/* MathMind — dark, editorial, mobile-first.
   Design language: near-black blue ground with a violet-blue accent gradient,
   serif math typography against a geometric sans UI, soft depth via layered
   shadows and 1px top-edge highlights. No external assets — everything inline. */

:root {
  --bg: #0a0e14;
  --bg-raise: #0e131b;
  --surface: #131a24;
  --surface-2: #1a2330;
  --border: #263243;
  --border-lit: rgba(255, 255, 255, 0.06);
  --text: #eceff3;
  --muted: #8a96a6;
  --faint: #5c6878;
  --accent: #5b9dff;
  --accent-2: #8b7cff;
  --grad: linear-gradient(120deg, #5b9dff, #8b7cff);
  --accent-dim: rgba(91, 157, 255, 0.13);
  --good: #43c380;
  --bad: #ef5f57;
  --warn: #d9a03e;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(0,0,0,.35), 0 8px 24px -12px rgba(0,0,0,.5);
  --math-font: 'STIX Two Math', 'Cambria Math', 'Times New Roman', Georgia, serif;
  --serif: ui-serif, 'Iowan Old Style', 'Palatino Linotype', Palatino, Georgia, serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  background:
    radial-gradient(1200px 500px at 50% -180px, rgba(91, 157, 255, 0.09), transparent 65%),
    radial-gradient(900px 400px at 110% 15%, rgba(139, 124, 255, 0.05), transparent 60%),
    var(--bg);
  background-attachment: fixed;
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
  line-height: 1.5;
  min-height: 100dvh;
  overscroll-behavior-y: none;
  -webkit-tap-highlight-color: transparent;
}

button { font: inherit; color: inherit; background: none; border: none; cursor: pointer; }
kbd.kbd-hint {
  font: 600 0.62rem/1 -apple-system, sans-serif;
  border: 1px solid rgba(255,255,255,.35);
  border-radius: 4px;
  padding: 2px 5px;
  margin-left: 8px;
  opacity: 0.65;
  vertical-align: 1px;
  display: none; /* desktop only */
}

/* ---------- math typography ---------- */

.m { font-family: var(--math-font); font-style: italic; }
.m b { font-style: normal; }
.m sub, .m sup { font-size: 0.62em; font-style: normal; }

.bigop { font-style: normal; font-size: 1.25em; }

.frac-v {
  display: inline-flex;
  flex-direction: column;
  vertical-align: middle;
  text-align: center;
  font-size: 0.85em;
  margin: 0 0.15em;
}
.frac-v > span:first-child { border-bottom: 1px solid currentColor; padding: 0 0.25em 0.05em; }
.frac-v > span:last-child { padding: 0 0.25em; }

.frac {
  display: inline-flex;
  flex-direction: column;
  vertical-align: middle;
  text-align: center;
  font-size: 0.8em;
  line-height: 1.15;
  margin: 0 0.05em;
}

.paren { font-size: 1.4em; font-weight: 300; vertical-align: middle; }

/* ---------- chrome ---------- */

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(38, 50, 67, 0.6);
  padding-top: env(safe-area-inset-top);
}
.topbar-inner {
  max-width: 680px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 16px;
}
.brand { font-weight: 700; font-size: 1.12rem; letter-spacing: -0.02em; display: inline-flex; align-items: center; }
.brand-sigma { margin-right: 7px; }
.brand-small { font-size: 0.98rem; }
.brand-sigma {
  font-size: 1.02em;
  font-style: normal;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  transform: translateY(-1px);
}
.brand-accent {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.topbar-right { display: flex; align-items: center; gap: 6px; }

.iconbtn {
  min-width: 40px;
  height: 40px;
  border-radius: 11px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--muted);
  transition: color .12s, background .12s;
}
.iconbtn:active { background: var(--surface); color: var(--text); }

/* bottom tab bar */
.tabbar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 10;
  display: flex;
  justify-content: center;
  gap: 4px;
  background: color-mix(in srgb, var(--bg) 84%, transparent);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border-top: 1px solid rgba(38, 50, 67, 0.6);
  padding: 6px 10px calc(6px + env(safe-area-inset-bottom));
}
.tab {
  flex: 1;
  max-width: 130px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  padding: 5px 0 3px;
  border-radius: 11px;
  color: var(--faint);
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: color .12s;
}
.tab svg { display: block; }
.tab-active { color: var(--text); }
.tab-active svg { color: var(--accent); }

