/* MathClash — styles */
:root {
  --bg: #0f1226;
  --bg-2: #161a3a;
  --panel: #1c2150;
  --panel-2: #232a63;
  --line: #313a7d;
  --ink: #eef1ff;
  --ink-dim: #aeb6e6;
  --ink-faint: #7a83bd;
  --you: #3ddc97;
  --you-ink: #0a1f17;
  --foe: #ff7a8a;
  --accent: #7c8cff;
  --accent-2: #b388ff;
  --gold: #ffd45e;
  --warn: #ffb454;
  --ok: #3ddc97;
  --bad: #ff6b7a;
  --radius: 16px;
  --shadow: 0 14px 40px rgba(0,0,0,.35);
  font-synthesis: none;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; }
body {
  font-family: "Inter", "Segoe UI", system-ui, -apple-system, sans-serif;
  background: radial-gradient(1200px 700px at 20% -10%, #21275e 0%, transparent 60%),
              radial-gradient(900px 600px at 95% 10%, #2a1f55 0%, transparent 55%),
              var(--bg);
  color: var(--ink);
  min-height: 100%;
  -webkit-font-smoothing: antialiased;
  line-height: 1.45;
}
a { color: var(--accent-2); }
button { font-family: inherit; cursor: pointer; }
.hidden { display: none !important; }
.mono { font-variant-numeric: tabular-nums; }

/* ---------- top bar ---------- */
.topbar {
  display: flex; align-items: center; gap: 16px;
  padding: 14px 26px; border-bottom: 1px solid var(--line);
  background: rgba(15,18,38,.7); backdrop-filter: blur(8px);
  position: sticky; top: 0; z-index: 20;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; letter-spacing: .3px; font-size: 19px; }
.brand .logo {
  width: 30px; height: 30px; border-radius: 9px; flex-shrink: 0;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  display: grid; place-items: center; color: #11132e;
}
.brand .logo svg { display: block; }
.brand .wordmark { white-space: nowrap; }      /* one flex item → no gap between "Math" and "Clash" */
.brand b { color: var(--accent-2); }
.topbar .spacer { flex: 1; }
.topbar-actions { display: flex; align-items: center; gap: 12px; }
.hamburger {
  display: none; background: transparent; border: 1px solid var(--line); color: var(--ink-dim);
  border-radius: 10px; padding: 6px 8px; cursor: pointer; line-height: 0;
}
.hamburger:hover { color: var(--ink); border-color: var(--accent); }
.hamburger svg { display: block; }
.who { display: flex; align-items: center; gap: 10px; font-size: 14px; color: var(--ink-dim); }
.who .avatar {
  width: 28px; height: 28px; border-radius: 50%; flex-shrink: 0;
  background: linear-gradient(135deg, #3ddc97, #7c8cff); color: #0a1330;
  display: grid; place-items: center; font-weight: 800; font-size: 13px;
}
.who .handle { color: var(--ink); font-weight: 700; }
.btn-ghost {
  background: transparent; color: var(--ink-dim); border: 1px solid var(--line);
  padding: 7px 12px; border-radius: 10px; font-size: 13px; cursor: pointer; white-space: nowrap;
}
.btn-ghost:hover { color: var(--ink); border-color: var(--accent); }

/* ---------- mobile topbar (hamburger menu) ---------- */
@media (max-width: 620px) {
  .topbar { padding: 12px 16px; gap: 10px; }
  .hamburger { display: grid; place-items: center; }
  .topbar-actions {
    display: none; position: absolute; top: calc(100% + 6px); right: 12px;
    flex-direction: column; align-items: stretch; gap: 8px;
    background: var(--bg-2); border: 1px solid var(--line); border-radius: 12px;
    padding: 12px; min-width: 200px; box-shadow: 0 14px 40px rgba(0,0,0,.45); z-index: 40;
  }
  .topbar.menu-open .topbar-actions { display: flex; }
  .topbar-actions .who { justify-content: flex-start; }
  .topbar-actions .btn-ghost { text-align: center; }
}

/* ---------- layout ---------- */
.wrap { max-width: 1180px; margin: 0 auto; padding: 26px; }
.grid-home { display: grid; grid-template-columns: 1.6fr 1fr; gap: 22px; align-items: start; }
@media (max-width: 920px) { .grid-home { grid-template-columns: 1fr; } }

