/* ============================================================
   Mario-AI Explainer — "Lab notebook meets NES phosphor terminal"
   Phosphor-green = the machine/search · Signal-red = levels/hazards
   ============================================================ */

:root {
  --ink:        #0c0b10;
  --ink-2:      #110f17;
  --panel:      #16131f;
  --panel-2:    #1d1929;
  --line:       #2a2438;
  --paper:      #ede7da;   /* body prose — slightly brighter */
  --paper-dim:  #c6bead;
  --mute:       #9491a0;
  --green:      #57f7a0;   /* the machine / search */
  --green-deep: #1f8f5a;
  --red:        #ff5d6c;   /* levels / hazards / Mario */
  --gold:       #ffd24a;   /* flags / wins */
  --blue:       #6db8ff;   /* learning / nets */
  --maxw: 1180px;
  --radius: 14px;
  --shadow: 0 24px 60px -28px rgba(0,0,0,.85);
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --serif: "Newsreader", Georgia, "Times New Roman", serif;
  --display: "Fraunces", Georgia, serif;
  --pixel: "Press Start 2P", monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 76px; }

/* Safari: normalize native control rendering + tap highlight */
button { -webkit-appearance: none; appearance: none; -webkit-tap-highlight-color: transparent; }

body {
  margin: 0;
  background:
    radial-gradient(1200px 600px at 80% -10%, rgba(87,247,160,.07), transparent 60%),
    radial-gradient(900px 500px at -5% 20%, rgba(255,93,108,.06), transparent 55%),
    var(--ink);
  color: var(--paper);
  font-family: var(--serif);
  font-size: 19px;
  line-height: 1.72;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

/* pixel-grid + scanline atmosphere */
body::before {
  content: "";
  position: fixed; inset: 0; z-index: 0; pointer-events: none;
  background-image:
    linear-gradient(rgba(255,255,255,.018) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.018) 1px, transparent 1px);
  background-size: 22px 22px;
  -webkit-mask-image: radial-gradient(circle at 50% 30%, #000 30%, transparent 90%);
  mask-image: radial-gradient(circle at 50% 30%, #000 30%, transparent 90%);
}
body::after {
  content: "";
  position: fixed; inset: 0; z-index: 0; pointer-events: none;
  background: repeating-linear-gradient(0deg, rgba(0,0,0,.10) 0 2px, transparent 2px 4px);
  mix-blend-mode: multiply; opacity: .20;
}

main, nav, footer { position: relative; z-index: 1; }

a { color: var(--green); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }

code, .mono { font-family: var(--mono); }
code {
  font-size: .91em; background: var(--panel-2);
  border: 1px solid var(--line); border-radius: 5px;
  padding: .08em .42em; color: #cfeede;
}

::selection { background: rgba(87,247,160,.28); color: #fff; }

/* ---------- layout ---------- */
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
section { padding: 92px 0; border-top: 1px solid var(--line); }
section:first-of-type { border-top: 0; }

.kicker {
  font-family: var(--pixel); font-size: 10px; letter-spacing: .12em;
  color: var(--green); text-transform: uppercase;
  display: inline-flex; align-items: center; gap: 10px; margin: 0 0 18px;
}
.kicker::before { content: ""; width: 26px; height: 2px; background: var(--green); display: inline-block; }

h2 {
  font-family: var(--display); font-weight: 800;
  font-size: clamp(30px, 4.6vw, 52px); line-height: 1.04;
  letter-spacing: -.02em; margin: 0 0 18px;
  font-optical-sizing: auto;
}
h2 em { font-style: italic; color: var(--green); }
h3 { font-family: var(--display); font-weight: 700; font-size: 24px; letter-spacing: -.01em; margin: 0 0 8px; }
.lede { font-size: 22px; color: var(--paper-dim); max-width: 70ch; }
p { max-width: 74ch; }
.dim { color: var(--mute); }

/* ---------- nav ---------- */
nav {
  position: sticky; top: 0; z-index: 50;
  -webkit-backdrop-filter: blur(14px) saturate(1.2);
  backdrop-filter: blur(14px) saturate(1.2);
  background: rgba(12,11,16,.72);
  border-bottom: 1px solid var(--line);
}
.nav-in { display: flex; align-items: center; gap: 18px; height: 60px; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.brand { font-family: var(--pixel); font-size: 11px; color: var(--paper); letter-spacing: .04em; }
.brand b { color: var(--red); }
.nav-links { margin-left: auto; display: flex; gap: 4px; flex-wrap: wrap; }
.nav-links a {
  font-family: var(--mono); font-size: 13px; color: var(--paper-dim);
  padding: 6px 12px; border-radius: 8px; letter-spacing: .02em;
}
.nav-links a:hover { color: var(--paper); background: var(--panel); text-decoration: none; }
.nav-links a.active { color: var(--ink); background: var(--green); }
@media (max-width: 880px){ .nav-links { display: none; } }

