/* SAT Math Quest
   Layout: a navy "quest" header band over a calm exam-paper body; one centered column
   (max 920px), cards only for things you act on. Gold is reserved for coins and progress. */
:root {
  --bg: #f3f5f9;
  --paper: #ffffff;
  --ink: #141c2c;
  --ink-2: #4d586c;
  --muted: #7d8799;
  --rule: #dfe4ec;
  --band: #16233f;          /* header band */
  --band-ink: #eef2fb;
  --band-ink-2: #a9b6d3;
  --accent: #2f55d4;
  --accent-ink: #ffffff;
  --accent-soft: #e7edfd;
  --gold: #e0a020;
  --gold-soft: #fdf3dc;
  --gold-ink: #7a5300;
  --ok: #157a46; --ok-soft: #e2f4ea;
  --bad: #c23d2a; --bad-soft: #fbe8e4;
  --warn: #946200; --warn-soft: #fbf0d4;
  /* chart series (validated categorical slots 1-4) */
  --s-algebra: #2a78d6; --s-advanced: #eb6834; --s-psda: #1baf7a; --s-geotrig: #eda100;
  --grid: #e1e0d9; --axis: #c3c2b7;
  --heat-0: #eef1f6; --heat-1: #b7d3f6; --heat-2: #6da7ec; --heat-3: #2a78d6; --heat-4: #184f95;
  --display: "Anuphan", "IBM Plex Sans Thai", system-ui, sans-serif;
  --body: "IBM Plex Sans Thai", "Segoe UI", system-ui, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, Menlo, monospace;
  --r: 12px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0e131c; --paper: #161d2a; --ink: #e6ebf3; --ink-2: #a9b3c4; --muted: #808a9c; --rule: #273145;
    --band: #0b1224; --band-ink: #eef2fb; --band-ink-2: #8f9cbc;
    --accent: #8aa6ff; --accent-ink: #0b1224; --accent-soft: #1e2a4a;
    --gold: #f2b33d; --gold-soft: #33280f; --gold-ink: #f6cd7a;
    --ok: #5ccf8f; --ok-soft: #13301f; --bad: #f08a72; --bad-soft: #3a1c16; --warn: #e6b84d; --warn-soft: #33290e;
    --s-algebra: #3987e5; --s-advanced: #d95926; --s-psda: #199e70; --s-geotrig: #c98500;
    --grid: #2c2c2a; --axis: #383835;
    --heat-0: #1c2433; --heat-1: #184f95; --heat-2: #256abf; --heat-3: #3987e5; --heat-4: #86b6ef;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0e131c; --paper: #161d2a; --ink: #e6ebf3; --ink-2: #a9b3c4; --muted: #808a9c; --rule: #273145;
  --band: #0b1224; --band-ink: #eef2fb; --band-ink-2: #8f9cbc;
  --accent: #8aa6ff; --accent-ink: #0b1224; --accent-soft: #1e2a4a;
  --gold: #f2b33d; --gold-soft: #33280f; --gold-ink: #f6cd7a;
  --ok: #5ccf8f; --ok-soft: #13301f; --bad: #f08a72; --bad-soft: #3a1c16; --warn: #e6b84d; --warn-soft: #33290e;
  --s-algebra: #3987e5; --s-advanced: #d95926; --s-psda: #199e70; --s-geotrig: #c98500;
  --grid: #2c2c2a; --axis: #383835;
  --heat-0: #1c2433; --heat-1: #184f95; --heat-2: #256abf; --heat-3: #3987e5; --heat-4: #86b6ef;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html, body { margin: 0; }
body { background: var(--bg); color: var(--ink); font: 16px/1.65 var(--body); -webkit-text-size-adjust: 100%; }
body::before { content: ""; position: fixed; inset: 0 0 auto; height: env(safe-area-inset-top, 0px); background: var(--band); z-index: 20; }
[hidden] { display: none !important; }
button, input, select, textarea { font: inherit; color: inherit; }
a { color: var(--accent); }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
h1, h2, h3 { font-family: var(--display); line-height: 1.25; text-wrap: balance; margin: 0; }
h1 { font-size: 1.7rem; font-weight: 700; }
h2 { font-size: 1.25rem; font-weight: 600; }
h3 { font-size: 1.02rem; font-weight: 600; }
.num { font-family: var(--mono); font-variant-numeric: tabular-nums; }
.muted { color: var(--muted); }
.ink2 { color: var(--ink-2); }
.small { font-size: .86rem; }
.boot { padding: 40px; text-align: center; color: var(--muted); }

