/*
  eeeyun —— 机架母题（rack motif）

  结构语言：云服务器的世界是「一层一层插进机架的设备」。每一块规格板 = 一个机架层，
  左侧带一个标签耳（tab）。首屏就是一台立起来的机架，五个版块是五层设备。

  配色：黑、白、灰三段式；唯一彩色是指示灯绿 --led，只出现在 6px 圆点、
  当前项标记与输入框聚焦线上。
*/

:root {
  --ink: #0c0c0d;
  --ink-2: #333336;
  --muted: #5c5c62;
  --ground: #ffffff;
  --band: #f4f4f3;
  --band-2: #eaeae8;
  --dark: #0d0d0e;
  --dark-2: #161617;
  --dark-3: #202022;
  --dark-4: #2b2b2e;
  --dark-ink: #f5f5f3;
  --dark-muted: #9d9d9f;
  --led: #3ddc84;

  --t-display: clamp(46px, 7.4vw, 104px);
  --t-head: clamp(25px, 2.9vw, 38px);
  --t-lead: clamp(17px, 1.25vw, 20px);
  --t-body: 17px;
  --t-small: 14px;

  --sans: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei",
          -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;

  --pad: 32px;
  --gap-sec: clamp(96px, 11vw, 168px);
}

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

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

body {
  margin: 0;
  background: var(--ground);
  color: var(--ink-2);
  font-family: var(--sans);
  font-size: var(--t-body);
  line-height: 1.62;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: inherit; text-decoration: none; }
a:hover { color: var(--ink); }
:focus-visible { outline: 2px solid var(--led); outline-offset: 3px; }

.wrap { max-width: 1240px; margin: 0 auto; padding: 0 var(--pad); }

.skip {
  position: absolute; left: -9999px; top: 0; z-index: 100;
  background: var(--ink); color: #fff; padding: 12px 20px;
}
.skip:focus { left: 16px; top: 16px; }

/* ---------- 顶部 ---------- */

.site-head { background: var(--dark); color: var(--dark-ink); }
.head-in {
  display: flex; align-items: center; justify-content: space-between;
  gap: 24px; padding-top: 26px; padding-bottom: 26px;
}
.brand {
  display: inline-flex; align-items: center; gap: 9px;
  font-size: 19px; font-weight: 700; letter-spacing: -0.03em; color: var(--dark-ink);
}
.brand:hover { color: #fff; }
.led {
  width: 7px; height: 7px; border-radius: 50%; background: var(--led);
  box-shadow: 0 0 0 3px rgba(61, 220, 132, .14);
}
.nav { display: flex; gap: 26px; flex-wrap: wrap; }
.nav a {
  font-size: 15px; color: var(--dark-muted); padding: 4px 0;
  transition: color .18s ease;
}
.nav a:hover { color: #fff; }
.nav a.on { color: #fff; }
.nav a.on::after {
  content: ""; display: block; height: 2px; width: 100%;
  background: var(--led); margin-top: 3px;
}

/* ---------- 首屏：立起来的机架 ---------- */

.hero {
  background: var(--dark); color: var(--dark-ink);
  padding: 64px 0 clamp(76px, 8vw, 116px); overflow: hidden;
}

.display {
  margin: 0 0 26px; color: #fff; font-weight: 700;
  font-size: var(--t-display); line-height: 0.98; letter-spacing: -0.045em;
}
.hero-sub {
  margin: 0 0 clamp(44px, 5vw, 64px); max-width: 42ch; color: var(--dark-muted);
  font-size: var(--t-lead); line-height: 1.55;
}

/* 机架：1px 缝隙即层间接缝，五层等宽，标签回到左侧导轨上 */
.rack {
  display: flex; flex-direction: column;
  gap: 1px; background: var(--dark-4);
}

.slab {
  position: relative;
  display: grid; grid-template-columns: 108px minmax(0, 1fr) auto 16px;
  align-items: center; gap: 24px;
  padding: 23px 26px 23px 26px;
  background: var(--dark-2); color: var(--dark-ink);
  transform: translateY(18px); opacity: 0;
  animation: slab-in .72s cubic-bezier(.22, .61, .36, 1) forwards;
  animation-delay: calc(var(--i) * 70ms + 120ms);
  transition: background .22s ease;
}
.slab::before {
  content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 3px;
  background: var(--led); transform: scaleY(0); transform-origin: 50% 0;
  transition: transform .26s cubic-bezier(.22, .61, .36, 1);
}
.slab:hover { background: var(--dark-3); }
.slab:hover::before { transform: scaleY(1); }
.slab:hover .slab-tab { color: #fff; }
.slab:hover .slab-meta { color: var(--dark-ink); }

