:root{--practice-nav-width: 320px;--practice-transition: .25s cubic-bezier(.4, 0, .2, 1)}.practice-container{display:flex;height:100%;overflow:hidden;background:var(--bg-primary)}.practice-nav{width:var(--practice-nav-width);min-width:var(--practice-nav-width);background:var(--bg-secondary);border-right:1px solid var(--border-color);display:flex;flex-direction:column;overflow:hidden}.practice-nav-header{padding:20px;border-bottom:1px solid var(--border-color);display:flex;align-items:center;gap:12px}.practice-back-btn{display:flex;align-items:center;gap:8px;padding:8px 12px;background:transparent;border:none;color:var(--text-secondary);cursor:pointer;border-radius:var(--r-sm);transition:all var(--practice-transition);font-size:14px;font-weight:500}.practice-back-btn:hover{background:var(--bg-tertiary);color:var(--text-primary)}.practice-nav-title{font-size:18px;font-weight:600;color:var(--text-primary);margin:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.practice-nav-content{flex:1;overflow-y:auto;padding:12px}.practice-nav-label{display:block;font-family:Fira Mono,monospace;font-size:.66rem;color:var(--text-tertiary);text-transform:lowercase;letter-spacing:.04em;padding:2px 6px 10px}.practice-section{margin-bottom:8px;border-radius:var(--r);overflow:hidden;background:var(--card-bg);border:1px solid var(--border-color);transition:all var(--practice-transition)}.practice-section:hover{border-color:var(--accent-primary)}.practice-section-header{display:flex;align-items:center;width:100%;padding:14px 16px;border:0;background:transparent;color:inherit;font:inherit;text-align:left;cursor:pointer;-webkit-user-select:none;-moz-user-select:none;user-select:none;transition:all var(--practice-transition)}.practice-section-header:hover{background:var(--bg-tertiary)}.practice-progress-ring{width:28px;height:28px;margin-right:12px;position:relative;flex-shrink:0}.practice-progress-ring svg{transform:rotate(-90deg);width:100%;height:100%}.practice-progress-ring-bg{fill:none;stroke:var(--border-color);stroke-width:3}.practice-progress-ring-fill{fill:none;stroke:var(--accent-primary);stroke-width:3;stroke-linecap:round;transition:stroke-dashoffset .5s ease}.practice-section-info{flex:1;min-width:0}.practice-section-title{display:block;font-size:14px;font-weight:600;color:var(--text-primary);margin:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.practice-section-meta{display:block;font-size:12px;color:var(--text-tertiary);margin-top:2px}.practice-section-chevron{width:20px;height:20px;color:var(--text-tertiary);transition:transform var(--practice-transition);flex-shrink:0}.practice-section.expanded .practice-section-chevron{transform:rotate(180deg)}.practice-topics-list{max-height:0;overflow:hidden;transition:max-height .3s ease;background:var(--bg-secondary)}.practice-section.expanded .practice-topics-list{max-height:2000px;padding:8px 0 2px}.practice-section.expanded{border-color:var(--accent-primary)}.practice-topic-item{display:flex;align-items:center;width:calc(100% - 20px);padding:10px 13px;margin:0 10px 8px;cursor:pointer;transition:border-color var(--practice-transition),background-color var(--practice-transition);border:1px solid var(--border-color);border-radius:var(--r-sm);background:var(--card-bg);color:inherit;font:inherit;text-align:left}.practice-topic-item:hover{border-color:var(--accent-primary);background:var(--bg-secondary)}.practice-topic-item.active{border-color:var(--accent-primary);background:var(--accent-light)}.practice-topic-item.active .practice-topic-name{color:var(--accent-secondary);font-weight:600}.practice-topic-progress{display:flex;align-items:center;justify-content:center;min-width:36px;height:20px;border-radius:var(--r-sm);font-size:11px;font-weight:600;margin-right:10px;flex-shrink:0;background:var(--bg-tertiary);color:var(--text-tertiary)}.practice-topic-progress.has-progress{background:var(--accent-light);color:var(--accent-primary)}.practice-topic-progress.complete{background:var(--success);color:#fff}.practice-topic-name{font-size:13px;color:var(--text-secondary);flex:1;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.practice-topic-empty{font-size:11px;color:var(--text-tertiary);padding:2px 