/* CANDUsim — site + four selectable art directions.
   The whole page (chrome, mockups, live panel) restyles from `html[data-look]`. */

@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:wght@400;500;600;700&family=IBM+Plex+Mono:wght@400;500;600&family=Barlow+Condensed:wght@500;600;700&family=VT323&display=swap');

:root {
  /* ---- default look: "hpHMI" (Refurb High-Performance HMI) ---- */
  --bg: #2e3136; --bg-2: #383b41; --panel: #43474e; --panel-2: #4d525a; --line: #5d626b;
  --ink: #f2f3f5; --ink-2: #c9ccd2; --ink-3: #9aa0a9;
  --accent: #3987e5; --accent-ink: #ffffff;
  --lamp-off: #2a2d32; --lamp-alarm: #e66767; --lamp-ack: #eda100; --lamp-ok: #1baf7a; --lamp-info: #3987e5;
  --meter-face: #1f2226; --meter-ink: #e8eaee; --meter-needle: #ff5b4d;
  --crt-bg: #16181c; --crt-ink: #dfe4ea; --crt-accent: #3987e5; --crt-warn: #eda100;
  --font-ui: 'IBM Plex Sans', system-ui, sans-serif; --font-mono: 'IBM Plex Mono', ui-monospace, monospace; --font-label: 'Barlow Condensed', 'IBM Plex Sans', sans-serif;
  --radius: 6px; --shadow: 0 2px 10px rgba(0,0,0,.35); --panel-texture: none; --scanlines: none;
  --series-1: #3987e5; --series-2: #d95926; --series-3: #199e70; --series-4: #c98500; --series-5: #d55181;
  --grid: rgba(255,255,255,.08);
}
[data-look="heritage"] {
  --bg: #b9b3a3; --bg-2: #cfc9b8; --panel: #dbd5c4; --panel-2: #e8e3d4; --line: #8f8a7b;
  --ink: #1d1c18; --ink-2: #3d3b33; --ink-3: #6a665a;
  --accent: #b5451b; --accent-ink: #fff;
  --lamp-off: #6c6659; --lamp-alarm: #ff3b2f; --lamp-ack: #ffb000; --lamp-ok: #37c25d; --lamp-info: #ffffff;
  --meter-face: #f4efe2; --meter-ink: #1d1c18; --meter-needle: #c62828;
  --crt-bg: #0b1a10; --crt-ink: #67ff9c; --crt-accent: #ffb000; --crt-warn: #ff6a3d;
  --font-ui: 'IBM Plex Sans', Helvetica, Arial, sans-serif; --font-mono: 'IBM Plex Mono', monospace; --font-label: 'IBM Plex Sans', Helvetica, sans-serif;
  --radius: 3px; --shadow: 0 1px 0 rgba(255,255,255,.6) inset, 0 3px 8px rgba(0,0,0,.25);
  --panel-texture: repeating-linear-gradient(0deg, rgba(0,0,0,.025) 0 1px, transparent 1px 3px);
  --series-1: #2a78d6; --series-2: #eb6834; --series-3: #1baf7a; --series-4: #eda100; --series-5: #e87ba4;
  --grid: rgba(0,0,0,.1);
}
[data-look="glass"] {
  --bg: #050a16; --bg-2: #0a1226; --panel: rgba(16,28,56,.65); --panel-2: rgba(30,48,90,.55); --line: rgba(80,190,255,.35);
  --ink: #e6f6ff; --ink-2: #9fd3ee; --ink-3: #5f92b0;
  --accent: #39e6ff; --accent-ink: #001018;
  --lamp-off: rgba(60,120,180,.15); --lamp-alarm: #ff4d6d; --lamp-ack: #ffc857; --lamp-ok: #2ee6a6; --lamp-info: #39e6ff;
  --meter-face: rgba(5,15,35,.8); --meter-ink: #bff1ff; --meter-needle: #ff4d6d;
  --crt-bg: rgba(3,10,25,.85); --crt-ink: #bff1ff; --crt-accent: #39e6ff; --crt-warn: #ffc857;
  --font-ui: 'IBM Plex Sans', system-ui, sans-serif; --font-mono: 'IBM Plex Mono', monospace; --font-label: 'Barlow Condensed', sans-serif;
  --radius: 10px; --shadow: 0 0 0 1px rgba(80,190,255,.25), 0 0 24px rgba(57,230,255,.12);
  --series-1: #39e6ff; --series-2: #ff8a5b; --series-3: #2ee6a6; --series-4: #ffc857; --series-5: #ff7ab8;
  --grid: rgba(80,190,255,.15);
}
[data-look="dcc"] {
  --bg: #050705; --bg-2: #0a0f0a; --panel: #0b120c; --panel-2: #10190f; --line: #1f4a25;
  --ink: #48ff7a; --ink-2: #33c95d; --ink-3: #1f8a3c;
  --accent: #48ff7a; --accent-ink: #000;
  --lamp-off: #0d1a0f; --lamp-alarm: #48ff7a; --lamp-ack: #2f9e4f; --lamp-ok: #1f6b33; --lamp-info: #48ff7a;
  --meter-face: #050705; --meter-ink: #48ff7a; --meter-needle: #48ff7a;
  --crt-bg: #050705; --crt-ink: #48ff7a; --crt-accent: #c6ff9e; --crt-warn: #c6ff9e;
  --font-ui: 'VT323', 'IBM Plex Mono', monospace; --font-mono: 'VT323', monospace; --font-label: 'VT323', monospace;
  --radius: 0; --shadow: none;
  --scanlines: repeating-linear-gradient(0deg, rgba(0,0,0,.35) 0 1px, transparent 1px 3px);
  --series-1: #48ff7a; --series-2: #c6ff9e; --series-3: #1f8a3c; --series-4: #9dffb8; --series-5: #2f9e4f;
  --grid: rgba(72,255,122,.15);
}
html[data-look="dcc"] body { font-size: 19px; }
html[data-look="dcc"] body::after { content: ''; position: fixed; inset: 0; pointer-events: none; background: var(--scanlines); z-index: 999; mix-blend-mode: multiply; }

