:root{color-scheme:light;--surface:#fff;--surface-soft:#f8fafc}
html[data-theme="dark"]{
  color-scheme:dark;
  --card:var(--surface);--accent:#285cd3;--good:#91deb1;--warn:#ffd18a;--bad:#ffafa9;
  --bg:#0e1625;--surface:#162135;--surface-soft:#1d2a40;
  --text:#e8edf6;--muted:#aab8ce;--line:#35445d;
  --primary:#9abbff;--primary-dark:#bdd1ff;--primary-soft:#20365a;
  --success:#91deb1;--success-soft:#183c30;--warning:#ffd18a;--warning-soft:#44351f;
  --danger:#ffafa9;--danger-soft:#44282f;--purple:#cdb7ff;
  --shadow:0 14px 40px rgba(0,0,0,.28);--shadow-soft:0 6px 22px rgba(0,0,0,.2);
  --dm-text:#e8edf6;--dm-muted:#b5c1d3;--dm-subtle:#a3b2c9;
  --dm-surface:#162135;--dm-soft:#1d2a40;--dm-line:#35445d;--dm-video:#0a1020;
  --dm-blue:#a8c4ff;--dm-purple:#d1baff;--dm-green:#99e2b8;--dm-amber:#ffd395;--dm-red:#ffb3af;
  --dm-tint-blue:#203451;--dm-tint-purple:#342b4d;--dm-tint-green:#183b30;--dm-tint-amber:#42351f;--dm-tint-red:#44282f;
  --dm-border-blue:#4f6e9d;--dm-border-purple:#73608f;--dm-border-green:#3e785d;--dm-border-amber:#81623b;--dm-border-red:#87525a;
  --dm-solid-blue:#285cd3;--dm-solid-purple:#6440ac;--dm-solid-green:#17633e;--dm-solid-amber:#815016;--dm-solid-red:#9e3037;
  --dm-glass:rgba(22,33,53,.96);--dm-shadow:rgba(0,0,0,.3);--dm-blue-glow:rgba(102,151,255,.2);
}
html[data-theme="dark"] .btn.primary,html[data-theme="dark"] .brand-icon,html[data-theme="dark"] .brand-mark,html[data-theme="dark"] .step-badge,html[data-theme="dark"] .study-tab.active{background:#285cd3;color:#fff}
html[data-theme="dark"] .btn.primary:hover{background:#346ae0}
html[data-theme="dark"] input,html[data-theme="dark"] select,html[data-theme="dark"] textarea{background:var(--surface-soft);color:var(--text);border-color:var(--line)}
html[data-theme="dark"] a{color:var(--primary)}
html[data-theme="dark"] .btn.secondary,html[data-theme="dark"] .btn.ghost{color:var(--text)}
html[data-theme="dark"] ::selection{background:#395c94;color:#fff}
.theme-toggle{border:1px solid var(--line);background:var(--surface);color:var(--text);border-radius:10px;padding:7px 10px;cursor:pointer;display:inline-flex;align-items:center;justify-content:center;gap:7px;min-width:44px;min-height:44px;white-space:nowrap;font-size:.84rem}
.theme-toggle>span:first-child{font-size:1.15rem;line-height:1}
.auth-theme-control{position:fixed;right:max(18px,env(safe-area-inset-right));top:max(16px,env(safe-area-inset-top));z-index:45}
.theme-choices{display:flex;flex-wrap:wrap;gap:8px}
.theme-choices button[aria-pressed="true"]{background:var(--primary-soft);border-color:var(--primary);color:var(--primary)}
.expression-translation p{margin:4px 0 0}.expression-translation small{font-size:.78rem;color:var(--muted)}
.expression-glossary{margin-top:14px}.expression-glossary-status{color:var(--muted);font-size:.8rem}
.theme-toggle:focus-visible,.theme-choices button:focus-visible{outline:2px solid var(--primary);outline-offset:3px}
@media(max-width:700px){.top-actions .theme-label,.admin-top-actions .theme-label{display:none}.top-actions{gap:6px}.auth-screen{padding-top:80px}.theme-choices .btn{min-height:44px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}.paragraph-glossary-hint>span{transition:none}}