8px;background:var(--bg-tertiary);border-radius:6px;flex-shrink:0;margin-left:4px}.practice-content-panel{flex:1;display:flex;flex-direction:column;overflow:hidden;background:var(--bg-primary)}.practice-content-header{padding:24px 32px 0;border-bottom:1px solid var(--border-color);background:var(--bg-primary)}.practice-content-title{font-size:22px;font-weight:700;color:var(--text-primary);margin:0 0 4px}.practice-content-subtitle{font-size:13px;color:var(--text-tertiary);margin:0 0 16px}.practice-tabs{display:flex;gap:0;margin-bottom:-1px}.practice-tab{padding:10px 20px;border:none;background:transparent;color:var(--text-tertiary);font-size:14px;font-weight:500;cursor:pointer;border-bottom:2px solid transparent;transition:all var(--practice-transition)}.practice-tab:hover{color:var(--text-primary)}.practice-tab.active{color:var(--accent-primary);border-bottom-color:var(--accent-primary)}.practice-tab-count{display:inline-flex;align-items:center;justify-content:center;min-width:20px;height:20px;border-radius:var(--r-sm);background:var(--bg-tertiary);color:var(--text-tertiary);font-size:11px;font-weight:600;margin-left:6px;padding:0 6px}.practice-tab.active .practice-tab-count{background:var(--accent-light);color:var(--accent-primary)}.practice-content-scroll{flex:1;overflow-y:auto;padding:24px 32px 48px}.practice-question-nav{display:flex;gap:8px;margin-bottom:20px;flex-wrap:wrap}.practice-q-pill{width:36px;height:36px;border-radius:var(--r-sm);border:1.5px solid var(--border-color);background:var(--card-bg);color:var(--text-secondary);font-size:14px;font-weight:600;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:all var(--practice-transition)}.practice-q-pill:hover{border-color:var(--accent-primary);color:var(--accent-primary)}.practice-q-pill.active{background:var(--accent-primary);border-color:var(--accent-primary);color:#fff}.practice-q-pill.answered-correct{background:var(--success);border-color:var(--success);color:#fff}.practice-q-pill.answered-incorrect{background:var(--error);border-color:var(--error);color:#fff}.practice-question-card{background:var(--card-bg);border-radius:var(--r);border:1px solid var(--border-color);box-shadow:var(--shadow-sm);overflow:hidden;animation:practiceCardFadeIn .3s ease}@keyframes practiceCardFadeIn{0%{opacity:0;transform:translateY(12px)}to{opacity:1;transform:translateY(0)}}.practice-question-header{display:flex;align-items:center;justify-content:space-between;padding:20px 24px;border-bottom:1px solid var(--border-color)}.practice-question-number{font-size:13px;font-weight:600;color:var(--accent-primary);text-transform:uppercase;letter-spacing:.5px}.practice-question-marks{font-size:12px;color:var(--text-tertiary);background:var(--bg-tertiary);padding:4px 10px;border-radius:var(--r-sm);font-weight:500}.practice-question-body{padding:24px}.practice-question-text{font-size:15px;line-height:1.7;color:var(--text-primary);margin:0 0 20px;white-space:pre-wrap}.practice-mcq-options{display:flex;flex-direction:column;gap:10px}.practice-mcq-option{display:flex;align-items:center;width:100%;gap:14px;padding:14px 18px;background:var(--bg-secondary);border:1.5px solid var(--border-color);border-radius:var(--r);cursor:pointer;transition:all var(--practice-transition);font-size:14px;color:var(--text-primary);font-family:inherit;text-align:left}.practice-mcq-option:hover:not(.disabled){border-color:var(--accent-primary);background:rgba(var(--accent-primary-rgb),.05)}.practice-mcq-option.selected{border-color:var(--accent-primary);background:var(--accent-light)}.practice-mcq-option.correct{border-color:var(--success);background:var(--success-bg)}.practice-mcq-option.incorrect{border-color:var(--error);background:var(--error-bg)}.practice-mcq-option.correct-answer{border-color:var(--success);background:var(--success-bg)}.practice-mcq-option.disabled{cursor:default;opacity:.8}.practice-mcq-letter{width:32px;height:32px;border-radius:var(--r-sm);background:var(--bg-tertiary);display:flex;align-items:center;justify-content:center;font-weight:700;font-size:14px;color:var(--text-secondary);flex-shrink:0;transition:all