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; font-family: var(--font-ui); background: var(--bg); color: var(--ink); line-height: 1.5; font-size: 15px; }
a { color: var(--accent); }
h1, h2, h3, h4 { font-family: var(--font-label); letter-spacing: .01em; line-height: 1.15; margin: 1.6em 0 .5em; }
h1 { font-size: 2.6rem; margin-top: .4em; } h2 { font-size: 1.9rem; border-bottom: 1px solid var(--line); padding-bottom: .25em; } h3 { font-size: 1.35rem; } h4 { font-size: 1.05rem; text-transform: uppercase; letter-spacing: .06em; color: var(--ink-2); }
p, li { max-width: 78ch; }
code, pre { font-family: var(--font-mono); font-size: .9em; }
pre { background: var(--crt-bg); color: var(--crt-ink); padding: 14px 16px; border-radius: var(--radius); overflow-x: auto; border: 1px solid var(--line); line-height: 1.45; }
code:not(pre code) { background: var(--panel-2); padding: .08em .35em; border-radius: 3px; color: var(--ink); }
table { border-collapse: collapse; width: 100%; font-size: .92em; margin: 1em 0; }
th, td { border: 1px solid var(--line); padding: 6px 9px; text-align: left; vertical-align: top; }
th { background: var(--panel-2); font-family: var(--font-label); text-transform: uppercase; letter-spacing: .05em; font-size: .85em; }
.table-wrap { overflow-x: auto; }
hr { border: 0; border-top: 1px solid var(--line); margin: 2.5em 0; }
.wrap { max-width: 1240px; margin: 0 auto; padding: 0 24px 80px; }
.narrow { max-width: 900px; }
.muted { color: var(--ink-3); }
.small { font-size: .85em; }
.callout { border-left: 4px solid var(--accent); background: var(--panel); padding: 12px 16px; border-radius: var(--radius); margin: 1.2em 0; }
.callout.warn { border-left-color: var(--lamp-ack); }
.callout.danger { border-left-color: var(--lamp-alarm); }
.grid-2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 18px; }
.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 18px; }
.card { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px 18px; box-shadow: var(--shadow); background-image: var(--panel-texture); }
.card h3 { margin-top: .2em; }
.tag { display: inline-block; font-family: var(--font-label); text-transform: uppercase; letter-spacing: .08em; font-size: .72rem; padding: 2px 8px; border: 1px solid var(--line); border-radius: 999px; color: var(--ink-2); margin-right: 6px; }
.tag.ok { border-color: var(--lamp-ok); color: var(--lamp-ok); } .tag.warn { border-color: var(--lamp-ack); color: var(--lamp-ack); } .tag.bad { border-color: var(--lamp-alarm); color: var(--lamp-alarm); }

