/* Shared styles for the review engine (skill runner + review home). */
:root{
  --bg:#faf6ef; --surface:#fff; --ink:#2a241f; --ink-2:#5b5349; --muted:#938a7d;
  --line:rgba(42,36,31,.10); --line-soft:rgba(42,36,31,.06);
  --accent:oklch(0.62 0.12 45); --accent-ink:oklch(0.38 0.08 45);
  --indigo:#6366f1; --indigo-soft:#eef2ff; --teal:#0d9488; --teal-soft:#ecfdf5;
  --amber:#c9873a; --amber-soft:#fdf6ec; --rose:#b55a55; --rose-soft:#fbeeed;
  --radius-xl:22px; --radius-md:12px; --radius-sm:8px;
  --shadow-sm:0 1px 2px rgba(42,36,31,.04),0 2px 6px rgba(42,36,31,.04);
  --shadow-md:0 4px 14px rgba(42,36,31,.06),0 12px 32px rgba(42,36,31,.06);
}
*{box-sizing:border-box;}
body{margin:0;font-family:"Inter",Helvetica,Arial,sans-serif;font-size:16px;line-height:1.5;color:var(--ink);background:var(--bg);-webkit-font-smoothing:antialiased;}
.page{max-width:680px;margin:0 auto;padding:24px 22px 90px;}
.math{font-family:"Cambria Math",Georgia,"Times New Roman",serif;}
sup{font-size:.72em;}
.hidden{display:none!important;}
.center{text-align:center;}

.link-back{font-size:14px;font-weight:500;color:var(--muted);text-decoration:none;} .link-back:hover{color:var(--ink);} .link-back::before{content:"\2190  ";}

.head{display:flex;align-items:center;justify-content:space-between;gap:12px;margin:18px 0 6px;flex-wrap:wrap;}
h1.title{font-family:"Fraunces",serif;font-weight:400;font-size:clamp(1.9rem,4.6vw,2.6rem);letter-spacing:-.02em;margin:0;}
h1.title em{font-style:italic;color:var(--accent-ink);font-weight:300;}

/* practice toggle */
.ptoggle{display:inline-flex;align-items:center;gap:8px;font-size:12.5px;color:var(--muted);cursor:pointer;user-select:none;}
.ptoggle input{position:absolute;opacity:0;width:0;height:0;}
.ptoggle .sw{width:38px;height:22px;border-radius:999px;background:var(--line);position:relative;transition:background .15s;flex:none;}
.ptoggle .sw::after{content:"";position:absolute;top:2px;left:2px;width:18px;height:18px;border-radius:50%;background:#fff;box-shadow:var(--shadow-sm);transition:transform .15s;}
.ptoggle input:checked + .sw{background:var(--amber);}
.ptoggle input:checked + .sw::after{transform:translateX(16px);}
.pbanner{display:none;background:var(--amber-soft);border:1px solid var(--amber);color:#8a5a1f;border-radius:var(--radius-md);padding:10px 14px;font-size:13.5px;font-weight:600;margin:10px 0 0;}
.pbanner.show{display:block;}

.stepper{display:flex;gap:8px;margin:16px 0 18px;}
.stepper .s{flex:1;text-align:center;font-size:11px;font-weight:700;text-transform:uppercase;letter-spacing:.06em;color:var(--muted);padding:8px 4px;border-radius:999px;background:var(--line-soft);}
.stepper .s.active{background:var(--ink);color:#fff;}
.stepper .s.done{background:var(--teal-soft);color:#2d6f4b;}

.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-xl);padding:24px;box-shadow:var(--shadow-sm);margin-bottom:16px;}
.rule-name{font-size:12px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--indigo);}
.rule-big{font-family:"Cambria Math",Georgia,serif;font-size:1.9rem;text-align:center;background:var(--indigo-soft);color:#312e81;border-radius:14px;padding:18px 12px;margin:12px 0;}
.rule-plain{color:var(--ink-2);font-size:1.05rem;margin:4px 0 12px;}
.ex{background:#fbfbfd;border:1px dashed var(--line);border-radius:var(--radius-md);padding:14px 16px;}
.ex .etag{font-size:11px;font-weight:800;text-transform:uppercase;letter-spacing:.08em;color:var(--teal);}
.ex .step{font-family:"Cambria Math",Georgia,serif;font-size:1.1rem;margin:6px 0;color:var(--ink-2);}
.ex .step .res{color:var(--teal);font-weight:700;}
.watch{border-left:4px solid var(--amber);background:var(--amber-soft);border-radius:0 10px 10px 0;padding:11px 14px;margin-top:12px;font-size:.95rem;color:#8a5a1f;}
.watch b{color:#6f4518;}

/* inline teaching diagrams (SVG) */
.diagram{margin:14px 0;padding:16px 14px;background:#fff;border:1px solid var(--line);border-radius:var(--radius-md);text-align:center;}
.diagram svg{max-width:100%;height:auto;display:block;margin:0 auto;}
.diagram img{max-width:100%;height:auto;display:block;margin:0 auto;border-radius:10px;}
.diagram .legend{display:flex;flex-wrap:wrap;gap:14px;justify-content:center;margin-top:12px;font-size:12px;color:var(--ink-2);}
.diagram .legend span{display:inline-flex;align-items:center;gap:6px;}
.diagram .legend i{width:12px;height:12px;border-radius:3px;display:inline-block;}
.diagram .cap{font-size:12px;color:var(--muted);margin-top:8px;}
/* hover-highlight for labeled SVG parts */
.diagram .node{cursor:default;transition:opacity .15s, transform .15s;}
.diagram .node:hover{opacity:.85;}
.diagram text{font-family:"Inter",sans-serif;}

