/* ============================================================
   亚文网 · 站内索引册 / 共享站点样式
   文件路径：/assets/site.css
   负责：reset、变量、中文排版、页头页脚、通用组件、网格与图片容器
   ============================================================ */

/* ---------- 1. Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: 136px;
}
@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}

body, h1, h2, h3, h4, h5, p, figure, blockquote, dl, dd, ul, ol { margin: 0; }
ul, ol { padding: 0; list-style: none; }
img, svg { display: block; max-width: 100%; }
img { height: auto; }
button, input, select, textarea { font: inherit; color: inherit; background: none; border: 0; }
button { cursor: pointer; }
table { border-collapse: collapse; width: 100%; }

/* ---------- 2. 设计变量 ---------- */
:root {
  /* 品牌色 */
  --ink: #101C26;
  --jiang: #1E3748;
  --porcelain: #F7F3E9;
  --linen: #E6D8BD;
  --celadon: #C7DAD5;
  --cinnabar: #B23A2E;
  --cinnabar-soft: #D9634F;
  --patina: #4F6F68;
  --mist: #7A8C96;

  /* 透明层级 */
  --ink-12: rgba(16, 28, 38, .12);
  --ink-24: rgba(16, 28, 38, .24);
  --ink-70: rgba(16, 28, 38, .70);
  --light-08: rgba(247, 243, 233, .08);
  --light-14: rgba(247, 243, 233, .14);
  --light-22: rgba(247, 243, 233, .22);
  --light-70: rgba(247, 243, 233, .70);

  /* 字体 */
  --font-display: "Songti SC", "STSong", "Noto Serif SC", "Source Han Serif SC", Georgia, "Times New Roman", serif;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", "Source Han Sans SC", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, "SF Mono", Consolas, "Liberation Mono", monospace;

  /* 尺度 */
  --frame-max: 1440px;
  --gutter: clamp(1rem, 4vw, 2.5rem);
  --rail-w: 224px;
  --cut: 16px;
  --ease: cubic-bezier(.22, .61, .36, 1);
  --shadow-frame: 0 20px 44px -32px rgba(16, 28, 38, .9);
}

/* ---------- 3. 基础与中文排版 ---------- */
body {
  min-height: 100vh;
  background-color: var(--porcelain);
  background-image:
    radial-gradient(circle at 6% -10%, rgba(199, 218, 213, .55), transparent 46%),
    repeating-linear-gradient(0deg, rgba(16, 28, 38, .03) 0 1px, transparent 1px 5px);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.75;
  letter-spacing: .01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.26;
  letter-spacing: .01em;
  color: var(--ink);
}
h1 { font-size: clamp(2.1rem, 5.2vw, 3.5rem); letter-spacing: -.01em; }
h2 { font-size: clamp(1.55rem, 3.2vw, 2.2rem); }
h3 { font-size: clamp(1.16rem, 2vw, 1.45rem); }
h4 { font-size: 1.02rem; letter-spacing: .04em; }

p { margin: 0; }
a { color: inherit; text-decoration: none; }
small { font-size: .82em; }

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

/* ---------- 4. 通用工具 ---------- */
.container {
  width: min(calc(100% - var(--gutter) * 2), var(--frame-max));
  margin-inline: auto;
}

.section { padding-block: clamp(2.5rem, 6vw, 4.5rem); }

.stack > * + * { margin-top: var(--stack-gap, 1rem); }

.prose {
  max-width: 78ch;
  font-size: clamp(1rem, 1.05vw, 1.08rem);
  color: var(--ink);
}
.prose > * + * { margin-top: 1.1em; }
.prose h2 { margin-top: 2.1em; }
.prose h3 { margin-top: 1.7em; }
.prose a {
  color: var(--cinnabar);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: .22em;
}
.prose ul { list-style: disc; padding-left: 1.3rem; }
.prose ol { list-style: decimal; padding-left: 1.5rem; }
.prose li { margin: .35rem 0; }
.prose li::marker { color: var(--patina); }
.prose strong { font-weight: 600; }