.wrap { max-width: 920px; margin: 0 auto; padding-left: max(16px, env(safe-area-inset-left, 0px)); padding-right: max(16px, env(safe-area-inset-right, 0px)); }
.stack { display: flex; flex-direction: column; gap: 16px; }
.row { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; }
.row > * { min-width: 0; }
.spacer { flex: 1; }
.grid2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 16px; }
.grid2 > * { min-width: 0; }

/* Header band */
.band { background: var(--band); color: var(--band-ink); position: sticky; top: env(safe-area-inset-top, 0px); z-index: 10; }
.band .wrap { display: flex; align-items: center; gap: 12px; padding-block: 10px; min-height: 58px; }
.brand { font: 700 1.05rem var(--display); letter-spacing: .01em; display: flex; align-items: center; gap: 8px; color: var(--band-ink); text-decoration: none; }
.brand svg { flex: none; }
.band .who { display: flex; align-items: center; gap: 8px; color: var(--band-ink-2); font-size: .9rem; min-width: 0; }
.band .who b { color: var(--band-ink); font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.coinpill { display: inline-flex; align-items: center; gap: 6px; background: rgba(242,179,61,.16); color: #f6cd7a; border: 1px solid rgba(242,179,61,.35); padding: 3px 10px 3px 6px; border-radius: 999px; font: 600 .9rem var(--mono); }
.bandbtn { background: transparent; border: 1px solid rgba(255,255,255,.22); color: var(--band-ink); border-radius: 8px; padding: 5px 10px; font-size: .85rem; cursor: pointer; }
.bandbtn:hover { background: rgba(255,255,255,.08); }
.tabs { display: flex; gap: 4px; overflow-x: auto; padding-bottom: 2px; }
.tabs a { color: var(--band-ink-2); text-decoration: none; padding: 6px 10px; border-radius: 8px; font-size: .9rem; white-space: nowrap; }
.tabs a[aria-current="page"] { color: var(--band-ink); background: rgba(255,255,255,.10); }
.badge { display: inline-block; min-width: 18px; padding: 0 5px; border-radius: 9px; background: var(--gold); color: #1d1400; font: 600 .72rem/18px var(--mono); text-align: center; margin-left: 4px; }

main { padding-block: 22px 70px; }

/* Buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; border: 1px solid var(--rule); background: var(--paper); color: var(--ink); border-radius: 10px; padding: 9px 16px; font-weight: 500; cursor: pointer; text-decoration: none; line-height: 1.3; }
.btn:hover { border-color: var(--accent); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.btn.primary:hover { filter: brightness(1.06); }
.btn.big { padding: 13px 22px; font-size: 1.05rem; border-radius: 12px; }
.btn.ghost { background: transparent; }
.btn.danger { color: var(--bad); }
.btn[disabled] { opacity: .5; cursor: not-allowed; }
.linkbtn { background: none; border: 0; padding: 0; color: var(--accent); cursor: pointer; text-decoration: underline; }

