/* =========================================================
   永信217主页 · 共享样式表 /assets/site.css
   目录型内容地图 · 瓷白水绿 · 切角与索引轨道
   ========================================================= */

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

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

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

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

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

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

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

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

/* ---------- 2. 变量 ---------- */
:root {
  --porcelain: #F7FAF8;
  --mist: #E6F2ED;
  --aqua: #35B9A4;
  --deep-aqua: #1E7C6E;
  --electric: #00D9B5;
  --vermilion: #C8453A;
  --copper: #B98A4B;
  --ink: #14231F;
  --slate: #5C6B66;
  --deep-ink: #0E1F1B;

  --rail-w: 76px;
  --header-h: 64px;
  --maxw: 1180px;
  --cut: 18px;

  --font-display: "HarmonyOS Sans SC", "PingFang SC", "Helvetica Neue", "Microsoft YaHei", sans-serif;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;

  --ease: cubic-bezier(.22, .61, .36, 1);
}

/* ---------- 3. 基础排版 ---------- */
body {
  min-height: 100vh;
  padding-top: var(--header-h);
  padding-left: var(--rail-w);
  background-color: var(--porcelain);
  background-image:
    repeating-linear-gradient(0deg, rgba(20, 35, 31, .022) 0 1px, transparent 1px 4px),
    repeating-linear-gradient(90deg, rgba(20, 35, 31, .016) 0 1px, transparent 1px 5px);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.75;
  letter-spacing: .01em;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  line-height: 1.3;
  letter-spacing: .02em;
}

h1 { font-size: clamp(34px, 5vw, 56px); font-weight: 900; }
h2 { font-size: clamp(26px, 3.6vw, 36px); font-weight: 900; }
h3 { font-size: clamp(20px, 2.2vw, 22px); font-weight: 700; }
h4 { font-size: 18px; font-weight: 700; }

strong { font-weight: 700; }

::selection { background: rgba(0, 217, 181, .28); }

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

#main-content { scroll-margin-top: calc(var(--header-h) + 20px); }

/* ---------- 4. 工具类 ---------- */
.mono {
  font-family: var(--font-mono);
  letter-spacing: .06em;
  font-variant-numeric: tabular-nums;
}

.link-underline {
  color: var(--deep-aqua);
  padding-bottom: 2px;
  background-image: linear-gradient(var(--aqua), var(--aqua));
  background-repeat: no-repeat;
  background-position: 0 100%;
  background-size: 0% 1.5px;
  transition: background-size .18s var(--ease), color .18s var(--ease);
}
.link-underline:hover,
.link-underline:focus-visible { background-size: 100% 1.5px; }

/* ---------- 5. Skip link ---------- */
.skip-link {
  position: fixed;
  top: -72px;
  left: 14px;
  z-index: 200;
  padding: 11px 18px;
  background: var(--deep-ink);
  color: var(--porcelain);
  font-size: 14px;
  letter-spacing: .08em;
  border-radius: 2px;
  transition: top .18s var(--ease);
}
.skip-link:focus { top: 14px; }

/* ---------- 6. 站点头部 ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: var(--rail-w);
  right: 0;
  z-index: 60;
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 0 clamp(14px, 2.6vw, 30px);
  background: var(--porcelain);
  border-bottom: 1px solid rgba(20, 35, 31, .1);
}

.site-header::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: linear-gradient(90deg, var(--aqua) 0%, var(--electric) 16%, rgba(53, 185, 164, 0) 48%);
  pointer-events: none;
}

.brand {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 2px;
  min-width: 0;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: .07em;
  color: var(--ink);
  transition: color .16s var(--ease);
}

.brand-sub {
  font-family: var(--font-mono);
  font-size: 10.5px;
  line-height: 1.2;
  letter-spacing: .1em;
  color: var(--slate);
  white-space: nowrap;
}

.brand:hover .brand-name,
.brand:focus-visible .brand-name { color: var(--deep-aqua); }

.header-meta {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-shrink: 0;
}

.header-index {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--copper);
  padding: 3px 9px;
  border: 1px solid rgba(185, 138, 75, .42);
  border-radius: 2px;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  height: 38px;
  padding: 0 13px;
  border: 1px solid rgba(20, 35, 31, .16);
  border-radius: 2px;
  transition: border-color .16s var(--ease), background .16s var(--ease);
}
.nav-toggle:hover { border-color: var(--aqua); background: var(--mist); }

.nav-toggle-bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  background: var(--ink);
  transition: background .18s var(--ease);
}
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: var(--ink);
  transition: transform .2s var(--ease);
}
.nav-toggle-bars::before { top: -6px; }
.nav-toggle-bars::after { top: 6px; }