.card {
  background: linear-gradient(180deg, var(--panel) 0%, var(--bg-2) 130%);
  border: 1px solid var(--line); border-radius: var(--radius);
  box-shadow: var(--shadow); padding: 22px;
}
.card h2 { font-size: 15px; letter-spacing: .6px; text-transform: uppercase; color: var(--ink-faint); margin-bottom: 14px; }
.card.hero { padding: 26px 26px 22px; }
.stack { display: grid; gap: 22px; }

/* ---------- hero / play setup ---------- */
.hero h1 { font-size: 26px; line-height: 1.2; margin-bottom: 4px; }
.hero .sub { color: var(--ink-dim); font-size: 14.5px; margin-bottom: 20px; }

.field { margin-bottom: 18px; }
.field > label { display: block; font-size: 13px; color: var(--ink-faint); margin-bottom: 8px; letter-spacing: .4px; text-transform: uppercase; }
.modes { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
@media (max-width: 560px) { .modes { grid-template-columns: 1fr; } }
.mode-card {
  text-align: left; background: var(--panel-2); border: 1.5px solid var(--line);
  border-radius: 14px; padding: 14px 16px; color: var(--ink); transition: .12s;
}
.mode-card:hover { border-color: var(--accent); }
.mode-card.sel { border-color: var(--you); background: rgba(61,220,151,.1); }
.mode-card .mc-t { font-weight: 800; font-size: 15px; display: flex; align-items: center; gap: 8px; }
.mode-card .mc-d { font-size: 12.5px; color: var(--ink-dim); margin-top: 4px; }
.mode-card .pill { font-size: 10.5px; padding: 2px 7px; border-radius: 999px; background: var(--accent); color: #11132e; font-weight: 800; letter-spacing: .3px; }

.subject-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; }
@media (max-width: 560px) { .subject-grid { grid-template-columns: 1fr; } }
.subj {
  text-align: left; background: var(--panel-2); border: 1.5px solid var(--line);
  border-radius: 12px; padding: 11px 13px; color: var(--ink); transition: .12s;
}
.subj:hover { border-color: var(--accent); }
.subj.sel { border-color: var(--you); background: rgba(61,220,151,.1); }
.subj .s-name { font-weight: 700; font-size: 14px; display: flex; justify-content: space-between; align-items: baseline; gap: 8px; }
.subj .s-grades { font-size: 11px; color: var(--ink-faint); font-weight: 600; white-space: nowrap; }
.subj .s-blurb { font-size: 11.5px; color: var(--ink-dim); margin-top: 3px; line-height: 1.35; }
.subj .demo-tag { font-size: 10px; color: var(--gold); font-weight: 800; letter-spacing: .3px; }

.grade-row { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.grade-row select {
  background: var(--panel-2); color: var(--ink); border: 1.5px solid var(--line);
  border-radius: 10px; padding: 8px 12px; font-size: 14px;
}
.btn-text { background: none; border: none; color: var(--accent-2); font-size: 13px; text-decoration: underline; }

.play-row { display: flex; align-items: center; gap: 14px; margin-top: 6px; flex-wrap: wrap; }
.btn-start {
  background: linear-gradient(135deg, var(--you), #2fc7ff);
  color: #08221a; border: none; border-radius: 14px;
  padding: 15px 30px; font-size: 17px; font-weight: 900; letter-spacing: .3px;
  box-shadow: 0 12px 30px rgba(61,220,151,.28);
}
.btn-start:hover { filter: brightness(1.06); transform: translateY(-1px); }
.btn-start:active { transform: translateY(0); }
.btn-start:disabled { opacity: .5; cursor: not-allowed; filter: none; transform: none; }
.play-meta { font-size: 13px; color: var(--ink-dim); }
.play-meta b { color: var(--ink); }

/* ---------- stats ---------- */
.stat-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.stat {
  background: var(--panel-2); border: 1px solid var(--line); border-radius: 12px; padding: 13px 14px;
}
.stat .v { font-size: 22px; font-weight: 900; line-height: 1.1; }
.stat .v.you { color: var(--you); }
.stat .v.gold { color: var(--gold); }
.stat .k { font-size: 11.5px; color: var(--ink-faint); margin-top: 3px; letter-spacing: .3px; text-transform: uppercase; }
.stat .sub { font-size: 11px; color: var(--ink-dim); margin-top: 2px; }
.rankline { display: flex; align-items: baseline; gap: 8px; margin-top: 14px; font-size: 13px; color: var(--ink-dim); }
.rankline .big { font-size: 18px; font-weight: 900; color: var(--ink); }

