:root {
  --bg: #f7f6f3;
  --surface: #ffffff;
  --surface-2: #f0eee9;
  --border: #e2dfd8;
  --text: #1f1d1a;
  --muted: #6f6a62;
  --accent: #3b5bdb;
  --accent-soft: #e6ebfd;
  --ok: #2b8a3e;
  --ok-soft: #e3f4e6;
  --bad: #c92a2a;
  --bad-soft: #fbe5e5;
  --warn: #b35c00;
  --new: #1c7ed6;
  --learn: #d9480f;
  --due: #2b8a3e;
  --power: #ae3ec9;
  --radius: 10px;
  --shadow: 0 1px 2px rgba(0,0,0,.05), 0 4px 16px rgba(0,0,0,.04);
  color-scheme: light;
}
/* Dark theme: follows the system unless the user picked a theme (html[data-theme]) */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #151517;
    --surface: #1e1e21;
    --surface-2: #26262a;
    --border: #34343a;
    --text: #ecebe8;
    --muted: #9b9890;
    --accent: #7b93ff;
    --accent-soft: #252c48;
    --ok: #63c574;
    --ok-soft: #1d3322;
    --bad: #ff7676;
    --bad-soft: #3d2020;
    --warn: #f0a050;
    --new: #5aa9f5;
    --learn: #ff8a50;
    --due: #63c574;
    --power: #d98bf0;
    --shadow: none;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #151517;
  --surface: #1e1e21;
  --surface-2: #26262a;
  --border: #34343a;
  --text: #ecebe8;
  --muted: #9b9890;
  --accent: #7b93ff;
  --accent-soft: #252c48;
  --ok: #63c574;
  --ok-soft: #1d3322;
  --bad: #ff7676;
  --bad-soft: #3d2020;
  --warn: #f0a050;
  --new: #5aa9f5;
  --learn: #ff8a50;
  --due: #63c574;
  --power: #d98bf0;
  --shadow: none;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, sans-serif;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
h2 { margin: 4px 0 14px; font-size: 1.45rem; letter-spacing: -.01em; }
h3 { margin: 14px 0 8px; font-size: 1.1rem; }
kbd {
  font: 11px ui-monospace, SFMono-Regular, Menlo, monospace;
  padding: 1px 5px; margin-left: 6px;
  border: 1px solid var(--border); border-bottom-width: 2px; border-radius: 4px;
  color: var(--muted); background: var(--surface-2);
}

/* layout */
.topbar {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; gap: 20px; flex-wrap: wrap;
  padding: 10px 20px;
  background: color-mix(in srgb, var(--surface) 92%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.brand { font-weight: 700; color: var(--text); font-size: 1.05rem; }
.brand:hover { text-decoration: none; }
nav { display: flex; gap: 2px; flex-wrap: wrap; }
nav a { color: var(--muted); padding: 6px 10px; border-radius: 8px; font-weight: 500; }
nav a:hover { background: var(--surface-2); text-decoration: none; color: var(--text); }
nav a.active { background: var(--accent-soft); color: var(--accent); }
main { max-width: 960px; margin: 0 auto; padding: 24px 20px 80px; }

.row { display: flex; align-items: center; gap: 12px; }
.row.wrap { flex-wrap: wrap; }
.row.between { justify-content: space-between; }
.row.end { justify-content: flex-end; }
.gap-s { gap: 8px; }
.gap { gap: 16px; }
.grow { flex: 1 1 auto; min-width: 0; }
.stack { display: flex; flex-direction: column; gap: 12px; }
.muted { color: var(--muted); }
.small { font-size: .85rem; }
.warn { color: var(--warn); }
.label { font-size: .75rem; font-weight: 700; letter-spacing: .04em; color: var(--muted); text-transform: uppercase; }
.empty { text-align: center; padding: 48px 16px; }
.panel { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 12px 16px; margin: 12px 0; }
details > summary { cursor: pointer; font-weight: 600; }

/* controls */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 4px;
  font: inherit; font-weight: 500;
  padding: 7px 14px;
  background: var(--surface); color: var(--text);
  border: 1px solid var(--border); border-radius: 8px;
  cursor: pointer; white-space: nowrap;
  transition: background .12s, border-color .12s;
}
.btn:hover:not(:disabled) { background: var(--surface-2); text-decoration: none; }
.btn:disabled { opacity: .45; cursor: default; }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn.primary:hover:not(:disabled) { background: color-mix(in srgb, var(--accent) 88%, #000); }
.btn.primary kbd { background: transparent; color: rgba(255,255,255,.8); border-color: rgba(255,255,255,.35); }
.btn.ghost { background: transparent; border-color: transparent; color: var(--muted); }
.btn.ghost:hover:not(:disabled) { color: var(--text); }
.btn.danger, .btn.ghost.danger { color: var(--bad); }
.btn.danger:not(.ghost) { border-color: var(--bad); }
.btn.small { padding: 4px 10px; font-size: .88rem; }
.btn.tiny { padding: 2px 8px; font-size: .8rem; }
.btn.big { padding: 12px 28px; font-size: 1.05rem; }
.btn.on { background: var(--accent-soft); border-color: var(--accent); color: var(--accent); }
.icon-btn { background: none; border: 0; font-size: 1.5rem; line-height: 1; color: var(--muted); cursor: pointer; padding: 0 4px; }
.linkish { background: none; border: 0; padding: 2px 6px; color: var(--accent); cursor: pointer; font: inherit; font-size: .88rem; }
.linkish:hover { text-decoration: underline; }

