/* ============================================================
   Examly Web — shared design system (teal / cream)
   Extracted from the production app screenshots.
   ============================================================ */
@import url('https://fonts.googleapis.com/css2?family=Nunito:wght@400;500;600;700;800;900&family=Noto+Sans+TC:wght@400;500;600;700;800;900&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
  /* ---- brand / teal ---- */
  --teal:        #0E7C6F;
  --teal-700:    #0A5F55;
  --teal-600:    #0C6E62;
  --teal-300:    #5FA89E;
  --teal-100:    #CFE6E1;
  --teal-50:     #E7F2EF;
  --banner-from: #167A6F;
  --banner-to:   #0A554C;

  /* ---- ink / neutrals (warm green-black) ---- */
  --ink:      #1C2B29;
  --ink-2:    #3C4A47;
  --muted:    #8A938F;
  --faint:    #AAB2AD;
  --page:     #F5F6F3;
  --surface:  #FFFFFF;
  --raised:   #FBFBF8;
  --sunk:     #F0F2EE;
  --line:     #ECEEEA;
  --line-2:   #E1E4DF;

  /* ---- semantic accents ---- */
  --gold:     #E3A815;  --gold-bg: #FCF1CC;  --gold-ink: #7A5A12;
  --coral:    #EE6C4D;  --coral-bg:#FCE7E0;  --coral-ink:#C1492C;
  --green:    #3E9D58;  --green-bg:#E8F3E6;  --green-ink:#2E6B3C;
  --purple:   #7C4DB8;  --purple-bg:#EEE5F8; --purple-ink:#5A3690;
  --amber:    #DC9A30;  --amber-bg:#FBEFCB;  --amber-ink:#7A5712;

  /* ---- type families ---- */
  --font: 'Noto Sans TC','Nunito',system-ui,-apple-system,'PingFang TC','Microsoft JhengHei',sans-serif;
  --font-num: 'Nunito','Noto Sans TC',system-ui,sans-serif;
  --font-mono: 'JetBrains Mono',ui-monospace,Menlo,monospace;

  /* ---- tweakables (overridden by shell from localStorage) ---- */
  --ts: 1;          /* text scale */
  --rm: 1;          /* radius multiplier */
  --dens: 1;        /* density multiplier for padding/gap */

  /* ---- radii ---- */
  --r-xs:  calc(8px  * var(--rm));
  --r-sm:  calc(12px * var(--rm));
  --r-md:  calc(16px * var(--rm));
  --r-lg:  calc(22px * var(--rm));
  --r-xl:  calc(28px * var(--rm));
  --r-pill: 999px;

  /* ---- spacing built around density ---- */
  --card-pad: calc(22px * var(--dens));
  --gap:      calc(20px * var(--dens));
  --gap-sm:   calc(12px * var(--dens));

  /* ---- shadows (soft, cool-neutral) ---- */
  --sh-xs: 0 1px 2px rgba(22,42,38,.05);
  --sh-sm: 0 1px 2px rgba(22,42,38,.04), 0 4px 14px rgba(22,42,38,.05);
  --sh-md: 0 2px 6px rgba(22,42,38,.06), 0 10px 28px rgba(22,42,38,.08);
  --sh-pop: 0 12px 40px rgba(22,42,38,.16);

  --ease: cubic-bezier(.2,.7,.2,1);
  --ease-spring: cubic-bezier(.34,1.4,.5,1);

  --sidebar-w: 248px;
  --sidebar-collapsed: 76px;
}

* { box-sizing: border-box; }
html { color-scheme: light; font-size: calc(16px * var(--ts)); }
body {
  margin: 0;
  font-family: var(--font);
  font-size: 0.9375rem;          /* 15px @ ts=1 */
  line-height: 1.6;
  color: var(--ink);
  background: var(--page);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}
h1,h2,h3,h4 { margin: 0; font-weight: 800; line-height: 1.2; letter-spacing: -0.01em; color: var(--ink); }
p { margin: 0; text-wrap: pretty; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; }
.tnum { font-variant-numeric: tabular-nums; font-family: var(--font-num); }
.mono { font-family: var(--font-mono); }

/* ============================================================
   App shell layout
   ============================================================ */
.app {
  min-height: 100vh;
  display: grid;
  grid-template-columns: var(--sidebar-w) 1fr;
  transition: grid-template-columns .26s var(--ease);
}
.app.collapsed { grid-template-columns: var(--sidebar-collapsed) 1fr; }