.page {
  max-width: 680px;
  margin: 0 auto;
  padding: 22px 18px calc(48px + env(safe-area-inset-bottom));
}
.page.has-tabbar { padding-bottom: calc(96px + env(safe-area-inset-bottom)); }

.view-title { font-size: 1.5rem; letter-spacing: -0.025em; margin-bottom: 2px; }
.view-sub { color: var(--muted); font-size: 0.9rem; margin-bottom: 16px; }

/* ---------- welcome ---------- */

.welcome {
  position: relative;
  overflow: hidden;
  background: linear-gradient(160deg, var(--surface), var(--bg-raise));
  border: 1px solid var(--border);
  border-top-color: var(--border-lit);
  border-radius: 18px;
  box-shadow: var(--shadow);
  padding: 26px 22px;
  margin-bottom: 26px;
}
.welcome-glyph {
  position: absolute;
  right: -22px;
  top: -38px;
  font-size: 11rem;
  font-style: normal;
  color: transparent;
  background: linear-gradient(150deg, rgba(91,157,255,.16), rgba(139,124,255,.03));
  -webkit-background-clip: text;
  background-clip: text;
  pointer-events: none;
  user-select: none;
}
.welcome h1 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 1.7rem;
  line-height: 1.2;
  letter-spacing: -0.015em;
  margin-bottom: 10px;
}
.welcome h1 em { font-style: italic; color: var(--accent); }
.welcome p { color: var(--muted); font-size: 0.92rem; margin-bottom: 18px; max-width: 46ch; }
.welcome input { margin-bottom: 10px; }

/* ---------- hero ---------- */

.hero { position: relative; margin-bottom: 30px; }
.hero-glyph {
  position: absolute;
  right: -10px;
  top: -26px;
  font-size: 9rem;
  font-style: normal;
  line-height: 1;
  color: transparent;
  background: linear-gradient(155deg, rgba(91,157,255,.13), rgba(139,124,255,.02));
  -webkit-background-clip: text;
  background-clip: text;
  pointer-events: none;
  user-select: none;
}
.hero-track { display: flex; align-items: baseline; gap: 10px; }
.hero-label { color: var(--faint); font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.14em; font-weight: 700; }
.track-pill {
  font-family: var(--serif);
  font-size: 1.85rem;
  font-weight: 650;
  letter-spacing: -0.02em;
  padding: 0;
}
.pill-chev { color: var(--faint); font-weight: 400; }
.track-pill:active .pill-chev, .track-pill:hover .pill-chev { color: var(--accent); }
.hero-tag { color: var(--muted); margin-top: 2px; font-size: 0.92rem; }

.statline { display: flex; gap: 10px; margin: 18px 0 14px; }
.statline + .statline { margin-top: -4px; }
.stat {
  flex: 1;
  background: linear-gradient(170deg, var(--surface), var(--bg-raise));
  border: 1px solid var(--border);
  border-top-color: var(--border-lit);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 11px 13px;
  display: flex;
  flex-direction: column;
}
.stat b { font-size: 1.4rem; font-weight: 700; letter-spacing: -0.02em; font-variant-numeric: tabular-nums; }
.stat b i { font-style: normal; font-size: 0.85rem; color: var(--faint); font-weight: 600; }
.stat span { color: var(--muted); font-size: 0.76rem; }

.all-clear { color: var(--muted); text-align: center; padding: 10px 0; font-size: 0.92rem; }

/* ---------- levels & rows ---------- */

.level { margin-bottom: 34px; }
.level-head { display: flex; gap: 14px; margin-bottom: 13px; align-items: baseline; }
.level-num {
  font-family: var(--serif);
  font-size: 1.6rem;
  font-weight: 650;
  line-height: 1;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  min-width: 40px;
}
.level h2 { font-size: 1.08rem; font-weight: 700; letter-spacing: -0.01em; }
.section-title { font-size: 1.02rem; font-weight: 700; letter-spacing: -0.01em; margin-bottom: 8px; }
.level-desc { color: var(--muted); font-size: 0.86rem; margin: 2px 0 10px; }

