.8125rem;
  margin-bottom: 0.65rem;
}
.case-block span {
  display: block;
  color: var(--ink-faint);
  margin-bottom: 0.25rem;
}
.case-block div {
  padding: 0.5rem 0.6rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  background: var(--paper);
}
.case-block div.after {
  background: rgba(15, 118, 110, 0.06);
  border-color: rgba(15, 118, 110, 0.25);
}
.case-foot {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--accent-hover);
  margin-top: 0.5rem;
}

/* 关于双栏 */
.split {
  max-width: var(--max);
  margin: 0 auto;
  display: grid;
  gap: 2rem;
  align-items: start;
}
@media (min-width: 900px) {
  .split {
    grid-template-columns: 1fr 1fr;
  }
}

.checklist {
  list-style: none;
  padding: 0;
  margin: 0;
}
.checklist li {
  position: relative;
  padding-left: 1.6rem;
  margin-bottom: 0.75rem;
  color: var(--ink-muted);
}
.checklist li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.45rem;
  width: 0.55rem;
  height: 0.55rem;
  border-radius: 50%;
  background: var(--accent);
}

/* 页脚 */
.site-footer {
  margin-top: auto;
  background: #1c1914;
  color: #d6d0c8;
  padding: 3rem 1.25rem 2rem;
  font-size: 0.9rem;
}
.site-footer a {
  color: #b8e6e1;
}
.site-footer a:hover {
  color: #fff;
}

.site-footer__inner {
  max-width: var(--max);
  margin: 0 auto;
  display: grid;
  gap: 2rem;
}
@media (min-width: 768px) {
  .site-footer__inner {
    grid-template-columns: 1.2fr 1fr 1fr;
  }
}

.site-footer h3 {
  font-size: 0.8125rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #9c958a;
  margin: 0 0 1rem;
}

.site-footer ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.site-footer li {
  margin-bottom: 0.5rem;
}

.footer-meta {
  border-top: 1px solid #3d3830;
  margin-top: 2rem;
  padding-top: 1.5rem;
  text-align: center;
  color: #8a8278;
  font-size: 0.8125rem;
}

/* 文章页 */
.article-shell {
  padding: 2rem 1.25rem 4rem;
}

.breadcrumb {
  max-width: var(--article);
  margin: 0 auto 1.25rem;
  font-size: 0.8125rem;
  color: var(--ink-faint);
}
.breadcrumb a {
  color: var(--ink-muted);
}

.article {
  max-width: var(--article);
  margin: 0 auto;
}

.article header h1 {
  font-family: var(--font-serif);
  font-size: clamp(1.65rem, 3vw, 2.15rem);
  line-height: 1.25;
  margin: 0 0 0.75rem;
}

.article-meta {
  font-size: 0.875rem;
  color: var(--ink-faint);
  margin-bottom: 2rem;
}

.article-body h2 {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  margin: 2.25rem 0 0.75rem;
  line-height: 1.3;
}
.article-body h3 {
  font-size: 1.1rem;
  margin: 1.5rem 0 0.5rem;
}
.article-body p {
  margin: 0 0 1rem;
  color: var(--ink-muted);
}
.article-body ul,
.article-body ol {
  margin: 0 0 1rem;
  padding-left: 1.25rem;
  color: var(--ink-muted);
}
.article-body li {
  margin-bottom: 0.35rem;
}
.article-body strong {
  color: var(--ink);
  font-weight: 600;
}

.callout {
  border-left: 4px solid var(--accent);
  padding: 0.85rem 1rem;
  background: var(--accent-soft);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 1.25rem 0;
  font-size: 0.9375rem;
  color: var(--ink-muted);
}

.callout--warn {
  border-left-color: var(--warn);
  background: rgba(180, 83, 9, 0.08);
}

/* 指南索引 */
.guide-list {
  max-width: var(--max);
  margin: 0 auto;
  display: grid;
  gap: 0.75rem;
}
.guide-row {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  padding: 1rem 1.1rem;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
@media (min-width: 700px) {
  .guide-row {
    flex-direction: row;
    align-items: baseline;
    justify-content: space-between;
  }
}
.guide-row h2 {
  font-size: 1.05rem;
  margin: 0;
  font-family: var(--font-sans);
  font-weight: 700;
}
.guide-row p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--ink-muted);
  max-width: 36rem;
}
.guide-row a.title {
  color: var(--ink);
  text-decoration: none;
}
.guide-row a.title:hover {
  color: var(--accent);
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0.5rem;
  z-index: 100;
  padding: 0.5rem 1rem;
  background: var(--ink);
  color: #fff;
}
.skip-link:focus {
  left: 0.5rem;
}