:root {
  --fog: #e7eef3;
  --paper: #f7f4ef;
  --ink: #2c3540;
  --mute: #6a7680;
  --blue: #6a86a0;
  --blue-2: #8aa4b8;
  --soft: #d0894a;
  --serif: "Noto Serif SC", "Songti SC", serif;
  --sans: "Noto Sans SC", "PingFang SC", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, Menlo, monospace;
}
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
section[id] { scroll-margin-top: 76px; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: var(--sans); font-size: 16px; line-height: 1.8; }
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
.app-link { color: var(--blue); text-decoration: underline; text-underline-offset: 3px; }
button { font-family: inherit; cursor: pointer; }
code { font-family: var(--mono); background: rgba(106, 134, 160, 0.12); padding: 0.05em 0.35em; }
.veil { pointer-events: none; position: fixed; inset: 0; z-index: 6; opacity: 0.2; background-image: url("images/texture.webp"); background-size: 420px auto; mix-blend-mode: multiply; }
.skip { position: absolute; left: -999px; }
.skip:focus { left: 10px; top: 10px; z-index: 80; background: #fff; padding: 8px; }
.softbar { position: sticky; top: 0; z-index: 50; display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 12px 22px; background: rgba(247, 244, 239, 0.92); backdrop-filter: blur(12px); }
.brand { font-family: var(--serif); font-size: 22px; }
.brand small { display: block; font-family: var(--mono); font-size: 10px; letter-spacing: 0.16em; color: var(--mute); }
.nav-toggle { display: none; background: var(--blue); color: #fff; border: 0; border-radius: 999px; padding: 8px 14px; }
.soft-nav { display: flex; gap: 14px; align-items: center; font-size: 13px; }
.soft-nav a { color: var(--mute); }
.soft-nav a.is-active, .soft-nav a:hover { color: var(--ink); }
.soft-nav a.live { background: var(--blue); color: #fff; padding: 7px 14px; border-radius: 999px; }
.quiet-hero { position: relative; min-height: 86vh; display: grid; align-items: end; }
.quiet-hero > img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.quiet-hero::after { content: ""; position: absolute; inset: 0; background: linear-gradient(180deg, rgba(247,244,239,0.15), rgba(247,244,239,0.92) 70%); }
.qh-copy { position: relative; z-index: 1; padding: 10vh 8vw 8vh; max-width: 720px; }
.kicker { font-family: var(--mono); letter-spacing: 0.16em; font-size: 11px; color: var(--blue); margin: 0 0 12px; }
h1, h2, h3 { font-family: var(--serif); margin: 0 0 16px; line-height: 1.2; font-weight: 600; }
h1 { font-size: clamp(34px, 5.4vw, 58px); }
h2 { font-size: clamp(24px, 3vw, 36px); }
.lead { max-width: 40em; }
.quiet { color: var(--mute); max-width: 46em; }
.grade-demo { margin: 20px 0; padding: 16px 18px; background: rgba(255,255,255,0.7); border-radius: 18px; }
.grade-btns { display: flex; flex-wrap: wrap; gap: 8px; }
.grade-btns button { background: #fff; border: 1px solid rgba(106,134,160,0.3); border-radius: 999px; padding: 8px 14px; }
.grade-btns button.on { background: var(--blue); color: #fff; }
#grade-msg { margin: 10px 0 0; font-size: 14px; }
.cta { display: flex; flex-wrap: wrap; gap: 10px; }
.btn { display: inline-flex; align-items: center; padding: 10px 16px; border-radius: 999px; }
.btn.fill { background: var(--blue); color: #fff; }
.btn.ghost { border: 1px solid var(--ink); background: transparent; }
.room { width: min(1000px, calc(100% - 48px)); margin: 0 auto; padding: 80px 0; }
.fog { background: var(--fog); }
.tri { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-top: 28px; }
.tri article, .grid6 article, .grid3 article, .io > div { background: #fff; border-radius: 18px; padding: 18px 20px; box-shadow: 0 8px 24px rgba(44,53,64,0.05); }
.tri ul, .io ul, .bound { margin: 0; padding-left: 1.1em; }
.row { display: grid; grid-template-columns: 1fr 1fr; gap: 32px; align-items: center; margin: 36px 0; }
.row.rev { direction: rtl; }
.row.rev > * { direction: ltr; }
.num { font-family: var(--mono); color: var(--blue); font-size: 12px; letter-spacing: 0.12em; }
.row figure { margin: 0; }
.row img { border-radius: 18px; }
.row figcaption { margin-top: 8px; font-size: 13px; color: var(--mute); }
.grid6, .grid3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin-top: 28px; }
.io { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-top: 24px; }
.bound { max-width: 44em; }
footer { padding: 22px 24px 40px; font-family: var(--mono); font-size: 12px; color: var(--mute); }
@media (max-width: 900px) {
  .tri, .row, .row.rev, .grid6, .grid3, .io { grid-template-columns: 1fr; }
  .row.rev { direction: ltr; }
  .nav-toggle { display: inline-block; }
  .soft-nav { display: none; position: absolute; right: 12px; top: 56px; flex-direction: column; background: var(--paper); border-radius: 16px; padding: 12px; min-width: 180px; box-shadow: 0 12px 30px rgba(44,53,64,0.12); }
  .soft-nav.open { display: flex; }
}