:root {
  --bg: #f3f1ec;
  --bg-soft: #faf8f4;
  --panel: rgba(255, 255, 255, 0.78);
  --panel-strong: rgba(255, 255, 255, 0.92);
  --panel-deep: rgba(30, 30, 30, 0.94);
  --ink: #181818;
  --muted: #69645d;
  --muted-strong: #4f4a44;
  --line: rgba(24, 24, 24, 0.08);
  --accent: #222222;
  --accent-soft: rgba(34, 34, 34, 0.06);
  --ui-font: "Avenir Next", "Futura", "Trebuchet MS", sans-serif;
  --title-font: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", serif;
  --shadow: 0 12px 36px rgba(18, 18, 18, 0.04);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: linear-gradient(180deg, #f8f7f3 0%, var(--bg) 100%);
  color: var(--ink);
  font-family: var(--ui-font);
}

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

.site-shell {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 20px 0 72px;
}

.masthead {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 12px 0 18px;
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(18px);
  background: rgba(243, 241, 236, 0.78);
  border-bottom: 1px solid var(--line);
}

.brand {
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
}

.brand-mark,
.eyebrow,
.section-kicker,
.note-label,
.footer-mark,
.book-tag,
.book-stage {
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-size: 12px;
  color: var(--muted);
}

.brand-name {
  font-family: var(--title-font);
  font-size: 24px;
  line-height: 1;
}

.topnav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 18px;
  color: var(--muted);
  font-size: 14px;
}

.topnav a {
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
  transition: 180ms ease;
}

.topnav a:hover {
  border-color: rgba(24, 24, 24, 0.16);
  color: var(--ink);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(280px, 0.75fr);
  gap: 44px;
  min-height: 56vh;
  align-items: end;
  padding: 28px 0 34px;
  position: relative;
}

.hero::before {
  display: none;
}

.hero h1,
.section-heading h2,
.guidance-card h3,
.intro-grid h3,
.path-card h3,
.library-group-head h3,
.book-card h3,
.about-card h3 {
  font-family: var(--title-font);
  font-weight: 600;
  letter-spacing: -0.02em;
}

.hero h1 {
  margin: 8px 0 14px;
  font-size: clamp(34px, 4.6vw, 52px);
  line-height: 1.04;
  max-width: 7ch;
  font-weight: 500;
}

.lede,
.hero-note p,
.intro-grid p,
.guidance-card p,
.site-footer p,
.path-card p,
.archive-panel p,
.library-group-head p,
.about-card p,
.about-card li {
  color: var(--muted);
  line-height: 1.72;
  font-size: 16px;
}

.lede {
  max-width: 54ch;
  color: var(--muted-strong);
}

.lede-secondary {
  margin-top: 10px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 18px;
  border-radius: 999px;
  border: 1px solid var(--line);
  font-size: 14px;
  transition: 180ms ease;
}

.button-solid {
  background: var(--ink);
  color: #fff;
  border-color: var(--ink);
  box-shadow: 0 6px 18px rgba(24, 24, 24, 0.1);
}

.button-solid:hover {
  background: #000;
}

.button-ghost {
  background: rgba(255, 255, 255, 0.5);
}

.button-ghost:hover {
  background: rgba(255, 255, 255, 0.92);
}

.note-card,
.quote-panel,
.guidance-card,
.book-card,
.path-card,
.archive-panel,
.about-card {
  background: var(--panel);
  backdrop-filter: blur(10px);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.hero-note {
  display: flex;
  justify-content: flex-end;
}

.hero-stack {
  display: grid;
  gap: 10px;
  width: min(290px, 100%);
}

.note-card {
  padding: 16px;
  border-radius: 16px;
}

.note-card-accent {
  background: var(--panel-deep);
  color: #f7f7f5;
}

.note-card-accent .note-label,
.note-card-accent p {
  color: rgba(247, 247, 245, 0.88);
}

.hero-pillars ul,
.hero-downloads ul {
  margin: 12px 0 0;
  padding-left: 18px;
  color: var(--muted);
  line-height: 1.8;
}

.hero-downloads ul {
  list-style: none;
  padding-left: 0;
  margin-top: 10px;
  display: grid;
  gap: 8px;
}

.hero-downloads li {
  border-bottom: 1px solid var(--line);
  padding-bottom: 8px;
}