.section-label {
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  font-family: var(--font-mono);
  font-size: .7rem;
  font-weight: 500;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--patina);
}
.section-label::before {
  content: "";
  width: 9px;
  height: 9px;
  flex: none;
  background: var(--cinnabar);
  clip-path: polygon(0 0, 100% 0, 100% 58%, 58% 100%, 0 100%);
}

.mono {
  font-family: var(--font-mono);
  font-size: .78rem;
  font-weight: 500;
  letter-spacing: .12em;
}

.tag {
  display: inline-block;
  padding: .14rem .5rem .18rem;
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .12em;
  color: var(--jiang);
  background: var(--celadon);
}

.annotation {
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .24em;
  color: var(--mist);
  writing-mode: vertical-rl;
  text-orientation: upright;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

/* ---------- 5. 按钮 ---------- */
.btn {
  --btn-bg: var(--ink);
  --btn-fg: var(--porcelain);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
  padding: .62rem 1.15rem;
  font-family: var(--font-body);
  font-size: .88rem;
  font-weight: 600;
  letter-spacing: .06em;
  line-height: 1.3;
  color: var(--btn-fg);
  background: var(--btn-bg);
  border: 0;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 10px), calc(100% - 10px) 100%, 0 100%);
  transition: transform .18s var(--ease), background-color .18s var(--ease), color .18s var(--ease);
}
.btn:hover { transform: translateY(-1px); }
.btn:active { transform: none; }
.btn--cinnabar { --btn-bg: var(--cinnabar); --btn-fg: #FFF6F2; }
.btn--cinnabar:hover { --btn-bg: #C24A3B; }
.btn--ghost { --btn-bg: var(--linen); --btn-fg: var(--ink); }
.btn--ghost:hover { --btn-bg: var(--celadon); }
.btn--line {
  --btn-bg: transparent;
  --btn-fg: var(--ink);
  clip-path: none;
  border: 1px solid var(--ink-24);
}
.btn--line:hover { --btn-bg: var(--ink); --btn-fg: var(--porcelain); border-color: var(--ink); }

/* ---------- 6. 网格 ---------- */
.grid { display: grid; gap: clamp(1rem, 2.5vw, 1.75rem); }
.grid--two { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--three { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--aside { grid-template-columns: minmax(0, 1fr) minmax(240px, 320px); }

/* ---------- 7. 卡片（切角面板） ---------- */
.card {
  position: relative;
  padding: clamp(1.1rem, 2vw, 1.5rem);
  background: var(--porcelain);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--cut)), calc(100% - var(--cut)) 100%, 0 100%);
}
.card--paper { background: var(--linen); }
.card--celadon { background: var(--celadon); }
.card--ink { background: var(--jiang); color: var(--porcelain); }
.card__label {
  display: block;
  margin-bottom: .5rem;
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .18em;
  color: var(--cinnabar);
}
.card--ink .card__label { color: var(--cinnabar-soft); }
.card__title {
  font-family: var(--font-display);
  font-size: clamp(1.1rem, 1.8vw, 1.35rem);
  font-weight: 700;
  line-height: 1.35;
}
.card__text {
  margin-top: .6rem;
  font-size: .95rem;
  line-height: 1.7;
  color: var(--ink-70);
}
.card--ink .card__text { color: var(--light-70); }

/* ---------- 8. 图片容器（供页面阶段放置占位） ---------- */
.media {
  position: relative;
  margin: 0;
  background: var(--linen);
  overflow: hidden;
}
.media__frame {
  aspect-ratio: var(--media-ratio, 16 / 10);
  overflow: hidden;
  background-color: var(--celadon);
  background-image: repeating-linear-gradient(135deg, rgba(16, 28, 38, .07) 0 10px, transparent 10px 20px);
}
.media__frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media--wide { --media-ratio: 21 / 9; }
.media--tall { --media-ratio: 3 / 4; }
.media__caption {
  padding: .5rem .1rem 0;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .08em;
  line-height: 1.6;
  color: var(--patina);
}

