/* smacmath — modern premium site; each course is its own "world" (original art, retro-game nods in small pixel labels) */
:root {
  color-scheme: dark;
  --display: "Space Grotesk", "Inter", system-ui, sans-serif;
  --body: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --pixel: "Press Start 2P", ui-monospace, monospace;
  --bg: #08080d;
  --surface: rgba(255,255,255,.035);
  --surface-2: rgba(255,255,255,.06);
  --border: rgba(255,255,255,.09);
  --text: #f3f3f7;
  --muted: #a3a3b8;
  --faint: #6e6e85;
  --radius: 22px;
  /* world colors (overridden per course) */
  --c1: #7c5cff;
  --c2: #22d3ee;
  --c: var(--c1);
  --glow: rgba(124,92,255,.35);
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0; min-height: 100vh; color: var(--text); background: var(--bg);
  font: 16.5px/1.6 var(--body); -webkit-font-smoothing: antialiased;
  background-image:
    radial-gradient(900px 520px at 85% -10%, var(--glow), transparent 70%),
    radial-gradient(700px 480px at -10% 20%, color-mix(in srgb, var(--c2) 18%, transparent), transparent 70%);
  background-repeat: no-repeat;
}
a { color: inherit; }
.wrap { max-width: 1120px; margin: 0 auto; padding: 0 20px; }

/* ---------- Nav ---------- */
.top { position: sticky; top: 0; z-index: 10; backdrop-filter: saturate(160%) blur(16px); -webkit-backdrop-filter: saturate(160%) blur(16px); background: rgba(8,8,13,.7); border-bottom: 1px solid var(--border); }
.top .wrap { display: flex; align-items: center; gap: 18px; min-height: 68px; flex-wrap: wrap; padding-top: 8px; padding-bottom: 8px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; font-family: var(--display); font-weight: 700; font-size: 1.2rem; letter-spacing: -.02em; }
.brand span { background: linear-gradient(90deg, #ffcc33, #ff6ad5); -webkit-background-clip: text; background-clip: text; color: transparent; }
.brand svg { width: 26px; height: 26px; }
.nav { display: flex; gap: 4px; flex-wrap: wrap; margin-left: auto; }
.nav a { text-decoration: none; font-size: .9rem; font-weight: 500; color: var(--muted); padding: 8px 14px; border-radius: 999px; transition: color .2s, background .2s; }
.nav a:hover { color: var(--text); background: var(--surface-2); }
.nav a[aria-current="page"] { color: #0b0b10; background: var(--text); }

/* ---------- Hero ---------- */
.hero { padding: 64px 0 28px; display: grid; grid-template-columns: 1.15fr .85fr; gap: 32px; align-items: center; }
.hero.solo { grid-template-columns: 1fr; padding-bottom: 8px; }
.eyebrow { font-family: var(--pixel); font-size: .6rem; letter-spacing: .12em; color: var(--c2); margin: 0 0 18px; display: inline-flex; gap: 10px; align-items: center; }
.eyebrow::before { content: ""; width: 8px; height: 8px; background: var(--c2); box-shadow: 0 0 12px var(--c2); }
.hero h1 { font-family: var(--display); font-weight: 700; letter-spacing: -.035em; line-height: 1.02; margin: 0 0 18px; font-size: clamp(2.4rem, 6.4vw, 4.6rem); }
.hero h1 .grad { background: linear-gradient(100deg, var(--c1), var(--c2)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero p { margin: 0; color: var(--muted); font-size: 1.15rem; max-width: 56ch; }
.hero-art { width: 100%; max-width: 440px; justify-self: end; filter: drop-shadow(0 30px 60px var(--glow)); animation: float 7s ease-in-out infinite; }
@keyframes float { 50% { transform: translateY(-10px); } }
.stats-row { display: flex; gap: 28px; margin-top: 28px; flex-wrap: wrap; }
.stat b { display: block; font-family: var(--display); font-size: 1.8rem; letter-spacing: -.02em; }
.stat span { font-size: .8rem; color: var(--faint); text-transform: uppercase; letter-spacing: .08em; }

