/* ==========================================================
   星落平原 · 深空编辑风（Deep-Sky Editorial）
   设计语言：墨黑夜空 + 暖星光金 + 等宽读数
   性能原则：星星纯 CSS 背景绘制（零 DOM 节点），
   动画仅 transform/opacity（GPU 合成），尊重减少动态偏好
   ========================================================== */

:root {
  /* 墨色夜空 */
  --ink-0: #08090d;            /* 页面最深底色 */
  --ink-1: #0d0f16;            /* 面板底 */
  --ink-2: #12141d;            /* 卡片底 */
  /* 暖星光金 */
  --gold: #d9b380;
  --gold-bright: #f0d6a4;
  --gold-dim: rgba(217, 179, 128, 0.5);
  /* 暖纸白文字 */
  --paper: #ece7dc;
  --paper-dim: #98948a;
  /* 线与状态 */
  --line: rgba(217, 179, 128, 0.16);
  --line-strong: rgba(217, 179, 128, 0.4);
  --online: #8fce9f;

  --mono: ui-monospace, "Cascadia Code", "JetBrains Mono", Consolas, monospace;
  --sans: "PingFang SC", "Microsoft YaHei", "Segoe UI", system-ui, sans-serif;
  /* 标题衬线：编辑风的骨架，jsdelivr 字体加载失败回退系统宋体 */
  --display: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  color: var(--paper);
  background: linear-gradient(180deg, #06070b 0%, var(--ink-0) 40%, #0a0c12 100%);
  min-height: 100vh;
  overflow-x: hidden;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

::selection { background: var(--gold-dim); color: #0a0b0f; }

/* ==========================================================
   星空背景层：一个 DOM 节点承载全部夜空
   多重背景：地平线暖光 → 银河斜带 → 暖白金色星星
   ========================================================== */
.sky {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    /* 地平线暖光：星光落在平原上 */
    linear-gradient(to top, rgba(217, 179, 128, 0.07), transparent 26%),
    /* 银河斜带：右上方一道极淡的暖白光带 */
    radial-gradient(ellipse 70% 38% at 72% 8%, rgba(236, 231, 220, 0.05), transparent 70%),
    /* 星星：暖白 / 香槟金，12 颗一单元平铺 */
    radial-gradient(1px 1px at 20% 30%, #f5efe2 50%, transparent 51%),
    radial-gradient(1px 1px at 40% 70%, #e8cda0 50%, transparent 51%),
    radial-gradient(1.5px 1.5px at 60% 20%, #f7f2e6 50%, transparent 51%),
    radial-gradient(1px 1px at 80% 50%, #ecdfc2 50%, transparent 51%),
    radial-gradient(2px 2px at 10% 80%, #f5efe2 50%, transparent 51%),
    radial-gradient(1px 1px at 90% 15%, #f7f2e6 50%, transparent 51%),
    radial-gradient(1.5px 1.5px at 30% 90%, #e8cda0 50%, transparent 51%),
    radial-gradient(1px 1px at 70% 85%, #f5efe2 50%, transparent 51%),
    radial-gradient(1px 1px at 50% 45%, #ecdfc2 50%, transparent 51%),
    radial-gradient(2px 2px at 5% 10%, #f7f2e6 50%, transparent 51%),
    radial-gradient(1px 1px at 95% 75%, #e8cda0 50%, transparent 51%),
    radial-gradient(1.5px 1.5px at 15% 55%, #f5efe2 50%, transparent 51%);
  background-size:
    100% 100%,
    100% 100%,
    420px 420px, 420px 420px, 420px 420px, 420px 420px, 420px 420px,
    420px 420px, 420px 420px, 420px 420px, 420px 420px, 420px 420px,
    420px 420px;
  animation: sky-drift 300s linear infinite;
  will-change: transform;
}

/* 星星整体缓慢漂移（位移 = 平铺单元整数倍，无缝循环） */
@keyframes sky-drift {
  from { transform: translate3d(0, 0, 0); }
  to   { transform: translate3d(-420px, -420px, 0); }
}