.hero-downloads li:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.hero-downloads a {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.hero-downloads a::after {
  content: "查看";
  color: var(--muted);
  font-size: 12px;
}

.section {
  padding: 22px 0 32px;
}

.section-heading {
  max-width: 880px;
  margin-bottom: 18px;
}

.section-heading h2 {
  margin: 8px 0 0;
  font-size: clamp(24px, 3vw, 32px);
  line-height: 1.18;
  max-width: 20ch;
  font-weight: 500;
}

.intro-grid,
.guidance-grid,
.library-grid,
.path-grid,
.stacked-sections,
.about-grid,
.compact-grid {
  display: grid;
  gap: 16px;
}

.compact-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.compact-card {
  padding: 20px;
  border-radius: 20px;
  background: var(--panel-strong);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.compact-card h2 {
  margin: 8px 0 10px;
  font-family: var(--title-font);
  font-size: 24px;
  line-height: 1.2;
  font-weight: 500;
}

.compact-card p {
  margin: 0;
  color: var(--muted-strong);
  line-height: 1.7;
  font-size: 15px;
}

.compact-card-download {
  background: #1f1f1f;
  color: #f7f7f5;
}

.compact-card-download .section-kicker,
.compact-card-download p,
.compact-card-download h2 {
  color: #f7f7f5;
}

.compact-card-download .button-solid {
  background: #f7f7f5;
  color: #1f1f1f;
  border-color: #f7f7f5;
}

.compact-actions {
  margin-top: 16px;
}

.variant-page .site-shell {
  padding-bottom: 40px;
}

.cover-layout,
.entry-layout {
  min-height: calc(100vh - 110px);
}

.cover-hero {
  min-height: 72vh;
  display: grid;
  place-items: center;
}

.cover-panel {
  width: min(720px, 100%);
  padding: 44px;
  border-radius: 28px;
  background: var(--panel-strong);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.cover-panel h1,
.library-first-copy h1,
.entry-intro h1 {
  margin: 10px 0 14px;
  font-family: var(--title-font);
  font-size: clamp(34px, 5vw, 56px);
  line-height: 1.04;
  font-weight: 500;
}

.cover-panel p,
.library-first-copy p,
.entry-intro p,
.quick-book-card p,
.entry-link-card p {
  color: var(--muted-strong);
  line-height: 1.72;
  font-size: 16px;
}

.library-first-copy p {
  max-width: 34ch;
}

.cover-detail {
  padding-top: 12px;
}

.library-first-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) auto;
  gap: 20px;
  align-items: end;
  padding: 12px 0 18px;
}

.library-first-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.quick-books {
  padding-top: 8px;
}

.quick-book-grid,
.entry-card-grid,
.browse-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.quick-book-card,
.entry-link-card,
.browse-card {
  padding: 20px;
  border-radius: 20px;
  background: var(--panel-strong);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.quick-book-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.quick-book-use {
  padding: 4px 8px;
  border-radius: 999px;
  background: rgba(24, 24, 24, 0.05);
  color: var(--muted);
  font-size: 12px;
  line-height: 1.2;
}

.quick-book-card h3,
.entry-link-card h2,
.browse-card h3 {
  margin: 10px 0 10px;
  font-family: var(--title-font);
  font-size: 22px;
  line-height: 1.2;
  font-weight: 500;
}

.browse-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.browse-card p {
  margin: 0;
  color: var(--muted-strong);
  line-height: 1.72;
  font-size: 15px;
}

.browse-card-link {
  text-decoration: none;
  transition: 180ms ease;
  min-height: 220px;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
}

.browse-card-link:hover {
  transform: translateY(-2px);
  border-color: rgba(24, 24, 24, 0.16);
}

.quick-book-card .download-link {
  margin-top: 8px;
}

.variant-footer-action {
  margin-top: 18px;
}

.entry-layout {
  display: grid;
  align-content: center;
  gap: 24px;
}

.entry-intro {
  max-width: 620px;
}

.entry-link-card {
  text-decoration: none;
}

.entry-link-card-dark {
  background: var(--panel-deep);
}

.entry-link-card-dark .section-kicker,
.entry-link-card-dark h2,
.entry-link-card-dark p {
  color: #f7f7f5;
}

.intro-grid,
.path-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.intro-grid article {
  padding: 18px;
  border-top: 0;
  background: var(--panel-strong);
  border: 1px solid var(--line);
  border-radius: 18px;
}

