/* Brand shell. Reading surfaces and game colour semantics remain independent. */
:root{--lab-bg:#0b1224;--lab-panel:#14213b;--lab-raised:#1c2d4a;--lab-text:#f3f6fc;--lab-muted:#b8c6df;--lab-accent:#8dbbff;--lab-line:#425674;--lab-focus:#ffd580}
.lab-header{background:var(--lab-bg);color:var(--lab-text);border-bottom:1px solid var(--lab-line);position:relative;z-index:20}
.lab-header .lab-nav{width:min(1120px,calc(100% - 40px));margin:auto;display:flex;align-items:center;justify-content:space-between;gap:16px;flex-wrap:wrap;padding:16px 0;min-height:76px;font:16px/1.5 system-ui,sans-serif}
.lab-brand{font-weight:750;text-decoration:none;white-space:nowrap;color:var(--lab-text)}.lab-brand span{color:var(--lab-accent);font-size:26px;vertical-align:middle}
.lab-links{display:flex;gap:8px;flex-wrap:wrap}.lab-header a,.lab-menu summary{display:inline-flex;align-items:center;min-height:44px;padding:8px 12px;border-radius:8px;text-decoration:none}.lab-header a:hover,.lab-header [aria-current=page]{background:var(--lab-raised);color:var(--lab-accent)}.lab-header [aria-current=page]{box-shadow:inset 0 -2px var(--lab-accent)}
.lab-menu{position:relative}.lab-menu summary{cursor:pointer;list-style:revert}.lab-menu[open]>div{position:absolute;right:0;top:100%;width:160px;padding:8px;background:var(--lab-panel);border:1px solid var(--lab-line);border-radius:12px}.lab-menu div a{display:flex}
.lab-footer{background:var(--lab-bg);color:var(--lab-muted);padding:28px max(20px,calc((100% - 1120px)/2));font:14px/1.8 system-ui,sans-serif;display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;border-top:1px solid var(--lab-line)}.lab-footer div{display:flex;gap:16px;flex-wrap:wrap}.lab-footer a{color:inherit;min-height:44px;display:inline-flex;align-items:center}
:where(.lab-header,.lab-footer,.lab-catalog) :focus-visible{outline:3px solid var(--lab-focus);outline-offset:4px}
/* Legacy tools keep a light document within the navy brand frame. */
body.lab-reading{background:var(--lab-bg);--ink:#18243b;--muted:#465671;--paper:#f7f9fd;--line:#cbd5e3;--green:#b8d4ff;color:var(--ink)}
.lab-reading>main{background:#f7f9fd;border-radius:0 0 16px 16px;padding:24px;max-width:1120px;margin:0 auto 32px;width:calc(100% - 40px)}
.lab-reading .cta,.lab-reading .primary,.lab-reading .button:not(.secondary){background:#203f70;color:#fff}.lab-reading .tag,.lab-reading .badge,.lab-reading .usage-example{background:#e7effb;color:#28466e;border-color:#b5c8e4}.lab-reading :focus-visible{outline:3px solid #3469ad;outline-offset:3px}
.lab-reading input,.lab-reading select,.lab-reading textarea{color:#18243b;background:#fff}
.lab-catalog{margin:0;background:var(--lab-bg);color:var(--lab-text);font:16px/1.8 system-ui,-apple-system,'Noto Sans TC',sans-serif;color-scheme:dark}.lab-catalog *{box-sizing:border-box}.lab-catalog a{color:inherit;text-underline-offset:5px}.lab-catalog main{width:min(1120px,calc(100% - 40px));margin:auto}.lab-hero{padding:72px 0 48px;max-width:850px}.lab-kicker{font-size:13px;letter-spacing:.12em;color:var(--lab-accent)}.lab-hero h1{font-size:clamp(34px,5vw,60px);line-height:1.25;letter-spacing:-.04em;margin:16px 0 24px}.lab-hero p{color:var(--lab-muted);font-size:18px;max-width:650px}.lab-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:28px}.lab-button{display:inline-flex;min-height:48px;align-items:center;justify-content:center;background:var(--lab-accent);color:var(--lab-bg)!important;padding:10px 20px;border-radius:8px;text-decoration:none;font-weight:700}.lab-button.secondary{background:transparent;color:var(--lab-text)!important;border:1px solid var(--lab-line)}.lab-section{padding:24px 0 40px;scroll-margin-top:20px}.lab-section h2{font-size:26px;margin:0 0 8px}.lab-section>p{color:var(--lab-muted);margin:0 0 24px}.lab-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}.lab-card{min-width:0;background:var(--lab-panel);border:1px solid var(--lab-line);border-radius:16px;padding:26px;display:flex;flex-direction:column}.lab-card h3{font-size:22px;line-height:1.4;margin:12px 0}.lab-card p{color:var(--lab-muted);margin:0 0 22px}.lab-card .lab-button{margin-top:auto;align-self:start}.lab-label{font-size:12px;color:var(--lab-accent);letter-spacing:.05em}.lab-note{padding:24px;background:var(--lab-panel);border:1px solid var(--lab-line);border-radius:12px;color:var(--lab-muted);margin:16px 0 48px}.lab-note summary{cursor:pointer;min-height:44px;display:flex;align-items:center;color:var(--lab-text)}.lab-skip{position:absolute;top:-100px;left:20px;z-index:30;background:var(--lab-panel);padding:12px}.lab-skip:focus{top:12px}
@media(max-width:760px){.lab-grid{grid-template-columns:1fr}.lab-hero{padding:40px 0 24px}.lab-header .lab-nav{gap:8px}.lab-links{width:100%;justify-content:space-between}.lab-card{padding:22px}.lab-reading>main{padding:16px;width:calc(100% - 24px)}.lab-back{font-size:14px}}
@media print{.lab-header,.lab-footer{display:none!important}body.lab-reading{background:white;color:#000}.lab-reading>main{background:white;border:0;padding:0;margin:0;width:auto;max-width:none}.lab-reading input,.lab-reading textarea{color:#000}.lab-catalog{background:white;color:#000}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto!important}}
.lab-header .lab-context{display:flex;flex-wrap:wrap;gap:8px;width:min(1120px,calc(100% - 40px));margin:0 auto;padding:0 0 12px;font:14px/1.5 system-ui,sans-serif}