/* ============================================================
   site.css — 9登录主站 共享外壳
   技术蓝图网格 / 悬浮胶囊导航 / 归档式页脚
   ============================================================ */

:root {
  --abyss: #06111f;
  --deep: #0b1f3a;
  --line: #173b5e;
  --cyan: #38e8e8;
  --teal: #1aa7b8;
  --amber: #f2b84b;
  --ice: #eaf7ff;
  --mist: #93afc0;
  --glass: #12324d;
  --mint: #5be49b;

  --shell: 1240px;
  --gut: clamp(16px, 4vw, 44px);

  --font-display: "Barlow Condensed", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Consolas, "Liberation Mono", monospace;

  color-scheme: dark;
}

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

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

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

ul[class],
ol[class] { list-style: none; }

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

button,
input,
select,
textarea {
  font: inherit;
  color: inherit;
}

button {
  background: none;
  border: 0;
  cursor: pointer;
}

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

[hidden] { display: none !important; }

::selection {
  background: rgba(56, 232, 232, 0.32);
  color: #ffffff;
}

/* ---------- base / 中文排版 ---------- */
body {
  min-height: 100vh;
  background:
    radial-gradient(1100px 560px at 12% -6%, rgba(26, 167, 184, 0.18), transparent 62%),
    radial-gradient(900px 520px at 92% 2%, rgba(56, 232, 232, 0.1), transparent 58%),
    var(--abyss);
  color: var(--ice);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.8;
  letter-spacing: 0.01em;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(23, 59, 94, 0.55) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(23, 59, 94, 0.45) 1px, transparent 1px);
  background-size: 128px 128px;
  opacity: 0.5;
}

main {
  display: block;
  position: relative;
  z-index: 1;
}

#main-content { scroll-margin-top: clamp(90px, 12vh, 130px); }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.16;
  letter-spacing: -0.01em;
  color: var(--ice);
}

p { max-width: 68ch; }

strong { color: #ffffff; font-weight: 700; }

code, kbd, samp, pre {
  font-family: var(--font-mono);
  font-size: 0.88em;
}

:where(a, button, [tabindex]):focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  box-shadow: 0 0 0 5px rgba(242, 184, 75, 0.28);
  border-radius: 6px;
}

/* ---------- 可访问性工具 ---------- */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 200;
  padding: 10px 20px;
  border-radius: 999px;
  background: var(--cyan);
  color: #04121c;
  font-weight: 700;
  font-size: 0.9rem;
  transform: translateY(-180%);
  transition: transform 0.18s ease;
}

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

/* ---------- 布局容器 / 章节 ---------- */
.container {
  width: min(calc(100% - var(--gut) * 2), var(--shell));
  margin-inline: auto;
}

.section { padding-block: clamp(44px, 7vw, 92px); }

.section-head {
  display: grid;
  gap: 12px;
  max-width: 66ch;
  margin-bottom: clamp(22px, 4vw, 40px);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan);
}

.eyebrow::before {
  content: "";
  width: 26px;
  height: 1px;
  background: currentColor;
}

.section-title {
  font-size: clamp(1.8rem, 3vw, 2.8rem);
  letter-spacing: 0.01em;
}

.section-note {
  color: var(--mist);
  font-size: 0.95rem;
  max-width: 62ch;
}

.mono {
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
}

/* ---------- 按钮 / 标签 / 芯片 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 12px 22px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-size: 0.92rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: transform 0.18s ease, background 0.18s ease, border-color 0.18s ease, color 0.18s ease, box-shadow 0.18s ease;
}

.btn:hover { transform: translateY(-2px); }

.btn--primary {
  background: var(--cyan);
  border-color: var(--cyan);
  color: #04121c;
  box-shadow: 0 12px 32px -14px rgba(56, 232, 232, 0.7);
}

.btn--primary:hover { background: #63f1f1; border-color: #63f1f1; }

.btn--ghost {
  background: rgba(18, 50, 77, 0.4);
  border-color: rgba(56, 232, 232, 0.35);
  color: var(--ice);
}

.btn--ghost:hover { border-color: var(--cyan); color: var(--cyan); }

.btn--amber {
  background: rgba(242, 184, 75, 0.08);
  border-color: rgba(242, 184, 75, 0.42);
  color: var(--amber);
}

