:root{color-scheme:light;--bg:#f7f8fb;--panel:#ffffff;--text:#171923;--muted:#667085;--line:#d9dee8;--primary:#116466;--primary-strong:#0b4d4f;--accent:#d98e04;--danger:#b42318}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font-family:Arial,Helvetica,sans-serif}a{color:inherit;text-decoration:none}button,input,select{font:inherit}input,select{background:white;border:1px solid var(--line);border-radius:8px;min-height:40px;padding:8px 10px;width:100%}code{background:#eef2f6;border-radius:6px;padding:2px 5px}.shell{min-height:100vh}.topbar{align-items:center;background:var(--panel);border-bottom:1px solid var(--line);display:flex;gap:18px;justify-content:space-between;padding:14px 24px;position:-webkit-sticky;position:sticky;top:0;z-index:10}.brand{font-size:18px;font-weight:700}.nav{align-items:center;display:flex;flex-wrap:wrap;gap:10px}.language-form{min-width:118px}.language-form select{min-height:38px;padding:7px 10px;width:100%}.current-set{align-items:center;border:1px solid var(--line);border-radius:8px;color:var(--muted);display:inline-flex;font-size:13px;font-weight:700;min-height:38px;max-width:220px;padding:8px 10px;text-overflow:ellipsis}.current-set,.sr-only{overflow:hidden;white-space:nowrap}.sr-only{clip:rect(0,0,0,0);border:0;height:1px;margin:-1px;padding:0;position:absolute;width:1px}.button,.nav a,button{align-items:center;background:var(--panel);border:1px solid var(--line);border-radius:8px;color:var(--text);cursor:pointer;display:inline-flex;gap:8px;min-height:38px;padding:8px 12px;text-align:center;white-space:normal}.button.primary,button.primary{background:var(--primary);border-color:var(--primary);color:white}.button.primary:hover,button.primary:hover{background:var(--primary-strong)}.button.danger,button.danger{border-color:#f4b8b1;color:var(--danger)}.container{margin:0 auto;max-width:1120px;padding:28px 24px 48px}.container.narrow{max-width:560px}.page-title{margin:0 0 8px;font-size:30px}.muted{color:var(--muted)}.grid{display:grid;grid-gap:16px;gap:16px}.grid.three{grid-template-columns:repeat(3,minmax(0,1fr))}.grid.two{grid-template-columns:repeat(2,minmax(0,1fr))}.card{background:var(--panel);border:1px solid var(--line);border-radius:8px;padding:18px;overflow-wrap:anywhere}.stat{display:grid;grid-gap:6px;gap:6px}.stat strong{font-size:28px}.stack-row{align-items:center;border-top:1px solid var(--line);display:flex;gap:16px;justify-content:space-between;padding:14px 0}.stack-row:first-child{border-top:0}.study-card{background:var(--panel);border:1px solid var(--line);border-radius:8px;margin:20px auto;max-width:760px;min-height:340px;padding:32px;overflow-wrap:anywhere}.prompt{font-size:34px;line-height:1.2;margin:18px 0 28px}.field{border-top:1px solid var(--line);padding:14px 0}.field:first-child{border-top:0}.field-label{color:var(--muted);font-size:13px;font-weight:700;margin-bottom:6px;text-transform:uppercase}.rating-row{display:grid;grid-gap:10px;gap:10px;grid-template-columns:repeat(4,minmax(0,1fr))}.rating-row button{justify-content:center;min-height:52px}.toolbar{gap:10px;justify-content:space-between;margin:18px 0}.button-row,.toolbar{align-items:center;display:flex;flex-wrap:wrap}.button-row{gap:8px;justify-content:flex-end}.badge{border:1px solid var(--line);border-radius:999px;display:inline-flex;font-size:13px;font-weight:700;padding:4px 9px}.badge.enabled{background:#e7f6ef;border-color:#bde7d0;color:#17613a}.badge.disabled{background:#fff0ee;border-color:#f4b8b1;color:var(--danger)}.progress-track{background:#eef2f6;border-radius:999px;height:8px;overflow:hidden}.progress-fill{background:var(--primary);height:100%}.form-grid{display:grid;grid-gap:14px;gap:14px}.form-grid label{color:var(--muted);display:grid;font-size:14px;font-weight:700;grid-gap:6px;gap:6px}.auth-card{margin-top:48px}.error-text{color:var(--danger);font-weight:700}.text-link{color:var(--primary);font-weight:700}.option-grid{display:grid;grid-gap:10px;gap:10px;grid-template-columns:repeat(2,minmax(0,1fr))}.option{align-items:center;border:1px solid var(--line);border-radius:8px;cursor:pointer;display:flex;gap:10px;min-height:48px;padding:10px}.option input{min-height:auto;width:auto}.test-question{border-width:2px;transition:border-color .12s ease,box-shadow .12s ease}.test-question[data-active=true]{border-color:var(--primary);box-shadow:0 0 0 3px rgba(17,100,102,.16)}.analysis-card.correct{border-left:5px solid var(--primary)}.analysis-card.incorrect{border-left:5px solid var(--danger)}@media (max-width:980px){.container{max-width:920px}.study-card{max-width:100%}}@media (max-width:760px){.topbar{align-items:flex-start;flex-direction:column;padding:12px 14px}.nav{width:100%}.current-set,.nav a,.nav button,.nav form{flex:1 1 auto}.container{padding:18px 14px 36px}.grid.three,.grid.two,.option-grid,.rating-row{grid-template-columns:1fr}.page-title,.prompt{font-size:26px}.study-card{margin:12px auto;min-height:280px;padding:20px}.stack-row,.toolbar{align-items:stretch;flex-direction:column}}@media (max-width:420px){.nav{display:grid;grid-template-columns:repeat(2,minmax(0,1fr))}.current-set,.nav a,.nav button{justify-content:center;width:100%}.prompt{font-size:23px}}