.rows { display: flex; flex-direction: column; gap: 9px; }

/* "Why this matters" panel */
.why {
  background: var(--accent-dim);
  border: 1px solid color-mix(in srgb, var(--accent) 22%, var(--border));
  border-radius: 12px;
  margin-bottom: 12px;
  overflow: hidden;
}
.why summary {
  list-style: none;
  cursor: pointer;
  padding: 10px 14px;
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  display: flex;
  align-items: center;
  gap: 8px;
}
.why summary::-webkit-details-marker { display: none; }
.why summary::before { content: '◇'; font-size: 0.85em; }
.why[open] summary::before { content: '◆'; }
.why p {
  padding: 0 14px 13px;
  color: var(--text);
  font-size: 0.9rem;
  line-height: 1.55;
  opacity: 0.92;
}

.primer-link {
  display: block;
  width: 100%;
  text-align: center;
  color: var(--muted);
  font-size: 0.86rem;
  padding: 10px 0 0;
}
.primer-link b { color: var(--accent); font-weight: 650; }
.primer-row { margin-bottom: 16px; }

.primer-sec { margin-bottom: 26px; }
.primer-p { color: var(--muted); font-size: 0.92rem; line-height: 1.6; margin-bottom: 10px; }
.primer-p b, .primer-list b { color: var(--text); }
.primer-list { padding-left: 22px; color: var(--muted); font-size: 0.92rem; line-height: 1.6; display: flex; flex-direction: column; gap: 8px; margin-bottom: 10px; }

.row {
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
  text-align: left;
  background: linear-gradient(170deg, var(--surface), var(--bg-raise));
  border: 1px solid var(--border);
  border-top-color: var(--border-lit);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 13px 15px;
  transition: border-color .15s, transform .06s;
}
.row:active { transform: scale(0.99); }
.row-active { border-color: var(--accent); }
.row-main { flex: 1; min-width: 0; }
.row-title { font-weight: 600; font-size: 0.95rem; }
.row-title .tag {
  font-size: 0.66rem;
  font-weight: 700;
  color: var(--accent);
  background: var(--accent-dim);
  border-radius: 5px;
  padding: 1px 6px;
  vertical-align: middle;
  letter-spacing: 0.04em;
}
.row-meta { display: flex; gap: 10px; color: var(--muted); font-size: 0.78rem; margin-top: 2px; flex-wrap: wrap; }
.row-side { flex-shrink: 0; }
.check { color: var(--accent); font-size: 1.1rem; }

.due-chip { color: var(--warn); font-weight: 650; }
.quiz-chip { color: var(--accent); font-weight: 650; }

.ring {
  --pct: 0;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background:
    radial-gradient(closest-side, var(--surface) 72%, transparent 73% 100%),
    conic-gradient(#5b9dff calc(var(--pct) * 1%), #8b7cff calc(var(--pct) * 1%), var(--surface-2) calc(var(--pct) * 1% + 0.5%));
  display: flex;
  align-items: center;
  justify-content: center;
}
.ring span { font-size: 0.7rem; color: var(--muted); font-weight: 700; font-variant-numeric: tabular-nums; }

/* ---------- buttons ---------- */

.btn {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-top-color: var(--border-lit);
  border-radius: var(--radius);
  padding: 13px 18px;
  font-weight: 650;
  font-size: 0.95rem;
  transition: filter .12s, transform .05s, box-shadow .15s;
}
.btn:active { transform: scale(0.985); filter: brightness(1.15); }
.btn-primary {
  background: var(--grad);
  border-color: transparent;
  color: #fff;
  text-shadow: 0 1px 2px rgba(0,0,0,.2);
}
.btn-glow { box-shadow: 0 4px 24px -6px rgba(91, 157, 255, 0.45); }
.btn-wide { width: 100%; display: block; }
.btn-danger { color: var(--bad); border-color: color-mix(in srgb, var(--bad) 40%, var(--border)); }
.btn-ghosted { opacity: 0.55; }
.actions { display: flex; flex-direction: column; gap: 10px; margin: 18px 0 14px; }
.actions-row { flex-direction: row; }
.actions-row .btn { flex: 1; }

/* ---------- sublevel ---------- */

.sub-head { margin-bottom: 16px; }
.crumb { color: var(--faint); font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.1em; font-weight: 650; }
.sub-head h1 { font-family: var(--serif); font-size: 1.5rem; letter-spacing: -0.02em; margin: 3px 0 7px; font-weight: 650; }
.sub-stats { display: flex; gap: 12px; color: var(--muted); font-size: 0.85rem; flex-wrap: wrap; }