/* ---------- Sections & panels ---------- */
section { margin: 40px 0; }
h2 { font-family: var(--display); font-weight: 600; font-size: 1.35rem; letter-spacing: -.02em; margin: 0 0 16px; }
.sec-head { display: flex; align-items: baseline; justify-content: space-between; gap: 12px; margin-bottom: 16px; }
.sec-head h2 { margin: 0; }
.sec-head a { color: var(--muted); font-size: .9rem; text-decoration: none; }
.sec-head a:hover { color: var(--text); }
.panel, .unit { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px 26px; }
.empty { color: var(--faint); margin: 0; }
.two { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 20px; }

/* ---------- World cards (home) ---------- */
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 20px; }
.card {
  --c1: var(--k1); --c2: var(--k2);
  position: relative; overflow: hidden; display: flex; flex-direction: column; text-decoration: none;
  min-height: 360px; padding: 24px; border-radius: var(--radius); border: 1px solid var(--border);
  background:
    radial-gradient(120% 80% at 100% 0%, color-mix(in srgb, var(--k1) 55%, transparent), transparent 60%),
    radial-gradient(90% 70% at 0% 100%, color-mix(in srgb, var(--k2) 35%, transparent), transparent 60%),
    #101018;
  transition: transform .35s cubic-bezier(.2,.8,.2,1), box-shadow .35s, border-color .35s;
}
.card:hover, .card:focus-visible { transform: translateY(-6px); border-color: color-mix(in srgb, var(--k2) 60%, transparent); box-shadow: 0 24px 60px -20px var(--k1); outline: none; }
.card .art { position: absolute; right: -30px; top: -30px; width: 210px; opacity: .55; transition: transform .5s cubic-bezier(.2,.8,.2,1); }
.card:hover .art { transform: rotate(-6deg) scale(1.06); }
.card .w { font-family: var(--pixel); font-size: .55rem; letter-spacing: .1em; color: var(--k2); position: relative; }
.card h3 { position: relative; margin: auto 0 8px; font-family: var(--display); font-size: 1.55rem; line-height: 1.1; letter-spacing: -.02em; }
.card .zone { position: relative; font-size: .85rem; color: var(--k2); font-weight: 600; margin-bottom: 10px; }
.card p { position: relative; margin: 0 0 18px; color: #c4c4d4; font-size: .95rem; }
.card .go { position: relative; display: flex; justify-content: space-between; align-items: center; font-size: .85rem; color: var(--muted); border-top: 1px solid var(--border); padding-top: 14px; }
.card .go b { color: var(--text); font-weight: 600; }
.card .go i { font-style: normal; width: 34px; height: 34px; display: grid; place-items: center; border-radius: 50%; background: var(--text); color: #0b0b10; transition: transform .3s; }
.card:hover .go i { transform: translateX(4px); }

/* ---------- Lists ---------- */
.list { list-style: none; margin: 0; padding: 0; }
.list li { padding: 12px 0; border-bottom: 1px solid var(--border); display: flex; gap: 14px; align-items: baseline; }
.list li:last-child { border-bottom: 0; }
.date { flex: 0 0 auto; min-width: 96px; font-size: .78rem; color: var(--faint); font-variant-numeric: tabular-nums; text-transform: uppercase; letter-spacing: .04em; }
.tag { display: inline-block; font-size: .68rem; font-weight: 700; letter-spacing: .03em; padding: 3px 9px; border-radius: 999px; color: #0b0b10; background: var(--c); margin-right: 8px; vertical-align: 1px; }

