:root{--bg:#f6f7fb;--card:#fff;--text:#152033;--muted:#667085;--line:#e4e7ec;--primary:#2563eb;--primary2:#1d4ed8;--good:#087443;--bad:#b42318;--warn:#b54708;--shadow:0 10px 30px rgba(16,24,40,.08);--radius:20px;--tap:52px}body.dark{--bg:#0f172a;--card:#111c31;--text:#eef4ff;--muted:#a8b3c7;--line:#25324a;--primary:#60a5fa;--primary2:#3b82f6;--shadow:0 10px 30px rgba(0,0,0,.25)}*{box-sizing:border-box}body{margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;background:var(--bg);color:var(--text);line-height:1.45}.app-shell{max-width:980px;margin:0 auto;padding:14px 14px 90px}.topbar{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:10px 2px 14px}.eyebrow{font-size:12px;text-transform:uppercase;color:var(--primary);font-weight:800;letter-spacing:.08em}h1{font-size:26px;margin:2px 0 0}h2{font-size:23px;margin:0 0 12px}h3{font-size:18px}.icon-btn,.ghost-btn,.primary-btn,.danger-btn,.tab,.mode-card,.option{min-height:var(--tap);border:0;border-radius:15px;font-weight:750;cursor:pointer;touch-action:manipulation}.icon-btn{width:52px;background:var(--card);color:var(--text);box-shadow:var(--shadow)}.tabs{position:sticky;top:0;z-index:5;display:flex;gap:8px;overflow:auto;padding:8px 0 12px;background:linear-gradient(var(--bg),var(--bg) 80%,transparent)}.tab{white-space:nowrap;padding:0 14px;background:var(--card);color:var(--muted);border:1px solid var(--line)}.tab.active{background:var(--primary);color:white;border-color:var(--primary)}.view{display:none}.view.active{display:block}.hero-card,.question-card,.result-card,.feedback,.term-card,.theory-card,.stat-card,.exam-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:18px}.hero-card p,.muted{color:var(--muted);margin:0}.mode-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin:14px 0}.mode-card{text-align:left;background:var(--card);border:1px solid var(--line);padding:14px;color:var(--text);box-shadow:var(--shadow)}.mode-card.active{border-color:var(--primary);outline:3px solid color-mix(in srgb,var(--primary) 15%,transparent)}.mode-card span{display:block;color:var(--muted);font-weight:500;font-size:13px;margin-top:5px}.section-title{margin:22px 0 10px}.exam-list,.stack{display:grid;gap:12px}.exam-card{display:grid;gap:8px}.exam-card-top{display:flex;justify-content:space-between;gap:10px}.exam-card h3{margin:0}.badge{display:inline-flex;align-items:center;border-radius:999px;padding:5px 10px;font-size:12px;font-weight:800;background:color-mix(in srgb,var(--primary) 12%,transparent);color:var(--primary)}.primary-btn{background:var(--primary);color:#fff;padding:0 18px}.primary-btn:active{background:var(--primary2)}.ghost-btn{background:var(--card);color:var(--text);border:1px solid var(--line);padding:0 16px}.danger-btn{background:#fee4e2;color:#b42318;padding:0 16px}.quiz-top,.quiz-actions,.result-actions,.toolbar{display:flex;gap:10px;align-items:center;justify-content:space-between;margin:12px 0}.quiz-actions{position:sticky;bottom:0;background:linear-gradient(transparent,var(--bg) 20%,var(--bg));padding:20px 0 8px}.quiz-meta{font-size:13px;color:var(--muted);display:flex;gap:10px;flex-wrap:wrap}.progress{height:9px;background:var(--line);border-radius:999px;overflow:hidden;margin:8px 0 14px}.progress div{height:100%;background:var(--primary);width:0%;transition:.25s}.topic-pill{display:inline-flex;margin-bottom:10px;color:var(--primary);font-weight:800;font-size:13px}.options{display:grid;gap:10px}.option{display:grid;grid-template-columns:38px 1fr;gap:10px;text-align:left;align-items:center;background:var(--bg);color:var(--text);border:2px solid var(--line);padding:10px}.option .letter{display:grid;place-items:center;width:34px;height:34px;border-radius:12px;background:var(--card);font-weight:900}.option.selected{border-color:var(--primary);background:color-mix(in srgb,var(--primary) 10%,var(--bg))}.option.correct{border-color:var(--good);background:color-mix(in srgb,var(--good) 10%,var(--bg))}.option.wrong{border-color:var(--bad);background:color-mix(in srgb,var(--bad) 10%,var(--bg))}.feedback{margin-top:12px}.feedback.good{border-color:color-mix(in srgb,var(--good) 35%,var(--line))}.feedback.bad{border-color:color-mix(in srgb,var(--bad) 35%,var(--line))}.feedback h3{margin:0 0 