.nav-toggle[aria-expanded="true"] .nav-toggle-bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after { transform: translateY(-6px) rotate(-45deg); }

.nav-toggle-text {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--ink);
}

/* ---------- 7. 侧边索引轨道 ---------- */
.rail {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 70;
  width: var(--rail-w);
  display: flex;
  flex-direction: column;
  padding-bottom: 20px;
  background: linear-gradient(180deg, var(--porcelain) 0%, var(--mist) 20%, var(--mist) 100%);
  border-right: 1px solid rgba(20, 35, 31, .1);
}

.rail::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 2px;
  height: 58%;
  background: linear-gradient(180deg, var(--aqua), rgba(53, 185, 164, 0));
  opacity: .55;
  pointer-events: none;
}

.rail-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-top: calc(var(--header-h) + 22px);
}

.rail-item { position: relative; }

.rail-link {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 46px;
  color: var(--slate);
  transition: background .16s var(--ease), color .16s var(--ease);
}

.rail-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
  font-variant-numeric: tabular-nums;
  transition: color .16s var(--ease);
}

.rail-label {
  position: absolute;
  left: calc(100% + 10px);
  top: 50%;
  z-index: 5;
  transform: translate(-6px, -50%);
  padding: 7px 12px;
  background: var(--deep-ink);
  color: var(--porcelain);
  font-size: 12.5px;
  line-height: 1;
  letter-spacing: .08em;
  white-space: nowrap;
  border-radius: 2px;
  opacity: 0;
  pointer-events: none;
  transition: opacity .16s var(--ease), transform .18s var(--ease);
}

.rail-link:hover,
.rail-link:focus-visible {
  background: rgba(53, 185, 164, .13);
  color: var(--deep-aqua);
}

.rail-link:hover .rail-label,
.rail-link:focus-visible .rail-label {
  opacity: 1;
  transform: translate(0, -50%);
}

.rail-link[aria-current="page"] {
  background: rgba(0, 217, 181, .16);
  color: var(--deep-aqua);
}

.rail-link[aria-current="page"]::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 3px;
  height: 22px;
  transform: translateY(-50%);
  background: var(--electric);
}

/* ---------- 8. 移动遮罩 ---------- */
.nav-scrim {
  position: fixed;
  inset: 0;
  z-index: 65;
  background: rgba(14, 31, 27, .4);
  opacity: 0;
  visibility: hidden;
  transition: opacity .22s var(--ease), visibility 0s linear .22s;
}
.nav-scrim[data-open] {
  opacity: 1;
  visibility: visible;
  transition: opacity .22s var(--ease), visibility 0s linear 0s;
}

/* ---------- 9. 站点页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 9vw, 118px);
  padding: clamp(46px, 7vw, 84px) clamp(20px, 4vw, 48px) clamp(26px, 3.4vw, 40px);
  background: var(--deep-ink);
  color: #D9E8E3;
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(0deg, rgba(247, 250, 248, .028) 0 1px, transparent 1px 5px);
  pointer-events: none;
}

.footer-inner {
  position: relative;
  max-width: var(--maxw);
  margin: 0 auto;
}

.footer-band { position: relative; padding-bottom: clamp(26px, 4vw, 42px); }

.footer-band + .footer-band {
  padding-top: clamp(26px, 4vw, 42px);
  border-top: 1px solid rgba(247, 250, 248, .13);
}

.footer-band + .footer-band::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 104px;
  height: 3px;
  background: linear-gradient(90deg, var(--copper), rgba(185, 138, 75, 0));
}

.footer-eyebrow {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .22em;
  color: var(--copper);
}

.footer-heading {
  margin: 6px 0 20px;
  font-family: var(--font-display);
  font-size: clamp(20px, 2.4vw, 26px);
  font-weight: 900;
  letter-spacing: .05em;
  color: var(--porcelain);
}

.footer-nav {
  display: grid;
  gap: 12px 28px;
  grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
}

.footer-link {
  display: inline-block;
  font-size: 15px;
  color: #CFE2DC;
  padding-bottom: 2px;
  background-image: linear-gradient(var(--electric), var(--electric));
  background-repeat: no-repeat;
  background-position: 0 100%;
  background-size: 0% 1px;
  transition: background-size .18s var(--ease), color .18s var(--ease);
}
.footer-link:hover,
.footer-link:focus-visible {
  color: var(--porcelain);
  background-size: 100% 1px;
}

.footer-contact { display: grid; gap: 14px; }

.footer-contact li {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  gap: 16px;
  align-items: baseline;
}

