:root{--brand-50:#eef2ff;--brand-100:#e0e7ff;--brand-200:#c7d2fe;--brand-400:#818cf8;--brand-500:#6366f1;--brand-600:#4f46e5;--brand-700:#4338ca;--brand-800:#3730a3;--gray-25:#fcfcfd;--gray-50:#f9fafb;--gray-100:#f3f4f6;--gray-200:#e5e7eb;--gray-300:#d1d5db;--gray-400:#9ca3af;--gray-500:#6b7280;--gray-600:#4b5563;--gray-700:#374151;--gray-800:#1f2937;--gray-900:#111827;--success-50:#ecfdf5;--success-100:#d1fae5;--success-500:#10b981;--success-600:#059669;--success-700:#047857;--danger-50:#fef2f2;--danger-100:#fee2e2;--danger-500:#ef4444;--danger-600:#dc2626;--warning-50:#fffbeb;--warning-500:#f59e0b;--radius-sm:6px;--radius-md:10px;--radius-lg:14px;--radius-xl:20px;--radius-full:9999px;--shadow-xs:0 1px 2px rgba(0,0,0,0.04);--shadow-sm:0 1px 3px rgba(0,0,0,0.06),0 1px 2px rgba(0,0,0,0.04);--shadow-md:0 4px 6px -1px rgba(0,0,0,0.07),0 2px 4px -1px rgba(0,0,0,0.04);--shadow-lg:0 10px 15px -3px rgba(0,0,0,0.07),0 4px 6px -2px rgba(0,0,0,0.03);--shadow-xl:0 20px 25px -5px rgba(0,0,0,0.08),0 10px 10px -5px rgba(0,0,0,0.03);--transition-fast:150ms ease;--transition-base:200ms ease}*,:after,:before{box-sizing:border-box}html{scroll-behavior:smooth;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}body{margin:0;font-family:Inter,system-ui,-apple-system,sans-serif;background:var(--gray-50);color:var(--gray-900);line-height:1.6;font-size:15px}button,input,select,textarea{font:inherit}img{max-width:100%;display:block}a{color:var(--brand-600);text-decoration:none;transition:color var(--transition-fast)}a:hover{color:var(--brand-700)}.container{max-width:1200px;margin:0 auto;padding:0 24px}.page-main{min-height:calc(100vh - 200px)}.navbar{position:-webkit-sticky;position:sticky;top:0;z-index:40;background:rgba(255,255,255,.92);-webkit-backdrop-filter:blur(16px) saturate(180%);backdrop-filter:blur(16px) saturate(180%);border-bottom:1px solid var(--gray-200)}.navbar-inner{max-width:1200px;margin:0 auto;padding:0 24px;height:60px;justify-content:space-between}.navbar-brand,.navbar-inner{display:flex;align-items:center}.navbar-brand{gap:10px;font-weight:700;font-size:1.05rem}.navbar-brand,.navbar-brand:hover{color:var(--gray-900);text-decoration:none}.navbar-brand svg{color:var(--brand-500)}.navbar-toggle{display:none;background:none;border:none;color:var(--gray-700);padding:8px;cursor:pointer;border-radius:var(--radius-sm)}.navbar-toggle:hover{background:var(--gray-100)}.navbar-links{display:flex;gap:4px;list-style:none;margin:0;padding:0}.navbar-auth{display:flex;align-items:center;gap:10px;margin-left:10px}.navbar-auth-links a{display:inline-flex;align-items:center;gap:6px}.navbar-user{color:var(--gray-700);font-size:.85rem;font-weight:600}.navbar-auth-btn,.navbar-signup{border:1px solid var(--gray-200);background:#fff;border-radius:var(--radius-full);padding:8px 14px;font-size:.84rem;font-weight:600;color:var(--gray-700);cursor:pointer}.navbar-signup{background:var(--brand-600);color:#fff!important;border-color:var(--brand-600)}.navbar-links a{display:block;padding:8px 16px;font-size:.875rem;font-weight:500;color:var(--gray-500);border-radius:var(--radius-sm);transition:all var(--transition-fast)}.navbar-links a:hover{color:var(--gray-900);background:var(--gray-100);text-decoration:none}.navbar-links a.active{color:var(--brand-600);background:var(--brand-50)}.hero{background:linear-gradient(135deg,var(--brand-700) 0,var(--brand-500) 50%,var(--brand-400) 100%);padding:64px 