.slab-tab {
  font-size: 13px; font-weight: 600; color: var(--dark-muted);
  letter-spacing: .02em; white-space: nowrap;
  transition: color .18s ease;
}

.slab-title { font-size: 20px; font-weight: 600; letter-spacing: -0.02em; color: #fff; }
.slab-meta {
  font-size: var(--t-small); color: var(--dark-muted); white-space: nowrap;
  font-variant-numeric: tabular-nums; transition: color .18s ease;
}
.slab-go {
  font-size: 15px; line-height: 1; color: #6a6a6e; text-align: right;
  transition: color .18s ease, transform .22s cubic-bezier(.22, .61, .36, 1);
}
.slab:hover .slab-go { color: var(--led); transform: translateX(3px); }

/* 第五层：浅色「面板」，与上面四层用较宽的缝隙隔开 */
.slab-front {
  margin-top: 13px; background: var(--band); color: var(--ink);
  grid-template-columns: 108px minmax(0, 1fr) auto;
  padding: 30px 26px;
  animation-delay: 480ms;
}
.slab-front:hover { background: #fff; }
.slab-front .slab-title { color: var(--ink); font-size: 24px; }
.slab-front .slab-tab { color: var(--muted); }
.slab-front:hover .slab-tab { color: var(--ink); }

@keyframes slab-in {
  to { transform: translateY(0); opacity: 1; }
}

/* ---------- 按钮 ---------- */

.btn {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 13px 24px; background: var(--ink); color: #fff;
  font-size: 15px; font-weight: 600; border: 0; border-radius: 2px;
  transition: background .18s ease, transform .18s ease;
}
.btn:hover { background: #000; color: #fff; transform: translateY(-1px); }
.btn:active { transform: translateY(0); }
.btn .led { width: 6px; height: 6px; box-shadow: none; }
.btn-ghost {
  background: transparent; color: var(--ink);
  border: 0; padding: 13px 4px; font-weight: 600;
  border-bottom: 2px solid var(--band-2);
}
.btn-ghost:hover { border-bottom-color: var(--ink); background: transparent; }

/* ---------- 内容区 ---------- */

/* 页面抬头（内页）：白底大字，深色只留给首屏与页脚 */
.mast { padding: 46px 0 54px; background: var(--ground); }
.mast h1 {
  margin: 0 0 22px; color: var(--ink); font-weight: 700;
  font-size: clamp(34px, 4.6vw, 62px); line-height: 1.02; letter-spacing: -0.04em;
  max-width: 24ch;
}
.mast .lede {
  margin: 0; max-width: 46ch; color: var(--muted);
  font-size: var(--t-lead); line-height: 1.55;
}
.crumbs {
  display: flex; flex-wrap: wrap; gap: 8px; align-items: center;
  padding: 26px 0 0; font-size: 14px; color: var(--muted);
}
.crumbs a { color: var(--muted); }
.crumbs a:hover { color: var(--ink); }
.crumbs .sep { color: var(--band-2); }

.sec { padding: var(--gap-sec) 0; }
.sec--band { background: var(--band); }
.sec-h {
  margin: 0 0 22px; color: var(--ink); font-weight: 700;
  font-size: var(--t-head); line-height: 1.16; letter-spacing: -0.03em;
}
.sec-h a { color: inherit; }
.sec-sub { margin: 0 0 40px; font-size: var(--t-lead); color: var(--muted); max-width: 44ch; }

.sub-h {
  margin: 40px 0 12px; font-size: 16px; font-weight: 600;
  color: var(--ink); letter-spacing: -0.01em;
}
.sub-h:first-child { margin-top: 0; }

.body-p { margin: 0 0 20px; max-width: 42ch; color: var(--ink-2); }
.body-p.strong {
  margin: 0; max-width: 26ch; color: var(--ink);
  font-size: clamp(22px, 2.2vw, 30px); font-weight: 600;
  line-height: 1.32; letter-spacing: -0.025em;
}
.formula {
  margin: 0 0 20px; padding: 22px 26px; background: var(--band);
  font-size: 19px; color: var(--ink); overflow-x: auto;
  border-left: 4px solid var(--ink);
}
.footnote { font-size: var(--t-small); color: var(--muted); max-width: 56ch; }
.note {
  margin: 0; padding: 26px 30px; background: var(--band-2);
  font-size: 15px; color: var(--ink-2); max-width: 62ch;
}

