:root{--text:#c7d0dd;--text-h:#efeff5;--bg:#212324;--card-bg:#383737;--border:#cbd5e1;--accent:#f59e0b;--accent-hover:#d97706;--primary:#1e1b4b;--primary-hover:#312e81;--danger:#e73030;--success:#0bb047;--sans:"Inter", system-ui, sans-serif;--heading:Georgia, "Times New Roman", serif;--mono:"Courier New", monospace}*{box-sizing:border-box}body{font-family:var(--sans);background:var(--bg);color:var(--text);margin:0}.card{background:var(--card-bg);border-radius:16px;max-width:780px;margin:64px auto 0;padding:32px;box-shadow:0 4px 20px #00000014}.title{font-family:var(--heading);color:var(--text-h);margin:0 0 4px;font-size:30px;font-weight:700}.subtitle{color:var(--text);opacity:.8;margin:0 0 24px}.label{color:var(--text);margin:16px 0 6px;font-size:16px;font-weight:500;display:block}.label:first-of-type{margin-top:0}.error-text{color:var(--danger);margin:4px 0 0;font-size:15px}.text-input,.select-input{border:1px solid var(--border);width:100%;color:var(--text);background:#302f2f;border-radius:8px;outline:none;padding:10px 12px;font-size:16px;transition:border-color .15s,box-shadow .15s}.text-input:focus,.select-input:focus{border-color:#4a5bf9;box-shadow:0 0 0 3px #818cf840}.input-error{border-color:var(--danger)}.difficulty-group{gap:8px;display:flex}.difficulty-btn{border:1px solid var(--border);color:var(--text);text-transform:capitalize;cursor:pointer;background:#302f2f;border-radius:8px;flex:1;padding:10px 0;font-size:14px;transition:background .15s,color .15s,border-color .15s}.difficulty-btn.active{background:var(--primary);border-color:var(--primary);color:#fff}.start-quiz-btn{cursor:pointer;background:var(--accent);width:100%;color:var(--primary);border:none;border-radius:8px;margin-top:24px;padding:12px 0;font-size:17px;font-weight:600;transition:background .15s}.start-quiz-btn:hover{background:var(--accent-hover)}.quiz-header{color:var(--text);justify-content:space-between;align-items:center;margin-bottom:8px;font-size:15px;display:flex}.quit-btn{color:var(--danger);cursor:pointer;background:0 0;border:none;padding:0;font-size:13px}.quit-btn:hover{text-decoration:underline}.progress-track{background:#f1f5f9;border-radius:999px;width:100%;height:8px;margin-bottom:16px;overflow:hidden}.progress-fill{background:var(--primary);border-radius:999px;height:100%;transition:width .3s}.meta-row{justify-content:space-between;align-items:center;margin-bottom:16px;display:flex}.category-tag{text-transform:uppercase;letter-spacing:.05em;color:var(--accent-hover);font-size:14px;font-weight:600}.timer{font-family:var(--mono);color:var(--text);font-size:16px}.timer.timer-warning{color:var(--danger)}.question-text{font-family:var(--heading);color:var(--text-h);margin:0 0 20px;font-size:22px;font-weight:600}.options-list{flex-direction:column;gap:12px;display:flex}.option-btn{text-align:left;border:1px solid var(--border);cursor:pointer;color:var(--text);background:#302f2f;border-radius:8px;padding:12px 16px;font-size:17px;transition:border-color .15s,background .15s,opacity .15s}.option-btn:hover:not(:disabled){border-color:#818cf8}.option-btn:disabled{cursor:default}.option-btn .option-number{color:#94a3b8;margin-right:8px}.correct-option{border-color:var(--success);background:#055e20}.incorrect-option{border-color:var(--danger);background:#510505}.neutral-option{background:#302f2f}.results-heading{font-family:var(--heading);color:var(--text-h);margin:0 0 8px;font-size:26px;font-weight:700}.score-display{color:var(--accent-hover);margin:0 0 4px;font-size:40px;font-weight:700}.score-sub{color:#94a3b8;font-size:18px;font-weight:400}.message{color:var(--text);margin:0 0 24px}.review-heading{color:var(--text);margin:0 0 8px;font-weight:600}.review-list{flex-direction:column;gap:8px;margin-bottom:24px;display:flex}.review-item{border:1px solid var(--border);border-radius:8px;padding:12px}.review-question{color:var(--text);margin:0 0 4px;font-size:16px;font-weight:500}.review-answer{margin:0;font-size:16px}.review-answer.correct{color:var(--success)}.review-answer.timeout{color:var(--accent-hover)}.review-answer.incorrect{color:var(--danger)}.restart-btn{cursor:pointer;background:var(--primary);color:#fff;border:none;border-radius:8px;width:100%;padding:12px 0;font-size:17px;font-weight:600;transition:background .15s}.restart-btn:hover{background:var(--primary-hover)}.app-container{min-height:100vh;padding:40px 16px}