:root {
  --color-surface: #fafafa;
  --color-surface-alt: #f1f1f1;
  --color-surface-deep: #e4e5e4;
  --color-ink: #404a44;
  --color-ink-soft: #64726b;
  --color-ink-muted: #79867f;
  --color-line: #d9dad9;
  --color-primary: #6b7a72;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #e6e8e7;
  --color-accent: #128748;
  --color-accent-ink: #ffffff;
  --color-highlight: #d0e5da;
  --color-focus: #0a8040;
  --color-contrast-surface: #181c1a;
  --color-contrast-ink: #e4e7e5;
  --color-contrast-line: #454947;
  --color-contrast-accent: #1fe078;
  --overlay-scrim: linear-gradient(180deg, rgba(24, 28, 26, 0.35) 0%, rgba(24, 28, 26, 0.72) 55%, rgba(24, 28, 26, 0.92) 100%);
  --font-heading: STZhongsong, "Source Han Serif SC", "Songti SC", SimSun, serif;
  --font-body: "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: ui-monospace, Menlo, Consolas, monospace;
  --text-xs: 9.5px;
  --text-sm: 13.5px;
  --text-base: 16px;
  --text-lg: 22.6px;
  --text-xl: 32.0px;
  --text-2xl: 45.2px;
  --text-3xl: 64.0px;
  --text-4xl: 90.4px;
  --text-display: clamp(38px, 7.9vw, 101px);
  --text-figure: clamp(32px, 5.7vw, 73px);
  --weight-heading: 381;
  --weight-body: 400;
  --leading-body: 1.88;
  --leading-heading: 1.25;
  --tracking-heading: 0.008em;
  --radius-sm: 0px;
  --radius-md: 0px;
  --radius-lg: 0px;
  --radius-pill: 0px;
  --border-thin: 1px;
  --border-thick: 1px;
  --shadow-1: none;
  --shadow-2: none;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1260px;
  --measure: 62ch;
  --gutter: 24px;
  --section-y: 155px;
  --section-y-lg: 217px;
}

/* ==========================================================================
   BET9会馆 · 共享站点样式 /assets/site.css
   展墙底色 + 步骤刻度 + 展签小字
   ========================================================================== */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background-color: var(--color-surface);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--weight-body);
  line-height: var(--leading-body);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
h3,
h4,
h5,
h6,
p,
figure,
blockquote,
dl,
dd,
ol,
ul {
  margin: 0;
}

ol,
ul {
  padding: 0;
  list-style: none;
}

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

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  padding: 0;
  cursor: pointer;
}

table {
  border-collapse: collapse;
  width: 100%;
}

[id] {
  scroll-margin-top: calc(var(--space-8) + var(--space-4));
}

:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 3px;
}

::selection {
  background-color: var(--color-highlight);
  color: var(--color-ink);
}

/* ---------- 容器与区块 ---------- */

.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding-left: var(--gutter);
  padding-right: var(--gutter);
}

#main-content {
  display: block;
}

.section {
  padding-block: min(var(--section-y), 13vw);
}

.section--lg {
  padding-block: min(var(--section-y-lg), 17vw);
}

.section--tight {
  padding-block: min(var(--space-8), 8vw);
}

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-2) var(--space-4);
  padding-bottom: var(--space-3);
  border-bottom: 2px solid var(--color-ink);
}

.section-title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-xl);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}

.section-note {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.18em;
  color: var(--color-ink-muted);
  line-height: 1.8;
}

.rule {
  border: 0;
  height: 0;
  border-top: var(--border-thin) solid var(--color-line);
  margin: 0;
}

.rule--thick {
  border-top: 2px solid var(--color-ink);
}

.rule--double {
  border-top: 3px double var(--color-line);
}

/* ---------- 排版 ---------- */

.display {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-display);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}

.figure-numeral {
  font-family: var(--font-mono);
  font-weight: var(--weight-heading);
  font-size: var(--text-figure);
  line-height: 1;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--color-accent);
  display: block;
}

.lede {
  font-size: var(--text-lg);
  line-height: 1.62;
  color: var(--color-ink-soft);
  max-width: var(--measure);
}

.prose {
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

.prose > * + * {
  margin-top: var(--space-3);
}

.prose h2,
.prose h3 {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  margin-top: var(--space-6);
}

.prose h2 {
  font-size: var(--text-xl);
}

.prose h3 {
  font-size: var(--text-lg);
}

.prose a {
  color: var(--color-accent);
  border-bottom: var(--border-thin) solid var(--color-accent);
}

.plate {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  color: var(--color-ink-muted);
  line-height: 1.9;
}

