:root {
  --bg: #f6f7fb;
  --card: #ffffff;
  --text: #1b1f2a;
  --muted: #667085;
  --line: #e4e7ec;
  --accent: #4f46e5;
  --accent-soft: #eef0ff;
  --ok: #12925b;
  --ok-soft: #e3f6ec;
  --warn: #b25e09;
  --warn-soft: #fff1dc;
  --bad: #c0392b;
  --bad-soft: #fde8e6;
  --d1: #475467;
  --d1-soft: #eef1f5;
  --d2: #1d6fb8;
  --d2-soft: #e3f0fc;
  --d3: #b4235a;
  --d3-soft: #fde7ef;
  --shadow: 0 1px 2px rgba(16, 24, 40, .06), 0 1px 3px rgba(16, 24, 40, .08);
  --radius: 14px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f1117; --card: #181b24; --text: #e7e9ee; --muted: #98a2b3; --line: #2a2f3b;
    --accent: #8b87ff; --accent-soft: #24244a; --ok: #3ccf8e; --ok-soft: #133526; --warn: #f5a524; --warn-soft: #3a2a10;
    --bad: #ff6b5f; --bad-soft: #3d1b18; --d1: #b8c0cc; --d1-soft: #262b36; --d2: #6cb4ff; --d2-soft: #16304a;
    --d3: #ff7aa8; --d3-soft: #401a2a; --shadow: none; color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0f1117; --card: #181b24; --text: #e7e9ee; --muted: #98a2b3; --line: #2a2f3b;
  --accent: #8b87ff; --accent-soft: #24244a; --ok: #3ccf8e; --ok-soft: #133526; --warn: #f5a524; --warn-soft: #3a2a10;
  --bad: #ff6b5f; --bad-soft: #3d1b18; --d1: #b8c0cc; --d1-soft: #262b36; --d2: #6cb4ff; --d2-soft: #16304a;
  --d3: #ff7aa8; --d3-soft: #401a2a; --shadow: none; color-scheme: dark;
}

* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  background: var(--bg); color: var(--text);
  font: 15px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans", sans-serif;
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3 { margin: 0; line-height: 1.25; }
h2 { font-size: 1.05rem; margin-bottom: .6rem; display: flex; align-items: center; gap: .5rem; }
a { color: var(--accent); }
.muted { color: var(--muted); }
.tiny { font-size: .75rem; color: var(--muted); }
.nowrap { white-space: nowrap; }

/* layout: sidebar + main */
.app { display: grid; grid-template-columns: 220px minmax(0, 1fr); min-height: 100vh; }
.side {
  position: sticky; top: 0; height: 100vh; overflow-y: auto; background: var(--card); border-right: 1px solid var(--line);
  padding: 14px 10px; display: flex; flex-direction: column; gap: 12px;
}
.brand { display: flex; gap: 10px; align-items: center; padding: 0 6px; }
.logo { font-size: 26px; }
.brand-title { font-weight: 800; }
.brand-sub { font-size: .78rem; color: var(--muted); }
.nav { display: flex; flex-direction: column; gap: 2px; }
.nav a {
  display: flex; align-items: center; gap: 6px; padding: 8px 10px; border-radius: 10px; color: var(--text);
  text-decoration: none; font-weight: 600; font-size: .9rem; white-space: nowrap;
}
.nav a:hover { background: var(--accent-soft); }
.nav a.active { background: var(--accent); color: #fff; }
.nav-badge { margin-left: auto; background: var(--bad); color: #fff; border-radius: 999px; font-size: .7rem; padding: 0 7px; }
.nav-badge:empty { display: none; }
.mini-timer { margin-top: auto; text-align: center; font-weight: 800; background: var(--accent-soft); color: var(--accent); border-radius: 10px; padding: 8px; }
.main { max-width: 1180px; width: 100%; margin: 0 auto; padding: 16px; display: flex; flex-direction: column; gap: 16px; min-width: 0; }
.page-head h1 { font-size: 1.35rem; margin: 0 0 2px; }
.page-head p { margin: 0; }
@media (max-width: 860px) {
  .app { grid-template-columns: minmax(0, 1fr); }
  .side { min-width: 0; position: sticky; top: 0; z-index: 10; height: auto; flex-direction: row; align-items: center; padding: 8px 12px; border-right: 0; border-bottom: 1px solid var(--line); overflow: visible; }
  .brand-sub { display: none; }
  .nav { flex-direction: row; overflow-x: auto; scrollbar-width: none; flex: 1; min-width: 0; }
  .nav a { padding: 6px 10px; font-size: .82rem; }
  .mini-timer { margin: 0; padding: 4px 8px; font-size: .8rem; }
}