.input {
  font: inherit; color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border); border-radius: 8px;
  padding: 7px 10px; min-width: 0;
}
.input:focus { outline: 2px solid var(--accent); outline-offset: -1px; border-color: transparent; }
textarea.input { width: 100%; resize: vertical; }
.input.big { font-size: 1.05rem; padding: 10px 12px; }
.input.small { font-size: .85rem; padding: 4px 8px; }
.input.year { width: 90px; }
.input.mono { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: .9rem; }
input[type="checkbox"] { accent-color: var(--accent); }
.field { display: flex; flex-direction: column; gap: 4px; }
.field > span { font-size: .85rem; color: var(--muted); }

.segmented { display: inline-flex; border: 1px solid var(--border); border-radius: 9px; padding: 2px; background: var(--surface); }
.seg { font: inherit; border: 0; background: none; padding: 5px 14px; border-radius: 7px; cursor: pointer; color: var(--muted); }
.seg.on { background: var(--accent-soft); color: var(--accent); font-weight: 600; }

.chip { display: inline-flex; align-items: center; gap: 2px; padding: 2px 8px; border: 1px solid var(--border); border-radius: 99px; font-size: .85rem; background: var(--surface); cursor: pointer; }
.pill { display: inline-block; padding: 0 7px; border-radius: 99px; font-size: .75rem; font-weight: 600; background: var(--surface-2); color: var(--muted); text-transform: uppercase; letter-spacing: .03em; }
.pill.tossup { background: var(--accent-soft); color: var(--accent); }
.pill.bonus { background: var(--ok-soft); color: var(--ok); }
.pill.state-new { color: var(--new); text-transform: none; }
.pill.state-learning, .pill.state-relearning { color: var(--learn); text-transform: none; }
.pill.state-review { color: var(--due); text-transform: none; }

/* tables */
.table { width: 100%; border-collapse: collapse; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
.table th, .table td { padding: 9px 12px; border-bottom: 1px solid var(--border); text-align: left; }
.table th { font-size: .78rem; text-transform: uppercase; letter-spacing: .04em; color: var(--muted); font-weight: 600; background: var(--surface-2); }
.table tr:last-child td { border-bottom: 0; }
.table .num { text-align: right; width: 64px; font-variant-numeric: tabular-nums; }
.new { color: var(--new); } .learn { color: var(--learn); } .due { color: var(--due); }
.table.decks td.num { font-weight: 600; }
.bar-cell { display: flex; align-items: center; gap: 8px; min-width: 140px; }
.bar { height: 8px; border-radius: 4px; background: var(--accent); opacity: .7; }

/* accounts */
.user-box { margin-left: auto; display: flex; align-items: center; gap: 6px; }
body.logged-out .theme-toggle { margin-left: auto; }
.theme-toggle {
  display: inline-flex; align-items: center; justify-content: center;
  width: 34px; height: 34px; padding: 0;
  border: 1px solid var(--border); border-radius: 8px;
  background: var(--surface); color: var(--text); cursor: pointer;
}
.theme-toggle:hover { background: var(--surface-2); }
.theme-toggle svg { width: 18px; height: 18px; }
html.theme-anim, html.theme-anim * { transition: background-color .25s, border-color .25s, color .25s !important; }
body.logged-out nav, body.logged-out .user-box { display: none; }
.login { max-width: 380px; margin: 8vh auto 0; display: flex; flex-direction: column; gap: 14px; }
.login h2 { margin: 0; font-size: 1.8rem; }
.login .segmented { align-self: flex-start; }
.login .btn.big { width: 100%; }

body.logged-out .login .linkish { align-self: flex-start; padding: 0; }
.recovery-code { font: 600 1.4rem/1.2 ui-monospace, SFMono-Regular, Menlo, monospace; letter-spacing: .06em; text-align: center; padding: 14px; border: 1px dashed var(--accent); border-radius: 10px; background: var(--accent-soft); color: var(--accent); user-select: all; }
.account-box { padding-bottom: 12px; border-bottom: 1px solid var(--border); }