0 56px;position:relative;overflow:hidden}.hero:before{content:"";position:absolute;top:-50%;right:-20%;width:60%;height:200%;background:radial-gradient(circle,rgba(255,255,255,.06) 0,transparent 70%);pointer-events:none}.hero-container{max-width:1200px;margin:0 auto;padding:0 24px}.hero-content{max-width:660px}.hero h1{margin:16px 0 0;font-size:clamp(2rem,3.5vw,3rem);font-weight:800;line-height:1.15;letter-spacing:-.025em;color:#fff}.gradient-text{background:linear-gradient(135deg,#fbbf24,#f59e0b);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.hero-subtitle{margin:16px 0 0;color:rgba(255,255,255,.8);font-size:1.05rem;line-height:1.7;max-width:520px}.hero-features{display:flex;gap:12px;flex-wrap:wrap;margin-top:28px}.hero-feature{gap:6px;padding:8px 14px;border-radius:var(--radius-full);background:rgba(255,255,255,.15);-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);font-size:.82rem;font-weight:600;border:1px solid rgba(255,255,255,.2)}.badge,.hero-feature{display:inline-flex;align-items:center;color:#fff}.badge{padding:5px 14px;border-radius:var(--radius-full);background:rgba(255,255,255,.2);font-size:.75rem;font-weight:700;text-transform:uppercase;letter-spacing:.08em}.auth-page{padding:56px 0 72px}.auth-page-container{display:flex;justify-content:center}.auth-card{width:100%;max-width:680px;background:#fff;border:1px solid var(--gray-200);box-shadow:var(--shadow-lg);border-radius:var(--radius-xl);padding:32px}.auth-card-compact{max-width:560px}.auth-eyebrow{display:inline-flex;padding:6px 12px;border-radius:var(--radius-full);background:var(--brand-50);color:var(--brand-700);font-size:.78rem;font-weight:700;text-transform:uppercase;letter-spacing:.05em}.auth-card h1{margin:16px 0 10px;font-size:clamp(1.8rem,2vw,2.3rem);line-height:1.15}.auth-card p{color:var(--gray-600)}.auth-google-btn{margin-top:24px;width:100%;justify-content:center;display:inline-flex;align-items:center;gap:10px}.auth-google-btn:disabled{opacity:.45;cursor:not-allowed;pointer-events:none}.auth-google-btn svg{flex-shrink:0}.auth-divider{margin:24px 0 18px;display:flex;align-items:center;gap:12px;color:var(--gray-400);font-size:.82rem;text-transform:uppercase;letter-spacing:.08em}.auth-divider:after,.auth-divider:before{content:"";flex:1 1;height:1px;background:var(--gray-200)}.auth-form{display:grid;grid-gap:16px;gap:16px}.auth-form label{display:grid;grid-gap:8px;gap:8px;font-weight:600;color:var(--gray-700)}.auth-form input{width:100%;border:1px solid var(--gray-300);border-radius:var(--radius-md);padding:13px 14px;background:#fff}.auth-form input:focus{outline:none;border-color:var(--brand-500);box-shadow:0 0 0 3px rgba(99,102,241,.12)}.auth-switch{margin-top:18px;text-align:center}.auth-terms-label{display:flex;align-items:flex-start;gap:10px;font-size:.82rem;line-height:1.45;color:var(--gray-600);cursor:pointer}.auth-terms-label input[type=checkbox]{margin-top:2px;flex-shrink:0;width:18px;height:18px;accent-color:var(--brand-600);cursor:pointer}.auth-terms-label a{color:var(--brand-600);text-decoration:underline}.form-error{border-radius:var(--radius-md);background:var(--danger-50);color:var(--danger-600);padding:12px 