.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; box-shadow: var(--shadow); min-width: 0; }
.card-h { display: flex; justify-content: space-between; align-items: flex-start; gap: 10px; flex-wrap: wrap; margin-bottom: 6px; }
.eyebrow { font-size: .72rem; text-transform: uppercase; letter-spacing: .06em; color: var(--accent); font-weight: 700; }
.grid { display: grid; gap: 16px; }
.kpis { grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); }
.two { grid-template-columns: 1.4fr 1fr; }
.stack { display: flex; flex-direction: column; gap: 16px; min-width: 0; }
@media (max-width: 860px) { .two { grid-template-columns: 1fr; } }

.kpi-n { font-size: 1.8rem; font-weight: 800; font-variant-numeric: tabular-nums; }
.kpi-l { color: var(--muted); font-size: .82rem; }
.count { margin-left: auto; font-size: .8rem; background: var(--accent-soft); color: var(--accent); padding: 2px 8px; border-radius: 999px; }

/* buttons & inputs */
.btn {
  display: inline-flex; align-items: center; gap: 6px; border: 1px solid var(--accent); background: var(--accent); color: #fff;
  padding: 8px 14px; border-radius: 10px; font: inherit; font-weight: 600; cursor: pointer; text-decoration: none;
}
.btn.ghost { background: transparent; color: var(--accent); border-color: var(--line); }
.btn.ghost:hover { border-color: var(--accent); }
.btn.danger { background: var(--bad); border-color: var(--bad); }
.btn.sm { padding: 4px 10px; font-size: .8rem; border-radius: 8px; }
input, select, textarea {
  font: inherit; color: var(--text); background: var(--bg); border: 1px solid var(--line); border-radius: 8px; padding: 7px 9px; width: 100%;
}
input[type="checkbox"] { width: 18px; height: 18px; accent-color: var(--accent); flex: none; margin: 0; }
label { display: flex; flex-direction: column; gap: 4px; font-size: .82rem; color: var(--muted); }
label.full { margin-top: 10px; }
.hint { font-size: .8rem; color: var(--muted); margin: 10px 0 0; }

.chip { display: inline-block; font-size: .72rem; font-weight: 700; padding: 2px 8px; border-radius: 999px; background: var(--accent-soft); color: var(--accent); white-space: nowrap; }
.chip.ok { background: var(--ok-soft); color: var(--ok); }
.chip.warn { background: var(--warn-soft); color: var(--warn); }
.chip.bad { background: var(--bad-soft); color: var(--bad); }
.chip.new { background: var(--d3-soft); color: var(--d3); }
.chip.fH { background: var(--bad-soft); color: var(--bad); }
.chip.fM { background: var(--warn-soft); color: var(--warn); }
.chip.fL { background: var(--d1-soft); color: var(--d1); }
.depth { display: inline-block; font-size: .68rem; font-weight: 800; letter-spacing: .04em; padding: 2px 7px; border-radius: 6px; }
.depth.d1 { background: var(--d1-soft); color: var(--d1); }
.depth.d2 { background: var(--d2-soft); color: var(--d2); }
.depth.d3 { background: var(--d3-soft); color: var(--d3); }

.bar { height: 8px; background: var(--line); border-radius: 999px; overflow: hidden; min-width: 60px; flex: 1; }
.bar span { display: block; height: 100%; background: var(--accent); border-radius: 999px; transition: width .3s; }
.bar.big { height: 10px; }
.progress-line { display: flex; align-items: center; gap: 10px; margin: 12px 0; font-size: .82rem; color: var(--muted); }