/* ---- sidebar ---- */
.sidebar {
  position: sticky; top: 0; height: 100vh;
  background: var(--surface);
  border-right: 1px solid var(--line);
  display: flex; flex-direction: column;
  padding: 18px 14px;
  z-index: 40;
}
.sb-logo {
  display: flex; align-items: center; gap: 10px;
  padding: 6px 8px 18px; min-height: 44px;
}
.sb-logo img { width: 36px; height: 36px; flex-shrink: 0; }
.sb-logo .word { font-weight: 900; font-size: 1.3rem; letter-spacing: -0.02em; color: var(--ink); }
.collapsed .sb-logo .word, .collapsed .sb-cta span, .collapsed .nav-item span,
.collapsed .sb-foot .uinfo, .collapsed .sb-section, .collapsed .sb-collapse span { display: none; }
.collapsed .sb-logo { justify-content: center; padding-left: 0; padding-right: 0; }

.sb-cta {
  display: flex; align-items: center; justify-content: center; gap: 8px;
  background: var(--teal); color: #fff; font-weight: 800;
  border: none; border-radius: var(--r-md);
  padding: 13px 16px; cursor: pointer; font-size: 0.95rem;
  box-shadow: 0 2px 8px rgba(14,124,111,.28);
  transition: background .14s var(--ease), transform .12s var(--ease);
  margin-bottom: 16px;
}
.sb-cta:hover { background: var(--teal-700); }
.sb-cta svg { width: 20px; height: 20px; flex-shrink: 0; }
.sb-cta:active { transform: scale(.98); }
.collapsed .sb-cta { padding: 13px 0; }

.sb-section { font-size: 0.7rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase;
  color: var(--faint); padding: 4px 12px; margin-top: 8px; }
.nav { display: flex; flex-direction: column; gap: 3px; }
.nav-item {
  display: flex; align-items: center; gap: 13px;
  padding: 11px 12px; border-radius: var(--r-sm);
  color: var(--ink-2); font-weight: 600; font-size: 0.95rem;
  cursor: pointer; transition: background .14s var(--ease), color .14s var(--ease);
  position: relative;
}
.nav-item svg { width: 22px; height: 22px; flex-shrink: 0; stroke-width: 1.9; }
.nav-item:hover { background: var(--sunk); }
.nav-item.active { background: var(--teal-50); color: var(--teal); }
.nav-item.active svg { color: var(--teal); }
.nav-item .badge { margin-left: auto; background: var(--coral); color: #fff; font-size: 0.66rem;
  font-weight: 800; padding: 2px 7px; border-radius: 999px; }
.collapsed .nav-item { justify-content: center; padding: 11px 0; }
.collapsed .nav-item .badge { display: none; }

.sb-foot { margin-top: auto; padding-top: 14px; }
.sb-user {
  display: flex; align-items: center; gap: 10px;
  padding: 9px; border-radius: var(--r-md); cursor: pointer;
  border: 1px solid var(--line); background: var(--raised);
  transition: border-color .14s var(--ease);
}
.sb-user:hover { border-color: var(--line-2); }
.sb-user .av { width: 38px; height: 38px; border-radius: 50%; flex-shrink: 0;
  background: var(--teal-50); display: grid; place-items: center; overflow: hidden; }
.sb-user .av img { width: 100%; height: 100%; object-fit: cover; }
.sb-user .uinfo { min-width: 0; }
.sb-user .uinfo .nm { font-weight: 800; font-size: 0.9rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.sb-user .uinfo .pl { font-size: 0.72rem; color: var(--muted); }
.collapsed .sb-user { justify-content: center; padding: 9px 0; }

.sb-collapse {
  display: flex; align-items: center; justify-content: center; gap: 8px;
  margin-top: 10px; padding: 8px; border-radius: var(--r-sm);
  background: none; border: none; color: var(--muted); cursor: pointer;
  font-size: 0.8rem; font-weight: 600; transition: background .14s var(--ease);
}
.sb-collapse:hover { background: var(--sunk); color: var(--ink-2); }
.sb-collapse svg { width: 18px; height: 18px; transition: transform .26s var(--ease); }
.collapsed .sb-collapse svg { transform: rotate(180deg); }