14px;font-size:.92rem}.modal-backdrop{position:fixed;inset:0;background:rgba(17,24,39,.62);display:flex;align-items:center;justify-content:center;padding:20px;z-index:120}.auth-modal{position:relative;width:100%;max-width:560px;background:#fff;border-radius:24px;box-shadow:var(--shadow-xl);padding:28px}.modal-close{position:absolute;top:18px;right:18px;border:0;background:var(--gray-100);width:34px;height:34px;border-radius:999px;cursor:pointer}.auth-modal-icon{width:48px;height:48px;border-radius:16px;display:inline-flex;align-items:center;justify-content:center;background:linear-gradient(135deg,var(--brand-100),#fef3c7);color:var(--brand-700)}.auth-modal h3{margin:16px 0 10px;font-size:1.45rem}.auth-modal p{color:var(--gray-600)}.auth-modal-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:20px}.auth-modal-note{margin-top:16px;font-size:.86rem}.question-actions-panel{display:flex;gap:10px;flex-wrap:wrap;margin-top:16px}.mini-action-btn{display:inline-flex;align-items:center;gap:7px;border:1px solid var(--gray-200);background:#fff;color:var(--gray-700);border-radius:999px;padding:9px 14px;font-weight:600;cursor:pointer}.mini-action-btn:hover{background:var(--gray-50)}.mini-action-btn:disabled{opacity:.6;cursor:wait}.question-explanation-box,.validation-consensus-box{margin-top:16px;border-radius:var(--radius-lg);padding:16px;background:var(--gray-50);border:1px solid var(--gray-200)}.question-feedback-row{display:flex;gap:8px;flex-wrap:wrap;align-items:center;margin-top:12px}.feedback-chip{display:inline-flex;padding:6px 10px;background:var(--success-50);color:var(--success-700);border-radius:999px;font-size:.8rem;font-weight:700}.stats-grid{display:grid;grid-template-columns:repeat(3,1fr);grid-gap:20px;gap:20px;margin:-36px 0 0;position:relative;z-index:5}.stat-card{gap:16px;padding:24px;background:#fff;border-radius:var(--radius-lg);border:1px solid var(--gray-200);box-shadow:var(--shadow-md)}.stat-card,.stat-icon{display:flex;align-items:center}.stat-icon{width:48px;height:48px;justify-content:center;border-radius:var(--radius-md);background:var(--brand-50);color:var(--brand-600);flex-shrink:0}.stat-value{font-size:1.5rem;font-weight:800;color:var(--gray-900);line-height:1.2}.stat-label{font-size:.82rem;color:var(--gray-500);font-weight:500}.section-subjects{padding-top:48px;padding-bottom:24px}.section-exams{padding-top:8px;padding-bottom:48px}.section-howto{padding:48px 24px 64px;max-width:1200px;margin:0 auto}.section-header{display:flex;justify-content:space-between;align-items:flex-start;gap:24px;margin-bottom:32px}.section-header h2{margin:0;font-size:1.5rem;font-weight:800;color:var(--gray-900);letter-spacing:-.01em}.section-header p{margin:6px 0 0;color:var(--gray-500);font-size:.95rem}.search-box{position:relative;flex-shrink:0}.search-box svg{position:absolute;left:14px;top:50%;transform:translateY(-50%);color:var(--gray-400);pointer-events:none}.search-box input{width:280px;padding:10px 14px 10px 42px;border:1px solid var(--gray-300);border-radius:var(--radius-md);background:#fff;font-size:.9rem;color:var(--gray-900);transition:all var(--transition-fast)}.search-box input:focus{outline:none;border-color:var(--brand-400);box-shadow:0 0 0 3px rgba(99,102,241,.12)}.search-box input::placeholder{color:var(--gray-400)}.course-tabs{display:flex;gap:8px;margin-bottom:28px;overflow-x:auto;-webkit-overflow-scrolling:touch;scrollbar-width:none}.course-tabs::-webkit-scrollbar{display:none}.course-tab{display:inline-flex;align-items:center;gap:8px;padding:10px 20px;border-radius:var(--radius-lg);border:1px solid var(--gray-200);background:#fff;color:var(--gray-600);font-size:.9rem;font-weight:600;cursor:pointer;transition:all .15s ease;white-space:nowrap;flex-shrink:0}.course-tab:hover{border-color:var(--brand-300);background:var(--brand-50);color:var(--brand-700)}.course-tab.active{border-color:var(--brand-600);background:var(--brand-600);color:#fff}.course-tab-num{display:inline-flex;align-items:center;justify-content:center;width:24px;height:24px;border-radius:var(--radius-full);background:rgba(0,0,0,.08);font-size:.75rem;font-weight:700}.course-tab.active .course-tab-num{background:rgba(255,255,255,.25)}.course-tab-label{font-weight:600}.course-tab-count{font-size:.75rem;opacity:.7}.subject-group{margin-bottom:28px}.group-title{display:flex;gap:10px;margin:0 0 16px;font-size:.95rem;color:var(--gray-600)}.group-badge,.group-title{align-items:center;font-weight:700}.group-badge{display:inline-flex;justify-content:center;width:26px;height:26px;border-radius:var(--radius-full);background:var(--brand-100);color:var(--brand-700);font-size:.75rem}.family-tabs{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:24px}.family-tab{display:inline-flex;align-items:center;gap:6px;padding:8px 16px;border-radius:var(--radius-lg);border:1px solid var(--gray-200);background:#fff;color:var(--gray-600);font-size:.85rem;font-weight:600;cursor:pointer;transition:all .15s ease}.family-tab:hover{border-color:var(--gray-300);background:var(--gray-50)}.family-tab.active{border-color:transparent;color:#fff}.family-tab-count{font-size:.75rem;opacity:.8}.subject-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));grid-gap:16px;gap:16px}.subject-card{display:flex;flex-direction:column;padding:20px;background:#fff;border:1px solid var(--gray-200);border-radius:var(--radius-lg);transition:all var(--transition-base);box-shadow:var(--shadow-xs)}.subject-card,.subject-card:hover{text-decoration:none;color:inherit}.subject-card:hover{border-color:var(--brand-200);box-shadow:var(--shadow-md);transform:translateY(-2px)}.subject-card-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:10px}.subject-icon{color:var(--brand-500)}.subject-code{font-size:.72rem;font-weight:600;color:var(--gray-400);text-transform:uppercase;letter-spacing:.06em}.subject-name{margin:0 0 12px;font-size:.95rem;font-weight:600;color:var(--gray-800);line-height:1.4}.subject-meta{margin-top:auto;display:flex;flex-wrap:wrap;gap:12px}.subject-meta span{display:inline-flex;align-items:center;gap:4px;font-size:.78rem;color:var(--gray-400);font-weight:500}.subject-type-tag{background:var(--brand-50);color:var(--brand-700);padding:2px 8px;border-radius:var(--radius-sm);font-size:.72rem;font-weight:600}.section-howto h2{font-size:1.5rem;font-weight:800;margin:0 0 32px;text-align:center}.howto-grid{display:grid;grid-template-columns:repeat(3,1fr);grid-gap:24px;gap:24px}.howto-step{text-align:center;padding:32px 24px;background:#fff;border-radius:var(--radius-lg);border:1px solid var(--gray-200);box-shadow:var(--shadow-xs)}.howto-number{width:44px;height:44px;margin:0 auto 16px;display:flex;align-items:center;justify-content:center;border-radius:var(--radius-full);background:var(--brand-600);color:#fff;font-weight:800;font-size:1.1rem}.howto-step h3{margin:0 0 8px;font-size:1rem;font-weight:700}.howto-step p{margin:0;color:var(--gray-500);font-size:.9rem;line-height:1.6}.breadcrumbs{padding:20px 0 8px}.breadcrumbs ol{list-style:none;margin:0;padding:0}.breadcrumbs li,.breadcrumbs