/* ---------- leaderboard ---------- */
.lb { width: 100%; border-collapse: collapse; font-size: 13.5px; }
.lb th { text-align: left; font-size: 11px; text-transform: uppercase; letter-spacing: .5px; color: var(--ink-faint); padding: 6px 8px; border-bottom: 1px solid var(--line); }
.lb td { padding: 8px; border-bottom: 1px solid rgba(49,58,125,.5); }
.lb tr:hover td { background: rgba(255,255,255,.03); }
.lb tr.you td { background: rgba(61,220,151,.12); }
.lb tr.you td:first-child { box-shadow: inset 3px 0 0 var(--you); }
.lb .rk { width: 36px; color: var(--ink-faint); font-weight: 800; }
.lb .rk.top { color: var(--gold); }
.lb .nm { font-weight: 700; }
.lb .nm .badge-you { font-size: 10px; background: var(--you); color: #08221a; padding: 1px 6px; border-radius: 999px; margin-left: 6px; font-weight: 800; letter-spacing: .3px; }
.lb .pts { text-align: right; font-weight: 800; color: var(--ink); }
.lb-foot { margin-top: 12px; font-size: 12px; color: var(--ink-faint); }

/* ---------- matchmaking overlay ---------- */
.overlay {
  position: fixed; inset: 0; background: rgba(8,10,24,.82); backdrop-filter: blur(6px);
  display: grid; place-items: center; z-index: 50;
}
.match-box {
  background: linear-gradient(180deg, var(--panel), var(--bg-2)); border: 1px solid var(--line);
  border-radius: 20px; padding: 34px 40px; text-align: center; box-shadow: var(--shadow); width: min(440px, 92vw);
}
.match-box h3 { font-size: 20px; margin-bottom: 6px; }
.match-box p { color: var(--ink-dim); font-size: 14px; }
.radar { width: 90px; height: 90px; margin: 18px auto; border-radius: 50%; border: 2px solid var(--line); position: relative; overflow: hidden; }
.radar::before { content:""; position:absolute; inset:0; background: conic-gradient(from 0deg, transparent 0deg, rgba(61,220,151,.55) 40deg, transparent 60deg); animation: spin 1.1s linear infinite; }
.radar::after { content:""; position:absolute; inset: 30%; border-radius:50%; border:1px solid var(--line); }
@keyframes spin { to { transform: rotate(360deg); } }
.vs-reveal { display: flex; align-items: center; justify-content: center; gap: 14px; margin-top: 14px; }
.vs-reveal .p { display: flex; align-items: center; gap: 8px; font-weight: 800; }
.vs-reveal .av { width: 30px; height: 30px; border-radius: 50%; display: grid; place-items: center; font-weight: 800; font-size: 13px; color: #08221a; }
.vs-reveal .av.you { background: linear-gradient(135deg,#3ddc97,#7c8cff); }
.vs-reveal .av.foe { background: linear-gradient(135deg,#ff7a8a,#b388ff); }
.vs-reveal .vs { color: var(--ink-faint); font-weight: 900; }
.match-box .btn-start { margin-top: 16px; width: 100%; }

/* ---------- duel screen ---------- */
.duel-top { display: flex; align-items: center; gap: 16px; padding: 14px 26px; border-bottom: 1px solid var(--line); }
.duel-top .meta { color: var(--ink-dim); font-size: 13px; }
.duel-top .meta b { color: var(--ink); }

.arena { display: grid; grid-template-columns: 1fr 1.5fr 1fr; gap: 18px; align-items: stretch; max-width: 1180px; margin: 22px auto; padding: 0 26px; }
@media (max-width: 920px) { .arena { grid-template-columns: 1fr; } }