/* ---- main column ---- */
.main { min-width: 0; display: flex; flex-direction: column; }
.topbar {
  position: sticky; top: 0; z-index: 30;
  display: flex; align-items: center; gap: 16px;
  padding: 16px 32px;
  background: color-mix(in srgb, var(--page) 82%, transparent);
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.topbar .tb-title { font-size: 1.05rem; font-weight: 800; }
.topbar .tb-sub { font-size: 0.78rem; color: var(--muted); font-weight: 600; }
.tb-spacer { flex: 1; }
.tb-search {
  display: flex; align-items: center; gap: 9px;
  background: var(--surface); border: 1px solid var(--line-2);
  border-radius: var(--r-pill); padding: 9px 16px; min-width: 240px;
  color: var(--muted); transition: border-color .14s var(--ease), box-shadow .14s var(--ease);
}
.tb-search:focus-within { border-color: var(--teal-300); box-shadow: 0 0 0 3px var(--teal-50); }
.tb-search input { border: none; outline: none; background: none; flex: 1; font: inherit; font-size: 0.875rem; color: var(--ink); }
.tb-search svg { width: 18px; height: 18px; }
.icon-btn {
  width: 42px; height: 42px; border-radius: var(--r-md);
  border: 1px solid var(--line-2); background: var(--surface);
  display: grid; place-items: center; cursor: pointer; color: var(--ink-2);
  transition: background .14s var(--ease), border-color .14s var(--ease);
}
.icon-btn:hover { background: var(--sunk); }
.icon-btn svg { width: 20px; height: 20px; }

.content { padding: 28px 32px 64px; max-width: 1180px; width: 100%; margin: 0 auto; }
.content.wide { max-width: 1320px; }

/* ============================================================
   Components
   ============================================================ */
.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: var(--card-pad);
  box-shadow: var(--sh-sm);
}
.card.flat { box-shadow: none; }
.card.tight { padding: calc(16px * var(--dens)); }

/* section header w/ colored bar */
.sec-head { display: flex; align-items: center; gap: 11px; margin-bottom: 14px; }
.sec-head .bar { width: 4px; height: 20px; border-radius: 4px; background: var(--teal); flex-shrink: 0; }
.sec-head h3 { font-size: 1.12rem; }
.sec-head.purple .bar { background: var(--purple); }
.sec-head.coral .bar { background: var(--coral); }
.sec-head .more { margin-left: auto; font-size: 0.82rem; font-weight: 700; color: var(--teal); cursor: pointer; }

.eyebrow { font-size: 0.72rem; font-weight: 800; letter-spacing: .07em; text-transform: uppercase; color: var(--muted); }

/* buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  font-weight: 800; font-size: 0.95rem; line-height: 1;
  padding: 13px 22px; border-radius: var(--r-md);
  border: 1.5px solid transparent; cursor: pointer;
  transition: background .14s var(--ease), transform .12s var(--ease), border-color .14s var(--ease);
}
.btn:active { transform: scale(.98); }
.btn svg { width: 18px; height: 18px; }
.btn-primary { background: var(--teal); color: #fff; border-color: var(--teal); box-shadow: 0 2px 8px rgba(14,124,111,.25); }
.btn-primary:hover { background: var(--teal-700); border-color: var(--teal-700); }
.btn-ghost { background: var(--surface); color: var(--teal); border-color: var(--teal-100); }
.btn-ghost:hover { background: var(--teal-50); }
.btn-soft { background: var(--sunk); color: var(--ink); border-color: var(--line); }
.btn-soft:hover { background: var(--line); }
.btn-lg { padding: 16px 28px; font-size: 1.02rem; }
.btn-block { width: 100%; }

/* chips */
.chip {
  display: inline-flex; align-items: center; gap: 6px; white-space: nowrap;
  font-size: 0.78rem; font-weight: 700; line-height: 1;
  padding: 7px 13px; border-radius: var(--r-pill);
  background: var(--sunk); color: var(--ink-2); border: 1px solid var(--line);
}
.chip svg { width: 14px; height: 14px; }
.chip.teal { background: var(--teal-50); color: var(--teal); border-color: var(--teal-100); }
.chip.solid { background: var(--teal); color: #fff; border-color: var(--teal); }
.chip.coral { background: var(--coral-bg); color: var(--coral-ink); border-color: color-mix(in srgb,var(--coral) 32%,#fff); }
.chip.green { background: var(--green-bg); color: var(--green-ink); border-color: color-mix(in srgb,var(--green) 30%,#fff); }
.chip.gold  { background: var(--gold-bg); color: var(--gold-ink); border-color: color-mix(in srgb,var(--gold) 35%,#fff); }
.chip.amber { background: var(--amber-bg); color: var(--amber-ink); border-color: color-mix(in srgb,var(--amber) 35%,#fff); }
.chip.purple{ background: var(--purple-bg); color: var(--purple-ink); border-color: color-mix(in srgb,var(--purple) 28%,#fff); }

/* segmented tabs */
.segs { display: inline-flex; gap: 4px; background: var(--sunk); padding: 4px; border-radius: var(--r-pill); }
.segs button {
  border: none; background: none; cursor: pointer; font-family: inherit;
  font-weight: 700; font-size: 0.86rem; color: var(--muted);
  padding: 8px 16px; border-radius: var(--r-pill); transition: all .14s var(--ease);
}
.segs button.on { background: var(--surface); color: var(--teal); box-shadow: var(--sh-xs); }