.btn--amber:hover { background: rgba(242, 184, 75, 0.16); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: 1px solid rgba(56, 232, 232, 0.28);
  border-radius: 4px;
  background: rgba(56, 232, 232, 0.06);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  color: var(--cyan);
  white-space: nowrap;
}

.tag--amber {
  border-color: rgba(242, 184, 75, 0.35);
  background: rgba(242, 184, 75, 0.08);
  color: var(--amber);
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 14px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(11, 31, 58, 0.6);
  color: #c6dded;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  transition: border-color 0.16s ease, color 0.16s ease, background 0.16s ease;
}

.chip:hover { border-color: rgba(56, 232, 232, 0.45); color: var(--cyan); }

.chip[aria-pressed="true"] {
  background: rgba(56, 232, 232, 0.12);
  border-color: var(--cyan);
  color: var(--cyan);
}

/* ---------- 状态点 / 卡片 ---------- */
.status-dot {
  display: inline-block;
  flex: none;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--mint);
  box-shadow: 0 0 0 3px rgba(91, 228, 155, 0.15);
}

.status-dot--amber {
  background: var(--amber);
  box-shadow: 0 0 0 3px rgba(242, 184, 75, 0.18);
}

.card {
  position: relative;
  padding: clamp(18px, 2.4vw, 28px);
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--deep);
  transition: transform 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease;
}

.card:hover {
  transform: translateY(-2px);
  border-color: rgba(56, 232, 232, 0.42);
  box-shadow: 0 20px 44px -30px rgba(56, 232, 232, 0.6);
}

.card--glass {
  background: linear-gradient(160deg, rgba(18, 50, 77, 0.72), rgba(11, 31, 58, 0.55));
  border-color: rgba(56, 232, 232, 0.18);
  backdrop-filter: blur(12px);
}

.card--solid { background: var(--deep); }

/* ---------- 网格 ---------- */
.grid {
  display: grid;
  gap: clamp(14px, 2vw, 24px);
}

.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }

@media (min-width: 901px) {
  .col-4 { grid-column: span 4; }
  .col-6 { grid-column: span 6; }
  .col-8 { grid-column: span 8; }
  .col-12 { grid-column: span 12; }
}

/* ---------- 面包屑 ---------- */
.breadcrumbs {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--mist);
}

.breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.breadcrumbs li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.breadcrumbs li + li::before {
  content: "/";
  color: rgba(56, 232, 232, 0.45);
}

.breadcrumbs a {
  color: var(--mist);
  border-bottom: 1px solid transparent;
  transition: color 0.16s ease, border-color 0.16s ease;
}

.breadcrumbs a:hover {
  color: var(--cyan);
  border-bottom-color: rgba(56, 232, 232, 0.5);
}

.breadcrumbs [aria-current="page"] { color: var(--cyan); }

/* ---------- 图片容器基础（页面阶段放占位图） ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border: 1px solid var(--line);
  border-radius: 12px;
  background-color: var(--deep);
  background-image:
    linear-gradient(to right, rgba(56, 232, 232, 0.09) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(56, 232, 232, 0.09) 1px, transparent 1px),
    radial-gradient(120% 90% at 18% 0%, rgba(26, 167, 184, 0.22), transparent 60%);
  background-size: 40px 40px, 40px 40px, 100% 100%;
}

.media-frame::before {
  content: "";
  position: absolute;
  inset: 10px;
  z-index: 2;
  border: 1px dashed rgba(56, 232, 232, 0.2);
  border-radius: 8px;
  pointer-events: none;
}

.media-frame img {
  position: relative;
  z-index: 1;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--tall { aspect-ratio: 4 / 5; }

.media-frame__tag {
  position: absolute;
  top: 12px;
  left: 12px;
  z-index: 3;
}

.media-frame__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 3;
  padding: 12px 14px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  color: #d6ecf7;
  background: linear-gradient(180deg, transparent, rgba(6, 17, 31, 0.9));
}

/* ============================================================
   头部
   ============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  padding-top: 10px;
  pointer-events: none;
}

.site-header::before {
  content: "";
  position: absolute;
  inset: 0 0 -22px;
  z-index: -1;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(6, 17, 31, 0.94), rgba(6, 17, 31, 0.6) 62%, transparent);
}

