:root {
  --ink: #0b0d0c;
  --ink-soft: #121513;
  --paper: #f0eee6;
  --muted: #aaa9a2;
  --line: rgba(240,238,230,.16);
  --line-strong: rgba(240,238,230,.34);
  --signal: #ff6945;
  --cyan: #8adce1;
  --max: 1120px;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; background: var(--ink); }
body { margin: 0; color: var(--paper); background: radial-gradient(circle at 78% 6%, rgba(138,220,225,.08), transparent 25rem), var(--ink); font: 16px/1.65 "Space Grotesk", "Noto Sans SC", system-ui, sans-serif; }
a { color: inherit; text-decoration: none; }
button { font: inherit; }
.lang-en { display: none !important; }
body[data-lang="en"] .lang-zh { display: none !important; }
body[data-lang="en"] .lang-en { display: initial !important; }
::selection { color: var(--ink); background: var(--signal); }

.case-header { position: sticky; top: 0; z-index: 20; display: flex; justify-content: space-between; align-items: center; min-height: 78px; padding: 0 max(1.2rem, calc((100vw - var(--max)) / 2)); border-bottom: 1px solid var(--line); background: rgba(11,13,12,.86); backdrop-filter: blur(12px); }
.case-brand { display: inline-flex; align-items: center; gap: .65rem; font-size: .78rem; font-weight: 700; letter-spacing: .16em; }
.case-brand i { width: .5rem; aspect-ratio: 1; border-radius: 50%; background: var(--signal); box-shadow: 0 0 0 5px rgba(255,105,69,.1); }
.case-nav { display: flex; align-items: center; gap: 1.25rem; color: var(--muted); font-size: .68rem; font-weight: 700; letter-spacing: .1em; }
.case-nav a:hover, .case-nav a:focus-visible { color: var(--paper); }
.lang-toggle { padding: .55rem .72rem; border: 1px solid var(--line-strong); color: var(--paper); background: transparent; cursor: pointer; }
.lang-toggle:hover, .lang-toggle:focus-visible { color: var(--ink); background: var(--paper); }

main, .case-footer { width: min(var(--max), calc(100% - 3rem)); margin-inline: auto; }
.case-hero { min-height: calc(100svh - 78px); display: grid; grid-template-columns: 1.02fr .98fr; gap: 5rem; align-items: center; padding: 6rem 0; }
.case-kicker, .section-kicker { margin: 0 0 .8rem; color: var(--signal); font-size: .62rem; font-weight: 700; letter-spacing: .2em; }
.case-hero h1 { margin: 0; font: 500 clamp(4.2rem, 9vw, 8rem)/.82 "Cormorant Garamond", "Noto Sans SC", serif; letter-spacing: -.055em; }
.case-hero h1 > span:last-child { display: block; color: var(--signal); font: 600 clamp(1rem, 2vw, 1.35rem)/1.3 "Space Grotesk", "Noto Sans SC", sans-serif; letter-spacing: .02em; margin-top: 1.6rem; }
.case-lead { max-width: 620px; margin: 2rem 0 0; color: #d1d0ca; font-size: 1.08rem; }
.case-tags { display: flex; flex-wrap: wrap; gap: .55rem; margin-top: 2rem; }
.case-tags span { padding: .35rem .62rem; border: 1px solid var(--line); color: var(--muted); font-size: .63rem; }
.case-status { display: inline-flex; align-items: center; gap: .55rem; margin-top: 2.5rem; color: var(--muted); font-size: .62rem; letter-spacing: .13em; }
.case-status i { width: .5rem; aspect-ratio: 1; border-radius: 50%; background: var(--signal); box-shadow: 0 0 0 5px rgba(255,105,69,.1); }