.footer-key {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: rgba(185, 138, 75, .95);
}

.footer-val {
  font-size: 14.5px;
  line-height: 1.7;
  color: #CFE2DC;
  overflow-wrap: anywhere;
}

.footer-note {
  margin-top: 18px;
  max-width: 46em;
  font-size: 13px;
  line-height: 1.8;
  color: rgba(217, 232, 227, .62);
}

.footer-band--legal {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 26px;
  padding-bottom: 0;
}

.footer-copy {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .06em;
  color: rgba(217, 232, 227, .66);
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  margin-left: auto;
}
.footer-legal .footer-link { font-size: 12.5px; }

/* ---------- 10. 通用容器与节奏 ---------- */
.container {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: clamp(20px, 4vw, 44px);
}

.section { padding-block: clamp(42px, 6vw, 84px); }
.section--tight { padding-block: clamp(24px, 3.6vw, 46px); }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: clamp(22px, 3vw, 38px);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--deep-aqua);
}
.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--copper);
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(26px, 3.6vw, 36px);
  font-weight: 900;
  line-height: 1.28;
  letter-spacing: .02em;
  color: var(--ink);
}

.lede {
  max-width: 34em;
  font-size: 16.5px;
  line-height: 1.8;
  color: var(--slate);
}

.meta-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 20px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--slate);
}

.slant-rule {
  position: relative;
  height: 1px;
  margin-block: clamp(28px, 4vw, 54px);
  background: rgba(20, 35, 31, .12);
}
.slant-rule::before {
  content: "";
  position: absolute;
  left: 0;
  top: -3px;
  width: 84px;
  height: 7px;
  background: var(--aqua);
  clip-path: polygon(0 0, 100% 0, calc(100% - 8px) 100%, 0 100%);
}

/* ---------- 11. 切角面板 ---------- */
.panel {
  --cut: 18px;
  position: relative;
  padding: clamp(20px, 2.6vw, 32px);
  background: #FFFFFF;
  border: 1px solid rgba(20, 35, 31, .1);
  clip-path: polygon(
    0 0,
    calc(100% - var(--cut)) 0,
    100% var(--cut),
    100% 100%,
    var(--cut) 100%,
    0 calc(100% - var(--cut))
  );
  transition: border-color .18s var(--ease), transform .18s var(--ease), background .18s var(--ease);
}

.panel--mist { background: var(--mist); border-color: rgba(53, 185, 164, .24); }

.panel--deep {
  background: var(--deep-ink);
  color: #E4F1EC;
  border-color: transparent;
}

.panel--interactive:hover,
.panel--interactive:focus-within {
  border-color: var(--aqua);
  transform: translateY(-2px);
}

.panel-num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--copper);
}

/* ---------- 12. 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--deep-aqua);
  background: var(--mist);
  border: 1px solid rgba(53, 185, 164, .3);
  border-radius: 2px;
  transition: background .12s var(--ease), color .12s var(--ease), border-color .12s var(--ease);
}

.tag--red {
  color: var(--vermilion);
  background: rgba(200, 69, 58, .08);
  border-color: rgba(200, 69, 58, .32);
}

.tag--gold {
  color: #8A642F;
  background: rgba(185, 138, 75, .12);
  border-color: rgba(185, 138, 75, .34);
}

/* ---------- 13. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 22px;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .06em;
  border: 1px solid transparent;
  border-radius: 2px;
  clip-path: polygon(
    0 0,
    calc(100% - 12px) 0,
    100% 12px,
    100% 100%,
    12px 100%,
    0 calc(100% - 12px)
  );
  transition: background .16s var(--ease), color .16s var(--ease),
              border-color .16s var(--ease), transform .16s var(--ease);
}

.btn--solid { background: var(--aqua); color: #FFFFFF; }
.btn--solid:hover,
.btn--solid:focus-visible { background: var(--deep-aqua); transform: translateY(-1px); }

.btn--ghost {
  background: transparent;
  color: var(--deep-aqua);
  border-color: rgba(30, 124, 110, .38);
}
.btn--ghost:hover,
.btn--ghost:focus-visible { background: var(--mist); border-color: var(--aqua); }

.btn--quiet {
  padding-inline: 0;
  background: transparent;
  color: var(--slate);
  clip-path: none;
}
.btn--quiet:hover,
.btn--quiet:focus-visible { color: var(--deep-aqua); }