/* 两颗流星：仅 opacity/transform 动画 */
.sky::before,
.sky::after {
  content: "";
  position: absolute;
  width: 2px;
  height: 90px;
  border-radius: 2px;
  background: linear-gradient(to bottom, transparent, #f5efe2);
  opacity: 0;
  animation: meteor 11s ease-in infinite;
}

.sky::before { left: 14%; top: -10%; animation-delay: 0s; }
.sky::after  { left: 66%; top: -10%; animation-delay: 6s; }

@keyframes meteor {
  0%, 55%  { opacity: 0; transform: translate3d(0, 0, 0) rotate(38deg); }
  60%      { opacity: 1; }
  75%      { opacity: 0; transform: translate3d(-420px, 420px, 0) rotate(38deg); }
  100%     { opacity: 0; transform: translate3d(-420px, 420px, 0) rotate(38deg); }
}

/* ==========================================================
   导航
   ========================================================== */
.nav {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px clamp(20px, 5vw, 64px);
  background: rgba(8, 9, 13, 0.78);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--paper);
}

.brand-logo {
  width: 26px;
  height: 26px;
  border-radius: 6px;
  object-fit: cover;
  border: 1px solid var(--line-strong);
}

.brand-name {
  font-weight: 700;
  letter-spacing: 0.14em;
  font-size: 0.95rem;
}

.nav-links { display: flex; align-items: center; gap: 28px; }

.nav-links a {
  color: var(--paper-dim);
  text-decoration: none;
  font-size: 0.85rem;
  letter-spacing: 0.1em;
  transition: color 0.2s;
}

.nav-links a:hover { color: var(--gold-bright); }

.nav-cta {
  padding: 7px 16px;
  border: 1px solid var(--line-strong);
  border-radius: 4px;
  color: var(--gold-bright);
  font-family: var(--mono);
  font-size: 0.78rem;
}

.nav-cta:hover {
  background: rgba(217, 179, 128, 0.1);
  color: var(--gold-bright);
}

/* ==========================================================
   Hero：左文案 + 右服务器照片（非对称双栏，文案为主视觉）
   ========================================================== */
.hero {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: clamp(36px, 5vw, 72px);
  align-items: center;
  max-width: 1120px;
  margin: 0 auto;
  padding: clamp(80px, 14vh, 150px) clamp(20px, 5vw, 64px) clamp(36px, 5vh, 56px);
}

/* ---------- 服务器照片展示区 ---------- */
.hero-gallery {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.hero-shot-wrap {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 10;
  border: 1px solid var(--line-strong);
  border-radius: 6px;
  overflow: hidden;
  background: var(--ink-1);
  /* 观测仪器取景框角标，呼应观测面板 */
}
.hero-shot-wrap::before,
.hero-shot-wrap::after {
  content: "";
  position: absolute;
  width: 14px;
  height: 14px;
  border: 1px solid var(--gold);
  opacity: 0.7;
  pointer-events: none;
  z-index: 1;
}
.hero-shot-wrap::before { top: -1px; left: -1px; border-right: none; border-bottom: none; }
.hero-shot-wrap::after  { bottom: -1px; right: -1px; border-left: none; border-top: none; }

.hero-shot {
  display: block;
  width: 100%;
  height: 100%;
  /* contain: 自动缩放完整显示所有图片内容，不裁剪 */
  object-fit: contain;
  transition: opacity 0.4s ease;
  will-change: opacity;
}

/* 自动轮播进度条（贴在主图底部） */
.hero-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: rgba(217, 179, 128, 0.1);
  z-index: 2;
  overflow: hidden;
}
.hero-progress-bar {
  height: 100%;
  width: 0%;
  background: var(--gold-bright);
  box-shadow: 0 0 8px var(--gold-dim);
}
/* 进度动画：5 秒从 0 走到 100%，走完触发切换并重置 */
.hero-progress-bar.run {
  animation: hero-progress-fill 5s linear forwards;
}
@keyframes hero-progress-fill {
  from { width: 0%; }
  to   { width: 100%; }
}

/* 缩略图条 */
.hero-thumbs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.hero-thumb {
  flex: 0 0 auto;
  width: 96px;
  height: 60px;
  padding: 0;
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 4px;
  overflow: hidden;
  cursor: pointer;
  transition: border-color 0.2s, transform 0.2s;
}
.hero-thumb:hover { transform: translateY(-2px); border-color: var(--gold-dim); }
.hero-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.hero-thumb.is-active {
  border-color: var(--gold-bright);
  box-shadow: 0 0 0 1px var(--gold-bright);
}

