/* =========================================================
   月博登录中心 / 共享样式表 /assets/site.css
   月白底 + 深靛蓝结构 + 信号橙操作点
   ========================================================= */

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

:root {
  --moon: #F4F1E8;
  --indigo: #172A5A;
  --indigo-deep: #101E42;
  --orange: #F26B3A;
  --cold: #8A9BB8;
  --mint: #BFE3E0;
  --ink: #0E1626;
  --mist: #D9DDE2;
  --sand: #E7D9C4;
  --teal: #2F6F73;
  --peach: #FFD6C7;

  --font-sans: "PingFang SC", "Hiragino Sans GB", "Source Han Sans SC",
    "Noto Sans SC", "Microsoft YaHei", system-ui, -apple-system,
    "Segoe UI", Roboto, sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", Menlo, Consolas,
    "Liberation Mono", "Courier New", monospace;

  --shell: 1240px;
  --gutter: clamp(1rem, 4vw, 2.75rem);

  --r-pill: 999px;
  --r-lg: 28px;
  --r-md: 18px;
  --r-sm: 12px;

  --line: rgba(23, 42, 90, .14);
  --line-soft: rgba(23, 42, 90, .08);

  --shadow-float: 0 20px 44px -30px rgba(14, 22, 38, .62);
  --shadow-panel: 0 34px 66px -40px rgba(14, 22, 38, .7);

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 6.5rem;
  text-underline-offset: .22em;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink);
  background-color: var(--moon);
  background-image:
    radial-gradient(1100px 560px at 84% -10%, rgba(191, 227, 224, .55), transparent 70%),
    radial-gradient(860px 500px at 2% 6%, rgba(231, 217, 196, .55), transparent 72%),
    linear-gradient(to right, rgba(23, 42, 90, .045) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(23, 42, 90, .045) 1px, transparent 1px);
  background-size: auto, auto, 96px 96px, 96px 96px;
  background-position: 0 0, 0 0, -1px -1px, -1px -1px;
  background-repeat: no-repeat, no-repeat, repeat, repeat;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 .6em;
  font-family: var(--font-sans);
  font-weight: 800;
  line-height: 1.24;
  letter-spacing: -.012em;
  color: var(--indigo);
}

h1 { font-size: clamp(1.9rem, 4.2vw, 3.1rem); }
h2 { font-size: clamp(1.4rem, 2.6vw, 2.05rem); }
h3 { font-size: clamp(1.1rem, 1.8vw, 1.35rem); }

p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

a { color: var(--teal); text-decoration-thickness: 1px; }
a:hover { color: var(--indigo); }

ul, ol { margin: 0 0 1em; padding-left: 1.25em; }
li { margin-bottom: .3em; }

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

strong, b { font-weight: 800; color: var(--indigo); }

code, kbd, samp, pre {
  font-family: var(--font-mono);
  font-size: .92em;
}

hr {
  border: 0;
  height: 1px;
  background: var(--line);
  margin: 2rem 0;
}

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

/* ---------- 通用容器 ---------- */

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

.shell--narrow {
  width: min(880px, 100% - var(--gutter) * 2);
  margin-inline: auto;
}

.section {
  padding-block: clamp(2.2rem, 5vw, 4rem);
}

.grid {
  display: grid;
  gap: clamp(1rem, 2.4vw, 1.75rem);
}

.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)); }

/* ---------- 中文正文容器 ---------- */

.prose {
  max-width: 44ch;
  font-size: 1rem;
  line-height: 1.8;
  color: #22304F;
}

.prose--wide { max-width: 52ch; }

.prose h2,
.prose h3 { margin-top: 1.6em; }

.prose ul,
.prose ol { padding-left: 1.15em; }

.prose li { margin-bottom: .45em; }

/* ---------- 通用按钮 ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .78rem 1.4rem;
  border-radius: var(--r-pill);
  border: 1px solid transparent;
  font-family: var(--font-sans);
  font-size: .92rem;
  font-weight: 700;
  line-height: 1.2;
  text-decoration: none;
  cursor: pointer;
  transition: transform .22s var(--ease), background-color .22s var(--ease),
    color .22s var(--ease), border-color .22s var(--ease);
}

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

.btn--primary {
  background: var(--orange);
  color: var(--ink);
  border-color: rgba(14, 22, 38, .12);
}

.btn--primary:hover { background: #FF7A48; color: var(--ink); }

.btn--indigo {
  background: var(--indigo);
  color: var(--moon);
}

.btn--indigo:hover { background: var(--indigo-deep); color: var(--moon); }

.btn--ghost {
  background: transparent;
  color: var(--indigo);
  border-color: rgba(23, 42, 90, .28);
}