/* ---------- 表格：靠底色分带，不画细线 ---------- */

.panel { background: var(--ground); }
.sec--band .panel { background: var(--ground); }
.panel-foot {
  margin: 0; padding: 18px 22px; background: var(--band);
  display: flex; justify-content: space-between; gap: 20px; flex-wrap: wrap;
  font-size: 14px; color: var(--muted);
}
.panel-foot a { color: var(--ink); font-weight: 600; }

.tbl { width: 100%; border-collapse: collapse; font-size: 15px; }
.tbl caption {
  padding: 0 0 18px; text-align: left; color: var(--muted); font-size: 14px;
}
.tbl thead th {
  padding: 15px 20px; text-align: left; white-space: nowrap;
  background: var(--ink); color: #fff; font-size: 14px; font-weight: 600;
  letter-spacing: 0;
}
.tbl thead th:first-child { border-radius: 2px 0 0 0; }
.tbl thead th:last-child { border-radius: 0 2px 0 0; }
.tbl tbody th {
  padding: 16px 20px; text-align: left; font-weight: 600;
  font-size: 15px; color: var(--ink); white-space: nowrap;
  border-bottom: 0;
}
.tbl td {
  padding: 16px 20px; color: var(--ink-2); vertical-align: top; border-bottom: 0;
}
.tbl tbody tr:nth-child(odd) { background: var(--band); }
.tbl tbody tr:hover { background: var(--band-2); }
.tbl a { font-weight: 600; color: var(--ink); border-bottom: 2px solid transparent; }
.tbl a:hover { border-bottom-color: var(--ink); }
.tbl thead th.num { text-align: right; }
td.num, th.num {
  text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap;
}
.tbl td.num { color: var(--ink); font-weight: 600; }
.mono { font-variant-numeric: tabular-nums; }
.dim { color: var(--muted); }

.badge {
  display: inline-block; padding: 2px 9px; background: var(--band-2);
  color: var(--ink-2); font-size: 13px; font-weight: 600; border-radius: 2px;
}
.badge.accent { background: var(--ink); color: #fff; }
.badge.accent::before {
  content: ""; display: inline-block; width: 6px; height: 6px;
  border-radius: 50%; background: var(--led); margin-right: 7px; vertical-align: 1px;
}

/* ---------- 列表行 ---------- */

.row-list { display: flex; flex-direction: column; }
.row {
  display: flex; align-items: baseline; justify-content: space-between;
  gap: 24px; padding: 20px 22px; color: var(--ink-2);
  transition: background .18s ease, padding-left .18s ease;
}
.row:nth-child(odd) { background: var(--band); }
.row:hover { background: var(--band-2); padding-left: 30px; color: var(--ink); }
.row .row-k { font-size: 17px; font-weight: 600; color: var(--ink); }
.row-v { font-size: 14px; color: var(--muted); text-align: right; flex-shrink: 0; max-width: 48%; }

.dots { margin: 0 0 20px; padding-left: 22px; max-width: 42ch; }
.dots li { margin-bottom: 10px; }
.dots li::marker { color: var(--ink); }
.dots.warn li::marker { content: "— "; }

/* ---------- 栅格 ---------- */

.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; }
.grid-3 {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 40px;
}
.grid-3.tight { gap: 20px; }

.card {
  display: block; padding: 28px 26px; background: var(--band);
  transition: background .18s ease, transform .18s ease;
}
.card:hover { background: var(--band-2); transform: translateY(-3px); color: inherit; }
.card h3 {
  margin: 0 0 10px; color: var(--ink); font-size: 20px;
  font-weight: 700; letter-spacing: -0.02em;
}
.card p { margin: 0 0 18px; font-size: 15px; color: var(--muted); line-height: 1.6; }
.card.sm { padding: 20px 22px; }
.card.sm h3 { font-size: 17px; margin-bottom: 6px; }
.card.sm p { margin: 0; font-size: 14px; }
.card-go { font-size: 14px; font-weight: 600; color: var(--ink); }

/* ---------- 换算计算器 ---------- */

.calc { background: var(--ink); color: #fff; padding: 34px 32px; max-width: 660px; }
.calc label {
  display: block; margin-bottom: 16px; font-size: 15px; color: var(--dark-muted);
}
.calc-row { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
.calc input {
  width: 176px; padding: 12px 14px; font-size: 22px; font-weight: 600;
  color: var(--ink); background: #fff; border: 0; border-radius: 2px;
  font-variant-numeric: tabular-nums;
}
.calc input:focus { outline: none; box-shadow: 0 0 0 3px rgba(61, 220, 132, .55); }
.calc-eq { color: var(--dark-muted); font-size: 20px; }
.calc-out {
  font-size: 34px; font-weight: 700; color: #fff; letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums; word-break: break-all;
}
.calc-unit { font-size: 17px; color: var(--dark-muted); }