/* filter pills */
.filters { display: flex; gap: 9px; flex-wrap: wrap; }
.fpill {
  border: 1.5px solid var(--line-2); background: var(--surface); cursor: pointer;
  font-family: inherit; font-weight: 700; font-size: 0.82rem; color: var(--ink-2);
  padding: 8px 16px; border-radius: var(--r-pill); transition: all .14s var(--ease);
  display: inline-flex; align-items: center; gap: 7px;
}
.fpill:hover { border-color: var(--teal-300); }
.fpill.on { border-color: var(--teal); color: var(--teal); background: var(--teal-50); }
.fpill .n { color: var(--muted); font-weight: 700; }
.fpill.on .n { color: var(--teal); }

/* progress */
.bar-track { height: 9px; background: var(--sunk); border-radius: 999px; overflow: hidden; }
.bar-fill { height: 100%; border-radius: 999px; background: var(--teal); transition: width .5s var(--ease); }
.bar-fill.coral { background: var(--coral); }
.bar-fill.gold { background: var(--gold); }
.bar-fill.green { background: var(--green); }

/* stat card */
.stat {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--r-lg);
  padding: calc(20px * var(--dens)); box-shadow: var(--sh-sm);
  display: flex; flex-direction: column; gap: 10px;
}
.stat .ic { width: 44px; height: 44px; border-radius: 14px; display: grid; place-items: center; }
.stat .ic svg { width: 22px; height: 22px; }
.stat .big { font-size: 2rem; font-weight: 900; line-height: 1; }
.stat .lbl { font-size: 0.82rem; color: var(--muted); font-weight: 600; }
.ic.teal { background: var(--teal-50); color: var(--teal); }
.ic.green { background: var(--green-bg); color: var(--green); }
.ic.gold  { background: var(--gold-bg); color: var(--gold); }
.ic.coral { background: var(--coral-bg); color: var(--coral); }
.ic.purple{ background: var(--purple-bg); color: var(--purple); }

/* list rows */
.lrow {
  display: flex; align-items: center; gap: 14px;
  padding: 15px 4px; border-bottom: 1px solid var(--line); cursor: pointer;
}
.lrow:last-child { border-bottom: none; }
.lrow .li { width: 38px; height: 38px; border-radius: 11px; background: var(--sunk);
  display: grid; place-items: center; color: var(--ink-2); flex-shrink: 0; }
.lrow .li svg { width: 20px; height: 20px; }
.lrow .lt { font-weight: 700; }
.lrow .lv { margin-left: auto; color: var(--muted); font-weight: 600; display: flex; align-items: center; gap: 8px; }
.lrow .lv svg { width: 18px; height: 18px; color: var(--faint); }

/* teal banner (hero/marketing accent — the one sanctioned gradient) */
.banner {
  position: relative; overflow: hidden;
  border-radius: var(--r-xl);
  background: linear-gradient(135deg, var(--banner-from), var(--banner-to));
  color: #fff; padding: calc(26px * var(--dens)) calc(30px * var(--dens));
}
.banner .mascot { position: absolute; right: 18px; bottom: -6px; width: 132px; opacity: .96;
  filter: drop-shadow(0 6px 14px rgba(0,0,0,.18)); pointer-events: none; }
.banner .pill {
  display: inline-flex; align-items: center; gap: 6px;
  background: rgba(255,255,255,.16); border: 1px solid rgba(255,255,255,.32);
  padding: 6px 13px; border-radius: 999px; font-size: 0.78rem; font-weight: 800; backdrop-filter: blur(4px);
}
.banner .pill svg { width: 15px; height: 15px; }
.banner h2 { color: #fff; font-size: 1.7rem; margin: 12px 0 6px; }
.banner p { color: rgba(255,255,255,.85); font-size: 0.92rem; max-width: 60%; }

/* answer letter token */
.opt-letter {
  width: 30px; height: 30px; border-radius: 9px; flex-shrink: 0;
  display: grid; place-items: center; font-weight: 800; font-size: 0.85rem;
  background: var(--sunk); color: var(--ink-2);
}
.opt-letter svg { width: 17px; height: 17px; }

/* divider */
.dash { border: none; border-top: 1px dashed var(--line-2); margin: 14px 0; }

/* mascot note bubble */
.mnote { display: flex; gap: 12px; align-items: flex-start; }
.mnote .mav { width: 46px; height: 46px; border-radius: 50%; background: var(--teal-50);
  display: grid; place-items: center; flex-shrink: 0; overflow: hidden; }
.mnote .mav img { width: 40px; height: 40px; }

