/* =========================================================
   PG游艺中心 · /assets/site.css
   共享外壳：reset、变量、中文排版、头部、页脚、按钮、
   面包屑、正文容器、网格、基础组件
   ========================================================= */

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

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

body, h1, h2, h3, h4, p, ul, ol, li, figure, blockquote, dl, dd, fieldset { margin: 0; }
ul, ol { padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; }
button { font: inherit; color: inherit; background: none; border: 0; }
a { color: inherit; text-decoration: none; }
table { border-collapse: collapse; }
hr { border: 0; border-top: 1px solid rgba(143, 163, 184, 0.22); }

/* ---------- 变量 ---------- */
:root {
  --ink: #0A1626;
  --teal: #062A33;
  --slate: #16283D;
  --cyan: #2FE3C8;
  --orange: #FF7A33;
  --sand: #E6D3B3;
  --mist: #8FA3B8;
  --paper: #F4F7FA;
  --violet: #7C6BFF;
  --amber: #FFC24B;

  --dim: rgba(244, 247, 250, 0.66);
  --line: rgba(143, 163, 184, 0.22);
  --line-strong: rgba(47, 227, 200, 0.34);
  --cyan-soft: rgba(47, 227, 200, 0.10);
  --orange-soft: rgba(255, 122, 51, 0.14);

  --font-sans: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --fs-12: 12px;
  --fs-14: 14px;
  --fs-16: 16px;
  --fs-18: 18px;
  --fs-22: 22px;
  --fs-28: 28px;
  --fs-36: 36px;
  --fs-52: 52px;
  --fs-80: 80px;
  --fs-128: 128px;

  --wrap: 1180px;
  --gutter: 24px;
  --radius: 2px;
}

@media (max-width: 640px) {
  :root { --gutter: 18px; }
}

/* ---------- 基础排版 ---------- */
body {
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-sans);
  font-size: var(--fs-16);
  font-weight: 400;
  line-height: 1.85;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, .h1 {
  font-size: var(--fs-52);
  font-weight: 900;
  line-height: 0.95;
  letter-spacing: -0.03em;
}
h2, .h2 {
  font-size: var(--fs-36);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.015em;
  margin-bottom: 12px;
}
h3, .h3 {
  font-size: var(--fs-22);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.01em;
  margin-bottom: 8px;
}
@media (max-width: 900px) {
  h1, .h1 { font-size: var(--fs-36); }
  h2, .h2 { font-size: var(--fs-28); }
}
@media (max-width: 640px) {
  h1, .h1 { font-size: var(--fs-28); }
  h2, .h2 { font-size: var(--fs-22); }
}

p { text-wrap: pretty; }

strong, b { font-weight: 700; color: var(--paper); }

code, kbd, samp, .mono {
  font-family: var(--font-mono);
  font-size: 0.95em;
  letter-spacing: 0.02em;
}

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

:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 3px;
  border-radius: 1px;
}
a:focus:not(:focus-visible),
button:focus:not(:focus-visible) { outline: none; }

[id] { scroll-margin-top: 110px; }

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ---------- 容器与网格 ---------- */
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.grid { display: grid; gap: 24px; }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid--main { grid-template-columns: minmax(0, 7fr) minmax(0, 3fr); gap: 40px; }

@media (max-width: 900px) {
  .grid--3, .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--main { grid-template-columns: minmax(0, 1fr); gap: 28px; }
}
@media (max-width: 600px) {
  .grid--2, .grid--3, .grid--4 { grid-template-columns: minmax(0, 1fr); }
}

.section {
  position: relative;
  padding-block: clamp(48px, 7vw, 96px);
}
.section + .section { border-top: 1px solid var(--line); }
.section--teal { background: var(--teal); }
.section--sand { background: var(--sand); color: var(--ink); }
.section--sand h1, .section--sand h2, .section--sand h3,
.section--sand strong, .section--sand b { color: var(--ink); }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.18em;
  color: var(--cyan);
  margin-bottom: 14px;
}
.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: currentColor;
}