/* ---------- FAQ ---------- */

.faq { display: flex; flex-direction: column; gap: 18px; max-width: 56ch; }
.qa { background: var(--band); padding: 24px 26px; }
.qa .q { margin: 0 0 10px; font-size: 18px; font-weight: 700; color: var(--ink); }
.qa .a { margin: 0; font-size: 16px; color: var(--ink-2); }

/* ---------- 页脚：把字标做大 ---------- */

.foot { background: var(--dark); color: var(--dark-muted); padding: 88px 0 48px; overflow: hidden; }
.foot-mark {
  margin: 0; color: #fff; font-weight: 700;
  font-size: clamp(64px, 15vw, 220px); line-height: 0.84;
  letter-spacing: -0.055em;
}
.foot-mark .led {
  display: inline-block; width: 0.14em; height: 0.14em;
  margin-left: 0.06em; vertical-align: 0.62em;
}
.foot-grid {
  display: grid; grid-template-columns: 1.4fr 1fr; gap: 48px;
  margin-top: 56px; font-size: 14px;
}
.foot-links { display: flex; flex-wrap: wrap; gap: 14px 26px; }
.foot-links a { color: var(--dark-ink); font-size: 15px; }
.foot-links a:hover { color: #fff; }
.foot-note { margin: 26px 0 0; max-width: 62ch; line-height: 1.7; color: var(--dark-muted); }
.foot-legal { margin: 34px 0 0; font-size: 13px; color: #6e6e72; }
.foot-legal a { color: #6e6e72; }

/* ---------- 动效（无脚本时内容照常显示） ---------- */

.reveal { opacity: 1; transform: none; }
html.js .reveal {
  opacity: 0; transform: translateY(28px);
  transition: opacity .72s ease, transform .72s cubic-bezier(.22, .61, .36, 1);
}
html.js .reveal.is-in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html.js .reveal { opacity: 1; transform: none; transition: none; }
  .slab { animation: none; transform: none; opacity: 1; }
  .slab:hover, .card:hover, .btn:hover, .row:hover { transform: none; }
  html { scroll-behavior: auto; }
}

/* ---------- 响应式 ---------- */

@media (max-width: 900px) {
  :root { --pad: 22px; --gap-sec: clamp(72px, 9vw, 104px); }
  .grid-2 { grid-template-columns: 1fr; gap: 40px; }
  .foot-grid { grid-template-columns: 1fr; gap: 32px; }
  .slab { grid-template-columns: 84px minmax(0, 1fr) auto 14px; gap: 14px; padding: 20px 20px; }
  .slab-front { grid-template-columns: 84px minmax(0, 1fr) auto; padding: 24px 20px; }
  .slab-front .slab-title { font-size: 22px; }
  .slab-title { font-size: 18px; }
}

@media (max-width: 620px) {
  :root { --t-body: 16px; --pad: 18px; }
  .head-in { padding-top: 18px; padding-bottom: 18px; flex-wrap: wrap; gap: 12px; }
  .nav { gap: 18px; }
  .nav a { font-size: 14px; }
  .hero { padding-top: 36px; }
  .display { font-size: clamp(40px, 13vw, 64px); }
  .hero-sub { margin-bottom: 44px; }
  .slab, .slab-front {
    grid-template-columns: 1fr auto; align-items: baseline;
    gap: 6px 12px; padding: 16px 18px 18px;
  }
  .slab-tab { grid-column: 1; grid-row: 1; font-size: 12px; letter-spacing: .06em; }
  .slab-meta { grid-column: 2; grid-row: 1; font-size: 13px; }
  .slab-title { grid-column: 1 / -1; grid-row: 2; font-size: 18px; }
  .slab-go { display: none; }
  .slab-front { padding: 20px 18px; }
  .slab-front .slab-title { font-size: 19px; }
  .slab-front .btn { grid-column: 1 / -1; grid-row: 3; justify-self: start; margin-top: 10px; }
  .mast { padding: 34px 0 44px; }
  .row { flex-direction: column; gap: 6px; padding: 16px 16px; }
  .row:hover { padding-left: 16px; }
  .row-v { max-width: 100%; text-align: left; }
  .tbl { font-size: 14px; }
  .tbl thead th, .tbl td, .tbl tbody th { padding: 12px 14px; }
  .calc { padding: 24px 20px; }
  .calc-out { font-size: 28px; }
  .card { padding: 22px 20px; }
  .body-p.strong { font-size: 21px; max-width: 100%; }
}