.sym-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(52px, 1fr));
  gap: 7px;
  margin: 14px 0;
}
.sym-cell {
  aspect-ratio: 1;
  background: linear-gradient(170deg, var(--surface), var(--bg-raise));
  border: 1px solid var(--border);
  border-top-color: var(--border-lit);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  font-size: 1.15rem;
  color: var(--muted);
  padding: 3px;
}
.sym-cell .m { font-size: inherit; white-space: nowrap; transform: scale(0.9); }
.dot-seen { color: var(--text); border-color: #3a4654; }
.dot-mastered {
  color: var(--accent);
  border-color: color-mix(in srgb, var(--accent) 45%, var(--border));
  background: var(--accent-dim);
  box-shadow: 0 0 14px -4px rgba(91, 157, 255, 0.35);
}

.hint { color: var(--muted); font-size: 0.85rem; }

/* ---------- session ---------- */

.session-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 8px;
}
.session-kind { color: var(--faint); font-size: 0.74rem; text-transform: uppercase; letter-spacing: 0.14em; font-weight: 700; }
.session-progress { color: var(--muted); font-variant-numeric: tabular-nums; font-size: 0.88rem; }

.pbar {
  height: 3px;
  border-radius: 2px;
  background: var(--surface-2);
  overflow: hidden;
  margin-bottom: 14px;
}
.pbar-fill { height: 100%; background: var(--grad); border-radius: 2px; transition: width .25s ease; }

.mode-tabs {
  display: flex;
  background: var(--bg-raise);
  border: 1px solid var(--border);
  border-radius: 11px;
  padding: 3px;
  margin-bottom: 14px;
}
.mode-tab {
  flex: 1;
  padding: 8px 0;
  border-radius: 8px;
  color: var(--muted);
  font-size: 0.85rem;
  font-weight: 650;
  transition: color .12s, background .12s;
}
.mode-tab.active { background: var(--surface-2); color: var(--text); box-shadow: 0 1px 3px rgba(0,0,0,.3); }

.card {
  background: linear-gradient(165deg, var(--surface), var(--bg-raise));
  border: 1px solid var(--border);
  border-top-color: var(--border-lit);
  border-radius: 18px;
  box-shadow: var(--shadow);
  padding: 22px 18px;
}
.card-enter { animation: card-in .22s ease-out; }
@keyframes card-in {
  from { opacity: 0; transform: translateY(7px); }
  to { opacity: 1; transform: none; }
}
.card-front {
  font-size: 2.05rem;
  text-align: center;
  padding: 28px 6px 36px;
  overflow-x: auto;
}
.card-front-prose { font-size: 1.15rem; font-weight: 550; padding: 14px 4px 26px; text-align: left; line-height: 1.45; }

.answer { border-top: 1px solid var(--border); padding-top: 16px; margin-top: 4px; }
.answer-b { font-weight: 650; font-size: 1.05rem; }
.answer-notation { font-size: 1.4rem; padding: 6px 0; overflow-x: auto; }
.answer-p { color: var(--muted); font-size: 0.9rem; margin-top: 7px; }

.grade-row { display: flex; gap: 8px; margin-top: 16px; }
.grade { flex: 1; padding: 12px 4px; font-size: 0.88rem; }
.grade-again { color: var(--bad); }
.grade-hard { color: var(--warn); }
.grade-good { color: var(--good); }
.grade-easy { color: var(--accent); }
.grade-continue { flex: 2; color: #fff; }

.opts { display: flex; flex-direction: column; gap: 8px; }
.opt {
  text-align: left;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-top-color: var(--border-lit);
  border-radius: var(--radius);
  padding: 12px 14px;
  font-size: 0.92rem;
  transition: border-color .12s;
}
.opt:disabled { cursor: default; }
.opt-correct { border-color: var(--good); background: color-mix(in srgb, var(--good) 13%, var(--surface-2)); }
.opt-wrong { border-color: var(--bad); background: color-mix(in srgb, var(--bad) 13%, var(--surface-2)); }
.opt-body.m { font-size: 1.15rem; }

.verdict { font-weight: 750; margin: 14px 0 8px; letter-spacing: -0.01em; }
.verdict-ok { color: var(--good); }
.verdict-no { color: var(--bad); }

.typed-input, .name-input {
  width: 100%;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font: inherit;
  font-size: 1rem;
  padding: 13px 14px;
}
.typed-input { margin-bottom: 10px; }
.typed-input:focus, .name-input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(91,157,255,.15); }
.input-correct { border-color: var(--good); }
.input-wrong { border-color: var(--bad); }