.lead {
  font-size: var(--fs-18);
  line-height: 1.8;
  color: var(--dim);
  max-width: 34em;
}

/* ---------- 正文 ---------- */
.prose {
  max-width: 34em;
  font-size: var(--fs-18);
  line-height: 1.85;
  color: rgba(244, 247, 250, 0.88);
}
.prose > * + * { margin-top: 1em; }
.prose h2 { margin-top: 1.8em; }
.prose h3 { margin-top: 1.5em; }
.prose a {
  color: var(--cyan);
  border-bottom: 1px solid rgba(47, 227, 200, 0.42);
}
.prose a:hover { border-bottom-color: var(--cyan); }
.prose ul, .prose ol { padding-left: 0; }
.prose li {
  position: relative;
  padding-left: 20px;
  margin-top: 0.45em;
}
.prose li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 0.72em;
  width: 6px;
  height: 6px;
  background: var(--cyan);
  transform: rotate(45deg);
}
.prose ol { counter-reset: prose-ol; }
.prose ol li { counter-increment: prose-ol; }
.prose ol li::before {
  content: counter(prose-ol, decimal-leading-zero);
  width: auto; height: auto;
  background: none;
  transform: none;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  color: var(--cyan);
  top: 0.28em;
}
.section--sand .prose { color: rgba(10, 22, 38, 0.86); }
.section--sand .prose a { color: var(--ink); border-bottom-color: rgba(10, 22, 38, 0.4); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 12px 20px;
  font-family: var(--font-sans);
  font-size: var(--fs-16);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
  border: 1px solid transparent;
  border-radius: var(--radius);
  cursor: pointer;
  transition: background-color 0.18s ease, color 0.18s ease, border-color 0.18s ease, filter 0.18s ease;
}
.btn--primary {
  background: var(--orange);
  border-color: var(--orange);
  color: var(--ink);
}
.btn--primary:hover { filter: brightness(1.09); }
.btn--ghost {
  background: transparent;
  border-color: var(--line-strong);
  color: var(--cyan);
}
.btn--ghost:hover { background: var(--cyan-soft); color: var(--paper); }
.btn--link {
  padding: 0;
  border: 0;
  background: none;
  color: var(--cyan);
  border-bottom: 1px solid rgba(47, 227, 200, 0.45);
  border-radius: 0;
}
.btn--link:hover { color: var(--paper); border-bottom-color: var(--orange); }
.btn--sm { font-size: var(--fs-14); padding: 8px 14px; }

/* ---------- 跳转链接 ---------- */
.skip-link {
  position: absolute;
  left: 16px;
  top: -80px;
  z-index: 200;
  padding: 10px 18px;
  background: var(--orange);
  color: var(--ink);
  font-size: var(--fs-14);
  font-weight: 700;
  border-radius: var(--radius);
  transition: top 0.18s ease;
}
.skip-link:focus { top: 12px; }

/* =========================================================
   头部
   ========================================================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  background: var(--ink);
  color: var(--paper);
  border-bottom: 1px solid var(--line);
  transition: box-shadow 0.2s ease;
}
.site-header[data-condensed] {
  box-shadow: 0 14px 34px rgba(0, 0, 0, 0.48);
}

.header-rule {
  height: 3px;
  background:
    repeating-linear-gradient(90deg, var(--cyan) 0 16px, transparent 16px 24px),
    var(--teal);
  opacity: 0.85;
}

/* 报头三槽 */
.masthead {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
  align-items: center;
  gap: 16px;
  padding-block: 18px 14px;
  transition: padding 0.22s ease;
}
.masthead__side {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}
.masthead__side--left { justify-content: flex-start; }
.masthead__side--right { justify-content: flex-end; }

.masthead__path {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.08em;
  color: var(--dim);
  white-space: nowrap;
  transition: opacity 0.18s ease;
}
.masthead__path::before {
  content: "";
  width: 6px;
  height: 6px;
  background: var(--amber);
  transform: rotate(45deg);
  flex: none;
}