/* today */
.nav-date { display: flex; gap: 6px; align-items: center; }
.nav-date input { width: auto; }
.plan-title { font-weight: 700; margin: 4px 0 10px; }
.tasks { display: flex; flex-direction: column; gap: 6px; }
.task {
  flex-direction: row; align-items: flex-start; gap: 10px; color: var(--text); font-size: .92rem;
  padding: 10px 12px; border: 1px solid var(--line); border-radius: 10px; cursor: pointer;
}
.task span { flex: 1; }
.task em { font-style: normal; font-size: .75rem; color: var(--muted); white-space: nowrap; }
.task.done { background: var(--ok-soft); border-color: transparent; }
.task.done span { text-decoration: line-through; color: var(--muted); }
.log-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
@media (max-width: 520px) { .log-grid { grid-template-columns: 1fr 1fr; } }

.due { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 6px; }
.due label { flex-direction: row; gap: 8px; align-items: flex-start; color: var(--text); font-size: .85rem; }
.late { color: var(--bad); font-style: normal; font-size: .75rem; }

.hbars { display: flex; gap: 4px; align-items: flex-end; height: 120px; }
.hb { flex: 1; display: flex; flex-direction: column; align-items: center; gap: 4px; height: 100%; justify-content: flex-end; }
.hb-fill { width: 100%; background: var(--accent); border-radius: 4px 4px 0 0; min-height: 2px; opacity: .75; }
.hb-fill.hit { background: var(--ok); opacity: 1; }
.hb small { font-size: .65rem; color: var(--muted); }

/* tables */
.table-wrap { overflow-x: auto; }
.tbl { width: 100%; border-collapse: collapse; font-size: .88rem; }
.tbl th, .tbl td { padding: 8px 10px; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
.tbl th { font-size: .75rem; text-transform: uppercase; letter-spacing: .04em; color: var(--muted); }
.tbl .num { text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; }
.tbl .wide { min-width: 120px; }

/* plan */
.phases { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 12px; }
.phase { border: 1px solid var(--line); border-radius: 12px; padding: 12px; }
.phase span { display: block; font-size: .8rem; color: var(--accent); font-weight: 700; }
.phase p { margin: 6px 0 0; font-size: .85rem; color: var(--muted); }
.days { display: flex; flex-direction: column; gap: 4px; }
.wk { font-size: .9rem; margin: 14px 0 4px; color: var(--accent); }
.day-row { display: grid; grid-template-columns: 110px 1fr auto; gap: 10px; padding: 8px 10px; border-radius: 10px; cursor: pointer; border: 1px solid transparent; font-size: .88rem; }
.day-row:hover { background: var(--accent-soft); }
.day-row.today { border-color: var(--accent); background: var(--accent-soft); }
.day-row.past { opacity: .7; }
.dr-date { font-weight: 700; font-size: .8rem; color: var(--muted); }
.dr-sub { color: var(--muted); font-size: .82rem; }
@media (max-width: 560px) { .day-row { grid-template-columns: 1fr auto; } .dr-date { grid-column: 1 / -1; } }
.rules { margin: 0; padding-left: 20px; display: flex; flex-direction: column; gap: 6px; }