.btn--ghost:hover { background: var(--mint); border-color: var(--teal); }

.btn--sm { padding: .5rem 1rem; font-size: .82rem; }

/* ---------- 面包屑 ---------- */

.breadcrumb {
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .08em;
  color: var(--cold);
}

.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: .1rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.breadcrumb li { margin: 0; }

.breadcrumb li + li::before {
  content: "/";
  margin: 0 .5rem 0 .35rem;
  color: var(--mist);
}

.breadcrumb a {
  color: var(--teal);
  text-decoration: none;
}

.breadcrumb a:hover { text-decoration: underline; }

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

/* ---------- 小注释 / 标签 / 分隔 ---------- */

.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .24em;
  text-transform: uppercase;
  color: var(--teal);
}

.vertical-note {
  display: inline-block;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .32em;
  text-transform: uppercase;
  color: var(--cold);
  padding-block: .4rem;
  border-top: 1px solid var(--line);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: .35rem;
  padding: .28rem .72rem;
  border-radius: var(--r-pill);
  background: var(--mint);
  color: #0F3B3C;
  border: 1px solid rgba(47, 111, 115, .25);
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .04em;
  line-height: 1.5;
}

.tag--orange {
  background: var(--peach);
  color: #7A2A12;
  border-color: rgba(242, 107, 58, .32);
}

.tag--mono {
  font-family: var(--font-mono);
  letter-spacing: .1em;
  font-weight: 600;
}

.rule {
  height: 1px;
  border: 0;
  margin: 0;
  background: linear-gradient(90deg, var(--indigo), rgba(23, 42, 90, .04));
}

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: .04em;
}

/* ---------- 可复用图片容器 ---------- */

.media {
  position: relative;
  display: block;
  width: 100%;
  overflow: hidden;
  border-radius: var(--r-lg);
  border: 1px solid var(--line);
  aspect-ratio: 16 / 10;
  background-color: var(--sand);
  background-image:
    radial-gradient(420px 200px at 88% 4%, rgba(191, 227, 224, .85), transparent 72%),
    linear-gradient(to right, rgba(23, 42, 90, .07) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(23, 42, 90, .07) 1px, transparent 1px);
  background-size: auto, 28px 28px, 28px 28px;
}

.media > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

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

.media__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  margin: 0;
  padding: .75rem 1rem;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .1em;
  color: var(--moon);
  background: linear-gradient(180deg, rgba(14, 22, 38, 0), rgba(14, 22, 38, .78));
}

/* =========================================================
   页头：三枚悬浮胶囊浮岛
   ========================================================= */

.skip-link {
  position: fixed;
  top: .6rem;
  left: .6rem;
  z-index: 200;
  transform: translateY(-190%);
  padding: .7rem 1.2rem;
  border-radius: var(--r-pill);
  background: var(--indigo);
  color: var(--moon);
  font-size: .9rem;
  font-weight: 700;
  text-decoration: none;
  box-shadow: var(--shadow-float);
  transition: transform .2s var(--ease);
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  padding: .85rem 0 .55rem;
  background: linear-gradient(
    180deg,
    rgba(244, 241, 232, .97) 0%,
    rgba(244, 241, 232, .9) 62%,
    rgba(244, 241, 232, 0) 100%
  );
}

.site-header.is-scrolled {
  box-shadow: 0 18px 28px -30px rgba(14, 22, 38, .85);
}

.read-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 120;
  background: rgba(23, 42, 90, .1);
  pointer-events: none;
}

.read-progress span {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--teal) 0%, var(--mint) 46%, var(--orange) 100%);
  transition: width .12s linear;
}

.header-shell {
  position: relative;
  width: min(var(--shell), 100% - var(--gutter) * 2);
  margin-inline: auto;
  display: flex;
  align-items: center;
  gap: .7rem;
}

/* 品牌胶囊 */
.brand {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: .65rem;
  padding: .42rem 1.05rem .42rem .42rem;
  border-radius: var(--r-pill);
  background: var(--indigo);
  border: 1px solid rgba(255, 255, 255, .1);
  color: var(--moon);
  text-decoration: none;
  box-shadow: var(--shadow-float);
  transition: transform .22s var(--ease), background-color .22s var(--ease);
}

.brand:hover {
  transform: translateY(-2px);
  background: var(--indigo-deep);
  color: var(--moon);
}

.brand-mark {
  position: relative;
  display: grid;
  place-items: center;
  width: 2.1rem;
  height: 2.1rem;
  border-radius: var(--r-sm);
  background: var(--mint);
  color: var(--indigo-deep);
  font-size: .95rem;
  font-weight: 800;
  line-height: 1;
  letter-spacing: .02em;
}