/* 等宽小标签：贯穿全站的 eyebrow 母题 */
.eyebrow {
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.32em;
  color: var(--gold);
  margin-bottom: 22px;
}

.hero-title {
  font-family: var(--display);
  font-size: clamp(2.8rem, 7vw, 5rem);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: 0.04em;
  white-space: nowrap;
  color: var(--paper);
}

.star-mark {
  display: inline-block;
  font-size: 0.32em;
  vertical-align: 0.85em;
  margin-left: 0.15em;
  color: var(--gold-bright);
  text-shadow: 0 0 24px var(--gold-dim);
}

.hero-slogan {
  margin-top: 20px;
  font-size: clamp(1rem, 2vw, 1.15rem);
  color: var(--paper-dim);
  letter-spacing: 0.12em;
}

.hero-actions {
  display: flex;
  gap: 14px;
  margin-top: 44px;
  flex-wrap: wrap;
}

/* ---------- 按钮：小圆角、实色金 / 细线描边（拒绝胶囊+渐变） ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 34px;
  border-radius: 4px;
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-decoration: none;
  transition: transform 0.2s, background 0.2s, border-color 0.2s, box-shadow 0.2s;
  will-change: transform;
}

.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }

.btn-solid {
  color: #0d0f16;
  background: var(--gold-bright);
  box-shadow: 0 6px 28px rgba(217, 179, 128, 0.22);
}

.btn-solid:hover {
  background: #f6e2b8;
  box-shadow: 0 10px 36px rgba(217, 179, 128, 0.32);
}

.btn-line {
  color: var(--paper);
  border: 1px solid var(--line-strong);
  background: transparent;
}

.btn-line:hover {
  border-color: var(--gold);
  background: rgba(217, 179, 128, 0.07);
  color: var(--gold-bright);
}

/* ---------- 观测面板：Hero 下方独立块 ---------- */
.observatory {
  position: relative;
  max-width: 1120px;
  margin: 0 auto clamp(60px, 8vh, 90px);
  padding: 22px clamp(24px, 4vw, 40px);
  background: rgba(13, 15, 22, 0.82);
  border: 1px solid var(--line);
  border-radius: 6px;
  backdrop-filter: blur(8px);
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 28px;
  animation: hero-in 0.8s cubic-bezier(0.22, 1, 0.36, 1) 0.15s backwards;
}

/* 面板四角的取景框角标（观测仪器质感） */
.observatory::before,
.observatory::after {
  content: "";
  position: absolute;
  width: 14px;
  height: 14px;
  border: 1px solid var(--gold);
  opacity: 0.7;
}

.observatory::before { top: -1px; left: -1px; border-right: none; border-bottom: none; }
.observatory::after  { bottom: -1px; right: -1px; border-left: none; border-top: none; }

.obs-icon {
  width: 56px;
  height: 56px;
  border-radius: 8px;
  object-fit: cover;
  border: 1px solid var(--line-strong);
  animation: icon-float 5.5s ease-in-out infinite;
  will-change: transform;
}

@keyframes icon-float {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-6px); }
}

/* 钉钉进步体（官方免费商用 TTF 子集化自托管，仅含站点标题用字） */
@font-face {
  font-family: 'DingTalk JinBu Ti';
  src: url('/fonts/dingtalk-jinbuti.woff2') format('woff2');
  font-display: swap;
}

/* 图标 + 标题横排头部 */
.obs-head {
  display: flex;
  align-items: center;
  gap: 14px;
}

.obs-title {
  font-family: 'DingTalk JinBu Ti', var(--sans);
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--paper);
  white-space: nowrap;
}

/* Instatus 官方状态小组件（iframe 嵌入） */
.obs-embed {
  display: flex;
  justify-content: center;
}

.obs-embed iframe {
  display: block;
  max-width: 100%;
  margin: 0 auto;
}

.obs-foot {
  display: inline-block;
  margin-top: 18px;
  font-family: var(--mono);
  font-size: 0.62rem;
  letter-spacing: 0.3em;
  color: var(--gold-dim);
  text-decoration: none;
  transition: color 0.2s;
}