.masthead__brand {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  text-align: center;
  justify-self: center;
  padding-block: 2px;
}
.masthead__wordmark {
  font-size: var(--fs-36);
  font-weight: 900;
  line-height: 0.95;
  letter-spacing: -0.03em;
  color: var(--paper);
  transition: font-size 0.22s ease;
}
.masthead__tagline {
  display: block;
  max-height: 22px;
  overflow: hidden;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  line-height: 1.4;
  letter-spacing: 0.2em;
  color: var(--cyan);
  transition: max-height 0.22s ease, opacity 0.16s ease;
}

.masthead__cta { white-space: nowrap; }

/* 压实状态 */
.site-header[data-condensed] .masthead { padding-block: 8px; }
.site-header[data-condensed] .masthead__wordmark { font-size: var(--fs-22); }
.site-header[data-condensed] .masthead__tagline { max-height: 0; opacity: 0; }
.site-header[data-condensed] .masthead__path { opacity: 0; pointer-events: none; }

/* 移动开关 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 10px 13px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.14em;
  cursor: pointer;
  transition: border-color 0.18s ease, background-color 0.18s ease;
}
.nav-toggle:hover { background: var(--cyan-soft); }
.nav-toggle__bars {
  position: relative;
  display: block;
  width: 18px;
  height: 10px;
  flex: none;
}
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--cyan);
  transition: transform 0.2s ease;
}
.nav-toggle__bars::before { top: 0; }
.nav-toggle__bars::after { bottom: 0; }
.site-header[data-open] .nav-toggle__bars::before { transform: translateY(4px) rotate(45deg); }
.site-header[data-open] .nav-toggle__bars::after { transform: translateY(-4px) rotate(-45deg); }
.site-header[data-open] .nav-toggle { border-color: var(--orange); }

/* 目录行导航 */
.site-nav {
  position: relative;
  z-index: 1;
  border-top: 1px solid var(--line);
}
.site-nav__inner { display: flex; justify-content: center; }
.site-nav__list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: stretch;
  gap: 2px;
}
.site-nav__link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 14px 16px;
  font-size: var(--fs-16);
  font-weight: 500;
  letter-spacing: -0.01em;
  color: var(--mist);
  transition: color 0.18s ease, background-color 0.18s ease;
}
.site-nav__no {
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.04em;
  color: rgba(47, 227, 200, 0.55);
  transition: color 0.18s ease;
}
.site-nav__link::after {
  content: "";
  position: absolute;
  left: 16px;
  right: 16px;
  bottom: 8px;
  height: 2px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.2s ease, background-color 0.2s ease;
}
.site-nav__link:hover,
.site-nav__link:focus-visible { color: var(--paper); }
.site-nav__link:hover::after,
.site-nav__link:focus-visible::after { transform: scaleX(1); }
.site-nav__link[aria-current="page"] {
  color: var(--paper);
  font-weight: 700;
}
.site-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--orange);
}
.site-nav__link[aria-current="page"] .site-nav__no { color: var(--orange); }

.site-nav__item--cta { display: none; }

/* 滚动进度 */
.scroll-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: rgba(47, 227, 200, 0.12);
  pointer-events: none;
}
.scroll-progress__bar {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--cyan), var(--violet) 55%, var(--orange));
  transition: transform 0.12s linear;
}

@media (max-width: 1100px) {
  .masthead__wordmark { font-size: var(--fs-28); }
}
@media (max-width: 900px) {
  .masthead {
    grid-template-columns: minmax(0, 1fr) auto;
    padding-block: 12px;
  }
  .masthead__side--left { display: none; }
  .masthead__brand { justify-self: start; align-items: flex-start; text-align: left; }
  .masthead__wordmark { font-size: var(--fs-22); }
  .masthead__cta { display: none; }
  .nav-toggle { display: inline-flex; }