/* ---------- Units (levels) ---------- */
.unit { margin-bottom: 14px; padding: 0; overflow: hidden; transition: border-color .3s; }
.unit[open] { border-color: color-mix(in srgb, var(--c2) 45%, transparent); }
.unit > summary { cursor: pointer; list-style: none; padding: 20px 24px; display: flex; align-items: center; gap: 14px; flex-wrap: wrap; font-family: var(--display); font-weight: 600; font-size: 1.15rem; letter-spacing: -.01em; }
.unit > summary::-webkit-details-marker { display: none; }
.unit > summary .lv { font-family: var(--pixel); font-size: .5rem; color: #0b0b10; background: linear-gradient(90deg, var(--c1), var(--c2)); padding: 7px 9px; border-radius: 8px; letter-spacing: .06em; }
.unit > summary::after { content: "+"; margin-left: auto; font-size: 1.4rem; color: var(--muted); transition: transform .3s; }
.unit[open] > summary::after { transform: rotate(45deg); }
.unit .current { font-size: .7rem; font-family: var(--body); font-weight: 700; color: #0b0b10; background: var(--c2); padding: 4px 10px; border-radius: 999px; }
.groups { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 12px; padding: 0 24px 24px; }
.groups > div { background: var(--surface); border: 1px solid var(--border); border-radius: 16px; padding: 16px 18px; }
.groups h4 { margin: 0 0 8px; font-size: .72rem; text-transform: uppercase; letter-spacing: .1em; color: var(--c2); }
.groups ul { margin: 0; padding: 0; list-style: none; }
.groups li { padding: 6px 0; }
.groups a { font-weight: 600; text-decoration: none; background-image: linear-gradient(90deg, var(--c1), var(--c2)); background-size: 0 2px; background-position: 0 100%; background-repeat: no-repeat; transition: background-size .3s; }
.groups a:hover { background-size: 100% 2px; }
.groups a::after { content: " ↗"; color: var(--faint); font-size: .85em; }
.groups small { display: block; color: var(--faint); font-size: .78rem; }

.btn { display: inline-flex; align-items: center; gap: 8px; font: inherit; font-size: .9rem; font-weight: 600; cursor: pointer; text-decoration: none; color: var(--text); background: var(--surface-2); border: 1px solid var(--border); padding: 10px 18px; border-radius: 999px; transition: background .2s; }
.btn:hover { background: rgba(255,255,255,.12); }

/* ---------- Calendar ---------- */
.cal-bar { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-bottom: 18px; }
.cal-bar h2 { margin: 0 6px; min-width: 200px; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; margin-left: auto; }
.chip { font: inherit; font-size: .8rem; font-weight: 600; cursor: pointer; padding: 6px 14px; border-radius: 999px; background: transparent; color: var(--text); border: 1px solid var(--border); }
.chip::before { content: ""; display: inline-block; width: 8px; height: 8px; border-radius: 50%; background: var(--c); margin-right: 8px; }
.chip[aria-pressed="true"] { background: var(--text); color: #0b0b10; }
.grid { display: grid; grid-template-columns: repeat(7, minmax(0,1fr)); border: 1px solid var(--border); border-radius: 16px; overflow: hidden; }
.grid .dow { font-size: .7rem; font-weight: 700; text-transform: uppercase; letter-spacing: .08em; color: var(--faint); padding: 10px 8px; background: var(--surface); border-bottom: 1px solid var(--border); }
.grid .day { min-height: 104px; padding: 6px; border-right: 1px solid var(--border); border-bottom: 1px solid var(--border); font-size: .76rem; min-width: 0; overflow: hidden; }
.grid .day:nth-child(7n) { border-right: 0; }
.grid .day.out { opacity: .35; }
.grid .n { font-size: .78rem; font-weight: 700; color: var(--muted); display: inline-block; margin: 0 0 4px 2px; }
.grid .day.today .n { background: var(--text); color: #0b0b10; border-radius: 999px; padding: 0 7px; }
.ev { display: block; border-left: 3px solid var(--c); background: rgba(255,255,255,.05); border-radius: 4px; padding: 2px 6px; margin: 3px 0; line-height: 1.3; overflow-wrap: anywhere; }
.ev.big { background: var(--c); color: #0b0b10; font-weight: 700; }
.legend { display: flex; flex-wrap: wrap; gap: 12px; font-size: .82rem; color: var(--faint); margin-top: 14px; }
.gcal { width: 100%; height: 640px; border: 0; border-radius: 16px; background: #fff; display: block; }

footer { color: var(--faint); font-size: .82rem; padding: 56px 20px 40px; text-align: center; border-top: 1px solid var(--border); margin-top: 60px; }
footer .px { font-family: var(--pixel); font-size: .5rem; color: var(--muted); display: block; margin-bottom: 8px; letter-spacing: .1em; }
:focus-visible { outline: 2px solid var(--c2); outline-offset: 3px; }