.caption {
  display: flex;
  align-items: flex-start;
  gap: var(--space-2);
  padding-top: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  line-height: 1.9;
  color: var(--color-ink-muted);
}

.caption::before {
  content: "";
  flex: 0 0 auto;
  width: 22px;
  height: var(--border-thin);
  margin-top: 0.85em;
  background-color: var(--color-line);
}

.pullquote {
  margin: var(--space-6) 0;
  padding-left: var(--space-4);
  border-left: 2px solid var(--color-accent);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: 1.62;
  color: var(--color-ink);
  max-width: var(--measure);
}

.pullquote::before {
  content: "\201C";
  display: block;
  font-family: var(--font-heading);
  font-size: var(--text-3xl);
  line-height: 0.9;
  color: var(--color-primary);
  margin-bottom: var(--space-1);
}

.tag {
  display: inline-block;
  padding: 2px var(--space-1);
  background-color: var(--color-primary-soft);
  color: var(--color-ink-soft);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  line-height: 1.8;
}

/* ---------- 栅格 ---------- */

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gutter);
}

.grid > * {
  grid-column: 1 / -1;
  min-width: 0;
}

@media (min-width: 901px) {
  .grid > .col-3 { grid-column: span 3; }
  .grid > .col-4 { grid-column: span 4; }
  .grid > .col-5 { grid-column: span 5; }
  .grid > .col-6 { grid-column: span 6; }
  .grid > .col-7 { grid-column: span 7; }
  .grid > .col-8 { grid-column: span 8; }
  .grid > .col-9 { grid-column: span 9; }
}

/* ---------- 视觉容器（供页面阶段放置图片占位） ---------- */

.media {
  position: relative;
  display: block;
  width: 100%;
  overflow: hidden;
  border: 0;
  border-radius: var(--radius-sm);
  background-color: var(--color-surface-deep);
  background-image: repeating-linear-gradient(
    -45deg,
    transparent 0,
    transparent 9px,
    rgba(107, 122, 114, 0.14) 9px,
    rgba(107, 122, 114, 0.14) 10px
  );
}

.media > img,
.media > svg,
.media > video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media--21x9 { aspect-ratio: 21 / 9; }
.media--16x9 { aspect-ratio: 16 / 9; }
.media--4x3 { aspect-ratio: 4 / 3; }
.media--1x1 { aspect-ratio: 1 / 1; }
.media--4x5 { aspect-ratio: 4 / 5; }
.media--3x5 { aspect-ratio: 3 / 5; }

.media--scrim::after {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
  pointer-events: none;
}

.media-text {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 1;
  padding: var(--space-3) var(--space-4) var(--space-4);
  color: var(--color-contrast-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  line-height: 1.9;
}

/* ---------- 深色对比区块 ---------- */

.block-dark {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-top: 3px double var(--color-contrast-line);
  border-bottom: 3px double var(--color-contrast-line);
}

.block-dark a {
  color: var(--color-contrast-accent);
}

.block-dark .section-title,
.block-dark .display,
.block-dark .prose,
.block-dark .lede,
.block-dark .pullquote {
  color: var(--color-contrast-ink);
}

.block-dark .plate,
.block-dark .caption,
.block-dark .section-note,
.block-dark .lede {
  color: color-mix(in srgb, var(--color-contrast-ink) 62%, var(--color-contrast-surface));
}

.block-dark .section-head {
  border-bottom-color: var(--color-contrast-line);
}

.block-dark .caption::before,
.block-dark .rule,
.block-dark .rule--double {
  border-color: var(--color-contrast-line);
  background-color: var(--color-contrast-line);
}

.block-dark .pullquote {
  border-left-color: var(--color-contrast-accent);
}

.block-dark .pullquote::before {
  color: var(--color-contrast-accent);
}

/* ---------- 按钮 ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  min-height: 48px;
  padding: 0 var(--space-4);
  border: var(--border-thin) solid var(--color-ink);
  border-radius: var(--radius-sm);
  background-color: var(--color-surface);
  color: var(--color-ink);
  font-size: var(--text-sm);
  letter-spacing: 0.12em;
  line-height: 1.4;
  transition: background-color 240ms ease, color 240ms ease, border-color 240ms ease;
}

.btn:hover,
.btn:focus-visible {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}

.btn--accent {
  background-color: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-accent-ink);
}

.btn--accent:hover,
.btn--accent:focus-visible {
  background-color: var(--color-focus);
  border-color: var(--color-focus);
  color: var(--color-accent-ink);
}