/* ---------- hero ---------- */
.hero { padding: 92px 0 78px; }
.hero-grid { display: grid; grid-template-columns: 1.15fr .85fr; gap: 48px; align-items: center; }
@media (max-width: 900px){ .hero-grid { grid-template-columns: 1fr; } }
.hero h1 {
  font-family: var(--display); font-weight: 900;
  font-size: clamp(44px, 7.4vw, 92px); line-height: .96;
  letter-spacing: -.035em; margin: 14px 0 22px;
}
.hero h1 .grn { color: var(--green); }
.hero h1 .rd { color: var(--red); font-style: italic; }
.hero p { font-size: 21px; color: var(--paper-dim); max-width: 56ch; }
.forfun {
  display: inline-flex; gap: 9px; align-items: center; margin-top: 26px;
  font-family: var(--mono); font-size: 12.5px; color: var(--gold);
  border: 1px dashed rgba(255,210,74,.4); border-radius: 999px; padding: 7px 15px;
}

.statgrid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.stat {
  background: linear-gradient(180deg, var(--panel), var(--ink-2));
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 18px 18px 16px; position: relative; overflow: hidden;
}
.stat::after { content:""; position:absolute; right:-30px; top:-30px; width:80px; height:80px; background: radial-gradient(circle, rgba(87,247,160,.16), transparent 70%); }
.stat .n { font-family: var(--display); font-weight: 800; font-size: 34px; line-height: 1; color: var(--paper); }
.stat .n.g { color: var(--green); } .stat .n.r { color: var(--red); } .stat .n.y { color: var(--gold); }
.stat .l { font-family: var(--mono); font-size: 11px; color: var(--mute); margin-top: 8px; letter-spacing: .02em; }

/* ---------- generic panels / cards ---------- */
.panel {
  background: linear-gradient(180deg, var(--panel), var(--ink-2));
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px; box-shadow: var(--shadow);
}
.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; }
.grid3 { display: grid; grid-template-columns: repeat(3,1fr); gap: 18px; }
@media (max-width: 820px){ .grid2, .grid3 { grid-template-columns: 1fr; } }

.card { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; }
.card h3 { color: var(--paper); }
.card .tag { font-family: var(--mono); font-size: 11px; color: var(--green); letter-spacing: .03em; }

/* the loop diagram */
.loop { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin: 8px 0 4px; }
.loop .node {
  border: 1px solid var(--line); border-radius: 12px; padding: 18px; text-align: center;
  background: var(--panel-2); position: relative;
}
.loop .node .ico { font-size: 26px; }
.loop .node b { display: block; font-family: var(--mono); color: var(--paper); margin-top: 6px; font-size: 14px; }
.loop .node span { font-size: 14.5px; color: var(--paper-dim); }
.loop .node.s b { color: var(--green); }
.loop .node.d b { color: var(--blue); }
.loop .node.c b { color: var(--red); }
.loop-note { font-family: var(--mono); font-size: 13.5px; color: var(--paper-dim); text-align: center; margin-top: 14px; }

/* equation chip */
.eq {
  font-family: var(--mono); font-size: 15px; color: #d7f7e6;
  background: #0a1410; border: 1px solid var(--green-deep); border-radius: 10px;
  padding: 14px 18px; display: inline-block; margin: 6px 0;
}
.eq .v { color: var(--green); } .eq .op { color: var(--mute); }

/* toggle (representation) */
.toggle-row { display: inline-flex; background: var(--panel-2); border: 1px solid var(--line); border-radius: 999px; padding: 4px; gap: 4px; }
.toggle-row button {
  font-family: var(--mono); font-size: 12.5px; color: var(--paper-dim);
  background: transparent; border: 0; padding: 8px 16px; border-radius: 999px; cursor: pointer;
}
.toggle-row button.on { background: var(--green); color: var(--ink); font-weight: 700; }
.repr-body { margin-top: 18px; }
.repr-pane { display: none; } .repr-pane.show { display: block; animation: fade .3s ease; }