/* ---------- 9. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .4rem;
  margin-bottom: 1.25rem;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .1em;
  color: var(--patina);
}
.breadcrumb__item { display: inline-flex; align-items: center; gap: .4rem; }
.breadcrumb__link {
  color: var(--patina);
  border-bottom: 1px solid transparent;
  transition: color .18s var(--ease), border-color .18s var(--ease);
}
.breadcrumb__link:hover { color: var(--cinnabar); border-color: var(--cinnabar); }
.breadcrumb__sep { color: var(--mist); }
.breadcrumb__current { color: var(--ink); }

/* ---------- 10. 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: .5rem;
  left: .5rem;
  z-index: 200;
  padding: .7rem 1.15rem;
  font-size: .9rem;
  font-weight: 600;
  color: var(--ink);
  background: var(--porcelain);
  border: 2px solid var(--cinnabar);
  transform: translateY(-180%);
  transition: transform .18s var(--ease);
}
.skip-link:focus,
.skip-link:focus-visible { transform: translateY(0); outline-offset: 2px; }

/* ---------- 11. 页头（框架式索引条） ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: var(--jiang);
  color: var(--porcelain);
  border-bottom: 1px solid var(--light-22);
  box-shadow: var(--shadow-frame);
}

.read-progress {
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background: var(--light-14);
}
.read-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--cinnabar), var(--cinnabar-soft));
  transition: width .12s linear;
}

.header-frame {
  width: min(calc(100% - var(--gutter) * 2), var(--frame-max));
  margin-inline: auto;
}

.header-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: .7rem 0 .65rem;
  border-bottom: 1px solid var(--light-14);
}

.brand {
  display: flex;
  align-items: center;
  gap: .72rem;
  min-width: 0;
  color: var(--porcelain);
}
.brand:hover { color: var(--porcelain); }
.brand__mark {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  flex: none;
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1;
  color: #FFF6F2;
  background: var(--cinnabar);
  clip-path: polygon(0 0, 100% 0, 100% 72%, 72% 100%, 0 100%);
}
.brand__mark--light { color: var(--ink); background: var(--celadon); }
.brand__text { display: flex; flex-direction: column; min-width: 0; line-height: 1.22; }
.brand__name {
  font-family: var(--font-display);
  font-size: 1.02rem;
  font-weight: 700;
  letter-spacing: .04em;
  white-space: nowrap;
}
.brand__tagline {
  margin-top: .16rem;
  font-family: var(--font-mono);
  font-size: .66rem;
  font-weight: 500;
  letter-spacing: .2em;
  color: var(--celadon);
  white-space: nowrap;
}

.header-tools {
  display: flex;
  align-items: center;
  gap: clamp(.5rem, 1.4vw, 1.1rem);
  flex: none;
}

.utility-nav { display: flex; align-items: center; gap: 1rem; }
.utility-nav__item { display: inline-flex; }
.utility-nav__link {
  padding: .2rem 0;
  font-size: .82rem;
  font-weight: 500;
  letter-spacing: .06em;
  color: var(--celadon);
  border-bottom: 1px solid transparent;
  transition: color .18s var(--ease), border-color .18s var(--ease);
}
.utility-nav__link:hover { color: var(--porcelain); border-color: var(--cinnabar); }

.header-cta { white-space: nowrap; }

.nav-toggle {
  display: none;
  align-items: center;
  gap: .5rem;
  padding: .45rem .65rem;
  font-family: var(--font-mono);
  font-size: .7rem;
  font-weight: 500;
  letter-spacing: .16em;
  color: var(--porcelain);
  border: 1px solid var(--light-22);
}
.nav-toggle:hover { border-color: var(--celadon); }
.nav-toggle__bars {
  position: relative;
  display: block;
  width: 16px;
  height: 2px;
  background: currentColor;
  transition: background-color .18s var(--ease);
}
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 16px;
  height: 2px;
  background: currentColor;
  transition: transform .2s var(--ease), top .2s var(--ease);
}
.nav-toggle__bars::before { top: -5px; }
.nav-toggle__bars::after { top: 5px; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { top: 0; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { top: 0; transform: rotate(-45deg); }