.intro-grid h3,
.guidance-card h3 {
  margin: 0 0 10px;
  font-size: 18px;
  line-height: 1.25;
  font-weight: 500;
}

.quote-panel {
  border-radius: 20px;
  padding: 24px 26px;
  background: var(--panel-strong);
}

.quote-panel p {
  margin: 0;
  font-family: var(--title-font);
  font-size: clamp(20px, 2.1vw, 24px);
  line-height: 1.5;
  max-width: 30ch;
  color: var(--muted-strong);
}

.entry-panel {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(320px, 0.9fr);
  gap: 14px;
  padding: 18px;
  border-radius: 20px;
  background: var(--panel-strong);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.entry-copy h2 {
  margin: 10px 0 0;
  font-family: var(--title-font);
  font-size: clamp(24px, 2.6vw, 30px);
  line-height: 1.18;
  font-weight: 500;
  max-width: 16ch;
}

.entry-stats {
  display: grid;
  gap: 10px;
}

.entry-stat {
  padding: 14px;
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid var(--line);
}

.entry-stat strong,
.book-card h3 {
  display: block;
}

.entry-stat strong {
  font-family: var(--title-font);
  font-size: 19px;
  font-weight: 500;
  line-height: 1.15;
}

.entry-stat span {
  display: block;
  margin-top: 6px;
  color: var(--muted);
}

.stacked-sections {
  gap: 28px;
}

.library-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.path-card,
.archive-panel,
.about-card {
  border-radius: 20px;
}

.path-card,
.about-card {
  padding: 18px;
}

.path-step {
  color: var(--accent);
  font-size: 13px;
  letter-spacing: 0.12em;
  margin-bottom: 8px;
}

.path-card h3,
.library-group-head h3,
.about-card h3 {
  margin: 0 0 10px;
  font-size: 18px;
  line-height: 1.24;
  font-weight: 500;
}

.path-card p,
.library-group-head p,
.archive-panel p,
.about-card p {
  margin: 0;
}

.library-group-head {
  max-width: 760px;
  margin-bottom: 14px;
}

.book-card {
  border-radius: 20px;
  padding: 20px;
  background: var(--panel-strong);
}

.book-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}

.book-meta {
  display: flex;
  gap: 16px;
  margin-bottom: 8px;
  flex-wrap: wrap;
}

.book-use {
  flex: 0 0 auto;
  padding: 3px 8px;
  border-radius: 999px;
  background: rgba(24, 24, 24, 0.05);
  color: var(--muted-strong);
  font-size: 12px;
  line-height: 1.3;
}

.book-origin {
  margin-bottom: 8px;
  color: var(--muted);
  font-size: 13px;
}

.book-card h3 {
  margin: 0 0 10px;
  font-size: 21px;
  line-height: 1.2;
  font-weight: 500;
}

.book-card p {
  margin: 0 0 14px;
  color: var(--muted-strong);
  line-height: 1.62;
  font-size: 14px;
}

.downloads {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.download-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 38px;
  padding: 0 13px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid var(--line);
  font-size: 13px;
}

.library-grid {
  align-items: start;
}

.library-group-head p {
  max-width: 38ch;
}

.section-heading {
  max-width: 720px;
}

.section-heading h2 {
  max-width: 16ch;
}

.library-group + .library-group {
  padding-top: 4px;
}

.library-first-copy {
  max-width: 620px;
}

.library-first-copy .eyebrow {
  margin-bottom: 2px;
}

.library-first-copy h1 {
  max-width: 8ch;
}

.library-first-copy p + p {
  margin-top: 8px;
}

.site-footer {
  margin-top: 36px;
}

.button:hover,
.download-link:hover {
  transform: translateY(-1px);
}

.download-link span {
  color: var(--muted);
}

.guidance-grid,
.about-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.archive-panel {
  padding: 20px;
}

.archive-panel p + p,
.about-card p + p,
.about-card ul {
  margin-top: 12px;
}

.guidance-card {
  border-radius: 20px;
  padding: 20px;
}

.intro-grid p,
.path-card p,
.library-group-head p,
.guidance-card p,
.archive-panel p {
  max-width: 36ch;
}

.section-compact {
  padding-top: 4px;
  padding-bottom: 16px;
}

.section-library {
  padding-top: 10px;
}

.about-hero {
  min-height: auto;
  align-items: start;
  padding-bottom: 18px;
}