.header-shell {
  position: relative;
  width: min(calc(100% - var(--gut) * 2), var(--shell));
  margin-inline: auto;
  pointer-events: auto;
}

/* 索引刻度行 */
.header-rail {
  display: flex;
  align-items: center;
  gap: 12px;
  max-height: 28px;
  padding: 0 16px 8px;
  overflow: hidden;
  font-family: var(--font-mono);
  font-size: 0.64rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: rgba(147, 175, 192, 0.92);
  transition: max-height 0.22s ease, opacity 0.2s ease, padding 0.2s ease;
}

.rail-item { white-space: nowrap; }

.rail-rule {
  width: 44px;
  height: 1px;
  background: linear-gradient(90deg, rgba(56, 232, 232, 0.7), rgba(56, 232, 232, 0));
}

.rail-coord {
  margin-left: auto;
  color: rgba(242, 184, 75, 0.78);
  white-space: nowrap;
}

/* 悬浮胶囊 */
.header-pill {
  position: relative;
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 26px);
  padding: 9px 12px 9px 14px;
  border: 1px solid rgba(56, 232, 232, 0.18);
  border-radius: 999px;
  background: linear-gradient(180deg, rgba(18, 50, 77, 0.84), rgba(9, 26, 45, 0.8));
  box-shadow: 0 24px 54px -34px rgba(0, 0, 0, 0.95), inset 0 1px 0 rgba(234, 247, 255, 0.06);
  backdrop-filter: blur(16px) saturate(1.1);
  transition: padding 0.22s ease, background 0.22s ease, border-color 0.22s ease;
}

.site-header[data-scrolled="true"] .header-rail {
  max-height: 0;
  padding-bottom: 0;
  opacity: 0;
}

.site-header[data-scrolled="true"] .header-pill {
  padding-block: 6px;
  background: linear-gradient(180deg, rgba(11, 31, 58, 0.94), rgba(6, 17, 31, 0.92));
  border-color: rgba(56, 232, 232, 0.28);
}

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: none;
  padding: 4px 8px 4px 4px;
  border-radius: 999px;
}

.brand-mark {
  position: relative;
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border: 1px solid rgba(56, 232, 232, 0.4);
  border-radius: 12px;
  background: linear-gradient(150deg, rgba(56, 232, 232, 0.2), rgba(26, 167, 184, 0.05));
  box-shadow: inset 0 0 18px rgba(56, 232, 232, 0.16);
  font-family: var(--font-mono);
  font-size: 1.24rem;
  font-weight: 700;
  color: var(--cyan);
  transition: border-color 0.18s ease, box-shadow 0.18s ease;
}

.brand-mark::after {
  content: "";
  position: absolute;
  inset: 4px;
  border: 1px solid rgba(56, 232, 232, 0.16);
  border-radius: 8px;
}

.brand:hover .brand-mark {
  border-color: var(--cyan);
  box-shadow: 0 0 24px rgba(56, 232, 232, 0.34);
}

.brand-text {
  display: grid;
  line-height: 1.15;
  gap: 2px;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 1.16rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--ice);
}

.brand-descriptor {
  font-family: var(--font-mono);
  font-size: 0.6rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mist);
}

/* 状态灯 */
.brand-status {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border: 1px solid rgba(91, 228, 155, 0.22);
  border-radius: 999px;
  background: rgba(91, 228, 155, 0.06);
  font-family: var(--font-mono);
  font-size: 0.64rem;
  letter-spacing: 0.1em;
  color: #b9f5d3;
  white-space: nowrap;
}

@media (min-width: 1080px) {
  .brand-status { display: inline-flex; }
}

/* 导航 */
.site-nav { margin-left: auto; }

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
  counter-reset: nav;
}

.nav-list li {
  display: flex;
  counter-increment: nav;
}

.nav-link {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  padding: 9px 13px;
  border-radius: 999px;
  font-size: 0.86rem;
  color: #cfe6f3;
  white-space: nowrap;
  transition: color 0.16s ease, background 0.16s ease, box-shadow 0.16s ease;
}