/* syllabus */
.pills { display: flex; flex-wrap: wrap; gap: 6px; }
.pill { border: 1px solid var(--line); background: transparent; color: var(--text); padding: 5px 12px; border-radius: 999px; font: inherit; font-size: .82rem; cursor: pointer; }
.pill.on { background: var(--accent); color: #fff; border-color: var(--accent); }
.subj { padding: 0; overflow: hidden; }
.subj-h {
  width: 100%; display: grid; grid-template-columns: 1fr auto 160px 20px; gap: 12px; align-items: center;
  padding: 14px 16px; border: 0; background: transparent; color: var(--text); font: inherit; text-align: left; cursor: pointer;
}
.subj-name { font-weight: 700; }
.subj-meta { font-size: .78rem; color: var(--muted); }
@media (max-width: 760px) { .subj-h { grid-template-columns: 1fr 20px; } .subj-meta, .subj-bar { grid-column: 1; } }
.subj-b { padding: 0 16px 16px; }
.official { font-size: .82rem; color: var(--muted); background: var(--bg); border-radius: 10px; padding: 10px 12px; margin: 0 0 12px; }
.pyq-row { display: grid; grid-template-columns: 1fr 1fr 2fr; gap: 10px; align-items: end; margin-bottom: 12px; }
.pyq-prog { font-size: .8rem; color: var(--muted); display: flex; flex-direction: column; gap: 6px; }
@media (max-width: 560px) { .pyq-row { grid-template-columns: 1fr 1fr; } .pyq-prog { grid-column: 1 / -1; } }
.topics { display: flex; flex-direction: column; gap: 10px; }
.topic { border: 1px solid var(--line); border-radius: 12px; padding: 10px 12px; }
.topic.weak { border-color: var(--bad); }
.topic-h { display: flex; justify-content: space-between; align-items: center; gap: 8px; flex-wrap: wrap; }
.topic-name { border: 0; background: transparent; color: var(--text); font: inherit; font-weight: 700; cursor: pointer; padding: 0; text-align: left; }
.topic-name small { font-weight: 500; color: var(--muted); margin-left: 6px; }
.topic-ctrl { display: flex; flex-wrap: wrap; gap: 6px 12px; align-items: center; margin-top: 8px; }
.topic-ctrl select { width: auto; padding: 4px 6px; font-size: .8rem; }
.tk { flex-direction: row; align-items: center; gap: 5px; color: var(--text); font-size: .8rem; cursor: pointer; }
.subs { display: flex; flex-direction: column; gap: 8px; margin-top: 10px; }
.sub { background: var(--bg); border-radius: 10px; padding: 10px 12px; }
.sub.done { opacity: .65; }
.sub-h { flex-direction: row; align-items: center; gap: 8px; flex-wrap: wrap; color: var(--text); cursor: pointer; }
.sub-n { font-weight: 600; font-size: .9rem; }
.pts { margin: 6px 0 6px 26px; padding-left: 16px; font-size: .85rem; }
.pts li { margin: 2px 0; }
.meta { font-size: .8rem; color: var(--muted); margin-left: 26px; }
.meta.skip { color: var(--warn); }

/* forms */
.form-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 10px; align-items: end; }
.form-grid .full { grid-column: 1 / -1; margin: 0; }

/* chart */
.chart { width: 100%; height: auto; }
.chart .grid-l { stroke: var(--line); }
.chart .target-l { stroke: var(--ok); stroke-dasharray: 5 4; }
.chart .line { fill: none; stroke: var(--accent); stroke-width: 2.5; }
.chart .dot { fill: var(--accent); }
.chart .ax { fill: var(--muted); font-size: 11px; }
.chart .tgt { fill: var(--ok); }

/* errors */
.errs { display: flex; flex-direction: column; gap: 10px; margin-top: 12px; }
.err { border: 1px solid var(--line); border-radius: 10px; padding: 10px 12px; font-size: .88rem; display: flex; flex-direction: column; gap: 4px; }
.err.revised { opacity: .6; }
.err-h { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.rv { flex-direction: row; align-items: center; gap: 4px; margin-left: auto; }

.prompt { white-space: pre-wrap; background: var(--bg); padding: 12px; border-radius: 10px; font-size: .82rem; margin: 0; overflow-x: auto; }

#toast {
  position: fixed; left: 50%; bottom: 20px; transform: translateX(-50%) translateY(20px); opacity: 0; pointer-events: none;
  background: var(--text); color: var(--bg); padding: 10px 16px; border-radius: 10px; font-weight: 600; transition: .2s; z-index: 50;
}
#toast.show { opacity: 1; transform: translateX(-50%); }