.q-prompt{font-family:"Cambria Math",Georgia,serif;font-size:1.3rem;text-align:center;margin:6px 0 18px;color:var(--ink);}
.q-prompt.words{font-family:"Inter",sans-serif;font-size:1.08rem;text-align:left;line-height:1.55;}
.opts{display:grid;gap:10px;}
.opt{font:inherit;font-family:"Cambria Math",Georgia,serif;font-size:1.15rem;text-align:left;cursor:pointer;background:var(--surface);border:1.5px solid var(--line);border-radius:var(--radius-md);padding:14px 16px;transition:all .12s;color:var(--ink);}
.opt.words{font-family:"Inter",sans-serif;font-size:1rem;}
.opt:hover{border-color:var(--ink);}
.opt.sel{border-color:var(--indigo);background:var(--indigo-soft);}
.opt.correct{border-color:var(--teal);background:var(--teal-soft);color:#2d6f4b;}
.opt.wrong{border-color:var(--rose);background:var(--rose-soft);color:#8f4545;}
.opt:disabled{cursor:default;}
.fb{margin-top:14px;padding:13px 16px;border-radius:var(--radius-md);font-size:.97rem;display:none;}
.fb.show{display:block;}
.fb.ok{background:var(--teal-soft);color:#2d6f4b;}
.fb.no{background:var(--rose-soft);color:#8f4545;}
.fb b{font-weight:700;}
.reinforce-note{font-size:12px;color:var(--amber);font-weight:600;margin-bottom:8px;}

.btn{font:inherit;cursor:pointer;border:1px solid var(--ink);background:var(--ink);color:var(--bg);padding:13px 26px;border-radius:999px;font-weight:600;font-size:15px;transition:background .15s,transform .12s;text-decoration:none;display:inline-block;}
.btn:hover{background:var(--accent-ink);border-color:var(--accent-ink);}
.btn:active{transform:translateY(1px);}
.btn:disabled{opacity:.45;cursor:not-allowed;}
.btn.ghost{background:transparent;color:var(--ink-2);border-color:var(--line);}
.btn.ghost:hover{color:var(--ink);border-color:var(--ink);}
.actions{display:flex;justify-content:space-between;align-items:center;gap:10px;margin-top:18px;}
.progress-note{font-size:13px;color:var(--muted);}

.big-emoji{font-size:3rem;text-align:center;margin:6px 0;}
h2.sect{font-family:"Fraunces",serif;font-weight:400;font-size:1.5rem;letter-spacing:-.01em;margin:0 0 4px;}
.sub{color:var(--ink-2);margin:0 0 16px;}
.scorebig{font-family:"Fraunces",serif;font-size:3rem;color:var(--ink);text-align:center;margin:6px 0 0;}

/* ---------- review home (journey) ---------- */
.tag{font-size:11px;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:#fff;background:var(--ink);padding:4px 10px;border-radius:999px;}
.lede{color:var(--ink-2);margin:14px 0 22px;}
.day-head{display:flex;align-items:center;gap:10px;margin:26px 2px 12px;}
.day-head .dtag{font-size:11px;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:#fff;background:var(--ink);padding:4px 10px;border-radius:999px;}
.day-head h2{font-family:"Fraunces",serif;font-weight:400;font-size:1.3rem;margin:0;letter-spacing:-.01em;}
.day-head .dprog{margin-left:auto;font-size:12px;color:var(--muted);font-weight:600;}
.skill{display:grid;grid-template-columns:auto 1fr auto;align-items:center;gap:16px;padding:18px 20px;border:1px solid var(--line);border-radius:var(--radius-xl);background:var(--surface);text-decoration:none;color:inherit;margin-bottom:11px;transition:transform .16s,border-color .16s,box-shadow .16s;}
a.skill:hover{transform:translateY(-1px);border-color:var(--ink);box-shadow:var(--shadow-md);}
.skill.locked{opacity:.55;}
.badge{width:38px;height:38px;border-radius:11px;display:grid;place-items:center;font-size:1.15rem;flex:none;background:var(--line-soft);font-weight:700;color:var(--ink-2);}
.badge.done{background:var(--teal-soft);color:#2d6f4b;}
.s-label{font-family:"Fraunces",serif;font-weight:400;font-size:1.25rem;letter-spacing:-.01em;}
.s-meta{font-size:13px;color:var(--muted);margin-top:2px;}
.pill{font-size:11px;font-weight:700;letter-spacing:.05em;text-transform:uppercase;padding:4px 10px;border-radius:999px;white-space:nowrap;}
.pill.open{background:#312e81;color:#fff;}
.pill.done{background:var(--teal-soft);color:#2d6f4b;}
.pill.soon{background:var(--line-soft);color:var(--muted);}
.pill.locked{background:var(--line-soft);color:var(--muted);}
.foot{margin-top:24px;font-size:13px;color:var(--muted);line-height:1.6;}