  .site-nav {
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    visibility: hidden;
    transition: max-height 0.28s ease, opacity 0.2s ease, visibility 0.28s;
  }
  .site-header[data-open] .site-nav {
    max-height: calc(100vh - 90px);
    overflow-y: auto;
    opacity: 1;
    visibility: visible;
  }
  .site-nav__inner { display: block; padding-block: 6px 18px; }
  .site-nav__list { display: block; }
  .site-nav__item { border-bottom: 1px dashed var(--line); }
  .site-nav__item:last-child { border-bottom: 0; }
  .site-nav__link {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 14px 4px;
    font-size: var(--fs-18);
  }
  .site-nav__link::after { display: none; }
  .site-nav__link[aria-current="page"] {
    color: var(--cyan);
    box-shadow: inset 3px 0 0 var(--orange);
    padding-left: 12px;
  }
  .site-nav__item--cta {
    display: block;
    border-bottom: 0;
    padding-top: 14px;
  }
  .site-nav__cta { width: 100%; }
}
@media (max-width: 900px) and (prefers-reduced-motion: reduce) {
  .site-nav { transition: opacity 0.2s ease, visibility 0.2s; }
}

/* =========================================================
   页脚
   ========================================================= */
.site-footer {
  position: relative;
  background: var(--teal);
  border-top: 1px solid var(--line-strong);
  color: var(--paper);
}
.footer__edge {
  height: 4px;
  background: repeating-linear-gradient(90deg, var(--violet) 0 10px, transparent 10px 20px);
  opacity: 0.5;
}
.footer__top {
  display: grid;
  grid-template-columns: 1.7fr 1fr 1fr 1fr;
  gap: 36px 28px;
  padding-block: 52px 38px;
}
.footer__wordmark {
  font-size: var(--fs-28);
  font-weight: 900;
  line-height: 1;
  letter-spacing: -0.03em;
}
.footer__summary {
  margin-top: 12px;
  max-width: 26em;
  font-size: var(--fs-14);
  line-height: 1.8;
  color: var(--dim);
}
.footer__title {
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.16em;
  color: var(--cyan);
  margin-bottom: 14px;
}
.footer__list li + li { margin-top: 8px; }
.footer__link {
  font-size: var(--fs-14);
  color: var(--dim);
  border-bottom: 1px solid transparent;
  padding-bottom: 1px;
  transition: color 0.16s ease, border-color 0.16s ease;
}
.footer__link:hover,
.footer__link:focus-visible {
  color: var(--paper);
  border-bottom-color: var(--orange);
}
.footer__contact {
  margin-top: 16px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  line-height: 1.9;
  letter-spacing: 0.02em;
  color: var(--dim);
}
.footer__contact-line {
  display: block;
  word-break: break-word;
}

.footer__pathbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 18px;
  padding-block: 18px;
  border-top: 1px dashed rgba(143, 163, 184, 0.3);
  border-bottom: 1px dashed rgba(143, 163, 184, 0.3);
}
.footer__pathlabel {
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.14em;
  color: var(--amber);
}
.pathbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}
.pathbar__step {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: var(--fs-14);
}
.pathbar__step + .pathbar__step::before {
  content: "→";
  font-family: var(--font-mono);
  color: rgba(47, 227, 200, 0.6);
}
.pathbar__link {
  color: var(--dim);
  border-bottom: 1px solid rgba(47, 227, 200, 0.25);
  padding-bottom: 1px;
  transition: color 0.16s ease, border-color 0.16s ease;
}
.pathbar__link:hover,
.pathbar__link:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.footer__bottom {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 14px 24px;
  align-items: baseline;
  padding-block: 22px 34px;
}
.footer__note {
  grid-column: 1 / -1;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  line-height: 1.8;
  letter-spacing: 0.03em;
  color: var(--dim);
}
.footer__legal,
.footer__copy {
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.04em;
  color: var(--dim);
}

@media (max-width: 900px) {
  .footer__top {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 28px 24px;
    padding-block: 40px 30px;
  }
  .footer__brand { grid-column: 1 / -1; }
}
@media (max-width: 560px) {
  .footer__top { grid-template-columns: minmax(0, 1fr); }
  .footer__bottom { grid-template-columns: minmax(0, 1fr); }
}