8px}.explain-grid{display:grid;gap:8px;margin-top:10px}.explain-item{border:1px solid var(--line);border-radius:14px;padding:10px}.ru{color:var(--muted);font-size:14px}.hidden{display:none!important}.score-ring{width:122px;height:122px;margin:12px auto;border-radius:50%;display:grid;place-items:center;background:conic-gradient(var(--primary) var(--score,0%),var(--line) 0);font-size:28px;font-weight:950}.score-ring span{display:grid;place-items:center;width:92px;height:92px;background:var(--card);border-radius:50%}.result-details{display:grid;gap:10px;margin-top:12px}.toolbar input,.toolbar select{width:100%;min-height:50px;border-radius:14px;border:1px solid var(--line);background:var(--card);color:var(--text);padding:0 14px;font-size:16px}.glossary-list,.theory-list{display:grid;gap:12px}.term-card h3,.theory-card h3{margin:0 0 6px}.term-line{display:grid;grid-template-columns:1fr;gap:4px}.term-en{font-weight:800;color:var(--primary)}.term-ru{color:var(--muted)}.tag-row{display:flex;gap:6px;flex-wrap:wrap;margin-top:8px}.tag{font-size:12px;border:1px solid var(--line);border-radius:999px;padding:4px 8px;color:var(--muted)}.stats-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px;margin:12px 0}.stat-card strong{display:block;font-size:26px}@media (max-width:720px){.app-shell{padding:10px 10px 86px}h1{font-size:22px}h2{font-size:20px}.mode-grid{grid-template-columns:1fr}.quiz-actions{display:grid;grid-template-columns:1fr 1fr}.quiz-actions #checkAnswer,.quiz-actions #nextQuestion{grid-column:1/3}.option{grid-template-columns:32px 1fr;padding:9px}.option .letter{width:30px;height:30px}.toolbar{display:grid}.stats-grid{grid-template-columns:1fr}.exam-card-top{display:grid}.tabs{margin:0 -10px;padding-left:10px;padding-right:10px}.tab{padding:0 12px}}

.error-card{border-color:#ef4444!important}
button:disabled{opacity:.6;pointer-events:none}
body.is-busy{cursor:progress}


.feedback h3{font-size:24px;line-height:1.25}
.feedback p{font-size:18px;line-height:1.65;margin:10px 0}
.feedback .ru{font-size:17px;line-height:1.6}
.explain-grid{display:grid;gap:12px;margin-top:14px}
.explain-item{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:14px 16px}
.explain-item strong{display:block;font-size:18px;margin-bottom:6px}
.explain-item.is-correct{border:2px solid color-mix(in srgb,var(--good) 48%, var(--line));background:color-mix(in srgb,var(--good) 12%, var(--card));box-shadow:0 0 0 3px color-mix(in srgb,var(--good) 12%, transparent)}
.explain-item.is-correct strong{color:var(--good)}
.explain-item.is-selected-wrong{border:2px solid color-mix(in srgb,var(--bad) 48%, var(--line));background:color-mix(in srgb,var(--bad) 10%, var(--card))}
.explain-item.is-selected-wrong strong{color:var(--bad)}
.explain-item.is-neutral{border-color:var(--line);background:color-mix(in srgb,var(--bg) 55%, var(--card))}
.feedback-tip{margin-top:14px;border:2px solid color-mix(in srgb,var(--primary) 25%, var(--line));background:color-mix(in srgb,var(--primary) 7%, var(--card))}
.feedback-tip strong{color:var(--primary)}
.glossary-inline{display:grid;gap:10px;margin-top:10px}
.glossary-chip{border:1px solid var(--line);border-radius:16px;background:var(--card);padding:12px 14px}
.glossary-chip .de{display:block;font-size:17px;font-weight:850;line-height:1.35;color:var(--text)}
.glossary-chip .en{display:block;font-size:15px;font-weight:700;line-height:1.4;color:var(--primary);margin-top:3px}
.glossary-chip .ru{display:block;font-size:15px;line-height:1.45;color:var(--muted);margin-top:3px}
.option{font-size:17px;line-height:1.5}
.option .letter{font-size:16px}
.quiz-meta{font-size:14px}
.topic-pill{font-size:14px}
.question-card h2{line-height:1.35}
@media (max-width:720px){
  .feedback{padding:16px}
  .feedback h3{font-size:22px}
  .feedback p{font-size:17px;line-height:1.6}
  .feedback .ru{font-size:16px}
  .explain-item{padding:14px}
  .explain-item strong{font-size:17px}
  .glossary-chip{padding:14px}
  .glossary-chip .de{font-size:17px}
  .glossary-chip .en,.glossary-chip .ru{font-size:15px}
  .term-card,.theory-card{padding:16px}
  .term-card h3,.theory-card h3{font-size:19px;line-height:1.35}
  .term-card p,.theory-card p,.term-line,.term-en,.term-ru{font-size:16px;line-height:1.55}
  .tag{font-size:13px;padding:6px 10px}
}