/* deck picker & bulk note actions */
.deck-picker { display: flex; flex-wrap: wrap; gap: 6px; align-items: center; }
.deck-chip { display: inline-flex; align-items: center; gap: 6px; padding: 4px 10px; border: 1px solid var(--border); border-radius: 999px; font-size: .88rem; cursor: pointer; }
.deck-chip.on { border-color: var(--accent); background: var(--accent-soft); color: var(--accent); }
.bulk-bar { margin: 10px 0 4px; font-size: .9rem; }
.note-row .note-check { margin-top: 4px; flex: none; }

/* filters */
.filters .cats { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 10px 16px; margin-top: 8px; }
.filters .cat-name { font-weight: 600; cursor: pointer; }
.filters .subs { display: flex; flex-direction: column; margin: 2px 0 0 20px; }
.filters .sub { font-size: .88rem; color: var(--muted); cursor: pointer; }
.filters .subs .alts { margin-left: 18px; }
.filters .alts .sub { font-size: .82rem; }
.filters .alt-label { margin-top: 6px; font-size: .68rem; }

/* difficulty picker */
.diff-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 8px 20px; margin-top: 6px; }
.diff-group { display: flex; flex-direction: column; gap: 2px; }
.diff-group .label { margin: 4px 0 2px; }
.diff-option { display: grid; grid-template-columns: auto 22px 1fr; gap: 8px; align-items: start; padding: 6px 8px; border-radius: 8px; cursor: pointer; }
.diff-option:hover { background: var(--surface-2); }
.diff-option:has(input:checked) { background: var(--accent-soft); }
.diff-option input { margin-top: 3px; }
.diff-num { font-weight: 700; color: var(--accent); font-variant-numeric: tabular-nums; text-align: right; }
.diff-name { display: block; font-weight: 600; font-size: .9rem; }
.diff-desc { display: block; font-size: .8rem; color: var(--muted); line-height: 1.4; }

/* questions */
.qcard { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px 16px; margin: 10px 0; box-shadow: var(--shadow); }
.q-meta { font-size: .82rem; color: var(--muted); margin-bottom: 6px; }
.q-text { line-height: 1.65; margin: 6px 0; }
.q-answer { margin: 6px 0 10px; }
.bonus-part { border-left: 3px solid var(--border); padding-left: 12px; margin: 10px 0; }
.stats-block { font-size: .85rem; margin-top: 8px; padding: 8px 10px; border-radius: 8px; background: var(--surface-2); }
.saved-meta { margin-top: 10px; padding-top: 10px; border-top: 1px dashed var(--border); }
.saved-meta textarea { flex: 1 1 240px; width: auto; }
.results-section { margin-top: 20px; }
.pager { flex-wrap: wrap; }
.year-group { margin: 6px 0; line-height: 1.9; }

/* reader */
.stage { background: var(--surface); border: 1px solid var(--border); border-radius: 14px; padding: 22px 24px; margin: 12px 0; min-height: 260px; box-shadow: var(--shadow); }
.q-text.reading { font-size: 1.12rem; min-height: 120px; }
.power { color: var(--power); font-weight: 700; }
.buzz-mark { display: inline-block; padding: 0 4px; border-radius: 4px; background: var(--accent-soft); }
.answer-box { margin: 14px 0; display: flex; flex-direction: column; gap: 6px; }
.answer-box .input { width: 100%; }
.controls { margin-top: 18px; }
.result { margin: 16px 0 8px; padding: 12px 14px; border-radius: 10px; background: var(--surface-2); }
.verdict { font-weight: 700; padding: 2px 10px; border-radius: 6px; }
.verdict.ok { background: var(--ok-soft); color: var(--ok); }
.verdict.bad { background: var(--bad-soft); color: var(--bad); }
.verdict.none { background: var(--surface); color: var(--muted); }
.session { text-align: center; }
.keys { text-align: center; margin-top: 8px; }
.bonus-part .input { flex: 1; }

/* multiplayer */
.room-code { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; letter-spacing: .08em; color: var(--accent); }
.mp { display: grid; grid-template-columns: minmax(0, 1fr) 260px; gap: 16px; align-items: start; }
.mp-stage { margin: 12px 0 0; }
.mp-side { display: flex; flex-direction: column; gap: 12px; margin-top: 12px; }
.mp-side .panel { margin: 0; }
.board-table { width: 100%; border-collapse: collapse; margin-top: 6px; }
.board-table td { padding: 4px 0; border-bottom: 1px solid var(--border); }
.board-table tr:last-child td { border-bottom: 0; }
.board-table td.num { text-align: right; padding-left: 8px; font-variant-numeric: tabular-nums; white-space: nowrap; }
.board-table .pts { font-weight: 700; }
.board-table .dot { display: inline-block; width: 7px; height: 7px; border-radius: 50%; background: var(--ok); vertical-align: middle; }
.board-table tr.offline { opacity: .5; }
.board-table tr.offline .dot { background: var(--muted); }
.mp-chat { display: flex; flex-direction: column; gap: 8px; }
.mp-log { max-height: 280px; min-height: 120px; overflow-y: auto; display: flex; flex-direction: column; gap: 3px; font-size: .9rem; overflow-wrap: anywhere; }
.mp-chat .input { flex: 1; }
.buzz-mark.neg { background: var(--bad-soft); }
.live-answer { font-style: italic; }
@media (max-width: 760px) {
  .mp { grid-template-columns: 1fr; }
}