/* beam canvas */
.beamwrap { display: grid; grid-template-columns: 1fr 280px; gap: 22px; align-items: start; }
@media (max-width: 820px){ .beamwrap { grid-template-columns: 1fr; } }
#beam { width: 100%; height: 320px; background: #07100b; border: 1px solid var(--green-deep); border-radius: 12px; display: block; }
.beam-ctl button {
  font-family: var(--mono); font-size: 12.5px; cursor: pointer; margin-right: 8px; margin-top: 4px;
  background: var(--green); color: var(--ink); border: 0; border-radius: 8px; padding: 9px 14px; font-weight: 700;
}
.beam-ctl button.ghost { background: transparent; color: var(--green); border: 1px solid var(--green-deep); }

/* ---------- timeline ---------- */
.timeline { position: relative; margin-top: 10px; padding-left: 4px; }
.tl-rail { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 26px; }
.tl-rail button {
  font-family: var(--pixel); font-size: 10px; cursor: pointer;
  background: var(--panel-2); color: var(--paper-dim); border: 1px solid var(--line);
  border-radius: 8px; padding: 11px 13px; letter-spacing: .02em; transition: .15s;
}
.tl-rail button.on { background: var(--red); color: #fff; border-color: var(--red); }
.tl-rail button .ph { display: block; font-family: var(--mono); font-size: 8px; color: inherit; opacity: .7; margin-top: 4px; letter-spacing: 0; }
.tl-panel { border: 1px solid var(--line); border-left: 3px solid var(--green); border-radius: 12px; background: var(--panel); padding: 26px; }
.tl-panel .when { font-family: var(--mono); font-size: 13px; color: var(--green); letter-spacing: .04em; }
.tl-panel h3 { color: var(--paper); margin-top: 6px; font-size: 27px; }
.tl-panel.neg { border-left-color: var(--red); }
.tl-panel.neg .when { color: var(--red); }
.tl-panel.win { border-left-color: var(--gold); }
.tl-panel.win .when { color: var(--gold); }
.verdict { font-family: var(--mono); font-size: 14px; margin-top: 16px; padding: 14px 16px; border-radius: 9px; background: var(--panel-2); border: 1px solid var(--line); color: var(--paper-dim); }
.verdict b { color: var(--paper); }

/* ---------- saga tabs ---------- */
.tabs { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 22px; }
.tabs button {
  font-family: var(--mono); font-size: 13px; cursor: pointer; letter-spacing: .03em;
  background: var(--panel-2); color: var(--paper-dim); border: 1px solid var(--line);
  border-radius: 9px; padding: 10px 15px;
}
.tabs button.on { background: var(--green); color: var(--ink); font-weight: 700; border-color: var(--green); }
.saga { display: none; } .saga.show { display: grid; grid-template-columns: 1fr 1fr; gap: 26px; align-items: start; animation: fade .3s; }
@media (max-width: 820px){ .saga.show { grid-template-columns: 1fr; } }
.saga img { width: 100%; border: 1px solid var(--line); border-radius: 12px; cursor: zoom-in; background: #000; }
.saga .lvl { font-family: var(--pixel); font-size: 14px; color: var(--red); }
.bug { border-left: 3px solid var(--red); padding: 8px 0 8px 18px; margin: 18px 0; color: var(--paper-dim); font-size: 16.5px; line-height: 1.65; }
.bug b { color: var(--red); }

/* ---------- punchline table ---------- */
table.metric { width: 100%; border-collapse: collapse; font-family: var(--mono); font-size: 14.5px; margin-top: 10px; }
table.metric th, table.metric td { text-align: left; padding: 12px 13px; border-bottom: 1px solid var(--line); }
table.metric th { color: var(--mute); font-weight: 500; font-size: 12px; letter-spacing: .04em; text-transform: uppercase; }
table.metric td b { color: var(--green); }
table.metric tr.win td b { color: var(--gold); }
table.metric .x { color: var(--red); }

/* ---------- interview ---------- */
.labgrid { display: grid; grid-template-columns: repeat(3,1fr); gap: 18px; }
@media (max-width: 820px){ .labgrid { grid-template-columns: 1fr; } }
.lab { border: 1px solid var(--line); border-radius: 12px; padding: 22px; background: var(--panel); border-top: 3px solid var(--line); }
.lab.oai { border-top-color: #10b981; } .lab.ant { border-top-color: #d97757; } .lab.dm { border-top-color: #4285f4; }
.lab .name { font-family: var(--display); font-weight: 800; font-size: 22px; }
.lab .sig { font-family: var(--mono); font-size: 12px; color: var(--paper-dim); margin: 8px 0 14px; }
.lab ul { margin: 0; padding-left: 18px; font-size: 16.5px; color: var(--paper-dim); }
.lab li { margin: 7px 0; }