/* ---- nav ---- */
.nav { position: sticky; top: 0; z-index: 50; background: var(--bg-2); border-bottom: 1px solid var(--line); backdrop-filter: blur(8px); }
.nav .inner { max-width: 1240px; margin: 0 auto; padding: 8px 24px; display: flex; align-items: center; gap: 18px; flex-wrap: wrap; }
.brand { font-family: var(--font-label); font-weight: 700; font-size: 1.25rem; letter-spacing: .04em; text-decoration: none; color: var(--ink); display: flex; align-items: center; gap: 8px; }
.brand .dot { width: 10px; height: 10px; border-radius: 50%; background: var(--lamp-ok); box-shadow: 0 0 8px var(--lamp-ok); }
.nav a.link { color: var(--ink-2); text-decoration: none; font-family: var(--font-label); text-transform: uppercase; letter-spacing: .08em; font-size: .85rem; padding: 6px 4px; }
.nav a.link.active, .nav a.link:hover { color: var(--accent); }
.nav .spacer { flex: 1; }
.lookpick { display: flex; gap: 4px; align-items: center; font-size: .8rem; }
.lookpick label { color: var(--ink-3); font-family: var(--font-label); text-transform: uppercase; letter-spacing: .08em; margin-right: 4px; }
.lookpick button { background: var(--panel); color: var(--ink-2); border: 1px solid var(--line); padding: 4px 9px; cursor: pointer; font-family: var(--font-label); text-transform: uppercase; letter-spacing: .06em; font-size: .75rem; border-radius: var(--radius); }
.lookpick button.active { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }

/* ---- hero ---- */
.hero { padding: 48px 0 24px; display: grid; grid-template-columns: 1.2fr 1fr; gap: 32px; align-items: center; }
.hero h1 { margin: 0 0 .3em; font-size: 3.2rem; }
.hero .lede { font-size: 1.15rem; color: var(--ink-2); max-width: 60ch; }
.hero .cta { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 18px; }
.btn { display: inline-block; padding: 10px 16px; border-radius: var(--radius); background: var(--accent); color: var(--accent-ink); text-decoration: none; font-family: var(--font-label); text-transform: uppercase; letter-spacing: .08em; font-weight: 600; border: 1px solid var(--accent); cursor: pointer; }
.btn.ghost { background: transparent; color: var(--ink); border-color: var(--line); }
.btn.small { padding: 6px 10px; font-size: .78rem; }
.btn.danger { background: var(--lamp-alarm); border-color: var(--lamp-alarm); color: #fff; }
.btn:disabled { opacity: .45; cursor: not-allowed; }
@media (max-width: 900px) { .hero { grid-template-columns: 1fr; } .hero h1 { font-size: 2.4rem; } }

/* ---- artboards (look chooser) ---- */
.artboards { display: grid; grid-template-columns: repeat(auto-fit, minmax(440px, 1fr)); gap: 22px; margin-top: 18px; }
@media (max-width: 500px) { .artboards { grid-template-columns: 1fr; } }
.artboard { border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; background: var(--bg-2); box-shadow: var(--shadow); display: flex; flex-direction: column; }
.artboard .ab-head { display: flex; align-items: center; justify-content: space-between; padding: 10px 14px; border-bottom: 1px solid var(--line); gap: 8px; }
.artboard .ab-head h3 { margin: 0; font-size: 1.15rem; }
.artboard .ab-body { padding: 0; }
.artboard .ab-notes { padding: 12px 14px; font-size: .88rem; color: var(--ink-2); border-top: 1px solid var(--line); }
.artboard .ab-notes ul { margin: .3em 0 0 1.1em; padding: 0; }
.artboard.selected { outline: 3px solid var(--accent); }
/* Each artboard is its own scoped "look": it re-declares the variables via [data-look] on the artboard root */
.scene { background: var(--bg); color: var(--ink); font-family: var(--font-ui); padding: 14px; display: grid; grid-template-columns: 1fr 1fr; grid-template-rows: auto auto; gap: 10px; position: relative; }
.scene .viewport { grid-column: 1 / -1; height: 230px; border-radius: var(--radius); overflow: hidden; position: relative; border: 1px solid var(--line); background: var(--bg-2); }
.scene .viewport svg { width: 100%; height: 100%; display: block; }
.scene .hud { position: absolute; left: 10px; top: 8px; font-family: var(--font-mono); font-size: 11px; color: var(--ink-2); background: var(--crt-bg); padding: 4px 8px; border-radius: var(--radius); border: 1px solid var(--line); }
.scene .hud b { color: var(--crt-ink); }
.scene .hud-r { left: auto; right: 10px; }
.scene .mini { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 8px 10px; min-height: 120px; background-image: var(--panel-texture); }
.scene .mini h5 { margin: 0 0 6px; font-family: var(--font-label); text-transform: uppercase; letter-spacing: .08em; font-size: .7rem; color: var(--ink-3); }
.scene[data-scanlines] { background-image: var(--scanlines); }