.btn--quiet {
  border-color: var(--color-line);
  color: var(--color-ink-soft);
  background-color: transparent;
}

.btn--quiet:hover,
.btn--quiet:focus-visible {
  background-color: var(--color-primary-soft);
  border-color: var(--color-primary);
  color: var(--color-ink);
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2) var(--space-3);
}

.block-dark .btn {
  border-color: var(--color-contrast-line);
  background-color: transparent;
  color: var(--color-contrast-ink);
}

.block-dark .btn:hover,
.block-dark .btn:focus-visible {
  border-color: var(--color-contrast-accent);
  color: var(--color-contrast-accent);
}

/* ---------- 面包屑 ---------- */

.breadcrumb {
  padding-block: var(--space-3);
  border-bottom: var(--border-thin) solid var(--color-line);
}

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  color: var(--color-ink-muted);
}

.breadcrumb-list li {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.breadcrumb-list li + li::before {
  content: "/";
  color: var(--color-line);
}

.breadcrumb-list a {
  color: var(--color-ink-soft);
  transition: color 200ms ease;
}

.breadcrumb-list a:hover {
  color: var(--color-accent);
}

.breadcrumb-list [aria-current="page"] {
  color: var(--color-ink);
}

/* ---------- 目录 / 索引 ---------- */

.toc {
  padding-top: var(--space-3);
  border-top: 2px solid var(--color-ink);
}

.toc-title {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.22em;
  color: var(--color-ink-muted);
}

.toc-list {
  display: grid;
  gap: var(--space-2);
  margin-top: var(--space-3);
}

.toc-list a {
  position: relative;
  display: block;
  padding-left: var(--space-3);
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-ink-soft);
  transition: color 200ms ease;
}

.toc-list a::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.78em;
  width: 10px;
  height: var(--border-thin);
  background-color: var(--color-line);
  transition: width 240ms ease, background-color 240ms ease;
}

.toc-list a:hover {
  color: var(--color-ink);
}

.toc-list a[aria-current="true"] {
  color: var(--color-accent);
}

.toc-list a[aria-current="true"]::before {
  width: 18px;
  background-color: var(--color-accent);
}

/* ==========================================================================
   头部
   ========================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: var(--color-surface);
  border-bottom: var(--border-thin) solid var(--color-line);
}

.skip-link {
  position: absolute;
  top: 0;
  left: 0;
  z-index: 100;
  padding: var(--space-2) var(--space-3);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  letter-spacing: 0.1em;
  transform: translateY(-120%);
  transition: transform 200ms ease;
}

.skip-link:focus {
  transform: translateY(0);
}

.header-frame {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  column-gap: var(--space-3);
  row-gap: var(--space-2);
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: var(--space-3) var(--gutter);
}

.brand-block {
  grid-column: 1;
  grid-row: 1;
  min-width: 0;
}

.brand {
  display: block;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: 1.15;
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  transition: color 200ms ease;
}

.brand:hover {
  color: var(--color-accent);
}

.brand-signature {
  margin-top: 2px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.22em;
  line-height: 1.8;
  color: var(--color-ink-muted);
}

.nav-toggle {
  grid-column: 2;
  grid-row: 1;
  display: none;
  align-items: center;
  gap: var(--space-1);
  min-height: 44px;
  padding: 0 var(--space-2);
  border: var(--border-thin) solid var(--color-ink);
  background-color: var(--color-surface);
  color: var(--color-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  transition: background-color 200ms ease, color 200ms ease, border-color 200ms ease;
}

.nav-toggle[aria-expanded="true"] {
  background-color: var(--color-contrast-surface);
  border-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.nav-toggle-bars {
  display: inline-flex;
  flex-direction: column;
  gap: 5px;
  width: 18px;
}

.nav-toggle-bar {
  display: block;
  width: 18px;
  height: var(--border-thin);
  background-color: currentColor;
}

.nav-toggle-label {
  line-height: 1;
}

.site-nav {
  grid-column: 1 / -1;
  grid-row: 2;
}

.nav-scale {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  gap: 0;
}

.nav-scale-item > a {
  position: relative;
  display: block;
  padding: var(--space-3) 0;
  border-bottom: var(--border-thin) solid var(--color-line);
  font-size: var(--text-sm);
  letter-spacing: 0.14em;
  color: var(--color-ink-soft);
  transition: color 220ms ease;
}

.nav-scale-item > a:hover {
  color: var(--color-ink);
}

.nav-scale-item > a[aria-current="page"] {
  color: var(--color-accent);
}

.scroll-scale {
  position: absolute;
  left: 0;
  bottom: 0;
  z-index: 2;
  display: block;
  width: 0;
  height: 2px;
  background-color: var(--color-accent);
  transition: width 120ms linear;
}