.nav-link::before {
  content: counter(nav, decimal-leading-zero);
  font-family: var(--font-mono);
  font-size: 0.6rem;
  letter-spacing: 0.08em;
  color: rgba(147, 175, 192, 0.7);
  transition: color 0.16s ease;
}

.nav-link:hover {
  color: var(--cyan);
  background: rgba(56, 232, 232, 0.09);
}

.nav-link:hover::before { color: var(--amber); }

.nav-link[aria-current="page"] {
  color: var(--cyan);
  background: rgba(56, 232, 232, 0.12);
  box-shadow: inset 0 -2px 0 rgba(56, 232, 232, 0.85);
}

.nav-link[aria-current="page"]::before { color: var(--cyan); }

.nav-note {
  display: none;
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid rgba(23, 59, 94, 0.9);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  color: var(--mist);
  max-width: none;
}

/* 移动按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 9px 14px;
  border: 1px solid rgba(56, 232, 232, 0.3);
  border-radius: 999px;
  background: rgba(56, 232, 232, 0.08);
  color: var(--ice);
  transition: border-color 0.18s ease, color 0.18s ease, background 0.18s ease;
}

.nav-toggle-lines {
  display: grid;
  gap: 5px;
  width: 18px;
}

.nav-toggle-lines span {
  display: block;
  height: 2px;
  background: currentColor;
  transform-origin: center;
  transition: transform 0.18s ease;
}

.nav-toggle-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
}

.nav-toggle[aria-expanded="true"] {
  border-color: rgba(242, 184, 75, 0.55);
  background: rgba(242, 184, 75, 0.1);
  color: var(--amber);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-lines span:first-child {
  transform: translateY(3.5px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-lines span:last-child {
  transform: translateY(-3.5px) rotate(-45deg);
}

/* 阅读进度 */
.scroll-meter {
  position: relative;
  height: 2px;
  margin: 10px 16px 0;
  border-radius: 2px;
  background: rgba(23, 59, 94, 0.7);
  overflow: hidden;
}

.scroll-meter-fill {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--teal), var(--cyan) 58%, var(--amber));
  transition: transform 0.12s linear;
}

/* 头部响应式 */
@media (max-width: 900px) {
  .site-header { padding-top: 8px; }

  .header-shell {
    width: min(calc(100% - 24px), var(--shell));
  }

  .header-rail { display: none; }

  .header-pill {
    flex-wrap: wrap;
    gap: 10px;
    padding: 10px 12px;
    border-radius: 22px;
  }

  .brand-status { display: none; }

  .nav-toggle {
    display: inline-flex;
    margin-left: auto;
  }

  .site-nav {
    position: absolute;
    top: calc(100% + 10px);
    left: 0;
    right: 0;
    z-index: 5;
    display: none;
    margin: 0;
    padding: 14px;
    max-height: min(70vh, 520px);
    overflow-y: auto;
    border: 1px solid rgba(56, 232, 232, 0.22);
    border-radius: 18px;
    background: linear-gradient(180deg, rgba(11, 31, 58, 0.98), rgba(6, 17, 31, 0.98));
    box-shadow: 0 30px 60px -30px #000000;
    backdrop-filter: blur(18px);
  }

  .site-header[data-open="true"] .site-nav { display: block; }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    counter-reset: nav;
  }

  .nav-link {
    justify-content: flex-start;
    padding: 12px;
    border-radius: 10px;
    font-size: 0.95rem;
  }

  .nav-note { display: block; }

  .scroll-meter { margin: 8px 6px 0; }
}

/* ============================================================
   页脚
   ============================================================ */
.site-footer {
  position: relative;
  z-index: 1;
  margin-top: clamp(56px, 8vw, 110px);
  border-top: 1px solid rgba(56, 232, 232, 0.16);
  background: linear-gradient(180deg, rgba(11, 31, 58, 0.92), #06111f 72%);
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: linear-gradient(to right, rgba(23, 59, 94, 0.55) 1px, transparent 1px);
  background-size: 96px 100%;
  opacity: 0.35;
}

.footer-shell {
  position: relative;
  width: min(calc(100% - var(--gut) * 2), var(--shell));
  margin-inline: auto;
  padding-block: clamp(36px, 5vw, 64px) 24px;
}