.cards-q { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 10px; }
@media (max-width: 820px){ .cards-q { grid-template-columns: 1fr; } }
.flash {
  background: var(--panel); border: 1px solid var(--line); border-radius: 12px;
  padding: 20px; cursor: pointer; transition: .15s; position: relative;
}
.flash:hover { border-color: var(--green-deep); transform: translateY(-2px); }
.flash .q { font-family: var(--display); font-weight: 700; font-size: 19px; color: var(--paper); line-height: 1.35; }
.flash .hint { font-family: var(--mono); font-size: 12px; color: var(--mute); margin-top: 12px; }
.flash .a { display: none; margin-top: 14px; font-size: 16.5px; line-height: 1.68; color: var(--paper-dim); border-top: 1px solid var(--line); padding-top: 14px; }
.flash.open .a { display: block; animation: fade .25s; }
.flash.open .hint { color: var(--green); }

.cat { display: grid; grid-template-columns: 160px 1fr; gap: 14px; padding: 13px 0; border-bottom: 1px solid var(--line); }
.cat:last-child { border-bottom: 0; }
.cat .c { font-family: var(--mono); font-size: 13px; color: var(--green); }
.cat .d { font-size: 16.5px; color: var(--paper-dim); line-height: 1.55; }
.cat .d b { color: var(--paper); }
@media (max-width: 620px){ .cat { grid-template-columns: 1fr; gap: 4px; } }

/* ---------- collapsible deep-dive ---------- */
details.deep { border: 1px solid var(--line); border-radius: 12px; background: var(--panel); margin-top: 16px; overflow: hidden; }
details.deep > summary {
  cursor: pointer; list-style: none; padding: 16px 20px; font-family: var(--mono); font-size: 13.5px; color: var(--green);
  display: flex; align-items: center; gap: 10px;
}
details.deep > summary::-webkit-details-marker { display: none; }
details.deep > summary::before { content: "▸"; color: var(--green); transition: .2s; }
details.deep[open] > summary::before { transform: rotate(90deg); }
details.deep .body { padding: 8px 24px 26px; color: var(--paper); font-size: 17px; line-height: 1.72; }

/* ---------- artifacts / video / lightbox ---------- */
.video { width: 100%; border-radius: 12px; border: 1px solid var(--line); background: #000; }
.gallery { display: grid; grid-template-columns: repeat(3,1fr); gap: 14px; margin-top: 16px; }
@media (max-width: 700px){ .gallery { grid-template-columns: 1fr 1fr; } }
.gallery figure { margin: 0; }
.gallery img { width: 100%; border: 1px solid var(--line); border-radius: 10px; cursor: zoom-in; background: #000; }
.gallery figcaption { font-family: var(--mono); font-size: 11px; color: var(--mute); margin-top: 6px; }

#lightbox { position: fixed; inset: 0; z-index: 100; background: rgba(4,4,8,.92); display: none; align-items: center; justify-content: center; padding: 32px; cursor: zoom-out; -webkit-backdrop-filter: blur(4px); backdrop-filter: blur(4px); }
#lightbox.show { display: flex; animation: fade .2s; }
#lightbox img { max-width: 94vw; max-height: 90vh; border: 1px solid var(--line); border-radius: 10px; box-shadow: var(--shadow); }

/* ---------- footer ---------- */
footer { border-top: 1px solid var(--line); padding: 48px 0 70px; }
.foot-in { display: flex; justify-content: space-between; gap: 20px; flex-wrap: wrap; align-items: center; }
.foot-in .made { font-family: var(--mono); font-size: 13px; color: var(--mute); }
.foot-in .made b { color: var(--gold); }

/* ---------- reveal-on-scroll ---------- */
.rv { opacity: 0; transform: translateY(20px); transition: opacity .6s ease, transform .6s ease; }
.rv.in { opacity: 1; transform: none; }

@keyframes fade { from { opacity: 0; } to { opacity: 1; } }
@keyframes blink { 50% { opacity: .25; } }
.cursor { color: var(--green); animation: blink 1.1s steps(1) infinite; }

ul.clean { list-style: none; padding: 0; }
ul.clean li { padding-left: 24px; position: relative; margin: 9px 0; color: var(--paper-dim); }
ul.clean li::before { content: "▪"; color: var(--green); position: absolute; left: 4px; }
.pill { font-family: var(--mono); font-size: 11px; padding: 3px 9px; border-radius: 999px; border: 1px solid var(--line); color: var(--paper-dim); }
.pill.g { color: var(--green); border-color: var(--green-deep); }
.pill.r { color: var(--red); border-color: rgba(255,93,108,.4); }