.case-visual { position: relative; min-height: 520px; overflow: hidden; border: 1px solid var(--line); background: #303632; }
.case-visual::before { content: ""; position: absolute; inset: 0; background-image: linear-gradient(rgba(240,238,230,.07) 1px, transparent 1px), linear-gradient(90deg, rgba(240,238,230,.07) 1px, transparent 1px); background-size: 30px 30px; }
.case-visual::after { content: attr(data-label); position: absolute; left: 1.2rem; bottom: 1rem; color: rgba(240,238,230,.68); font-size: .58rem; letter-spacing: .16em; }
.diagram { position: absolute; inset: 13%; }
.diagram--robot .joint { position: absolute; z-index: 3; width: 58px; aspect-ratio: 1; border: 9px solid var(--paper); border-radius: 50%; background: var(--signal); }
.diagram--robot .joint:nth-child(1) { left: 5%; bottom: 8%; }.diagram--robot .joint:nth-child(3) { left: 42%; top: 42%; }.diagram--robot .joint:nth-child(5) { right: 4%; top: 10%; }
.diagram--robot .arm { position: absolute; z-index: 2; height: 22px; background: var(--paper); transform-origin: left center; }
.diagram--robot .arm:nth-child(2) { width: 51%; left: 14%; bottom: 20%; transform: rotate(-36deg); }.diagram--robot .arm:nth-child(4) { width: 48%; left: 51%; top: 49%; transform: rotate(-31deg); }
.diagram--mechanism { display: grid; place-items: center; }
.diagram--mechanism span { position: absolute; width: 78%; height: 15%; border: 1px solid var(--paper); background: rgba(240,238,230,.06); transform: rotate(-10deg); }
.diagram--mechanism span:nth-child(1) { translate: 0 -145px; }.diagram--mechanism span:nth-child(2) { translate: 0 -72px; }.diagram--mechanism span:nth-child(3) { background: var(--signal); border-color: var(--signal); }.diagram--mechanism span:nth-child(4) { translate: 0 72px; }.diagram--mechanism span:nth-child(5) { translate: 0 145px; }
.diagram--perception { display: grid; place-items: center; }
.diagram--perception .cube { position: relative; width: 190px; aspect-ratio: 1; border: 4px solid var(--ink); background: rgba(240,238,230,.78); transform: rotate(30deg) skew(-5deg); }
.diagram--perception .cube::before, .diagram--perception .cube::after { content: ""; position: absolute; inset: 16%; border: 2px solid var(--ink); }
.diagram--perception .cube::after { inset: 34%; background: var(--signal); }
.diagram--perception b { position: absolute; left: 50%; top: 50%; width: 220%; height: 2px; background: var(--ink); transform-origin: left; }
.diagram--perception b:nth-child(1) { transform: rotate(0); }.diagram--perception b:nth-child(2) { transform: rotate(120deg); }.diagram--perception b:nth-child(3) { transform: rotate(240deg); }