.footer-top {
  display: grid;
  grid-template-columns: 1.1fr 1.5fr 0.9fr;
  align-items: start;
  gap: clamp(28px, 4vw, 48px);
}

.footer-brand { display: grid; justify-items: start; }

.brand--footer { padding-left: 0; }

.brand--footer .brand-mark {
  width: 46px;
  height: 46px;
}

.brand--footer .brand-name { font-size: 1.28rem; }

.footer-statement {
  margin-top: 18px;
  max-width: 34ch;
  font-size: 0.92rem;
  color: var(--mist);
}

.footer-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 16px;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  color: rgba(242, 184, 75, 0.9);
}

.footer-nav { display: block; }

.footer-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}

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

.footer-col-title {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan);
}

.footer-col-title::after {
  content: "";
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, rgba(56, 232, 232, 0.35), transparent);
}

.footer-links { display: grid; gap: 8px; }

.footer-links a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding-block: 3px;
  border-bottom: 1px solid transparent;
  font-size: 0.9rem;
  color: #c6dded;
  transition: color 0.16s ease;
}

.footer-links a::before {
  content: "—";
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--line);
  transition: color 0.16s ease;
}

.footer-links a:hover { color: var(--cyan); }
.footer-links a:hover::before { color: var(--amber); }

.footer-contact {
  display: grid;
  align-content: start;
}

.contact-list { display: grid; gap: 12px; }

.contact-line {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 10px;
  font-size: 0.88rem;
  color: #c6dded;
}

.contact-label {
  padding: 2px 6px;
  border: 1px solid var(--line);
  border-radius: 3px;
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.14em;
  color: var(--mist);
}

.contact-value { color: var(--ice); }

.contact-value--mono {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.02em;
  word-break: break-all;
}

.contact-address {
  display: block;
  max-width: 26ch;
  font-size: 0.84rem;
  line-height: 1.7;
  color: var(--mist);
}

.contact-note {
  margin-top: 12px;
  font-size: 0.76rem;
  color: rgba(147, 175, 192, 0.82);
  max-width: 30ch;
}

.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 3px 10px;
  border: 1px solid rgba(56, 232, 232, 0.3);
  border-radius: 999px;
  background: rgba(56, 232, 232, 0.07);
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 0.64rem;
  letter-spacing: 0.1em;
  transition: background 0.16s ease, border-color 0.16s ease, color 0.16s ease;
}

.copy-btn:hover {
  background: rgba(56, 232, 232, 0.16);
  border-color: var(--cyan);
}

.copy-btn[data-state="done"] {
  color: var(--mint);
  border-color: rgba(91, 228, 155, 0.5);
  background: rgba(91, 228, 155, 0.12);
}

.copy-feedback {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.1em;
  color: var(--mint);
}

.footer-base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 20px;
  margin-top: clamp(28px, 4vw, 44px);
  padding-top: 18px;
  border-top: 1px solid rgba(23, 59, 94, 0.9);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  color: rgba(147, 175, 192, 0.88);
}

.footer-legal { max-width: none; }
.footer-copyright { max-width: none; }

.footer-coords {
  max-width: none;
  color: rgba(242, 184, 75, 0.75);
}

@media (max-width: 1000px) {
  .footer-top { grid-template-columns: 1fr 1fr; }
  .footer-contact { grid-column: 1 / -1; }
}

@media (max-width: 680px) {
  .footer-top { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-contact { grid-column: auto; }
}

@media (max-width: 420px) {
  .footer-grid { grid-template-columns: 1fr; }

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

/* ============================================================
   动效 / 响应式 / 减少动态
   ============================================================ */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.55s cubic-bezier(0.2, 0.7, 0.3, 1), transform 0.55s cubic-bezier(0.2, 0.7, 0.3, 1);
}

.js [data-reveal][data-revealed="true"] {
  opacity: 1;
  transform: none;
}

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

@media (max-width: 640px) {
  .grid--2,
  .grid--3,
  .grid--12 { grid-template-columns: minmax(0, 1fr); }

  .header-shell { width: calc(100% - 20px); }

  .footer-shell { width: calc(100% - 24px); }
}

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

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }

  .js [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .btn:hover,
  .card:hover { transform: none; }

  .scroll-meter-fill { transition: none; }
}