/* ---- annunciator windows ---- */
.annun { display: grid; grid-template-columns: repeat(4, 1fr); gap: 4px; }
.annun .win { font-family: var(--font-label); font-size: 9px; line-height: 1.1; text-transform: uppercase; letter-spacing: .03em; padding: 5px 4px; text-align: center; min-height: 30px; display: flex; align-items: center; justify-content: center; background: var(--lamp-off); color: var(--ink-3); border: 1px solid var(--line); border-radius: 2px; }
.annun .win.alarm { background: var(--lamp-alarm); color: #fff; animation: flash .8s steps(2) infinite; text-shadow: 0 0 4px rgba(0,0,0,.4); }
.annun .win.ack { background: var(--lamp-alarm); color: #fff; }
.annun .win.info { background: var(--lamp-info); color: var(--accent-ink); }
.annun .win.ok { background: var(--lamp-ok); color: #fff; }
html[data-look="dcc"] .annun .win.alarm, html[data-look="dcc"] .annun .win.ack, html[data-look="dcc"] .annun .win.info { color: #000; }
[data-look="dcc"] .annun .win.alarm, [data-look="dcc"] .annun .win.ack, [data-look="dcc"] .annun .win.info { color: #000; }
@keyframes flash { 50% { filter: brightness(.45); } }
.annun.big .win { font-size: 11px; min-height: 40px; }

/* ---- bar graphs (LZC) ---- */
.bars { display: flex; gap: 3px; align-items: flex-end; height: 80px; }
.bars .bar { flex: 1; background: var(--meter-face); border: 1px solid var(--line); position: relative; height: 100%; }
.bars .bar i { position: absolute; left: 0; right: 0; bottom: 0; background: var(--series-1); }
.bars .bar.warn i { background: var(--lamp-ack); }
.bars .bar b { position: absolute; left: 0; right: 0; bottom: -14px; font-size: 8px; text-align: center; color: var(--ink-3); font-family: var(--font-mono); font-weight: normal; }
.bars .bar .band { position: absolute; left: 0; right: 0; border-top: 1px dashed var(--ink-3); opacity: .5; }

/* ---- digital readouts ---- */
.readouts { display: grid; grid-template-columns: repeat(auto-fit, minmax(120px, 1fr)); gap: 8px; }
.ro { background: var(--crt-bg); border: 1px solid var(--line); border-radius: var(--radius); padding: 6px 10px; font-family: var(--font-mono); }
.ro .l { font-size: .68rem; color: var(--ink-3); text-transform: uppercase; letter-spacing: .06em; font-family: var(--font-label); }
.ro .v { font-size: 1.35rem; color: var(--crt-ink); line-height: 1.1; }
.ro .u { font-size: .7rem; color: var(--ink-3); margin-left: 2px; }
.ro.warn .v { color: var(--crt-warn); }
.ro.bad .v { color: var(--lamp-alarm); }