.brand-mark::after {
  content: "";
  position: absolute;
  top: -2px;
  right: -2px;
  width: .5rem;
  height: .5rem;
  border-radius: 50%;
  background: var(--orange);
  box-shadow: 0 0 0 2px var(--indigo);
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.brand-name {
  font-size: 1rem;
  font-weight: 800;
  letter-spacing: .02em;
  color: #FFFFFF;
}

.brand-tag {
  font-family: var(--font-mono);
  font-size: .62rem;
  letter-spacing: .12em;
  color: #9FB4D4;
}

/* 导航胶囊 */
.site-nav {
  flex: 0 1 auto;
  margin-inline: auto;
  display: flex;
  align-items: center;
  gap: .25rem;
  justify-content: center;
  padding: .32rem;
  border-radius: var(--r-pill);
  background: rgba(255, 255, 255, .66);
  border: 1px solid var(--line);
  box-shadow: 0 14px 34px -30px rgba(14, 22, 38, .9);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

.nav-list {
  display: flex;
  align-items: center;
  gap: .15rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav-list li { margin: 0; }

.nav-link {
  display: inline-block;
  padding: .5rem .82rem;
  border-radius: var(--r-pill);
  font-size: .86rem;
  font-weight: 600;
  line-height: 1.2;
  white-space: nowrap;
  color: var(--indigo);
  text-decoration: none;
  transition: background-color .2s var(--ease), color .2s var(--ease);
}

.nav-link:hover { background: var(--mint); color: var(--indigo-deep); }

.nav-link[aria-current="page"] {
  background: var(--indigo);
  color: var(--moon);
  box-shadow: 0 8px 18px -14px rgba(14, 22, 38, .95);
}

.nav-link[aria-current="page"]:hover { background: var(--indigo-deep); color: var(--moon); }

.nav-cta {
  display: none;
  align-items: center;
  justify-content: center;
  margin-top: .45rem;
  padding: .78rem 1.1rem;
  border-radius: var(--r-pill);
  background: var(--orange);
  border: 1px solid rgba(14, 22, 38, .12);
  color: var(--ink);
  font-size: .9rem;
  font-weight: 800;
  text-decoration: none;
}

.nav-cta:hover { background: #FF7A48; color: var(--ink); }

/* 行动胶囊 */
.header-cta {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  padding: .62rem 1.15rem;
  border-radius: var(--r-pill);
  background: var(--orange);
  border: 1px solid rgba(14, 22, 38, .12);
  color: var(--ink);
  font-size: .86rem;
  font-weight: 800;
  text-decoration: none;
  box-shadow: 0 16px 30px -22px rgba(242, 107, 58, .95);
  transition: transform .2s var(--ease), background-color .2s var(--ease);
}

.header-cta::before {
  content: "";
  width: .42rem;
  height: .42rem;
  border-radius: 50%;
  background: var(--ink);
  opacity: .78;
}

.header-cta:hover {
  transform: translateY(-2px);
  background: #FF7A48;
  color: var(--ink);
}

/* 移动开关 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: .5rem;
  padding: .55rem .95rem;
  border-radius: var(--r-pill);
  border: 1px solid rgba(23, 42, 90, .18);
  background: rgba(255, 255, 255, .72);
  color: var(--indigo);
  font-family: var(--font-sans);
  font-size: .82rem;
  font-weight: 700;
  line-height: 1.2;
  cursor: pointer;
  transition: background-color .2s var(--ease), color .2s var(--ease),
    border-color .2s var(--ease);
}

.nav-toggle:hover { background: var(--mint); }

.nav-toggle-bars {
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
  width: 16px;
}

.nav-toggle-bars span {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform .22s var(--ease);
}

.nav-toggle-label { letter-spacing: .04em; }

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

.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:first-child {
  transform: translateY(3px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:last-child {
  transform: translateY(-3px) rotate(-45deg);
}

/* =========================================================
   页脚：墨蓝黑观测站穹顶
   ========================================================= */

.site-footer {
  position: relative;
  margin-top: clamp(3rem, 8vw, 6rem);
  padding: clamp(2.4rem, 5vw, 4.2rem) 0 1.4rem;
  background: var(--ink);
  color: #C8D3E4;
  border-radius: clamp(28px, 5vw, 52px) clamp(28px, 5vw, 52px) 0 0;
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    radial-gradient(680px 340px at 88% 0%, rgba(242, 107, 58, .22), transparent 70%),
    radial-gradient(540px 320px at 4% 6%, rgba(191, 227, 224, .16), transparent 72%),
    linear-gradient(to right, rgba(191, 227, 224, .07) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(191, 227, 224, .07) 1px, transparent 1px);
  background-size: auto, auto, 72px 72px, 72px 72px;
}