var(--practice-transition)}.practice-mcq-option.selected .practice-mcq-letter{background:var(--accent-primary);color:#fff}.practice-mcq-option.correct .practice-mcq-letter{background:var(--success);color:#fff}.practice-mcq-option.incorrect .practice-mcq-letter{background:var(--error);color:#fff}.practice-mcq-option.correct-answer .practice-mcq-letter{background:var(--success);color:#fff}.practice-mcq-text{flex:1;line-height:1.5}.practice-mcq-icon{width:20px;height:20px;flex-shrink:0;display:none}.practice-mcq-option.correct .practice-mcq-icon,.practice-mcq-option.incorrect .practice-mcq-icon,.practice-mcq-option.correct-answer .practice-mcq-icon{display:block}.practice-explanation{margin-top:16px;padding:16px 20px;background:rgba(var(--accent-primary-rgb),.07);border-radius:0 var(--r-sm) var(--r-sm) 0;border-left:3px solid var(--accent-primary);animation:practiceCardFadeIn .3s ease}.practice-explanation-title{font-size:13px;font-weight:600;color:var(--accent-primary);margin:0 0 8px;text-transform:uppercase;letter-spacing:.5px}.practice-explanation-text{font-size:14px;line-height:1.6;color:var(--text-secondary);margin:0}.practice-structured-actions{display:flex;align-items:center;gap:12px;margin-top:20px;flex-wrap:wrap}.practice-action-btn{display:inline-flex;align-items:center;gap:8px;padding:10px 18px;border-radius:var(--r-sm);border:1.5px solid var(--border-color);background:var(--card-bg);color:var(--text-secondary);font-size:13px;font-weight:500;cursor:pointer;transition:all var(--practice-transition)}.practice-action-btn:hover{border-color:var(--accent-primary);color:var(--accent-primary);background:rgba(var(--accent-primary-rgb),.05)}.practice-action-btn.primary{background:var(--accent-primary);border-color:var(--accent-primary);color:#fff}.practice-action-btn.primary:hover{opacity:.9}.practice-action-btn svg{width:16px;height:16px}.practice-ai-checker{margin-top:16px;border-radius:var(--r);border:1.5px solid var(--border-color);overflow:hidden;animation:practiceCardFadeIn .3s ease;background:var(--bg-secondary)}.practice-ai-checker-header{display:flex;align-items:center;gap:8px;padding:12px 16px;background:var(--bg-tertiary);border-bottom:1px solid var(--border-color);font-size:13px;font-weight:600;color:var(--text-primary)}.practice-ai-checker-header svg{width:16px;height:16px;color:var(--accent-primary)}.practice-ai-checker-input{padding:16px}.practice-ai-textarea{width:100%;min-height:100px;padding:12px 16px;border:1.5px solid var(--border-color);border-radius:var(--r-sm);background:var(--card-bg);color:var(--text-primary);font-size:14px;line-height:1.6;resize:vertical;font-family:inherit;transition:border-color var(--practice-transition)}.practice-ai-textarea:focus{outline:none;border-color:var(--accent-primary)}.practice-ai-textarea::-moz-placeholder{color:var(--text-tertiary)}.practice-ai-textarea::placeholder{color:var(--text-tertiary)}.practice-ai-submit-row{display:flex;align-items:center;justify-content:flex-end;gap:8px;margin-top:10px}.practice-ai-response{padding:16px;border-top:1px solid var(--border-color);font-size:14px;line-height:1.7;color:var(--text-secondary)}.practice-ai-response p{margin:0 0 8px}.practice-ai-response strong{color:var(--text-primary)}.practice-ai-loading{display:flex;align-items:center;gap:10px;padding:16px;color:var(--text-tertiary);font-size:13px}.practice-ai-loading .spinner{width:16px;height:16px;border:2px solid var(--border-color);border-top-color:var(--accent-primary);border-radius:50%;animation:practiceAiSpin .6s linear infinite}@keyframes practiceAiSpin{to{transform:rotate(360deg)}}.practice-mark-scheme{margin-top:16px;padding:16px 