.site-nav { display: block; }
.site-nav__list { display: flex; align-items: stretch; }
.site-nav__item { flex: 1 1 0; min-width: 0; display: flex; }
.site-nav__link {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: .5rem;
  width: 100%;
  padding: .72rem 1rem .68rem;
  color: var(--light-70);
  border-left: 1px solid var(--light-14);
  transition: color .18s var(--ease), background-color .18s var(--ease);
}
.site-nav__item:first-child .site-nav__link { border-left: 0; padding-left: 0; }
.site-nav__code {
  font-family: var(--font-mono);
  font-size: .64rem;
  font-weight: 500;
  letter-spacing: .12em;
  color: rgba(199, 218, 213, .55);
  transition: color .18s var(--ease);
}
.site-nav__label {
  font-family: var(--font-display);
  font-size: .98rem;
  font-weight: 700;
  letter-spacing: .06em;
  white-space: nowrap;
}
.site-nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: var(--cinnabar);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .22s var(--ease);
}
.site-nav__link:hover { color: var(--porcelain); background: var(--light-08); }
.site-nav__link:hover::after { transform: scaleX(1); }
.site-nav__link[aria-current="page"] { color: var(--porcelain); background: rgba(178, 58, 46, .16); }
.site-nav__link[aria-current="page"] .site-nav__code { color: var(--cinnabar-soft); }
.site-nav__link[aria-current="page"]::after { transform: scaleX(1); }

@keyframes navIn {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: none; }
}

/* ---------- 12. 页脚（版权页 / colophon） ---------- */
.site-footer {
  margin-top: clamp(3rem, 7vw, 5.5rem);
  background: var(--ink);
  color: var(--light-70);
  border-top: 2px solid var(--cinnabar);
}
.footer-frame {
  width: min(calc(100% - var(--gutter) * 2), var(--frame-max));
  margin-inline: auto;
  padding: clamp(2.5rem, 5vw, 4rem) 0 1.4rem;
}

.footer-lead {
  display: grid;
  grid-template-columns: minmax(200px, 1fr) minmax(0, 1.85fr) minmax(240px, 1.1fr);
  gap: clamp(1.5rem, 3.5vw, 3rem);
  align-items: start;
}

.footer-brand { display: flex; flex-direction: column; align-items: flex-start; gap: .55rem; }
.footer-brand__name {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--porcelain);
}
.footer-brand__note {
  font-size: .86rem;
  line-height: 1.7;
  color: var(--light-70);
  max-width: 26ch;
}

.footer-cols {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(1rem, 2vw, 1.75rem);
}
.footer-col__title {
  display: flex;
  align-items: center;
  gap: .45rem;
  margin-bottom: .7rem;
  font-family: var(--font-mono);
  font-size: .7rem;
  font-weight: 600;
  letter-spacing: .18em;
  color: var(--celadon);
}
.footer-col__title::before {
  content: "";
  width: 7px;
  height: 7px;
  flex: none;
  background: var(--cinnabar);
}
.footer-list { display: flex; flex-direction: column; gap: .38rem; }
.footer-list__item { display: block; }
.footer-list__link {
  display: inline-block;
  font-size: .9rem;
  color: var(--light-70);
  border-bottom: 1px solid transparent;
  transition: color .18s var(--ease), border-color .18s var(--ease);
}
.footer-list__link:hover { color: var(--porcelain); border-color: var(--cinnabar-soft); }