.about-grid {
  align-items: start;
}

.about-card ul {
  padding-left: 18px;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  padding-top: 36px;
  margin-top: 26px;
  border-top: 1px solid var(--line);
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 12px 18px;
  color: var(--muted);
}

.feedback-layout {
  display: grid;
  grid-template-columns: minmax(280px, 0.9fr) minmax(0, 1.1fr);
  gap: 18px;
}

.feedback-form {
  display: grid;
  gap: 14px;
}

.feedback-form label {
  display: grid;
  gap: 8px;
}

.feedback-form span {
  font-size: 14px;
  color: var(--muted-strong);
}

.feedback-note {
  font-size: 12px;
  line-height: 1.6;
  color: var(--muted);
}

.feedback-form input,
.feedback-form select,
.feedback-form textarea {
  width: 100%;
  padding: 12px 14px;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.85);
  color: var(--ink);
  font: inherit;
}

.feedback-form textarea {
  resize: vertical;
  min-height: 160px;
}

.feedback-actions {
  display: grid;
  gap: 10px;
  margin-top: 4px;
}

.feedback-status {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.feedback-status[data-state="error"] {
  color: #a53b2a;
}

.feedback-status[data-state="success"] {
  color: #2f5c3b;
}

.feedback-honeypot {
  position: absolute;
  left: -9999px;
  opacity: 0;
  pointer-events: none;
}


.feedback-layout {
  display: grid;
  grid-template-columns: minmax(280px, 0.9fr) minmax(0, 1.1fr);
  gap: 18px;
}

.feedback-form {
  display: grid;
  gap: 14px;
}

.feedback-form label {
  display: grid;
  gap: 8px;
}

.feedback-form span {
  font-size: 14px;
  color: var(--muted-strong);
}

.feedback-form input,
.feedback-form select,
.feedback-form textarea {
  width: 100%;
  padding: 12px 14px;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.85);
  color: var(--ink);
  font: inherit;
}

.feedback-form textarea {
  resize: vertical;
  min-height: 160px;
}

.feedback-actions {
  margin-top: 4px;
}

@media (max-width: 980px) {
  .masthead,
  .hero,
  .entry-panel,
  .library-first-hero,
  .intro-grid,
  .guidance-grid,
  .library-grid,
  .path-grid,
  .site-footer,
  .about-grid,
  .compact-grid,
  .quick-book-grid,
  .entry-card-grid,
  .browse-grid {
    grid-template-columns: 1fr;
    display: grid;
  }

  .feedback-layout {
    grid-template-columns: 1fr;
  }

  .browse-card-link {
    min-height: 0;
  }

  .masthead {
    justify-content: stretch;
  }

  .topnav {
    justify-content: flex-start;
  }

  .hero {
    min-height: auto;
    padding-top: 18px;
    padding-bottom: 24px;
    gap: 18px;
  }

  .hero-note {
    justify-content: stretch;
  }

  .hero-stack {
    width: 100%;
  }
}

@media (max-width: 640px) {
  .site-shell {
    width: min(100% - 20px, 1180px);
    padding-top: 12px;
  }

  .hero h1 {
    max-width: none;
    font-size: clamp(30px, 11vw, 42px);
    line-height: 1.02;
  }

  .hero {
    padding: 18px 0 24px;
  }

  .lede,
  .hero-note p,
  .intro-grid p,
  .guidance-card p,
  .site-footer p,
  .path-card p,
  .archive-panel p,
  .library-group-head p,
  .about-card p,
  .about-card li {
    font-size: 16px;
    line-height: 1.72;
  }

  .book-card h3 {
    font-size: 26px;
  }

  .section-heading h2,
  .entry-copy h2 {
    max-width: none;
  }

  .quote-panel {
    padding: 24px 20px;
  }

  .entry-panel,
  .book-card,
  .path-card,
  .guidance-card,
  .archive-panel,
  .about-card,
  .note-card,
  .quick-book-card,
  .entry-link-card,
  .cover-panel {
    padding: 20px;
  }

  .entry-stat strong {
    font-size: 20px;
  }

  .book-head {
    flex-direction: column;
    align-items: flex-start;
  }

  .library-first-copy h1,
  .section-heading h2 {
    max-width: none;
  }
}