/* Surfaces */
.card { background: var(--paper); border: 1px solid var(--rule); border-radius: var(--r); padding: 18px; min-width: 0; }
.section { display: flex; flex-direction: column; gap: 12px; }
.section > header { display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap; }
.eyebrow { font: 600 .72rem var(--body); letter-spacing: .08em; text-transform: uppercase; color: var(--muted); }
.kpis { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 10px; }
.kpi { background: var(--paper); border: 1px solid var(--rule); border-radius: 10px; padding: 12px 14px; }
.kpi .v { font: 600 1.45rem var(--display); }
.kpi .l { font-size: .82rem; color: var(--muted); }
.chip { display: inline-flex; align-items: center; gap: 5px; font-size: .78rem; font-weight: 600; padding: 2px 9px; border-radius: 999px; border: 1px solid currentColor; white-space: nowrap; }
.chip.ok { color: var(--ok); background: var(--ok-soft); }
.chip.bad { color: var(--bad); background: var(--bad-soft); }
.chip.warn { color: var(--warn); background: var(--warn-soft); }
.chip.gold { color: var(--gold-ink); background: var(--gold-soft); }
.chip.plain { color: var(--ink-2); border-color: var(--rule); }
.d-E { color: var(--ok); } .d-M { color: var(--warn); } .d-H { color: var(--bad); }

/* Forms */
label.f { display: flex; flex-direction: column; gap: 5px; font-size: .9rem; color: var(--ink-2); }
input.t, select.t { border: 1px solid var(--rule); background: var(--bg); border-radius: 10px; padding: 9px 12px; min-width: 0; width: 100%; color: var(--ink); }
input.t:focus { border-color: var(--accent); outline: none; }
.err { color: var(--bad); font-size: .9rem; }

/* Login */
.loginwrap { max-width: 520px; margin: 0 auto; padding-block: 40px 60px; }
.hero { text-align: center; display: flex; flex-direction: column; align-items: center; gap: 8px; margin-bottom: 26px; }
.hero p { margin: 0; color: var(--ink-2); max-width: 40ch; }
.people { display: grid; grid-template-columns: repeat(auto-fill, minmax(130px, 1fr)); gap: 12px; }
.person { display: flex; flex-direction: column; align-items: center; gap: 8px; padding: 18px 10px; background: var(--paper); border: 1px solid var(--rule); border-radius: var(--r); cursor: pointer; }
.person:hover { border-color: var(--accent); }
.person b { font-weight: 600; }
.avatar { display: inline-grid; place-items: center; border-radius: 50%; color: #fff; font: 700 1rem var(--display); flex: none; }
.pinpad { display: grid; grid-template-columns: repeat(3, 72px); gap: 10px; justify-content: center; }
.pinpad button { height: 58px; border-radius: 14px; border: 1px solid var(--rule); background: var(--paper); font: 600 1.3rem var(--mono); cursor: pointer; }
.pinpad button:hover { border-color: var(--accent); }
.dots { display: flex; gap: 12px; justify-content: center; margin: 14px 0 18px; }
.dots span { width: 14px; height: 14px; border-radius: 50%; border: 2px solid var(--ink-2); }
.dots span.on { background: var(--ink); border-color: var(--ink); }

/* Home */
.quest { background: var(--band); color: var(--band-ink); border-radius: 16px; padding: 22px; display: grid; grid-template-columns: 1fr auto; gap: 18px; align-items: center; }
.quest h1 { color: var(--band-ink); font-size: 2rem; }
.quest p { margin: 4px 0 0; color: var(--band-ink-2); }
.quest .btn.primary { background: var(--gold); border-color: var(--gold); color: #1d1400; }
@media (max-width: 560px) { .quest { grid-template-columns: 1fr; } }
.week { display: flex; gap: 6px; }
.week .d { flex: 1; text-align: center; font-size: .74rem; color: var(--muted); }
.week .d i { display: block; height: 30px; border-radius: 8px; background: var(--heat-0); margin-bottom: 3px; border: 1px solid var(--rule); }
.week .d.on i { background: var(--gold); border-color: var(--gold); }
.week .d.today i { outline: 2px solid var(--accent); outline-offset: 1px; }
.path { display: flex; gap: 0; align-items: center; overflow-x: auto; padding: 6px 2px 10px; }
.node { flex: none; display: flex; flex-direction: column; align-items: center; gap: 4px; width: 76px; text-decoration: none; color: var(--ink); font-size: .78rem; }
.node .c { width: 46px; height: 46px; border-radius: 50%; display: grid; place-items: center; font: 600 .9rem var(--mono); border: 2px solid var(--rule); background: var(--paper); }
.node.done .c { border-color: var(--ok); color: var(--ok); }
.node.next .c { border-color: var(--gold); background: var(--gold); color: #1d1400; }
.node.lock .c { color: var(--muted); border-style: dashed; }
.link { flex: none; width: 22px; height: 2px; background: var(--rule); margin-bottom: 22px; }