/* utility */
.row { display: flex; align-items: center; gap: var(--gap-sm); }
.col { display: flex; flex-direction: column; }
.between { justify-content: space-between; }
.wrap { flex-wrap: wrap; }
.grid { display: grid; gap: var(--gap); }
.muted { color: var(--muted); }
.faint { color: var(--faint); }
.center { text-align: center; }

/* ============================================================
   Tweaks panel
   ============================================================ */
#tweakPanel {
  position: fixed; top: 0; right: 0; height: 100vh; width: 320px;
  background: var(--surface); border-left: 1px solid var(--line);
  box-shadow: var(--sh-pop); z-index: 100;
  transform: translateX(105%); transition: transform .3s var(--ease);
  display: flex; flex-direction: column;
}
#tweakPanel.open { transform: translateX(0); }
.twk-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 20px 22px; border-bottom: 1px solid var(--line);
  font-weight: 800; font-size: 1.05rem;
}
.twk-head button { width: 34px; height: 34px; border-radius: 10px; border: none;
  background: var(--sunk); cursor: pointer; display: grid; place-items: center; color: var(--ink-2); }
.twk-head button:hover { background: var(--line); }
.twk-head svg { width: 18px; height: 18px; }
.twk-body { padding: 22px; display: flex; flex-direction: column; gap: 24px; }
.twk-row { display: flex; flex-direction: column; gap: 10px; }
.twk-lbl { font-weight: 700; font-size: 0.9rem; display: flex; justify-content: space-between; }
.twk-lbl b { color: var(--teal); font-variant-numeric: tabular-nums; }
.twk-row input[type=range] { -webkit-appearance: none; appearance: none; height: 6px; border-radius: 999px;
  background: var(--sunk); outline: none; cursor: pointer; }
.twk-row input[type=range]::-webkit-slider-thumb { -webkit-appearance: none; appearance: none;
  width: 22px; height: 22px; border-radius: 50%; background: var(--teal); border: 3px solid #fff;
  box-shadow: var(--sh-sm); cursor: pointer; }
.twk-row input[type=range]::-moz-range-thumb { width: 22px; height: 22px; border-radius: 50%;
  background: var(--teal); border: 3px solid #fff; box-shadow: var(--sh-sm); cursor: pointer; }
.twk-seg { display: flex; gap: 4px; background: var(--sunk); padding: 4px; border-radius: var(--r-md); }
.twk-seg button { flex: 1; border: none; background: none; cursor: pointer; font-family: inherit;
  font-weight: 700; font-size: 0.86rem; color: var(--muted); padding: 9px; border-radius: calc(var(--r-md) - 4px);
  transition: all .14s var(--ease); }
.twk-seg button.on { background: var(--surface); color: var(--teal); box-shadow: var(--sh-xs); }
.twk-reset { margin-top: 6px; padding: 11px; border-radius: var(--r-md); border: 1.5px solid var(--line-2);
  background: var(--surface); color: var(--ink-2); font-family: inherit; font-weight: 700; cursor: pointer; }
.twk-reset:hover { background: var(--sunk); }

/* ============================================================
   Dashboard-specific
   ============================================================ */
.reco { display: flex; flex-direction: column; gap: 11px; padding: 18px;
  border: 1px solid var(--line); border-radius: var(--r-md); background: var(--raised); }
.reco-t { font-weight: 800; font-size: 1.05rem; }

.srow { display: flex; align-items: center; gap: 14px; padding: 13px 0; border-bottom: 1px solid var(--line); }
.srow:last-child { border-bottom: none; }
.srow .sn { font-family: var(--font-num); font-weight: 800; color: var(--faint); font-size: 0.9rem; width: 22px; }
.srow .smeta { flex: 1; min-width: 0; }
.srow .snm { font-weight: 700; }
.srow .spct { font-weight: 900; font-size: 1.1rem; width: 56px; text-align: right; }

.chart { display: flex; align-items: flex-end; gap: 14px; height: 180px; padding-top: 24px; }
.cbar { flex: 1; display: flex; flex-direction: column; align-items: center; gap: 8px; height: 100%; justify-content: flex-end; }
.cfill { width: 100%; max-width: 40px; background: var(--teal-100); border-radius: 8px 8px 4px 4px; position: relative;
  transition: height .5s var(--ease); }
.cfill.last { background: var(--teal); }
.cfill .ctip { position: absolute; top: -22px; left: 50%; transform: translateX(-50%);
  font-size: 0.72rem; font-weight: 800; color: var(--ink-2); opacity: 0; transition: opacity .14s; }
.cbar:hover .ctip { opacity: 1; }
.cbar:hover .cfill { background: var(--teal-300); }
.cbar:hover .cfill.last { background: var(--teal-700); }
.cwk { font-size: 0.72rem; color: var(--faint); font-weight: 700; }