@media (max-width: 820px) {
  .hero { grid-template-columns: 1fr; padding-top: 40px; }
  .hero-art { justify-self: start; max-width: 300px; order: -1; }
}
@media (max-width: 640px) {
  .grid .dow { padding: 6px 2px; font-size: .58rem; text-align: center; }
  .grid .day { min-height: 56px; padding: 3px; }
  .grid .ev { font-size: 0; height: 6px; padding: 0; border-left: 0; background: var(--c); border-radius: 3px; }
  .nav a { padding: 6px 10px; font-size: .85rem; }
  .card { min-height: 300px; }
}
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { animation: none !important; transition: none !important; } }

/* ---------- Worlds ---------- */
.theme-geometry        { --c1: #8b5cf6; --c2: #22d3ee; --glow: rgba(139,92,246,.40); }
.theme-college-algebra { --c1: #10b981; --c2: #a3e635; --glow: rgba(16,185,129,.35); }
.theme-calculus        { --c1: #f43f5e; --c2: #fb923c; --glow: rgba(244,63,94,.38); }
.theme-statistics      { --c1: #ec4899; --c2: #facc15; --glow: rgba(236,72,153,.38); }
.theme-calendar        { --c1: #38bdf8; --c2: #c084fc; --glow: rgba(56,189,248,.30); }
.theme-home            { --c1: #7c5cff; --c2: #ff6ad5; --glow: rgba(124,92,255,.35); }