@media (max-width: 900px) {
  .nav-toggle {
    display: inline-flex;
  }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    z-index: 5;
    display: none;
    padding: var(--space-1) var(--gutter) var(--space-4);
    background-color: var(--color-surface);
    border-top: var(--border-thin) solid var(--color-line);
    border-bottom: 2px solid var(--color-ink);
  }

  .site-nav[data-open] {
    display: block;
  }
}

@media (min-width: 901px) {
  .header-frame {
    grid-template-columns: auto minmax(0, 1fr);
    align-items: end;
  }

  .brand-block {
    grid-column: 1;
    grid-row: 1;
  }

  .site-nav {
    grid-column: 2;
    grid-row: 1;
    justify-self: end;
    align-self: end;
  }

  .nav-scale {
    flex-direction: row;
    align-items: flex-end;
    gap: var(--space-4);
  }

  .nav-scale-item > a {
    padding: var(--space-2) 0 2px;
    border-bottom: 0;
    white-space: nowrap;
  }

  .nav-scale-item > a::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 14px;
    height: 2px;
    background-color: var(--color-line);
    transition: width 320ms ease, background-color 320ms ease;
  }

  .nav-scale-item > a:hover::before,
  .nav-scale-item > a:focus-visible::before {
    width: 100%;
    background-color: var(--color-primary);
  }

  .nav-scale-item > a[aria-current="page"]::before {
    width: 100%;
    background-color: var(--color-accent);
  }
}

/* ==========================================================================
   页脚
   ========================================================================== */

.site-footer {
  margin-top: min(var(--section-y), 13vw);
  background-color: var(--color-surface-alt);
  border-top: 3px double var(--color-line);
  color: var(--color-ink);
}

.footer-frame {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-4);
  max-width: var(--container);
  margin: 0 auto;
  padding: var(--space-6) var(--gutter) var(--space-4);
}

.footer-lead {
  min-width: 0;
}

.footer-brand {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}

.footer-tagline {
  margin-top: var(--space-1);
  max-width: 26ch;
  font-size: var(--text-sm);
  line-height: 1.9;
  color: var(--color-ink-soft);
}

.footer-compare {
  display: inline-block;
  margin-top: var(--space-2);
  padding-bottom: 1px;
  border-bottom: var(--border-thin) solid var(--color-accent);
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  color: var(--color-accent);
  transition: color 200ms ease, border-color 200ms ease;
}

.footer-compare:hover {
  color: var(--color-focus);
  border-bottom-color: var(--color-focus);
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  column-gap: var(--space-4);
  row-gap: var(--space-2);
}

.footer-nav a {
  padding-bottom: 2px;
  border-bottom: var(--border-thin) solid transparent;
  font-size: var(--text-sm);
  letter-spacing: 0.1em;
  color: var(--color-ink-soft);
  transition: color 200ms ease, border-color 200ms ease;
}

.footer-nav a:hover {
  color: var(--color-ink);
  border-bottom-color: var(--color-accent);
}

.footer-foot {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-2) var(--space-4);
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid var(--color-line);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  line-height: 1.95;
  color: var(--color-ink-muted);
}

.footer-contact {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1) var(--space-3);
  min-width: 0;
}

.footer-contact-item {
  display: inline-block;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1) var(--space-3);
}

@media (min-width: 901px) {
  .footer-frame {
    grid-template-columns: minmax(0, 20ch) minmax(0, 1fr) minmax(0, 1fr);
    column-gap: var(--space-6);
    align-items: start;
  }

  .footer-lead {
    grid-column: 1;
  }

  .footer-nav {
    grid-column: 2 / -1;
    justify-content: flex-start;
  }

  .footer-foot {
    grid-column: 1 / -1;
  }
}

/* ==========================================================================
   动效
   ========================================================================== */

.is-reveal-ready [data-reveal] {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 400ms cubic-bezier(0.22, 0.61, 0.36, 1),
    transform 400ms cubic-bezier(0.22, 0.61, 0.36, 1);
}

.is-reveal-ready [data-reveal].is-revealed {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .is-reveal-ready [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }

  .scroll-scale,
  .nav-scale-item > a::before,
  .toc-list a::before {
    transition: none !important;
  }
}

@media (max-width: 600px) {
  .section-head {
    gap: var(--space-1);
  }

  .display {
    line-height: 1.18;
  }

  .footer-foot {
    flex-direction: column;
    align-items: flex-start;
  }
}