/* Play */
.playbar { background: var(--paper); border-bottom: 1px solid var(--rule); position: sticky; top: env(safe-area-inset-top, 0px); z-index: 10; }
.playbar .wrap { display: flex; align-items: center; gap: 10px; padding-block: 8px; flex-wrap: wrap; }
.timer { font: 600 1.25rem var(--mono); font-variant-numeric: tabular-nums; padding: 2px 10px; border-radius: 8px; }
.timer.low { color: var(--bad); background: var(--bad-soft); }
.qcard { background: var(--paper); border: 1px solid var(--rule); border-radius: var(--r); padding: 22px; min-width: 0; }
.qhead { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; margin-bottom: 12px; }
.qnum { display: inline-grid; place-items: center; min-width: 34px; height: 34px; padding: 0 8px; border-radius: 8px; background: var(--band); color: var(--band-ink); font: 600 .95rem var(--mono); }
.mark { display: inline-flex; align-items: center; gap: 6px; border: 1px solid var(--rule); background: transparent; border-radius: 8px; padding: 4px 10px; font-size: .85rem; cursor: pointer; color: var(--ink-2); }
.mark[aria-pressed="true"] { border-color: var(--warn); color: var(--warn); background: var(--warn-soft); }
.stem { font-size: 1.04rem; overflow-wrap: anywhere; }
.stem p { margin: 0 0 10px; }
.tbl { overflow-x: auto; margin: 8px 0 12px; }
.tbl table { border-collapse: collapse; font-variant-numeric: tabular-nums; }
.tbl th, .tbl td { border: 1px solid var(--rule); padding: 5px 12px; text-align: center; }
.tbl th { background: var(--bg); font-weight: 600; }
.choices { display: flex; flex-direction: column; gap: 10px; margin-top: 16px; }
.choice { display: grid; grid-template-columns: 34px 1fr; gap: 12px; align-items: center; text-align: left; width: 100%; border: 1.5px solid var(--rule); background: var(--paper); border-radius: 12px; padding: 12px 14px; cursor: pointer; }
.choice:hover { border-color: var(--accent); }
.choice .lt { display: grid; place-items: center; width: 30px; height: 30px; border-radius: 50%; border: 1.5px solid var(--ink-2); font: 600 .9rem var(--mono); }
.choice[aria-checked="true"] { border-color: var(--accent); background: var(--accent-soft); }
.choice[aria-checked="true"] .lt { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.choice > div { min-width: 0; overflow-wrap: anywhere; }
.spr { margin-top: 16px; display: flex; flex-direction: column; gap: 8px; max-width: 340px; }
.spr input { font: 600 1.3rem var(--mono); padding: 10px 14px; border: 1.5px solid var(--rule); border-radius: 12px; background: var(--bg); width: 100%; }
.spr input:focus { border-color: var(--accent); outline: none; }
.navgrid { display: grid; grid-template-columns: repeat(auto-fill, minmax(46px, 1fr)); gap: 8px; }
.navgrid button { height: 46px; border-radius: 10px; border: 1.5px dashed var(--muted); background: var(--paper); font: 600 .95rem var(--mono); cursor: pointer; position: relative; color: var(--ink); }
.navgrid button.ans { border-style: solid; border-color: var(--accent); background: var(--accent-soft); }
.navgrid button.cur { outline: 2px solid var(--ink); outline-offset: 2px; }
.navgrid button.mk::after { content: ""; position: absolute; top: -4px; right: -4px; width: 10px; height: 10px; border-radius: 50%; background: var(--warn); border: 2px solid var(--paper); }
.legend { display: flex; flex-wrap: wrap; gap: 14px; font-size: .82rem; color: var(--ink-2); }
.legend i { display: inline-block; width: 12px; height: 12px; border-radius: 3px; vertical-align: -1px; margin-right: 5px; }
.foot { display: flex; gap: 10px; justify-content: space-between; margin-top: 18px; flex-wrap: wrap; }