.rk { width: 24px; text-align: center; font-weight: 900; color: var(--faint); font-family: var(--font-num); flex-shrink: 0; }
.rk.top { color: var(--gold); }

/* ============================================================
   Drill page
   ============================================================ */
.drill-wrap { display: grid; grid-template-columns: 1fr 320px; gap: var(--gap); align-items: start; }
.drill-rail { position: sticky; top: 92px; }

.qflag { display: inline-flex; align-items: center; gap: 6px; border: 1px solid var(--line-2);
  background: var(--surface); color: var(--muted); font-family: inherit; font-weight: 700; font-size: 0.8rem;
  padding: 7px 13px; border-radius: var(--r-pill); cursor: pointer; transition: all .14s var(--ease); }
.qflag svg { width: 15px; height: 15px; }
.qflag:hover, .qflag.on { color: var(--gold-ink); background: var(--gold-bg); border-color: var(--gold); }

.qstem { font-size: 1.28rem; font-weight: 700; line-height: 1.6; margin: 14px 0 22px; letter-spacing: -0.01em; }
.qstem b { color: var(--coral-ink); }

.opts { display: flex; flex-direction: column; gap: 12px; }
.opt {
  display: flex; align-items: flex-start; gap: 14px; text-align: left;
  padding: 16px 18px; border-radius: var(--r-md); cursor: pointer; width: 100%;
  border: 1.5px solid var(--line-2); background: var(--surface); font-family: inherit;
  font-size: 1.02rem; line-height: 1.5; color: var(--ink);
  transition: border-color .14s var(--ease), background .14s var(--ease), transform .1s var(--ease);
}
.opt:hover { border-color: var(--teal-300); background: var(--teal-50); }
.opt:active { transform: scale(.995); }
.opt .opt-t { flex: 1; padding-top: 3px; }
.opt.sel { border-color: var(--teal); background: var(--teal-50); }
.opt.sel .opt-letter { background: var(--teal); color: #fff; }
.opt.correct { border-color: var(--green); background: var(--green-bg); cursor: default; }
.opt.correct .opt-letter { background: var(--green); color: #fff; }
.opt.wrong { border-color: var(--coral); background: var(--coral-bg); cursor: default; }
.opt.wrong .opt-letter { background: var(--coral); color: #fff; }
.opt.dim { opacity: .55; cursor: default; }
.opt.dim:hover { border-color: var(--line-2); background: var(--surface); }

.qfoot { display: flex; align-items: center; gap: 10px; margin-top: 24px; }

.qgrid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 8px; }
.qn {
  aspect-ratio: 1; border-radius: 10px; border: 1.5px solid var(--line-2);
  background: var(--surface); font-family: var(--font-num); font-weight: 800; font-size: 0.9rem;
  color: var(--muted); cursor: pointer; transition: all .12s var(--ease);
}
.qn:hover { border-color: var(--teal-300); }
.qn.ok { background: var(--green-bg); border-color: color-mix(in srgb,var(--green) 30%,#fff); color: var(--green-ink); }
.qn.wrong { background: var(--coral-bg); border-color: color-mix(in srgb,var(--coral) 30%,#fff); color: var(--coral-ink); }
.qn.flag { background: var(--gold-bg); border-color: var(--gold); color: var(--gold-ink); }
.qn.now { background: var(--teal); border-color: var(--teal); color: #fff; box-shadow: 0 2px 8px rgba(14,124,111,.3); }

@media (max-width: 1100px) { .drill-wrap { grid-template-columns: 1fr; } .drill-rail { position: static; } }

/* ============================================================
   Explanation page
   ============================================================ */
.exp-wrap { display: grid; grid-template-columns: 1fr 360px; gap: var(--gap); align-items: start; }
.exp-rail { position: sticky; top: 92px; }
.exp-foot { display: flex; gap: 10px; margin-top: var(--gap); padding-top: var(--gap);
  border-top: 1px solid var(--line); }

.opt-analysis { display: flex; flex-direction: column; gap: 12px; }
.oa { border: 1.5px solid var(--line-2); border-radius: var(--r-md); overflow: hidden; }
.oa.ok { border-color: color-mix(in srgb,var(--green) 28%,#fff); }
.oa.wrong { border-color: var(--coral); }
.oa-head { display: flex; align-items: flex-start; gap: 12px; padding: 14px 16px; background: var(--raised); }
.oa.wrong .oa-head { background: var(--coral-bg); }
.oa.ok .oa-head { background: var(--green-bg); }
.oa .opt-letter { background: rgba(255,255,255,.7); }
.oa-t { flex: 1; font-weight: 600; line-height: 1.5; padding-top: 4px; }
.oa-tag { align-self: flex-start; flex-shrink: 0; }
.oa-note { padding: 12px 16px; font-size: 0.88rem; color: var(--ink-2); line-height: 1.6; background: var(--surface); }