/* ---------- 14. 面包屑 ---------- */
.breadcrumb {
  padding-block: 16px 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--slate);
}
.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}
.breadcrumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--copper);
}
.breadcrumb a { color: var(--slate); transition: color .16s var(--ease); }
.breadcrumb a:hover,
.breadcrumb a:focus-visible { color: var(--deep-aqua); }
.breadcrumb [aria-current="page"] { color: var(--deep-aqua); }

/* ---------- 15. 正文排版 ---------- */
.prose {
  max-width: 36em;
  font-size: 16.5px;
  line-height: 1.85;
  color: #22332E;
}
.prose p + p { margin-top: 1em; }
.prose h2 {
  margin: 1.9em 0 .6em;
  font-family: var(--font-display);
  font-size: clamp(22px, 2.6vw, 28px);
  font-weight: 900;
  letter-spacing: .02em;
}
.prose h3 {
  margin: 1.5em 0 .5em;
  font-size: 19px;
  font-weight: 700;
}
.prose ul {
  display: grid;
  gap: .5em;
  margin: .9em 0;
}
.prose ul li {
  position: relative;
  padding-left: 1.2em;
}
.prose ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .74em;
  width: 6px;
  height: 6px;
  background: var(--aqua);
  border-radius: 1px;
}
.prose a {
  color: var(--deep-aqua);
  border-bottom: 1px solid rgba(53, 185, 164, .42);
  transition: border-color .16s var(--ease);
}
.prose a:hover,
.prose a:focus-visible { border-bottom-color: var(--deep-aqua); }

/* ---------- 16. 网格 ---------- */
.grid {
  display: grid;
  gap: clamp(18px, 2.4vw, 30px);
}
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--sidebar {
  grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  align-items: start;
}

/* ---------- 17. 图片容器 ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  background-color: var(--mist);
  background-image:
    repeating-linear-gradient(45deg, rgba(53, 185, 164, .07) 0 12px, transparent 12px 24px),
    linear-gradient(160deg, var(--mist), #DCEDE6);
  border: 1px solid rgba(20, 35, 31, .09);
  clip-path: polygon(
    0 0,
    calc(100% - var(--cut)) 0,
    100% var(--cut),
    100% 100%,
    var(--cut) 100%,
    0 calc(100% - var(--cut))
  );
}

.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame--wide { aspect-ratio: 16 / 9; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--tall { aspect-ratio: 3 / 4; }

.media-frame__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .08em;
  color: var(--slate);
}

/* ---------- 18. 筛选协议 ---------- */
[data-filter-item][hidden] { display: none; }

/* ---------- 19. 响应式 ---------- */
@media (max-width: 900px) {
  :root { --header-h: 58px; }

  body {
    padding-left: 0;
    padding-top: var(--header-h);
  }

  .site-header { left: 0; }

  .nav-toggle { display: inline-flex; }

  .rail {
    width: 272px;
    padding-bottom: 28px;
    transform: translateX(-100%);
    visibility: hidden;
    transition: transform .26s var(--ease), visibility 0s linear .26s;
  }

  .rail[data-open] {
    transform: translateX(0);
    visibility: visible;
    box-shadow: 14px 0 44px rgba(14, 31, 27, .24);
    transition: transform .26s var(--ease), visibility 0s linear 0s;
  }

  .rail-list {
    padding-top: calc(var(--header-h) + 26px);
    gap: 2px;
  }

  .rail-link {
    justify-content: flex-start;
    gap: 16px;
    height: 52px;
    padding: 0 22px;
  }

  .rail-label {
    position: static;
    transform: none;
    opacity: 1;
    padding: 0;
    background: none;
    color: inherit;
    font-family: var(--font-body);
    font-size: 15px;
    letter-spacing: .04em;
    pointer-events: auto;
  }

  .rail-link:hover .rail-label,
  .rail-link:focus-visible .rail-label { transform: none; }

  .rail-link[aria-current="page"]::before { height: 26px; }

  .brand-sub { display: none; }
}

@media (min-width: 901px) {
  .nav-scrim { display: none; }
}

@media (max-width: 820px) {
  .grid--2,
  .grid--3,
  .grid--sidebar { grid-template-columns: minmax(0, 1fr); }

  .footer-band--legal { gap: 10px 20px; }
  .footer-legal { margin-left: 0; }

  .footer-contact li { grid-template-columns: 48px minmax(0, 1fr); gap: 12px; }
}

@media (max-width: 520px) {
  body { font-size: 16px; }

  .header-index { display: none; }

  .nav-toggle { padding: 0 10px; }
  .nav-toggle-text { display: none; }

  .btn { width: 100%; justify-content: center; }
}

/* ---------- 20. 降低动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    transition-delay: 0s !important;
    scroll-behavior: auto !important;
  }
}