20px;background:var(--success-bg);border-radius:0 var(--r-sm) var(--r-sm) 0;border-left:3px solid var(--success);animation:practiceCardFadeIn .3s ease}.practice-mark-scheme-title{font-size:13px;font-weight:600;color:var(--success);margin:0 0 8px;text-transform:uppercase;letter-spacing:.5px}.practice-mark-scheme-text{font-size:14px;line-height:1.7;color:var(--text-secondary);margin:0;white-space:pre-wrap}.practice-question-footer{display:flex;align-items:center;justify-content:space-between;padding:16px 24px;border-top:1px solid var(--border-color);background:var(--bg-secondary)}.practice-footer-link{display:inline-flex;align-items:center;gap:6px;font-size:13px;color:var(--text-tertiary);text-decoration:none;cursor:pointer;transition:color var(--practice-transition);border:none;background:none;padding:0}.practice-footer-link:hover{color:var(--accent-primary)}.practice-footer-link svg{width:14px;height:14px}.practice-selection-view{max-width:900px;margin:0 auto;padding:32px;animation:practiceFadeIn .4s ease}@keyframes practiceFadeIn{0%{opacity:0}to{opacity:1}}.practice-selection-header{margin-bottom:32px}.practice-selection-title{font-size:28px;font-weight:700;color:var(--text-primary);margin:0 0 8px}.practice-selection-subtitle{font-size:15px;color:var(--text-secondary);margin:0}.practice-empty-state{display:flex;flex-direction:column;align-items:center;justify-content:center;height:100%;text-align:center;padding:48px}.practice-empty-icon{width:80px;height:80px;border-radius:20px;background:var(--accent-light);display:flex;align-items:center;justify-content:center;margin-bottom:24px}.practice-empty-icon svg{width:40px;height:40px;color:var(--accent-primary)}.practice-empty-title{font-size:20px;font-weight:600;color:var(--text-primary);margin:0 0 8px}.practice-empty-text{font-size:14px;color:var(--text-secondary);margin:0}.practice-topic-score{display:flex;align-items:center;gap:16px;padding:16px 20px;background:var(--card-bg);border-radius:var(--r);border:1px solid var(--border-color);margin-bottom:20px}.practice-score-circle{width:50px;height:50px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:16px;font-weight:700;flex-shrink:0}.practice-score-circle.good{background:var(--success-bg);color:var(--success)}.practice-score-circle.medium{background:var(--warning-bg);color:var(--warning)}.practice-score-circle.low{background:var(--error-bg);color:var(--error)}.practice-score-circle.none{background:var(--bg-tertiary);color:var(--text-tertiary)}.practice-score-details{flex:1}.practice-score-label{font-size:14px;font-weight:600;color:var(--text-primary);margin:0 0 2px}.practice-score-sub{font-size:12px;color:var(--text-tertiary);margin:0}.practice-score-reset{padding:6px 12px;border-radius:var(--r-sm);border:1px solid var(--border-color);background:transparent;color:var(--text-tertiary);font-size:12px;cursor:pointer;transition:all var(--practice-transition)}.practice-score-reset:hover{border-color:var(--error);color:var(--error)}.practice-back-banner{display:flex;align-items:center;gap:10px;padding:10px 16px;background:rgba(var(--accent-primary-rgb),.08);border-bottom:1px solid var(--border-color);cursor:pointer;transition:background var(--practice-transition)}.practice-back-banner:hover{background:rgba(var(--accent-primary-rgb),.14)}.practice-back-banner svg{width:16px;height:16px;color:var(--accent-primary)}.practice-back-banner span{font-size:13px;font-weight:500;color:var(--accent-primary)}@media(max-width:900px){.practice-nav{width:280px;min-width:280px}.practice-content-scroll{padding:20px}.practice-content-header{padding:20px 20px 0}}@media(max-width:768px){.practice-container{flex-direction:column}.practice-nav{width:100%;min-width:100%;max-height:50vh;border-right:none;border-bottom:1px solid var(--border-color)}.practice-content-scroll{padding:16px}.practice-content-header{padding:16px 16px 0}.practice-structured-actions{flex-direction:column;align-items:stretch}.practice-question-footer{flex-direction:column;gap:10px}}