.case-section { padding: 7rem 0; border-top: 1px solid var(--line); }
.section-head { display: grid; grid-template-columns: 100px 1fr; gap: 1.5rem; align-items: start; margin-bottom: 3.2rem; }
.section-index { color: var(--signal); font-size: .64rem; letter-spacing: .16em; padding-top: .8rem; }
.section-head h2 { margin: 0; font: 500 clamp(2.8rem, 6vw, 5rem)/.95 "Cormorant Garamond", "Noto Sans SC", serif; letter-spacing: -.04em; }
.case-grid { margin-left: 115px; display: grid; grid-template-columns: 1fr 1fr; gap: 1.2rem; }
.case-panel { padding: 1.5rem; border: 1px solid var(--line); background: rgba(240,238,230,.02); }
.case-panel b { display: block; margin-bottom: 1rem; color: var(--cyan); font-size: .61rem; letter-spacing: .16em; }
.case-panel p { margin: 0; color: var(--muted); }
.case-panel--accent { border-color: rgba(255,105,69,.42); }
.workflow { margin-left: 115px; list-style: none; padding: 0; border-top: 1px solid var(--line); }
.workflow li { display: grid; grid-template-columns: 64px 1fr 1.3fr; gap: 1.4rem; align-items: start; padding: 1.5rem 0; border-bottom: 1px solid var(--line); }
.workflow span { color: var(--signal); font-size: .65rem; }.workflow strong { font-size: 1.05rem; }.workflow p { margin: 0; color: var(--muted); font-size: .86rem; }
.evidence { margin-left: 115px; display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; }
.evidence article { min-height: 190px; display: flex; flex-direction: column; justify-content: space-between; padding: 1.2rem; border: 1px dashed var(--line-strong); }
.evidence span { color: var(--signal); font-size: .59rem; letter-spacing: .14em; }.evidence h3 { margin: 0; font-size: 1rem; }.evidence p { margin: .5rem 0 0; color: var(--muted); font-size: .78rem; }
.case-next { margin-left: 115px; max-width: 720px; }
.case-next p { color: var(--muted); font-size: 1.05rem; }
.back-link { display: inline-flex; gap: .65rem; margin-top: 1.4rem; padding-bottom: .25rem; border-bottom: 1px solid var(--signal); color: var(--signal); font-size: .68rem; font-weight: 700; letter-spacing: .13em; }
.case-footer { display: flex; justify-content: space-between; gap: 1rem; padding: 1.4rem 0 2.5rem; border-top: 1px solid var(--line); color: var(--muted); font-size: .65rem; }
:focus-visible { outline: 2px solid var(--signal); outline-offset: 4px; }

@media (max-width: 760px) {
  .case-header { padding-inline: 1rem; }
  .case-nav a:not(.case-back) { display: none; }
  main, .case-footer { width: min(100% - 2rem, var(--max)); }
  .case-hero { grid-template-columns: 1fr; gap: 3rem; padding: 4rem 0; }
  .case-visual { min-height: 380px; }
  .section-head { grid-template-columns: 48px 1fr; }
  .case-grid, .workflow, .evidence, .case-next { margin-left: 0; }
  .case-grid { grid-template-columns: 1fr; }
  .workflow li { grid-template-columns: 42px 1fr; }
  .workflow p { grid-column: 2; }
  .evidence { grid-template-columns: 1fr; }
  .case-footer { flex-direction: column; }
}

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

/* A switchable palette inspired by Reze's violet hair and green eyes. */
html[data-theme="reze"] { --ink: #100d17; --ink-soft: #1a1523; --paper: #f3edf5; --muted: #c0b5c8; --line: rgba(222,205,231,.18); --line-strong: rgba(222,205,231,.38); --signal: #c39be7; --cyan: #a8c9b8; }
.theme-toggle { display: inline-flex; align-items: center; gap: .48rem; padding: .62rem .82rem; border: 1px solid var(--line-strong); color: var(--paper); background: transparent; cursor: pointer; white-space: nowrap; font-size: .68rem; font-weight: 600; }
.theme-toggle:hover, .theme-toggle:focus-visible { border-color: var(--signal); color: var(--signal); }
.theme-toggle__dot { width: .55rem; height: .55rem; border-radius: 50%; background: var(--signal); box-shadow: 0 0 0 3px color-mix(in srgb, var(--signal) 18%, transparent); }
html[data-theme="reze"] body { background: radial-gradient(circle at 75% 9%, rgba(156,111,195,.18), transparent 30rem), radial-gradient(circle at 12% 52%, rgba(121,73,151,.10), transparent 30rem), var(--ink); }

html[data-theme="reze"] .case-header { background: rgba(16,13,23,.88); }
html[data-theme="reze"] .case-visual { background: #352b42; }
html[data-theme="reze"] .case-panel--accent { border-color: rgba(195,155,231,.5); }
@media (max-width: 760px) { .case-nav { gap: .5rem; flex-wrap: wrap; justify-content: flex-end; } .theme-toggle { padding: .5rem .6rem; } }