.formula { font-family: var(--font-mono); font-size: 1rem; background: var(--sunk);
  border: 1px solid var(--line); border-radius: var(--r-md); padding: 16px 20px; margin: 18px 0;
  text-align: center; color: var(--ink); letter-spacing: .02em; }
.formula sub { font-size: 0.7em; }

.callout { display: flex; gap: 14px; align-items: flex-start; margin-top: 18px;
  background: var(--teal-50); border: 1px solid var(--teal-100); border-radius: var(--r-md);
  padding: 16px 18px; line-height: 1.6; }
.callout .co-ic { width: 32px; height: 32px; flex-shrink: 0; border-radius: 50%; background: var(--teal);
  color: #fff; display: grid; place-items: center; }
.callout .co-ic svg { width: 18px; height: 18px; }

/* timeline */
.timeline { display: flex; flex-direction: column; }
.tl { display: flex; gap: 14px; padding-bottom: 20px; position: relative; }
.tl:not(:last-child)::before { content: ''; position: absolute; left: 6px; top: 16px; bottom: 0;
  width: 2px; background: var(--line-2); }
.tl-dot { width: 14px; height: 14px; border-radius: 50%; flex-shrink: 0; margin-top: 3px; z-index: 1;
  border: 3px solid var(--surface); box-shadow: 0 0 0 1px var(--line-2); }
.tl-dot.teal { background: var(--teal); } .tl-dot.gold { background: var(--gold); } .tl-dot.coral { background: var(--coral); }
.tl.now .tl-body { background: var(--coral-bg); border: 1px solid color-mix(in srgb,var(--coral) 30%,#fff);
  border-radius: var(--r-sm); padding: 10px 13px; margin: -6px 0 0; }
.tl-y { font-weight: 900; font-family: var(--font-num); }
.tl-q { font-size: 0.88rem; color: var(--ink-2); margin-top: 3px; line-height: 1.5; }

@media (max-width: 1100px) { .exp-wrap { grid-template-columns: 1fr; } .exp-rail { position: static; } }

/* ============================================================
   Essay page
   ============================================================ */
.essay-wrap { display: grid; grid-template-columns: 1fr 340px; gap: var(--gap); align-items: start; }
.essay-rail { position: sticky; top: 92px; }
.essay-input { width: 100%; min-height: 320px; resize: vertical; font-family: inherit;
  font-size: 1.02rem; line-height: 1.8; color: var(--ink); padding: 18px;
  border: 1.5px solid var(--line-2); border-radius: var(--r-md); background: var(--raised);
  outline: none; transition: border-color .14s var(--ease), box-shadow .14s var(--ease); }
.essay-input:focus { border-color: var(--teal-300); box-shadow: 0 0 0 3px var(--teal-50); background: var(--surface); }
.rubric { display: flex; flex-direction: column; }
.score-ring { text-align: center; padding: 8px 0 18px; border-bottom: 1px solid var(--line); margin-bottom: 16px; }
.score-big { font-size: 3.4rem; font-weight: 900; color: var(--teal); line-height: 1; }
.grade-list { display: flex; flex-direction: column; gap: 16px; }
.gl { }

@media (max-width: 1100px) { .essay-wrap { grid-template-columns: 1fr; } .essay-rail { position: static; } }

/* ============================================================
   Notes page — flip cards
   ============================================================ */
.notes-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: var(--gap); }
.ncard { perspective: 1200px; height: 210px; }
.ncard-inner { position: relative; width: 100%; height: 100%; transition: transform .55s var(--ease);
  transform-style: preserve-3d; }
.ncard.flipped .ncard-inner { transform: rotateY(180deg); }
.ncard-face { position: absolute; inset: 0; backface-visibility: hidden; -webkit-backface-visibility: hidden;
  border-radius: var(--r-lg); padding: 18px; display: flex; flex-direction: column; }
.ncard-face.front { background: var(--surface); border: 1px solid var(--line); box-shadow: var(--sh-sm); cursor: pointer; }
.ncard-face.front:hover { border-color: var(--teal-300); box-shadow: var(--sh-md); }
.ncard-face.back { background: linear-gradient(150deg,var(--teal),var(--teal-700)); color: #fff; transform: rotateY(180deg); }
.nc-q { font-size: 1.08rem; font-weight: 700; line-height: 1.5; margin: 14px 0 auto; letter-spacing: -0.01em; }
.nc-foot { display: flex; align-items: center; justify-content: space-between; }
.nc-flip { font-size: 0.76rem; font-weight: 700; color: var(--teal); display: inline-flex; align-items: center; gap: 3px; }
.nc-flip svg { width: 13px; height: 13px; }
.nc-a { font-size: 0.98rem; line-height: 1.6; margin: 10px 0 auto; color: rgba(255,255,255,.95); }
.nc-rate { display: flex; gap: 8px; }
.nr { flex: 1; border: none; border-radius: var(--r-sm); padding: 9px; font-family: inherit; font-weight: 800;
  font-size: 0.85rem; cursor: pointer; transition: transform .1s var(--ease); }
.nr:active { transform: scale(.96); }
.nr.bad { background: rgba(255,255,255,.18); color: #fff; }
.nr.bad:hover { background: rgba(255,255,255,.28); }
.nr.ok { background: #fff; color: var(--teal); }