/* Dialog */
.overlay { position: fixed; inset: 0; background: rgba(8,12,22,.55); display: grid; place-items: center; z-index: 50; padding: 16px; }
.dialog { background: var(--paper); border-radius: 16px; padding: 22px; width: min(460px, 100%); max-height: 86vh; overflow: auto; display: flex; flex-direction: column; gap: 14px; border: 1px solid var(--rule); }
.dialog.wide { width: min(720px, 100%); }
.refsheet { display: grid; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); gap: 12px; font-size: .9rem; }
.refsheet div { border: 1px solid var(--rule); border-radius: 10px; padding: 10px 12px; }

/* Results & review */
.scorebig { font: 700 3rem/1 var(--display); }
.bars { display: flex; flex-direction: column; gap: 10px; }
.bar { display: grid; grid-template-columns: minmax(110px, 1.1fr) 3fr auto; gap: 10px; align-items: center; font-size: .9rem; }
.bar .track { height: 10px; border-radius: 6px; background: var(--heat-0); overflow: hidden; }
.bar .fill { height: 100%; border-radius: 6px; background: var(--accent); }
.verdict { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.rchoice { display: grid; grid-template-columns: 30px 1fr auto; gap: 10px; align-items: center; padding: 10px 12px; border: 1.5px solid var(--rule); border-radius: 12px; }
.rchoice .lt { display: grid; place-items: center; width: 28px; height: 28px; border-radius: 50%; border: 1.5px solid var(--muted); font: 600 .85rem var(--mono); }
.rchoice.right { border-color: var(--ok); background: var(--ok-soft); }
.rchoice.right .lt { background: var(--ok); border-color: var(--ok); color: #fff; }
.rchoice.mine { border-color: var(--bad); background: var(--bad-soft); }
.rchoice.mine .lt { background: var(--bad); border-color: var(--bad); color: #fff; }
.rchoice > div { min-width: 0; overflow-wrap: anywhere; }
.why { border-left: 3px solid var(--bad); background: var(--bad-soft); border-radius: 0 10px 10px 0; padding: 12px 14px; }
.fix { border-left: 3px solid var(--warn); background: var(--warn-soft); border-radius: 0 10px 10px 0; padding: 12px 14px; }
.sol { border-top: 1px solid var(--rule); padding-top: 14px; }
.lang + .lang { margin-top: 6px; }
.lang .lb { font: 600 .68rem var(--mono); color: var(--muted); margin-right: 6px; }
.strip { display: flex; gap: 6px; overflow-x: auto; padding: 4px 2px; }
.strip button { flex: none; width: 34px; height: 34px; border-radius: 8px; border: 1.5px solid var(--rule); background: var(--paper); font: 600 .8rem var(--mono); cursor: pointer; color: var(--ink); }
.strip button.r { border-color: var(--ok); color: var(--ok); }
.strip button.w { border-color: var(--bad); color: var(--bad); }
.strip button.cur { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.seg { display: inline-flex; border: 1px solid var(--rule); border-radius: 9px; overflow: hidden; background: var(--paper); }
.seg button { border: 0; background: transparent; padding: 6px 12px; font-size: .85rem; cursor: pointer; color: var(--ink-2); }
.seg button + button { border-left: 1px solid var(--rule); }
.seg button[aria-pressed="true"] { background: var(--accent-soft); color: var(--accent); font-weight: 600; }