.palette {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(38px, 1fr));
  gap: 5px;
  margin-bottom: 12px;
  max-height: 132px;
  overflow-y: auto;
  border: 1px solid var(--border);
  border-radius: 11px;
  padding: 6px;
  background: var(--bg);
}
.pal {
  aspect-ratio: 1;
  border-radius: 8px;
  background: var(--surface-2);
  font-family: var(--math-font);
  font-size: 1.05rem;
  display: flex;
  align-items: center;
  justify-content: center;
}
.pal:active { background: var(--accent-dim); }

/* ---------- session end ---------- */

.end-panel { text-align: center; padding-top: 11vh; }
.end-headline {
  font-family: var(--serif);
  font-size: 3rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.end-headline.good { background: none; -webkit-background-clip: unset; background-clip: unset; color: var(--good); }
.end-headline.bad { background: none; -webkit-background-clip: unset; background-clip: unset; color: var(--bad); }
.end-detail { color: var(--muted); margin-top: 6px; }
.end-panel .actions { max-width: 340px; margin: 26px auto 0; }

/* ---------- library ---------- */

.searchbox {
  display: flex;
  align-items: center;
  gap: 9px;
  background: var(--bg-raise);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0 13px;
  color: var(--faint);
  margin-bottom: 18px;
}
.searchbox input {
  flex: 1;
  background: none;
  border: none;
  color: var(--text);
  font: inherit;
  font-size: 0.95rem;
  padding: 12px 0;
}
.searchbox input:focus { outline: none; }
.searchbox:focus-within { border-color: var(--accent); }

.lib-group {
  color: var(--faint);
  font-size: 0.76rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-weight: 700;
  margin: 20px 0 8px;
}
.lib-item {
  background: linear-gradient(170deg, var(--surface), var(--bg-raise));
  border: 1px solid var(--border);
  border-top-color: var(--border-lit);
  border-radius: 12px;
  margin-bottom: 7px;
  overflow: hidden;
}
.lib-item summary {
  list-style: none;
  cursor: pointer;
  padding: 12px 15px;
  display: flex;
  align-items: center;
}
.lib-item summary::-webkit-details-marker { display: none; }
.lib-front { font-size: 1.2rem; overflow-x: auto; white-space: nowrap; }
.lib-prose { font-size: 0.9rem; white-space: normal; font-weight: 550; }
.lib-body { padding: 0 15px 13px; border-top: 1px solid var(--border); padding-top: 11px; }
.lib-mastered { border-left: 2px solid var(--accent); }

/* ---------- account ---------- */

.account-head { display: flex; align-items: center; gap: 15px; margin: 6px 0 26px; }
.avatar {
  width: 58px;
  height: 58px;
  border-radius: 50%;
  background: var(--grad);
  color: #fff;
  font-family: var(--serif);
  font-size: 1.7rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 20px -6px rgba(91, 157, 255, 0.5);
  flex-shrink: 0;
}
.account-id { flex: 1; min-width: 0; }
.name-input {
  background: transparent;
  border-color: transparent;
  font-family: var(--serif);
  font-size: 1.45rem;
  font-weight: 650;
  letter-spacing: -0.02em;
  padding: 2px 6px;
  margin-left: -6px;
  border-radius: 8px;
}
.name-input:hover, .name-input:focus { border-color: var(--border); background: var(--bg-raise); }
.account-meta { display: flex; gap: 10px; align-items: center; color: var(--muted); font-size: 0.82rem; margin-top: 2px; }
.tier-badge {
  font-size: 0.68rem;
  font-weight: 750;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  background: var(--accent-dim);
  border: 1px solid color-mix(in srgb, var(--accent) 35%, transparent);
  border-radius: 6px;
  padding: 2px 7px;
}

.heat { margin-top: 12px; display: flex; align-items: center; gap: 12px; }
.heat-label { color: var(--faint); font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.09em; font-weight: 650; flex-shrink: 0; }
.heat-row { display: flex; gap: 4px; flex: 1; }
.heat-cell {
  flex: 1;
  height: 26px;
  border-radius: 5px;
  background: color-mix(in srgb, var(--accent) calc(var(--h) * 80%), var(--surface-2));
  border: 1px solid var(--border);
}