/* ---------- Geometry world: search, level tiles, lesson stages ---------- */
.search { position: relative; margin: 22px 0 6px; max-width: 560px; }
.search input { width: 100%; font: 500 1.02rem var(--body); color: var(--text); background: var(--surface-2); border: 1px solid var(--border); border-radius: 16px; padding: 15px 18px 15px 46px; outline: none;
  background-image: radial-gradient(circle at 23px 50%, transparent 7px, var(--muted) 7.5px, var(--muted) 9px, transparent 9.5px); }
.search input:focus { border-color: var(--c1); box-shadow: 0 0 0 4px color-mix(in srgb, var(--c1) 25%, transparent); }
.res { list-style: none; margin: 8px 0 0; padding: 6px; background: #12121b; border: 1px solid var(--border); border-radius: 16px; position: absolute; left: 0; right: 0; z-index: 20; box-shadow: 0 24px 60px rgba(0,0,0,.5); }
.res.static { position: static; box-shadow: none; background: transparent; border: 0; padding: 0; }
.res li a { display: block; padding: 10px 12px; border-radius: 10px; text-decoration: none; color: var(--text); }
.res li a:hover, .res li a:focus-visible { background: var(--surface-2); }
.res li a b { color: var(--c2); margin-right: 6px; font-family: var(--display); }
.res li small { display: block; color: var(--muted); font-size: .82rem; }
.res li.none { padding: 10px 12px; color: var(--muted); }
.today .when { margin: 0 0 6px; color: var(--muted); }
.qjump, .ljump { display: flex; flex-wrap: wrap; gap: 8px; margin: 18px 0 4px; }
.qjump { position: sticky; top: 64px; z-index: 5; padding: 10px 0; backdrop-filter: blur(10px); }
.qjump a, .ljump a { font: .55rem var(--pixel); text-decoration: none; color: var(--text); background: var(--surface-2); border: 1px solid var(--border); padding: 9px 11px; border-radius: 10px; }
.qjump a:hover, .ljump a:hover { border-color: var(--c1); color: var(--c2); }
.px-tag { font: .62rem var(--pixel); color: #0b0b10; background: linear-gradient(90deg, var(--c1), var(--c2)); padding: 6px 8px; border-radius: 8px; vertical-align: middle; margin-right: 6px; }
.tiles { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 14px; }
.tile { display: block; text-decoration: none; color: var(--text); background: var(--surface); border: 1px solid var(--border); border-radius: 18px; padding: 18px; transition: transform .2s, border-color .2s, background .2s; position: relative; overflow: hidden; }
.tile::after { content: ""; position: absolute; inset: auto -40px -40px auto; width: 120px; height: 120px; border-radius: 50%; background: radial-gradient(var(--glow), transparent 70%); opacity: .0; transition: opacity .3s; }
.tile:hover, .tile:focus-visible { transform: translateY(-3px); border-color: color-mix(in srgb, var(--c1) 60%, transparent); background: var(--surface-2); }
.tile:hover::after { opacity: 1; }
.tile .lv { font: .5rem var(--pixel); color: var(--c2); letter-spacing: .06em; }
.tile.boss .lv { color: #facc15; }
.tile.side .lv { color: #f472b6; }
.tile h3 { margin: 8px 0 8px; font: 600 1.15rem/1.25 var(--display); }
.tile .meta { margin: 8px 0 0; color: var(--muted); font-size: .85rem; }
.std { display: inline-block; font-size: .72rem; font-weight: 600; color: var(--muted); border: 1px solid var(--border); border-radius: 999px; padding: 2px 8px; margin: 0 4px 4px 0; }
.crumb { color: var(--muted); font-size: .9rem; margin: 18px 0 0; }
.crumb a { color: var(--muted); }
.unit-hero { padding-bottom: 8px; }
.stages { display: grid; gap: 14px; }
.stage { background: var(--surface); border: 1px solid var(--border); border-radius: 20px; padding: 18px 20px; scroll-margin-top: 80px; }
.stage:target { border-color: var(--c1); box-shadow: 0 0 0 4px color-mix(in srgb, var(--c1) 20%, transparent); }
.stage.review { border-color: color-mix(in srgb, #facc15 40%, transparent); background: linear-gradient(135deg, rgba(250,204,21,.06), transparent 60%); }
.st-head { display: flex; gap: 14px; align-items: center; margin-bottom: 12px; }
.st-head h3 { margin: 0 0 4px; font: 600 1.2rem/1.25 var(--display); }
.st-n { flex: none; min-width: 58px; height: 46px; padding: 0 8px; display: grid; place-items: center; border-radius: 12px; font: .62rem var(--pixel); color: #0b0b10; background: linear-gradient(135deg, var(--c1), var(--c2)); }
.st-n.boss { background: linear-gradient(135deg, #facc15, #fb923c); }
.vids { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 12px; }
.vid { position: relative; padding: 0; border: 1px solid var(--border); border-radius: 14px; overflow: hidden; cursor: pointer; width: 260px; aspect-ratio: 16/9; background: #000; }
.vid img { width: 100%; height: 100%; object-fit: cover; opacity: .85; transition: opacity .2s, transform .3s; }
.vid:hover img { opacity: 1; transform: scale(1.03); }
.vid .play { position: absolute; inset: 0; margin: auto; width: 54px; height: 54px; border-radius: 50%; display: grid; place-items: center; color: #0b0b10; font-size: 1.1rem; background: linear-gradient(135deg, var(--c1), var(--c2)); box-shadow: 0 8px 30px var(--glow); }
.vid-frame { width: min(100%, 640px); aspect-ratio: 16/9; border: 0; border-radius: 14px; }
.fbtns { display: flex; flex-wrap: wrap; gap: 8px; }
.fbtn { display: inline-flex; align-items: center; gap: 8px; text-decoration: none; color: var(--text); font-weight: 600; font-size: .92rem; background: var(--surface-2); border: 1px solid var(--border); border-radius: 12px; padding: 9px 13px; transition: border-color .2s, transform .2s; }
.fbtn:hover { border-color: var(--c1); transform: translateY(-1px); }
.fbtn i { font: normal .45rem var(--pixel); color: #0b0b10; background: var(--c2); border-radius: 6px; padding: 5px 5px; }
.fbtn.ln i { background: #f472b6; }
.fbtn.game i { background: #facc15; }
.fbtn.off { opacity: .45; cursor: not-allowed; font-weight: 500; }
details.old { margin-top: 10px; }
details.old summary { cursor: pointer; color: var(--muted); font-size: .85rem; margin-bottom: 8px; }
.pager { display: flex; justify-content: space-between; gap: 12px; margin: 26px 0; flex-wrap: wrap; }
ul.plain { margin: 0; padding-left: 18px; color: var(--muted); }
ul.plain li { margin: 6px 0; }
@media (max-width: 640px) { .vid { width: 100%; } .st-n { min-width: 48px; height: 40px; } .qjump { top: 56px; } }
.qjump { background: color-mix(in srgb, var(--bg) 88%, transparent); margin-left: -8px; padding-left: 8px; border-radius: 12px; }
.quarter, #extras { scroll-margin-top: 130px; }