.obs-foot:hover { color: var(--gold-bright); }

/* Hero 文案入场编排：错落 80ms */
.hero-copy > * { animation: hero-in 0.8s cubic-bezier(0.22, 1, 0.36, 1) backwards; }
.hero-copy .eyebrow     { animation-delay: 0s; }
.hero-copy .hero-title  { animation-delay: 0.08s; }
.hero-copy .hero-slogan { animation-delay: 0.16s; }
.hero-copy .hero-actions{ animation-delay: 0.24s; }

@keyframes hero-in {
  from { opacity: 0; transform: translateY(26px); }
}

/* ==========================================================
   通用章节
   ========================================================== */
.features, .join, .cta {
  max-width: 1120px;
  margin: 0 auto;
  padding: clamp(70px, 10vh, 110px) clamp(20px, 5vw, 64px);
}

.sec-head { margin-bottom: clamp(40px, 6vh, 64px); }

.sec-head h2 {
  font-family: var(--display);
  font-size: clamp(1.8rem, 4.5vw, 2.6rem);
  font-weight: 700;
  letter-spacing: 0.1em;
}

.sec-head .eyebrow { margin-bottom: 14px; }

/* ==========================================================
   特色玩法：编号卡片（无图标，金色大序号）
   ========================================================== */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1px;
  background: var(--line); /* 间隙即细线，卡片连成一块星图 */
  border: 1px solid var(--line);
  border-radius: 6px;
  overflow: hidden;
}

.feature-card {
  position: relative;
  padding: 36px 30px 34px;
  background: var(--ink-1);
  transition: background 0.3s;
  will-change: transform;
}

.feature-card:hover { background: var(--ink-2); }

.feature-no {
  display: block;
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.2em;
  color: var(--gold);
  margin-bottom: 40px;
}

/* 序号下的一小段金线 */
.feature-no::after {
  content: "";
  display: block;
  width: 28px;
  height: 1px;
  margin-top: 14px;
  background: var(--gold-dim);
  transition: width 0.35s cubic-bezier(0.22, 1, 0.36, 1);
}

.feature-card:hover .feature-no::after { width: 56px; }

.feature-card h3 {
  font-family: var(--display);
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  margin-bottom: 10px;
  color: var(--paper);
}

.feature-card p { font-size: 0.9rem; color: var(--paper-dim); }

/* ---------- 特色卡片：下滑时左右滑入 / 上滑时滑出 ----------
   纯 CSS 滚动驱动动画（零 JS、GPU 加速）：
   - animation-timeline: view() 让动画进度绑定滚动位置
   - 左卡从左滑入、右卡从右滑入、中卡原地淡入并轻轻上浮
   - 上拉返回 → 时间轴自动反向 → 各自滑出
   - 仅用 backwards 填充：动画结束后回归自然样式，
     hover 背景变化不受填充状态覆盖
   - 三张卡错落进场；不支持该特性的浏览器走 JS 降级 */
@keyframes card-from-left {
  from { opacity: 0; transform: translate3d(-88px, 0, 0); }
}

@keyframes card-from-right {
  from { opacity: 0; transform: translate3d(88px, 0, 0); }
}

@keyframes card-from-center {
  from { opacity: 0; transform: translate3d(0, 36px, 0); }
}

@supports (animation-timeline: view()) {
  @media (prefers-reduced-motion: no-preference) {
    .feature-card {
      animation: card-from-left 1ms linear backwards;
      animation-timeline: view();
      animation-range: entry 0% entry 80%;
    }
    .feature-card:nth-child(2) {
      animation-name: card-from-center;
      animation-range: entry 0% entry 90%;
    }
    .feature-card:nth-child(3) {
      animation-name: card-from-right;
      animation-range: entry 0% entry 100%;
    }
  }
}

/* JS 降级方案：不支持 animation-timeline 的浏览器由
   feature-anim.js 给 html 加 .card-fallback，配合
   IntersectionObserver 切换 .in-view 实现左右滑入/滑出 */
.card-fallback .feature-card {
  opacity: 0;
  transition: opacity 0.6s ease, transform 0.6s ease;
  will-change: transform;
}