ol{display:flex;align-items:center;gap:2px}.breadcrumbs li{font-size:.85rem}.breadcrumbs a{color:var(--gray-500);font-weight:500}.breadcrumbs a:hover{color:var(--brand-600)}.breadcrumb-sep{color:var(--gray-300);margin:0 4px}.breadcrumb-current{color:var(--gray-700);font-weight:600}.subject-hero{background:linear-gradient(135deg,var(--brand-700),var(--brand-500));padding:40px 0}.subject-hero-content{display:flex;align-items:flex-start;gap:20px}.subject-hero-icon{width:56px;height:56px;display:flex;align-items:center;justify-content:center;border-radius:var(--radius-md);background:rgba(255,255,255,.15);color:#fff;flex-shrink:0}.subject-hero-code{display:inline-block;font-size:.75rem;font-weight:700;color:rgba(255,255,255,.6);text-transform:uppercase;letter-spacing:.1em;margin-bottom:4px}.subject-hero h1{margin:0;font-size:1.8rem;font-weight:800;color:#fff;line-height:1.2}.subject-hero-meta{display:flex;flex-wrap:wrap;gap:16px;margin-top:12px}.subject-hero-meta span{font-size:.85rem;color:rgba(255,255,255,.7);font-weight:500}.exams-list{display:flex;flex-direction:column;gap:12px;margin-bottom:32px}.exam-card{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:20px 24px;background:#fff;border:1px solid var(--gray-200);border-radius:var(--radius-lg);transition:all var(--transition-base);box-shadow:var(--shadow-xs)}.exam-card,.exam-card:hover{text-decoration:none;color:inherit}.exam-card:hover{border-color:var(--brand-200);box-shadow:var(--shadow-md);transform:translateY(-1px)}.exam-card-left{display:flex;align-items:flex-start;gap:16px}.exam-card-icon{width:44px;height:44px;display:flex;align-items:center;justify-content:center;border-radius:var(--radius-md);background:var(--brand-50);color:var(--brand-600);flex-shrink:0}.exam-card h3{margin:0;font-size:.95rem;font-weight:600;color:var(--gray-800)}.exam-desc{margin:4px 0 0;font-size:.85rem;color:var(--gray-500)}.exam-meta{display:flex;gap:14px;margin-top:6px}.exam-meta span{display:inline-flex;align-items:center;gap:4px;font-size:.78rem;color:var(--gray-400);font-weight:500}.exam-card-action{display:flex;align-items:center;gap:6px;font-size:.85rem;font-weight:600;color:var(--brand-600);flex-shrink:0}.exam-hero{background:#fff;border-bottom:1px solid var(--gray-200);padding:24px 0}.exam-hero-row{display:flex;align-items:center;justify-content:space-between;gap:20px}.exam-hero .badge{background:var(--brand-50);color:var(--brand-700)}.exam-hero h1{margin:8px 0 0;font-size:1.4rem;font-weight:800;color:var(--gray-900)}.exam-hero-meta{display:flex;gap:16px;margin-top:8px}.exam-hero-meta span{display:inline-flex;align-items:center;gap:5px;font-size:.85rem;color:var(--gray-500);font-weight:500}.exam-hero-actions{flex-shrink:0}.score-badge{display:flex;align-items:center;gap:8px;padding:12px 24px;background:var(--brand-50);border:2px solid var(--brand-200);border-radius:var(--radius-lg);color:var(--brand-700);font-size:1.3rem;font-weight:800}.progress-bar-wrapper{background:#fff;border-bottom:1px solid var(--gray-100);padding:12px 0}.progress-bar{height:6px;background:var(--gray-200);border-radius:var(--radius-full);overflow:hidden}.progress-bar-fill{height:100%;background:linear-gradient(90deg,var(--brand-500),var(--brand-400));border-radius:var(--radius-full);transition:width .3s ease}.results-summary{display:flex;align-items:center;gap:24px;padding:16px 24px;background:#fff;border:1px solid var(--gray-200);border-radius:var(--radius-lg);margin:20px 