/* Tables */
.tablewrap { overflow-x: auto; }
table.data { border-collapse: collapse; width: 100%; font-size: .9rem; }
table.data th { text-align: left; font-weight: 600; color: var(--muted); font-size: .78rem; letter-spacing: .03em; padding: 8px 10px; border-bottom: 1px solid var(--rule); white-space: nowrap; }
table.data td { padding: 9px 10px; border-bottom: 1px solid var(--rule); vertical-align: middle; }
table.data td.n, table.data th.n { text-align: right; font-family: var(--mono); font-variant-numeric: tabular-nums; }
table.data tr.click { cursor: pointer; }
table.data tr.click:hover td { background: var(--bg); }
.minibar { display: inline-block; width: 70px; height: 7px; border-radius: 4px; background: var(--heat-0); vertical-align: middle; margin-right: 8px; overflow: hidden; }
.minibar i { display: block; height: 100%; background: var(--accent); border-radius: 4px; }
.up { color: var(--ok); } .down { color: var(--bad); }

/* Charts */
.chart { width: 100%; height: auto; display: block; overflow: visible; }
.chart text { fill: var(--muted); font: 11px var(--mono); }
.chart .gridl { stroke: var(--grid); stroke-width: 1; }
.chart .axisl { stroke: var(--axis); stroke-width: 1; }
.chartbox { position: relative; }
.tip { position: absolute; pointer-events: none; background: var(--paper); border: 1px solid var(--rule); border-radius: 8px; padding: 8px 10px; font-size: .8rem; box-shadow: 0 6px 18px rgba(0,0,0,.12); white-space: nowrap; z-index: 5; }
.heat { display: grid; grid-auto-flow: column; grid-template-rows: repeat(7, 14px); gap: 3px; overflow-x: auto; padding-bottom: 4px; }
.heat i { width: 14px; height: 14px; border-radius: 3px; background: var(--heat-0); display: block; }
.heat i.l1 { background: var(--heat-1); } .heat i.l2 { background: var(--heat-2); } .heat i.l3 { background: var(--heat-3); } .heat i.l4 { background: var(--heat-4); }
.heat i.future { background: transparent; }
.heatwrap { display: flex; gap: 8px; }
.heatdays { display: grid; grid-template-rows: repeat(7, 14px); gap: 3px; font-size: .66rem; color: var(--muted); line-height: 14px; }

#toast { position: fixed; left: 50%; bottom: calc(20px + env(safe-area-inset-bottom, 0px)); transform: translateX(-50%); background: var(--ink); color: var(--paper); padding: 10px 18px; border-radius: 10px; z-index: 60; font-size: .92rem; max-width: calc(100% - 32px); }

.empty { color: var(--muted); text-align: center; padding: 26px 10px; border: 1px dashed var(--rule); border-radius: var(--r); }
.katex { font-size: 1.05em; }
.katex-display { overflow-x: auto; overflow-y: hidden; padding: 4px 0; }
@media (prefers-reduced-motion: reduce) { * { transition: none !important; animation: none !important; } }

/* Phone header: menu gets its own full-width row */
@media (max-width: 680px) {
  .band .wrap { flex-wrap: wrap; row-gap: 4px; padding-block: 8px 6px; }
  .band .brand span { display: none; }
  .band .who b { display: none; }
  .tabs { order: 3; width: 100%; justify-content: space-between; }
  .tabs a { flex: 1; text-align: center; padding: 6px 4px; }
  .quest h1 { font-size: 1.7rem; }
}
/* Wide tables scroll sideways inside their card on phones instead of squeezing */
table.data.wide { min-width: 640px; }
table.data td.fixtip { min-width: 240px; }
@media (max-width: 680px) { .chart text { font-size: 19px; } }