.card-fallback .feature-card:nth-child(1) { transform: translate3d(-88px, 0, 0); }
.card-fallback .feature-card:nth-child(2) { transform: translate3d(0, 36px, 0); }
.card-fallback .feature-card:nth-child(3) { transform: translate3d(88px, 0, 0); }

.card-fallback .feature-card.in-view {
  opacity: 1;
  transform: translate3d(0, 0, 0);
}

/* 错落进场延迟（写在 .in-view 态 → 只作用于滑入方向） */
.card-fallback .feature-card.in-view:nth-child(2) { transition-delay: 0.08s; }
.card-fallback .feature-card.in-view:nth-child(3) { transition-delay: 0.16s; }

/* ==========================================================
   性能遥测：Plan 数据图表
   ========================================================== */
.metrics {
  max-width: 1120px;
  margin: 0 auto;
  padding: clamp(70px, 10vh, 110px) clamp(20px, 5vw, 64px);
}

.sec-desc {
  margin-top: 14px;
  font-size: 0.88rem;
  color: var(--paper-dim);
  letter-spacing: 0.04em;
}

/* 时间范围切换标签 */
.range-tabs {
  display: inline-flex;
  gap: 4px;
  margin-bottom: 28px;
  padding: 4px;
  background: var(--ink-1);
  border: 1px solid var(--line);
  border-radius: 6px;
}

.range-tab {
  padding: 8px 18px;
  background: transparent;
  border: none;
  border-radius: 4px;
  color: var(--paper-dim);
  font-family: var(--mono);
  font-size: 0.82rem;
  letter-spacing: 0.06em;
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
}

.range-tab:hover { color: var(--paper); }

.range-tab.active {
  background: rgba(217, 179, 128, 0.12);
  color: var(--gold-bright);
}

/* 图表卡片网格 */
.metric-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(380px, 1fr));
  gap: 20px;
}

.metric-card {
  padding: 24px 22px 18px;
  background: var(--ink-1);
  border: 1px solid var(--line);
  border-radius: 6px;
}

.metric-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 14px;
}

.metric-title {
  font-family: var(--display);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--paper);
}

.metric-now {
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: var(--gold-bright);
}

/* SVG 图表容器 */
.chart-wrap {
  width: 100%;
  height: 200px;
}

.chart-svg {
  display: block;
  width: 100%;
  height: 100%;
}

.chart-line {
  filter: drop-shadow(0 0 4px currentColor);
}

.grid-line {
  stroke: rgba(217, 179, 128, 0.08);
  stroke-width: 1;
}

.axis-label {
  font-family: var(--mono);
  font-size: 9px;
  fill: var(--paper-dim);
  letter-spacing: 0.04em;
}

.zone-fill {
  opacity: 0.6;
}

.chart-empty {
  display: grid;
  place-items: center;
  height: 100%;
  font-family: var(--mono);
  font-size: 0.82rem;
  color: var(--paper-dim);
  letter-spacing: 0.08em;
}

/* 图表加载骨架动画（切换时间范围时显示） */
.chart-loading {
  display: flex;
  align-items: center;
  height: 100%;
  padding: 0 8px;
}

.chart-loading-bar {
  flex: 1;
  height: 4px;
  background: var(--line);
  border-radius: 2px;
  overflow: hidden;
  position: relative;
}

/* 脉冲光带：从左到右循环滑动 */
.chart-loading-bar::after {
  content: "";
  position: absolute;
  top: 0;
  left: -30%;
  width: 30%;
  height: 100%;
  background: linear-gradient(90deg, transparent, var(--gold), transparent);
  animation: chart-loading-slide 1.2s ease-in-out infinite;
}

@keyframes chart-loading-slide {
  0%   { left: -30%; }
  100% { left: 100%; }
}

.metric-foot {
  margin-top: 18px;
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--paper-dim);
}

.metric-foot.error { color: #b74343; }

/* ==========================================================
   如何加入：竖向时间线
   ========================================================== */
.join { max-width: 760px; }


.steps {
  list-style: none;
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

/* 时间线主干 */
.steps::before {
  content: "";
  position: absolute;
  left: 17px;
  top: 22px;
  bottom: 22px;
  width: 1px;
  background: linear-gradient(to bottom, var(--gold-dim), var(--line));
}