/* =========================================================
   通用组件
   ========================================================= */

/* 面包屑 */
.breadcrumbs {
  padding-block: 16px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.06em;
  color: var(--dim);
}
.breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}
.breadcrumbs__item { display: inline-flex; align-items: center; }
.breadcrumbs__item + .breadcrumbs__item::before {
  content: "›";
  margin-right: 8px;
  color: rgba(47, 227, 200, 0.55);
}
.breadcrumbs__link {
  color: var(--dim);
  border-bottom: 1px solid transparent;
  transition: color 0.16s ease, border-color 0.16s ease;
}
.breadcrumbs__link:hover,
.breadcrumbs__link:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}
.breadcrumbs [aria-current="page"] { color: var(--paper); }

/* 卡片 */
.card {
  position: relative;
  padding: 22px 22px 24px;
  background: var(--slate);
  border: 1px solid var(--line);
  border-top: 2px solid var(--line-strong);
  border-radius: var(--radius);
  transition: border-top-color 0.18s ease, background-color 0.18s ease, transform 0.18s ease;
}
.card:hover { border-top-color: var(--cyan); background: rgba(22, 40, 61, 0.92); }
.card__label {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.12em;
  color: var(--cyan);
}
.card__title {
  font-size: var(--fs-22);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.015em;
  margin-bottom: 8px;
}
.card__text {
  font-size: var(--fs-16);
  line-height: 1.8;
  color: var(--dim);
}
.section--sand .card { background: rgba(255, 255, 255, 0.42); border-color: rgba(10, 22, 38, 0.18); }
.section--sand .card__text { color: rgba(10, 22, 38, 0.72); }

/* 纸白叠层卡 */
.paper {
  position: relative;
  padding: 28px 26px;
  background: var(--paper);
  color: var(--ink);
  border: 1px solid rgba(10, 22, 38, 0.16);
  border-radius: var(--radius);
  box-shadow:
    8px 8px 0 rgba(6, 42, 51, 0.55),
    16px 16px 0 rgba(47, 227, 200, 0.12);
}
.paper h2, .paper h3, .paper strong, .paper b { color: var(--ink); }
.paper a { color: var(--ink); border-bottom: 1px solid rgba(10, 22, 38, 0.38); }
.paper__label {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.14em;
  color: rgba(10, 22, 38, 0.62);
}

/* 标签 */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.08em;
  color: var(--cyan);
  background: rgba(47, 227, 200, 0.07);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
}
.tag--violet {
  color: var(--violet);
  border-color: rgba(124, 107, 255, 0.45);
  background: rgba(124, 107, 255, 0.1);
}
.tag--amber {
  color: var(--amber);
  border-color: rgba(255, 194, 75, 0.45);
  background: rgba(255, 194, 75, 0.1);
}
.tag--sand {
  color: var(--ink);
  background: var(--sand);
  border-color: var(--sand);
}

/* 三步节奏 */
.steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}
.step {
  position: relative;
  padding: 20px 20px 22px;
  background: rgba(22, 40, 61, 0.72);
  border-left: 2px solid var(--cyan);
}
.step__no {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: var(--fs-52);
  font-weight: 400;
  line-height: 0.9;
  letter-spacing: -0.04em;
  color: rgba(47, 227, 200, 0.3);
}
.step__title {
  font-size: var(--fs-22);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.015em;
  margin-bottom: 6px;
}
.step__text {
  font-size: var(--fs-16);
  line-height: 1.75;
  color: var(--dim);
}
.step--active { border-left-color: var(--orange); }
.step--active .step__no { color: var(--orange); }
@media (max-width: 760px) {
  .steps { grid-template-columns: minmax(0, 1fr); }
}

/* 横向滑轨 */
.rail {
  display: flex;
  gap: 16px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  padding-bottom: 14px;
}
.rail__item {
  flex: 0 0 min(320px, 82%);
  scroll-snap-align: start;
}
.rail::-webkit-scrollbar { height: 6px; }
.rail::-webkit-scrollbar-track { background: rgba(143, 163, 184, 0.14); }
.rail::-webkit-scrollbar-thumb { background: rgba(47, 227, 200, 0.45); }