.player-col { display: flex; flex-direction: column; gap: 14px; }
.pcard {
  background: linear-gradient(180deg, var(--panel), var(--bg-2)); border: 1.5px solid var(--line);
  border-radius: var(--radius); padding: 18px; box-shadow: var(--shadow);
}
.pcard.side-you { border-color: rgba(61,220,151,.5); }
.pcard.side-foe { border-color: rgba(255,122,138,.45); }
.pcard.active-turn { box-shadow: 0 0 0 2px var(--you), var(--shadow); }
.pcard .ph { display: flex; align-items: center; gap: 12px; }
.pcard .ph .av { width: 42px; height: 42px; border-radius: 50%; display: grid; place-items: center; font-weight: 900; font-size: 16px; color: #08221a; }
.side-you .ph .av { background: linear-gradient(135deg,#3ddc97,#7c8cff); }
.side-foe .ph .av { background: linear-gradient(135deg,#ff7a8a,#b388ff); }
.pcard .ph .nm { font-weight: 800; font-size: 16px; }
.pcard .ph .tag { font-size: 11px; color: var(--ink-faint); text-transform: uppercase; letter-spacing: .4px; }
.pcard .score { font-size: 40px; font-weight: 900; line-height: 1; margin-top: 14px; }
.side-you .score { color: var(--you); }
.side-foe .score { color: var(--foe); }
.pcard .score small { font-size: 14px; color: var(--ink-faint); font-weight: 700; }
.pcard .progress-dots { display: flex; gap: 5px; margin-top: 14px; flex-wrap: wrap; }
.pcard .dot { width: 16px; height: 8px; border-radius: 999px; background: var(--line); }
.pcard .dot.correct { background: var(--ok); }
.pcard .dot.wrong { background: var(--bad); }
.pcard .dot.current { background: var(--accent); animation: pulse 1s ease-in-out infinite; }
@keyframes pulse { 50% { opacity: .4; } }
.pcard .answeredline { font-size: 12.5px; color: var(--ink-dim); margin-top: 10px; min-height: 18px; }
.pcard .foe-status { font-size: 13px; color: var(--ink-dim); margin-top: 12px; }

.qcard { background: linear-gradient(180deg, var(--panel), var(--bg-2)); border: 1.5px solid var(--line); border-radius: var(--radius); padding: 22px; box-shadow: var(--shadow); display: flex; flex-direction: column; }
.q-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 6px; }
.q-head .qn { font-size: 12px; letter-spacing: .6px; text-transform: uppercase; color: var(--ink-faint); }
.q-head .qworth { font-size: 12px; font-weight: 800; color: var(--gold); }
.diffbar { display: flex; align-items: center; gap: 8px; margin-bottom: 16px; }
.diffbar .track { flex: 1; height: 6px; background: var(--line); border-radius: 999px; overflow: hidden; }
.diffbar .fill { height: 100%; background: linear-gradient(90deg, var(--ok), var(--warn), var(--bad)); }
.diffbar .lab { font-size: 11px; color: var(--ink-faint); white-space: nowrap; }
.q-prompt { font-size: 21px; font-weight: 700; line-height: 1.35; margin: 6px 0 20px; min-height: 64px; }
.choices { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
@media (max-width: 560px) { .choices { grid-template-columns: 1fr; } }
.choice {
  text-align: left; background: var(--panel-2); border: 1.5px solid var(--line); border-radius: 12px;
  padding: 14px 16px; font-size: 16px; color: var(--ink); transition: .1s; display: flex; align-items: center; gap: 10px;
}
.choice .key { width: 22px; height: 22px; border-radius: 6px; background: var(--line); display: grid; place-items: center; font-size: 12px; font-weight: 800; color: var(--ink-dim); flex-shrink: 0; }
.choice:hover:not(:disabled) { border-color: var(--accent); }
.choice:disabled { cursor: default; }
.choice.correct { border-color: var(--ok); background: rgba(61,220,151,.16); }
.choice.correct .key { background: var(--ok); color: #08221a; }
.choice.wrong { border-color: var(--bad); background: rgba(255,107,122,.14); }
.choice.wrong .key { background: var(--bad); color: #2a0a0e; }
.q-feedback { margin-top: 16px; font-size: 14px; min-height: 22px; font-weight: 700; }
.q-feedback.ok { color: var(--ok); }
.q-feedback.bad { color: var(--bad); }
.q-solution { margin-top: 12px; padding: 12px 15px; border: 1px solid var(--line); border-left: 3px solid var(--accent); border-radius: 10px; background: rgba(124,140,255,.08); font-size: 14px; color: var(--ink-dim); line-height: 1.55; }
.q-solution .sol-h { font-size: 11px; text-transform: uppercase; letter-spacing: .5px; color: var(--accent); font-weight: 800; margin-bottom: 4px; }
.q-solution b { color: var(--ink); }
.q-skiprow { margin-top: 14px; text-align: right; }
.q-skip { cursor: pointer; }
.q-skip:hover { filter: brightness(1.07); }
.q-skip:disabled { opacity: .5; cursor: default; filter: none; }
.q-timerbar { height: 6px; background: var(--line); border-radius: 999px; overflow: hidden; margin-bottom: 16px; }
.q-timerbar .t { height: 100%; background: linear-gradient(90deg, var(--accent), var(--accent-2)); transition: width .24s linear; }
.q-timerbar.low .t { background: linear-gradient(90deg, var(--warn), var(--bad)); }
.qtimer { font-variant-numeric: tabular-nums; color: var(--ink-dim); font-weight: 800; }
.qtimer.low { color: var(--bad); animation: pulse 1s ease-in-out infinite; }