.step {
  position: relative;
  display: flex;
  gap: 28px;
  padding: 18px 0;
}

.step-no {
  position: relative;
  z-index: 1;
  flex-shrink: 0;
  width: 35px;
  height: 35px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  font-family: var(--mono);
  font-size: 0.82rem;
  color: var(--gold-bright);
  background: var(--ink-1);
  border: 1px solid var(--line-strong);
}

.step-body h3 {
  font-family: var(--display);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  margin-bottom: 4px;
}

.step-body p { font-size: 0.88rem; color: var(--paper-dim); }

.join-note {
  margin-top: 34px;
  padding-left: 63px;
  font-size: 0.8rem;
  color: var(--paper-dim);
  letter-spacing: 0.06em;
}

.join-note::before { content: "※ "; color: var(--gold-dim); }

/* ==========================================================
   尾部 CTA
   ========================================================== */
.cta {
  text-align: center;
  padding-top: clamp(80px, 12vh, 140px);
  padding-bottom: clamp(90px, 14vh, 150px);
}

.cta-title {
  font-family: var(--display);
  font-size: clamp(1.7rem, 4.5vw, 2.6rem);
  font-weight: 700;
  letter-spacing: 0.1em;
  margin-bottom: 36px;
}

/* ==========================================================
   页脚 + 备案
   ========================================================== */
.footer {
  padding: 30px clamp(20px, 5vw, 64px) 34px;
  text-align: center;
  font-size: 0.78rem;
  color: var(--paper-dim);
  border-top: 1px solid var(--line);
  background: rgba(8, 9, 13, 0.7);
}

.icp { margin-top: 10px; }

.org-link {
  display: inline-flex;
  align-items: center;
  padding: 6px 10px;
  color: #ffd76a;
  background: linear-gradient(110deg, #ffe58a 0%, #ffc14f 46%, #f07a28 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  border: 1px solid rgba(214, 176, 96, 0.42);
  border-radius: 999px;
  font-style: italic;
  font-weight: 800;
  text-decoration: none;
  transition: background 0.2s, border-color 0.2s;
}

.org-link:hover {
  background: linear-gradient(110deg, #fff0ad 0%, #ffd06b 46%, #ff944c 100%);
  -webkit-background-clip: text;
  background-clip: text;
  border-color: var(--gold-bright);
}

.icp a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--paper-dim);
  text-decoration: none;
  transition: color 0.2s;
}

.icp a:hover { color: var(--gold-bright); }

.icp-emblem {
  width: 14px;
  height: 14px;
  object-fit: contain;
}

/* ==========================================================
   响应式
   ========================================================== */
@media (max-width: 900px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  /* 移动端：照片在上、文案在下 */
  .hero-gallery { order: -1; }
  /* 移动端允许标题换行，避免溢出 */
  .hero-title { white-space: normal; font-size: clamp(2.6rem, 12vw, 4rem); }

  /* 观测面板：横排 → 竖排堆叠 */
  .observatory {
    grid-template-columns: 1fr;
    gap: 16px;
    text-align: center;
    padding: 22px 20px;
  }
  .obs-head { justify-content: center; }
  .obs-title { white-space: normal; }
  .obs-embed iframe { margin: 0 auto; }
  .obs-foot { justify-self: center; }
}

@media (max-width: 640px) {
  .nav { padding: 14px 20px; }
  .nav-links { gap: 16px; }
  .nav-links a { font-size: 0.78rem; }
  .nav-cta { padding: 6px 12px; }
  .hero-title { letter-spacing: 0.02em; }
  .join-note { padding-left: 0; }

  /* 小屏：缩略图变小，方便横排不换行 */
  .hero-thumb { width: 72px; height: 45px; }
  .obs-icon { width: 48px; height: 48px; }
}

/* ==========================================================
   减少动态效果偏好
   ========================================================== */
@media (prefers-reduced-motion: reduce) {
  .sky, .sky::before, .sky::after, .obs-icon,
  .hero-copy > *, .observatory { animation: none; }
  .btn, .feature-card, .feature-no::after { transition: none; }
  html { scroll-behavior: auto; }
}