/* ---- live panel ---- */
.panel { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); background-image: var(--panel-texture); padding: 16px; display: grid; grid-template-columns: 1.1fr 1fr; gap: 16px; }
@media (max-width: 1000px) { .panel { grid-template-columns: 1fr; } }
.panel .col { display: flex; flex-direction: column; gap: 12px; min-width: 0; }
.ctl-row { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
.ctl-row label { font-family: var(--font-label); text-transform: uppercase; letter-spacing: .06em; font-size: .75rem; color: var(--ink-3); }
.ctl-row input[type=number], .ctl-row select { background: var(--crt-bg); color: var(--crt-ink); border: 1px solid var(--line); border-radius: var(--radius); padding: 6px 8px; font-family: var(--font-mono); width: 90px; }
.ctl-row select { width: auto; }
.switch { display: inline-flex; align-items: center; gap: 6px; padding: 5px 10px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--panel-2); cursor: pointer; font-family: var(--font-label); text-transform: uppercase; letter-spacing: .06em; font-size: .75rem; color: var(--ink-2); user-select: none; }
.switch i { width: 10px; height: 10px; border-radius: 50%; background: var(--lamp-off); border: 1px solid var(--line); }
.switch.on i { background: var(--lamp-ok); box-shadow: 0 0 6px var(--lamp-ok); }
.switch.trip { border-color: var(--lamp-alarm); color: var(--lamp-alarm); }
.switch.trip.on i { background: var(--lamp-alarm); box-shadow: 0 0 6px var(--lamp-alarm); }
.chart { background: var(--crt-bg); border: 1px solid var(--line); border-radius: var(--radius); position: relative; }
.chart canvas { width: 100%; height: 180px; display: block; }
.chart .legend { position: absolute; top: 6px; right: 10px; display: flex; gap: 12px; font-family: var(--font-label); font-size: .72rem; text-transform: uppercase; letter-spacing: .06em; color: var(--ink-2); }
.chart .legend i { display: inline-block; width: 12px; height: 3px; vertical-align: middle; margin-right: 4px; border-radius: 2px; }
.chart .tip { position: absolute; pointer-events: none; background: var(--panel-2); color: var(--ink); border: 1px solid var(--line); border-radius: var(--radius); padding: 4px 8px; font-family: var(--font-mono); font-size: .75rem; white-space: nowrap; display: none; }
.log { background: var(--crt-bg); color: var(--crt-ink); font-family: var(--font-mono); font-size: .78rem; height: 130px; overflow-y: auto; padding: 8px 10px; border: 1px solid var(--line); border-radius: var(--radius); }
.log .t { color: var(--ink-3); margin-right: 6px; }
.log .warn { color: var(--crt-warn); } .log .bad { color: var(--lamp-alarm); }

/* ---- diagrams ---- */
.diagram { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 10px; margin: 1em 0; overflow-x: auto; }
.diagram svg { width: 100%; height: auto; display: block; font-family: var(--font-label); }
.diagram .cap { font-size: .82rem; color: var(--ink-3); margin: 6px 4px 0; }

/* ---- tutorial ---- */
.lesson { border: 1px solid var(--line); border-radius: var(--radius); background: var(--panel); background-image: var(--panel-texture); margin: 18px 0; overflow: hidden; }
.lesson header { padding: 12px 16px; display: flex; gap: 12px; align-items: baseline; border-bottom: 1px solid var(--line); background: var(--panel-2); }
.lesson header .n { font-family: var(--font-mono); color: var(--accent); font-size: 1.1rem; }
.lesson header h3 { margin: 0; }
.lesson .body { padding: 12px 16px; }
.steps { counter-reset: s; list-style: none; padding: 0; margin: 0; }
.steps li { counter-increment: s; position: relative; padding-left: 40px; margin: 8px 0; max-width: none; }
.steps li::before { content: counter(s); position: absolute; left: 0; top: 0; width: 26px; height: 26px; border-radius: 50%; background: var(--accent); color: var(--accent-ink); font-family: var(--font-label); font-weight: 700; display: flex; align-items: center; justify-content: center; font-size: .85rem; }
.steps li .say { display: block; font-style: italic; color: var(--ink-2); }
.kbd { font-family: var(--font-mono); border: 1px solid var(--line); border-bottom-width: 2px; border-radius: 4px; padding: 0 5px; font-size: .85em; background: var(--panel-2); }
.toc { columns: 2; column-gap: 32px; font-size: .92rem; }
.toc a { text-decoration: none; }
.toc li { break-inside: avoid; }
@media (max-width: 700px) { .toc { columns: 1; } }
footer { margin-top: 60px; padding: 24px 0; border-top: 1px solid var(--line); color: var(--ink-3); font-size: .82rem; }