/* 可展开内容组 */
.accordion { border-top: 1px solid var(--line); }
.accordion__item { border-bottom: 1px solid var(--line); }
.accordion__trigger {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 18px;
  width: 100%;
  padding: 18px 2px;
  text-align: left;
  font-size: var(--fs-18);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--paper);
  cursor: pointer;
  transition: color 0.16s ease;
}
.accordion__trigger:hover { color: var(--cyan); }
.accordion__icon {
  position: relative;
  flex: none;
  width: 16px;
  height: 16px;
  margin-top: 6px;
  border: 1px solid var(--line-strong);
  transition: transform 0.2s ease, border-color 0.2s ease;
}
.accordion__icon::before,
.accordion__icon::after {
  content: "";
  position: absolute;
  background: var(--cyan);
  transition: opacity 0.2s ease;
}
.accordion__icon::before { left: 3px; right: 3px; top: 6px; height: 2px; }
.accordion__icon::after { top: 3px; bottom: 3px; left: 6px; width: 2px; }
.accordion__trigger[aria-expanded="true"] { color: var(--cyan); }
.accordion__trigger[aria-expanded="true"] .accordion__icon { transform: rotate(90deg); border-color: var(--orange); }
.accordion__trigger[aria-expanded="true"] .accordion__icon::after { opacity: 0; }
.accordion__panel {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 0.2s ease;
}
.accordion__panel > * { overflow: hidden; }
.accordion__panel[data-open] { grid-template-rows: 1fr; }
.accordion__body {
  padding: 0 2px 20px;
  font-size: var(--fs-16);
  line-height: 1.85;
  color: var(--dim);
}
.accordion__body > * + * { margin-top: 0.8em; }

/* 图片容器基础 */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--slate);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media--16x9 { aspect-ratio: 16 / 9; }
.media--4x3 { aspect-ratio: 4 / 3; }
.media--3x4 { aspect-ratio: 3 / 4; }
.media--wide { aspect-ratio: 21 / 9; }
.media--square { aspect-ratio: 1 / 1; }
.media--placeholder {
  background:
    repeating-linear-gradient(135deg, rgba(47, 227, 200, 0.09) 0 8px, transparent 8px 16px),
    var(--slate);
}
.media__tag {
  position: absolute;
  left: 12px;
  top: 12px;
  padding: 3px 9px;
  background: var(--ink);
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.1em;
  color: var(--cyan);
  border: 1px solid var(--line-strong);
}
.media__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  line-height: 1.7;
  letter-spacing: 0.03em;
  color: var(--dim);
}
@media (max-width: 600px) {
  .media--wide { aspect-ratio: 16 / 9; }
  .media--3x4 { aspect-ratio: 4 / 5; }
}

/* 旁注 */
.aside {
  padding-left: 18px;
  border-left: 1px solid var(--line-strong);
  font-size: var(--fs-16);
  line-height: 1.8;
  color: var(--dim);
}
.aside__title {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.14em;
  color: var(--cyan);
}
.note {
  padding: 14px 16px;
  background: var(--orange-soft);
  border-left: 2px solid var(--orange);
  font-size: var(--fs-16);
  line-height: 1.8;
  color: var(--paper);
}

/* 表格 */
.table {
  width: 100%;
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  letter-spacing: 0.02em;
}
.table th,
.table td {
  padding: 12px 14px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--line);
}
.table th {
  font-family: var(--font-sans);
  font-size: var(--fs-14);
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--cyan);
  white-space: nowrap;
}
.table td { color: var(--paper); }
.table caption {
  caption-side: top;
  padding-bottom: 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.1em;
  color: var(--dim);
  text-align: left;
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  .scroll-progress__bar { transition: none; }
  .site-nav { transition: opacity 0.2s ease, visibility 0.2s; }
}