/* cloze */
.cloze { color: var(--accent); font-weight: 700; }
.cloze-mark { background: var(--accent-soft); color: var(--accent); border-radius: 4px; padding: 0 3px; }
.cloze-mark::before { content: "c" attr(data-n) " "; font-size: .7em; opacity: .7; }
.preview { padding: 10px 12px; border: 1px dashed var(--border); border-radius: 8px; background: var(--surface); line-height: 1.6; }
.preview.small { font-size: .88rem; padding: 6px 10px; margin-top: 4px; }
.note-list { display: flex; flex-direction: column; gap: 8px; margin-top: 12px; }
.note-row { display: flex; gap: 12px; align-items: flex-start; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 10px 14px; }
.note-text { margin-bottom: 6px; line-height: 1.55; }

/* study */
.study-card { background: var(--surface); border: 1px solid var(--border); border-radius: 14px; padding: 32px 28px 14px; min-height: 240px; box-shadow: var(--shadow); }
.card-face { font-size: 1.2rem; line-height: 1.7; }
.card-extra { margin-top: 18px; padding-top: 14px; border-top: 1px solid var(--border); color: var(--muted); font-size: .95rem; }
.card-tools { margin-top: 28px; }
.study-foot { display: flex; justify-content: center; margin-top: 18px; }
.grades { display: grid; grid-template-columns: repeat(4, minmax(0, 120px)); gap: 10px; }
.grade { flex-direction: column; padding: 8px 6px; gap: 0; }
.grade.g1 { border-color: var(--bad); } .grade.g1 span:nth-child(2) { color: var(--bad); }
.grade.g2 span:nth-child(2) { color: var(--warn); }
.grade.g3 { border-color: var(--ok); } .grade.g3 span:nth-child(2) { color: var(--ok); }
.grade.g4 span:nth-child(2) { color: var(--new); }
.count { font-weight: 700; font-variant-numeric: tabular-nums; min-width: 22px; text-align: center; }
.count.new { color: var(--new); } .count.learn { color: var(--learn); } .count.due { color: var(--due); }

/* converter */
.drafts { display: flex; flex-direction: column; gap: 10px; max-height: 50vh; overflow: auto; padding-right: 4px; }
.draft { display: flex; gap: 10px; align-items: flex-start; }
.draft-check { padding-top: 8px; }
.draft .verdict.small { display: inline-block; font-size: .78rem; padding: 0 8px; margin-bottom: 4px; }
.missed-only { padding: 8px 10px; border-radius: 8px; background: var(--surface-2); }

/* modal + toast */
.overlay { position: fixed; inset: 0; background: rgba(0,0,0,.4); display: flex; align-items: flex-start; justify-content: center; padding: 6vh 16px; z-index: 50; overflow: auto; }
.modal { background: var(--surface); border: 1px solid var(--border); border-radius: 14px; width: min(480px, 100%); box-shadow: 0 20px 60px rgba(0,0,0,.25); }
.modal.wide { width: min(860px, 100%); }
.modal-head { display: flex; justify-content: space-between; align-items: center; padding: 14px 18px; border-bottom: 1px solid var(--border); }
.modal-head h3 { margin: 0; }
.modal-body { padding: 16px 18px; }
#toasts { position: fixed; bottom: 20px; left: 50%; transform: translateX(-50%); display: flex; flex-direction: column; gap: 8px; z-index: 100; }
.toast { background: var(--text); color: var(--bg); padding: 8px 16px; border-radius: 8px; font-size: .9rem; box-shadow: var(--shadow); transition: opacity .3s; }
.toast.error { background: var(--bad); color: #fff; }
.toast.out { opacity: 0; }

@media (max-width: 640px) {
  main { padding: 16px 16px 60px; }
  .topbar { padding: 8px 16px; gap: 8px; }
  nav a { padding: 4px 7px; font-size: .9rem; }
  .stage, .study-card { padding: 18px 16px; }
  .grades { grid-template-columns: repeat(4, 1fr); width: 100%; }
  .table th, .table td { padding: 7px 8px; }
}