/* ============================================================
   Library page
   ============================================================ */
.mode-card { display: flex; align-items: center; gap: 16px; padding: calc(22px * var(--dens));
  border-radius: var(--r-lg); color: #fff; box-shadow: var(--sh-sm); transition: transform .14s var(--ease), box-shadow .14s var(--ease); }
.mode-card:hover { transform: translateY(-2px); box-shadow: var(--sh-md); }
.mode-card.teal { background: linear-gradient(135deg,var(--banner-from),var(--banner-to)); }
.mode-card.purple { background: linear-gradient(135deg,#7C4DB8,#5A3690); }
.mode-card .mc-ic { width: 52px; height: 52px; border-radius: 16px; background: rgba(255,255,255,.18);
  display: grid; place-items: center; flex-shrink: 0; }
.mode-card .mc-ic svg { width: 26px; height: 26px; }
.mode-card .mc-t { font-weight: 800; font-size: 1.18rem; }
.mode-card .mc-d { font-size: 0.86rem; color: rgba(255,255,255,.85); margin-top: 2px; }
.mode-card .mc-arr { margin-left: auto; opacity: .8; }
.mode-card .mc-arr svg { width: 22px; height: 22px; }

.lib-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: var(--gap); }
.subj-card { display: block; background: var(--surface); border: 1px solid var(--line); border-radius: var(--r-lg);
  padding: var(--card-pad); box-shadow: var(--sh-sm); transition: transform .14s var(--ease), box-shadow .14s var(--ease), border-color .14s var(--ease); }
.subj-card:hover { transform: translateY(-2px); box-shadow: var(--sh-md); border-color: var(--teal-100); }
.subj-ic { width: 46px; height: 46px; border-radius: 14px; display: grid; place-items: center; }
.subj-ic svg { width: 24px; height: 24px; }
.subj-n { font-size: 1.3rem; font-weight: 800; margin: 14px 0 4px; }
.subj-ch { display: flex; flex-wrap: wrap; gap: 6px; }
.mini-chip { font-size: 0.74rem; font-weight: 600; color: var(--ink-2); background: var(--sunk);
  border: 1px solid var(--line); padding: 4px 10px; border-radius: 999px; }

/* ============================================================
   Profile page
   ============================================================ */
.prof-head { display: flex; align-items: center; gap: 22px; }
.prof-av { width: 88px; height: 88px; border-radius: 50%; background: var(--teal-50); flex-shrink: 0;
  display: grid; place-items: center; overflow: hidden; border: 3px solid var(--teal-100); }
.prof-av img { width: 76px; height: 76px; }
.goal { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.goal-count { text-align: center; flex-shrink: 0; }
.badges { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.badge-item { text-align: center; padding: 16px 8px; border-radius: var(--r-md); background: var(--raised);
  border: 1px solid var(--line); }
.badge-item.locked { opacity: .45; filter: grayscale(1); }
.bdg-ic { width: 46px; height: 46px; border-radius: 50%; margin: 0 auto 8px; display: grid; place-items: center;
  background: var(--gold-bg); color: var(--gold); }
.bdg-ic svg { width: 24px; height: 24px; }
.bdg-n { font-weight: 800; font-size: 0.85rem; }

@media (max-width: 900px) {
  .app { grid-template-columns: var(--sidebar-collapsed) 1fr; }
  .sidebar .word, .sidebar .sb-cta span, .nav-item span, .sb-user .uinfo, .sb-section, .sb-collapse span { display: none; }
  .sb-logo { justify-content: center; }
  .nav-item, .sb-user, .sb-cta { justify-content: center; }
  .content, .topbar { padding-left: 18px; padding-right: 18px; }
}