.footer-shell {
  position: relative;
  width: min(var(--shell), 100% - var(--gutter) * 2);
  margin-inline: auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.35fr .8fr .7fr 1.15fr;
  gap: clamp(1.6rem, 3.5vw, 3rem);
}

.footer-logo {
  display: inline-block;
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: .01em;
  color: #FFFFFF;
  text-decoration: none;
}

.footer-logo:hover { color: var(--mint); }

.footer-tagline {
  margin: .5rem 0 0;
  font-size: .9rem;
  line-height: 1.6;
  color: #9FB4D4;
}

.footer-readout {
  margin: .95rem 0 0;
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--orange);
}

.footer-title {
  margin: 0 0 .85rem;
  font-family: var(--font-mono);
  font-size: .68rem;
  font-weight: 600;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--mint);
}

.footer-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: .45rem;
}

.footer-list li { margin: 0; }

.footer-list a {
  display: inline-block;
  color: #C8D3E4;
  font-size: .88rem;
  line-height: 1.5;
  text-decoration: none;
  transition: color .18s var(--ease), padding-left .18s var(--ease);
}

.footer-list a:hover {
  color: #FFFFFF;
  padding-left: .25rem;
}

.contact-block {
  font-style: normal;
  display: flex;
  flex-direction: column;
  gap: .55rem;
}

.contact-row {
  display: flex;
  gap: .6rem;
  margin: 0;
  font-size: .86rem;
  line-height: 1.55;
}

.contact-key {
  flex: 0 0 2.6rem;
  padding-top: .18rem;
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .12em;
  color: var(--cold);
}

.contact-val {
  color: #DCE4F0;
  overflow-wrap: anywhere;
}

.footer-note {
  margin: .95rem 0 0;
  max-width: 34ch;
  font-size: .76rem;
  line-height: 1.7;
  color: #8FA0BC;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: .6rem 1.4rem;
  margin-top: clamp(2rem, 4vw, 3rem);
  padding-top: 1.1rem;
  border-top: 1px solid rgba(191, 227, 224, .16);
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .06em;
  color: #8FA0BC;
}

.footer-copy { margin: 0; }

.footer-icp {
  margin: 0;
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  color: #B9C8DE;
}

.footer-icp::before {
  content: "";
  width: .4rem;
  height: .4rem;
  border-radius: 50%;
  background: var(--mint);
}

/* =========================================================
   滚动显现与章节高亮
   ========================================================= */

.is-reveal-pending {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .6s var(--ease), transform .6s var(--ease);
}

.is-visible {
  opacity: 1;
  transform: none;
}

[data-toc] a.is-active {
  color: var(--indigo);
  background: var(--mint);
  font-weight: 700;
}

/* =========================================================
   响应式
   ========================================================= */

@media (max-width: 1120px) {
  .site-header { padding: .65rem 0 .5rem; }

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

  .header-cta { display: none; }

  .site-nav {
    position: absolute;
    top: calc(100% + .55rem);
    left: 0;
    right: 0;
    margin-inline: 0;
    flex-direction: column;
    align-items: stretch;
    gap: .2rem;
    padding: .6rem;
    border-radius: 24px;
    background: rgba(250, 248, 242, .985);
    box-shadow: var(--shadow-panel);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    pointer-events: none;
    transition: opacity .2s var(--ease), transform .2s var(--ease),
      visibility .2s linear;
  }

  .site-nav[data-open] {
    opacity: 1;
    visibility: visible;
    transform: none;
    pointer-events: auto;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: .2rem;
    width: 100%;
  }

  .nav-link {
    display: block;
    padding: .8rem 1rem;
    border-radius: 14px;
    font-size: .95rem;
    text-align: left;
    border-bottom: 1px solid var(--line-soft);
  }

  .nav-list li:last-child .nav-link { border-bottom: 0; }

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

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

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

@media (max-width: 620px) {
  .grid--2,
  .grid--3,
  .grid--4 { grid-template-columns: minmax(0, 1fr); }

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

  .footer-bottom { justify-content: flex-start; }

  .brand-tag { display: none; }

  .prose,
  .prose--wide { max-width: none; }
}

@media (max-width: 400px) {
  .brand-name { font-size: .92rem; }
  .nav-toggle-label { display: none; }
  .footer-note { max-width: none; }
}

/* =========================================================
   减少动态偏好
   ========================================================= */

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

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

  .is-reveal-pending { opacity: 1; transform: none; }

  .btn:hover,
  .brand:hover,
  .header-cta:hover { transform: none; }
}