.foe-peek { margin-top: 14px; padding: 12px 14px; border: 1px dashed var(--line); border-radius: 12px; background: rgba(255,255,255,.02); }
.foe-peek .pk-h { font-size: 11px; text-transform: uppercase; letter-spacing: .5px; color: var(--ink-faint); margin-bottom: 6px; }
.foe-peek .pk-q { font-size: 13.5px; color: var(--ink-dim); }
.foe-peek.blur .pk-q { filter: blur(5px); user-select: none; }

/* challenge-mode question picker */
.picker { margin-top: 16px; }
.picker .pk-title { font-size: 13px; color: var(--ink-dim); margin-bottom: 10px; }
.picker .pk-opt { width: 100%; text-align: left; background: var(--panel-2); border: 1.5px solid var(--line); border-radius: 12px; padding: 13px 15px; margin-bottom: 10px; color: var(--ink); font-size: 15px; transition: .1s; }
.picker .pk-opt:hover { border-color: var(--accent-2); }
.picker .pk-opt .pk-worth { font-size: 11px; color: var(--gold); font-weight: 800; float: right; }

/* result modal */
.result-box { background: linear-gradient(180deg, var(--panel), var(--bg-2)); border: 1px solid var(--line); border-radius: 20px; padding: 30px 36px; text-align: center; box-shadow: var(--shadow); width: min(460px, 92vw); }
.result-box .verdict { font-size: 30px; font-weight: 900; letter-spacing: .5px; }
.result-box .verdict.win { color: var(--you); }
.result-box .verdict.loss { color: var(--foe); }
.result-box .verdict.draw { color: var(--warn); }
.result-box .rscore { font-size: 18px; color: var(--ink-dim); margin-top: 6px; }
.result-box .rscore b { color: var(--ink); }
.result-box .rdelta { margin-top: 14px; font-size: 15px; }
.result-box .rdelta .gain { color: var(--gold); font-weight: 900; }
.result-box .rrank { margin-top: 6px; font-size: 14px; color: var(--ink-dim); }
.result-box .ractions { display: flex; gap: 12px; margin-top: 22px; }
.result-box .ractions a, .result-box .ractions button { flex: 1; }
.btn-primary { background: linear-gradient(135deg, var(--accent), var(--accent-2)); color: #11132e; border: none; border-radius: 12px; padding: 13px 18px; font-weight: 800; font-size: 15px; text-decoration: none; display: inline-block; text-align: center; }
.btn-primary:hover { filter: brightness(1.07); }
.btn-secondary { background: var(--panel-2); color: var(--ink); border: 1.5px solid var(--line); border-radius: 12px; padding: 13px 18px; font-weight: 700; font-size: 15px; text-decoration: none; display: inline-block; text-align: center; }
.btn-secondary:hover { border-color: var(--accent); }

.toast { position: fixed; bottom: 22px; left: 50%; transform: translateX(-50%); background: var(--panel-2); border: 1px solid var(--line); color: var(--ink); padding: 11px 18px; border-radius: 12px; font-size: 14px; box-shadow: var(--shadow); z-index: 60; }

footer.foot { text-align: center; color: var(--ink-faint); font-size: 12px; padding: 30px 0 24px; }
footer.foot code { color: var(--ink-dim); }