/* mock analysis */
.btn[disabled] { opacity: .55; cursor: default; }
.an-ways { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 12px; }
@media (max-width: 760px) { .an-ways { grid-template-columns: 1fr; } }
.way { border: 1px solid var(--line); border-radius: 12px; padding: 12px; display: flex; flex-direction: column; gap: 8px; }
.way p { margin: 0; font-size: .82rem; }
.rules.small { font-size: .82rem; gap: 2px; }
.an-status { font-weight: 600; margin: 10px 0 0; min-height: 1.2em; }
.two-eq { grid-template-columns: 1fr 1fr; margin: 8px 0 12px; }
.two-eq p { margin: 2px 0 0; font-size: .88rem; }
@media (max-width: 640px) { .two-eq { grid-template-columns: 1fr; } }
.lost-row { display: grid; grid-template-columns: minmax(120px, 190px) 1fr 44px; gap: 10px; align-items: center; font-size: .85rem; margin: 6px 0; }
.lost-row b { text-align: right; font-variant-numeric: tabular-nums; }
.bar.bad span { background: var(--bad); }
.bar.warn span { background: var(--warn); }
.bar.ok span { background: var(--ok); }
.buckets { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 12px; }
.bucket { border-radius: 12px; padding: 12px; border: 1px solid var(--line); border-top-width: 4px; }
.bucket.bad { border-top-color: var(--bad); }
.bucket.warn { border-top-color: var(--warn); }
.bucket.ok { border-top-color: var(--ok); }
.bucket h3 { font-size: .92rem; display: flex; gap: 6px; align-items: center; margin-bottom: 6px; }
.bucket ul { margin: 0; padding-left: 18px; display: flex; flex-direction: column; gap: 8px; font-size: .85rem; }
.act { color: var(--accent); font-size: .82rem; margin-top: 2px; }
.qtbl td { font-size: .84rem; }
.qtbl tr.q-wrong td:first-child { box-shadow: inset 3px 0 0 var(--bad); }
.qtbl tr.q-unattempted td:first-child { box-shadow: inset 3px 0 0 var(--warn); }
.qtbl tr.q-correct td:first-child { box-shadow: inset 3px 0 0 var(--ok); }


/* v3: plan, quiz, revision, pomodoro, maps */
.ok-card { border-color: var(--ok); background: linear-gradient(0deg, var(--ok-soft), var(--card) 70%); }
.bad-card { border-color: var(--bad); background: linear-gradient(0deg, var(--bad-soft), var(--card) 70%); }
.warn-text { color: var(--warn); font-weight: 600; }
.btn-row { display: inline-flex; flex-wrap: wrap; gap: 6px; align-items: center; }
.btn.good { background: var(--ok); border-color: var(--ok); }
.btn.bad { background: var(--bad); border-color: var(--bad); }
.btn.warn { background: var(--warn); border-color: var(--warn); }
.btn.on { border-color: var(--bad); color: var(--bad); }
.chip-btn { border: 0; cursor: pointer; font: inherit; font-size: .72rem; font-weight: 700; }
.piece { display: grid; grid-template-columns: auto 1fr auto auto; gap: 10px; align-items: center; padding: 10px 0; border-bottom: 1px solid var(--line); }
.piece:last-child { border-bottom: 0; }
.piece.done .piece-b { opacity: .55; text-decoration: line-through; }
.piece em { font-style: normal; font-size: .75rem; color: var(--muted); white-space: nowrap; }
.piece-b { min-width: 0; font-size: .9rem; }
.rev-row { display: flex; justify-content: space-between; gap: 10px; align-items: center; flex-wrap: wrap; padding: 8px 0; border-bottom: 1px solid var(--line); font-size: .88rem; }
.rev-row:last-child { border-bottom: 0; }
label.rev-row { flex-direction: row; color: var(--text); cursor: pointer; }
.study-row td { font-weight: 600; }
.day-row.sun { opacity: .75; }
.topic.tdone { border-color: var(--ok); }
.empty-card ul { margin: 8px 0; }
.note-card textarea { font-family: inherit; }
details.card summary { cursor: pointer; }

.heat { display: inline-block; padding: 3px 8px; margin: 2px; border-radius: 6px; font-size: .78rem; background: var(--line); color: var(--text); }
.heat.h0 { background: transparent; color: var(--muted); }
.heat.h1 { background: var(--accent-soft); }
.heat.h2 { background: color-mix(in srgb, var(--accent) 35%, var(--card)); }
.heat.h3 { background: color-mix(in srgb, var(--accent) 60%, var(--card)); color: #fff; }
.heat.h4 { background: var(--accent); color: #fff; }
.heat-tbl .subj-row td { background: var(--bg); }