.footer-contact {
  padding: 1rem 1.1rem 1.1rem;
  background: rgba(247, 243, 233, .06);
  border-left: 2px solid var(--cinnabar);
}
.footer-contact__title {
  margin-bottom: .7rem;
  font-family: var(--font-mono);
  font-size: .7rem;
  font-weight: 600;
  letter-spacing: .18em;
  color: var(--celadon);
}
.contact-list { display: flex; flex-direction: column; gap: .42rem; }
.contact-list__item {
  display: grid;
  grid-template-columns: 3.1em minmax(0, 1fr);
  gap: .5rem;
  align-items: baseline;
  font-size: .84rem;
  line-height: 1.6;
}
.contact-list__key {
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .1em;
  color: var(--mist);
}
.contact-list__value { color: var(--porcelain); word-break: break-word; }
.footer-note {
  margin-top: .85rem;
  padding-top: .7rem;
  font-size: .78rem;
  line-height: 1.7;
  color: var(--light-70);
  border-top: 1px dashed var(--light-22);
}

.footer-base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: .6rem 1.25rem;
  margin-top: clamp(1.5rem, 3vw, 2.5rem);
  padding-top: 1rem;
  border-top: 1px solid var(--light-14);
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .08em;
  color: rgba(247, 243, 233, .6);
}
.footer-base__icp,
.footer-base__copy { margin: 0; }
.footer-legal { display: flex; flex-wrap: wrap; gap: .9rem; }
.footer-legal__item { display: inline-flex; }
.footer-legal__link {
  color: rgba(247, 243, 233, .6);
  border-bottom: 1px solid transparent;
  transition: color .18s var(--ease), border-color .18s var(--ease);
}
.footer-legal__link:hover { color: var(--porcelain); border-color: var(--cinnabar-soft); }

/* ---------- 13. 滚动交互协议 ---------- */
.has-js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
}
[data-reveal] {
  transition: opacity .42s var(--ease), transform .42s var(--ease);
}
.has-js [data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

[data-index-link].is-active {
  color: var(--cinnabar);
  font-weight: 600;
}
[data-index-link].is-active .site-nav__code { color: var(--cinnabar); }

/* ---------- 14. 响应式 ---------- */
@media (max-width: 1180px) {
  .site-nav__link { padding: .7rem .6rem .66rem; }
  .site-nav__label { font-size: .92rem; letter-spacing: .04em; }
  .grid--aside { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 1000px) {
  .footer-lead { grid-template-columns: minmax(0, 1fr) minmax(0, 1.5fr); }
  .footer-contact { grid-column: 1 / -1; }
}

@media (max-width: 900px) {
  html { scroll-padding-top: 112px; }

  .utility-nav { display: none; }
  .nav-toggle { display: inline-flex; }

  .site-nav {
    display: none;
    padding: .35rem 0 1rem;
    border-top: 1px solid var(--light-14);
  }
  .site-nav[data-open] {
    display: block;
    animation: navIn .22s var(--ease);
  }
  .site-nav__list { flex-direction: column; }
  .site-nav__item { flex: 0 0 auto; }
  .site-nav__link {
    justify-content: space-between;
    align-items: center;
    padding: .85rem .15rem;
    border-left: 0;
    border-top: 1px solid var(--light-14);
  }
  .site-nav__item:first-child .site-nav__link { border-top: 0; padding-left: .15rem; }
  .site-nav__label { font-size: 1.05rem; letter-spacing: .08em; }
  .site-nav__link::after { left: 0; right: auto; width: 58%; }

  .grid--two,
  .grid--three { grid-template-columns: minmax(0, 1fr); }

  .footer-cols { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1.25rem; }
}

@media (max-width: 720px) {
  .footer-lead { grid-template-columns: minmax(0, 1fr); }
  .footer-brand__note { max-width: none; }
  .footer-base { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 600px) {
  .brand__tagline { display: none; }
  .brand__name { font-size: .95rem; }
  .brand__mark { width: 34px; height: 34px; font-size: .95rem; }
  .header-cta { padding: .5rem .8rem; font-size: .8rem; }
  .header-tools { gap: .45rem; }
}

@media (max-width: 420px) {
  .footer-cols { grid-template-columns: minmax(0, 1fr); }
  .nav-toggle__label { display: none; }
}

/* ---------- 15. 动效与打印偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  .has-js [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
  }
}

@media print {
  .site-header,
  .site-footer,
  .skip-link { display: none !important; }
  body { background: #fff; color: #000; }
  a { text-decoration: underline; }
}