/* ---------- installer (mobile.mathmind.science) ---------- */

.installer { padding-top: 9vh; max-width: 480px; }
.inst-icon {
  width: 76px;
  height: 76px;
  border-radius: 18px;
  background: linear-gradient(160deg, var(--surface), var(--bg-raise));
  border: 1px solid var(--border);
  border-top-color: var(--border-lit);
  box-shadow: var(--shadow), 0 8px 32px -8px rgba(91, 157, 255, 0.35);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.6rem;
  font-style: normal;
  background-clip: padding-box;
  color: transparent;
  margin-bottom: 16px;
}
.inst-icon::before { content: '∑'; background: var(--grad); -webkit-background-clip: text; background-clip: text; }
.inst-tag {
  color: var(--faint);
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-weight: 700;
}
.installer h1 {
  font-family: var(--serif);
  font-size: 1.75rem;
  font-weight: 650;
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin: 6px 0 8px;
}
.inst-sub { color: var(--muted); margin-bottom: 18px; }
.inst-sub a, .fine a { color: var(--accent); text-decoration: none; }
.inst-btn { margin-bottom: 14px; text-align: center; text-decoration: none; }
.inst-note { color: var(--muted); font-size: 0.88rem; margin-top: 14px; }

.steps {
  list-style: none;
  counter-reset: step;
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 6px 0;
}
.steps li {
  counter-increment: step;
  position: relative;
  background: linear-gradient(170deg, var(--surface), var(--bg-raise));
  border: 1px solid var(--border);
  border-top-color: var(--border-lit);
  border-radius: var(--radius);
  padding: 13px 15px 13px 46px;
  font-size: 0.95rem;
  line-height: 1.45;
}
.steps li::before {
  content: counter(step);
  position: absolute;
  left: 16px;
  top: 12px;
  font-family: var(--serif);
  font-weight: 700;
  color: var(--accent);
}
.share-glyph {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.35em;
  height: 1.35em;
  border: 1.5px solid var(--accent);
  border-radius: 5px;
  color: var(--accent);
  font-weight: 700;
  font-size: 0.85em;
  vertical-align: -0.2em;
}
.url-chip {
  font-family: ui-monospace, Menlo, monospace;
  font-size: 0.88em;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 7px;
  padding: 2px 7px;
}
.link-btn {
  color: var(--accent);
  font-weight: 650;
  text-decoration: underline;
  text-underline-offset: 3px;
  padding: 0;
}
.copy-ok { color: var(--good); font-size: 0.85rem; }
.fine { color: var(--faint); font-size: 0.84rem; margin-top: 26px; }

/* ---------- signup form ---------- */

.hp-field {
  position: absolute;
  left: -9999px;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}
.form-status { font-size: 0.86rem; margin-top: 8px; color: var(--muted); min-height: 1.2em; }
.form-status.err { color: var(--bad); }
.form-status.ok { color: var(--good); }
.gsi-slot { margin: 10px 0 4px; min-height: 44px; }
.row-static { cursor: default; }

.login-divider {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--faint);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin: 14px 0;
}
.login-divider::before, .login-divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}
#magic-form .typed-input { margin-bottom: 10px; }

.end-wall-note {
  color: var(--muted);
  font-size: 0.92rem;
  max-width: 380px;
  margin: 14px auto 0;
}

/* ---------- settings ---------- */

.settings-tabs { max-width: 360px; }

/* ---------- desktop ---------- */

@media (min-width: 700px) {
  .page { padding-top: 34px; }
  kbd.kbd-hint { display: inline-block; }
  .row:hover { border-color: color-mix(in srgb, var(--accent) 45%, var(--border)); }
  .btn:hover { filter: brightness(1.12); }
  .btn-glow:hover { box-shadow: 0 6px 30px -6px rgba(91, 157, 255, 0.55); }
  .opt:not(:disabled):hover { border-color: var(--accent); }
  .mode-tab:hover { color: var(--text); }
  .iconbtn:hover { background: var(--surface); color: var(--text); }
  .pal:hover { background: var(--accent-dim); }
  .tab:hover { color: var(--text); }
  .lib-item summary:hover { background: rgba(255,255,255,0.02); }
  .card { padding: 32px 30px; }
  .card-front { font-size: 2.4rem; }
  .sym-grid { grid-template-columns: repeat(auto-fill, minmax(58px, 1fr)); }
  .tabbar {
    left: 50%;
    right: auto;
    transform: translateX(-50%);
    bottom: 18px;
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 6px 8px;
    width: 380px;
    box-shadow: var(--shadow);
  }
}