.gantt { display: flex; flex-direction: column; gap: 6px; }
.g-row { display: grid; grid-template-columns: 170px 1fr 170px; gap: 10px; align-items: center; font-size: .82rem; }
.g-track { position: relative; height: 12px; background: var(--line); border-radius: 999px; }
.g-bar { position: absolute; top: 0; bottom: 0; border-radius: 999px; }
.trA, .g-bar.trA { background: var(--d3); }
.trB, .g-bar.trB { background: var(--d2); }
.trG, .g-bar.trG { background: var(--warn); }
.g-key { display: inline-block; width: 12px; height: 12px; border-radius: 3px; vertical-align: middle; margin: 0 4px 0 10px; }
@media (max-width: 640px) { .g-row { grid-template-columns: 1fr; } }

.qcard { display: flex; flex-direction: column; gap: 12px; }
.q-meta { display: flex; flex-wrap: wrap; gap: 6px; align-items: center; }
.q-timer { margin-left: auto; font-weight: 800; font-variant-numeric: tabular-nums; }
.qimg { max-width: 100%; height: auto; border: 1px solid var(--line); border-radius: 10px; background: #fff; }
.qtext { white-space: pre-wrap; font-size: .95rem; line-height: 1.6; }
.opts { display: flex; flex-direction: column; gap: 6px; }
.opt { flex-direction: row; align-items: flex-start; gap: 10px; color: var(--text); font-size: .92rem; border: 1px solid var(--line); border-radius: 10px; padding: 10px 12px; cursor: pointer; }
.opt input { margin-top: 2px; }
.opt-ok { border-color: var(--ok); background: var(--ok-soft); }
.opt-bad { border-color: var(--bad); background: var(--bad-soft); }
.q-res { border: 1px solid var(--line); border-radius: 12px; padding: 12px; }
.q-res p { margin: 6px 0; }

.pomo { display: flex; flex-direction: column; align-items: center; gap: 12px; text-align: center; }
.pomo-time { font-size: 4rem; font-weight: 800; font-variant-numeric: tabular-nums; letter-spacing: .02em; }
.pomo label { width: min(420px, 100%); }

@media print {
  .side, .pills, .btn, #toast { display: none !important; }
  .app { display: block; }
  .card { box-shadow: none; break-inside: avoid; }
  details { display: block; }
}

/* detailed day plan */
.depth-line { display: flex; flex-wrap: wrap; gap: 6px; align-items: center; font-size: .78rem; color: var(--muted); margin: 4px 0; }
.piece .pts { margin: 4px 0 4px 0; }
.piece .meta { margin-left: 0; }
.qchips { display: flex; flex-wrap: wrap; gap: 6px; margin: 6px 0; }
.qchip { border: 1px solid var(--line); background: var(--bg); color: var(--text); border-radius: 8px; padding: 3px 8px; font: inherit; font-size: .78rem; cursor: pointer; }
.qchip small { color: var(--muted); }
.qchip.ok { border-color: var(--ok); background: var(--ok-soft); }
.qchip.bad { border-color: var(--bad); background: var(--bad-soft); }
.kpis .kpi { padding: 4px 0; }

/* PYQ hint / concept / solution */
.xpl { border-top: 1px dashed var(--line); padding-top: 10px; display: flex; flex-direction: column; gap: 8px; }
.xsec { border: 1px solid var(--line); border-radius: 12px; padding: 12px 14px; line-height: 1.6; }
.xsec h3 { margin: 4px 0 8px; font-size: 1rem; }
.xsec h4 { margin: 12px 0 4px; font-size: .95rem; }
.xsec p { margin: 6px 0; }
.xsec ul, .xsec ol { margin: 6px 0 6px 20px; padding: 0; }
.xsec li { margin: 3px 0; }
.xsec code { font-family: ui-monospace, Menlo, Consolas, monospace; font-size: .9em; padding: 1px 4px; border-radius: 4px; background: rgba(127,127,127,.15); }
.xcode { font-family: ui-monospace, Menlo, Consolas, monospace; font-size: .85rem; white-space: pre; overflow-x: auto; padding: 10px; border-radius: 8px; background: rgba(127,127,127,.12); margin: 8px 0; }
.x-hint { border-color: #e6b800; }
.x-sol { border-color: #2e9b5f; }