0;box-shadow:var(--shadow-sm)}.results-correct{color:var(--success-600)}.results-correct,.results-wrong{display:flex;align-items:center;gap:6px;font-weight:600;font-size:.95rem}.results-wrong{color:var(--danger-600)}.results-percent{margin-left:auto;font-size:1.5rem;font-weight:800;color:var(--brand-600)}.exam-questions{padding-top:24px;padding-bottom:64px}.exam-layout{display:grid;grid-template-columns:minmax(0,1fr) 300px;grid-gap:28px;gap:28px;align-items:flex-start}.exam-main,.exam-sidebar{display:flex;flex-direction:column;gap:16px}.exam-sidebar{position:-webkit-sticky;position:sticky;top:80px}.question-card{padding:24px;background:#fff;border:1px solid var(--gray-200);border-radius:var(--radius-lg);box-shadow:var(--shadow-xs);transition:border-color var(--transition-fast)}.question-card:hover{border-color:var(--gray-300)}.question-header{display:flex;align-items:center;gap:12px;margin-bottom:12px}.question-number{font-size:.75rem;font-weight:700;color:var(--brand-600);text-transform:uppercase;letter-spacing:.06em}.question-reliability{font-weight:600;color:var(--gray-400)}.question-reliability,.question-result{font-size:.72rem;text-transform:uppercase;letter-spacing:.04em}.question-result{margin-left:auto;display:inline-flex;align-items:center;padding:3px 10px;border-radius:var(--radius-full);font-weight:700}.question-result.correct{background:var(--success-50);color:var(--success-700)}.question-result.wrong{background:var(--danger-50);color:var(--danger-600)}.question-result.unanswered{background:var(--gray-100);color:var(--gray-500)}.question-text{margin:0 0 16px;font-size:1.02rem;font-weight:600;line-height:1.55;color:var(--gray-800)}.question-context{color:var(--gray-600);font-size:.9rem;line-height:1.65;padding:12px 16px;background:var(--gray-50);border-radius:var(--radius-sm);border-left:3px solid var(--brand-200);margin-bottom:16px}.answers-list{display:flex;flex-direction:column;gap:8px}.answer-btn{display:flex;align-items:flex-start;gap:10px;text-align:left;padding:14px 16px;border-radius:var(--radius-md);border:1.5px solid var(--gray-200);background:#fff;color:var(--gray-700);font-size:.9rem;cursor:pointer;transition:all var(--transition-fast);line-height:1.5}.answer-btn:hover:not(:disabled){border-color:var(--gray-300);background:var(--gray-50)}.answer-btn:disabled{cursor:default}.answer-btn.selected{border-color:var(--brand-500);background:var(--brand-50);color:var(--brand-700);font-weight:500}.answer-btn.correct{border-color:var(--success-500);background:var(--success-50);color:var(--success-700)}.answer-btn.wrong{border-color:var(--danger-500);background:var(--danger-50);color:var(--danger-600)}.answer-indicator{flex-shrink:0;width:16px;height:24px;display:flex;align-items:center}.explanation-section{margin-top:16px;padding:16px;border-radius:var(--radius-md);background:var(--gray-50);border:1px solid var(--gray-200)}.correct-answer-label{display:flex;align-items:center;gap:8px;font-size:.88rem;font-weight:600;color:var(--success-600);margin-bottom:10px}.explanation-content{margin-top:14px;padding:16px;border-radius:var(--radius-md);background:#fff;border:1px solid var(--gray-200)}.explanation-content p{margin:0;font-size:.9rem;color:var(--gray-600);line-height:1.7}.explanation-feedback{display:flex;gap:8px;margin-top:12px}.feedback-textarea{width:100%;min-height:80px;margin-top:12px;border-radius:var(--radius-sm);border:1px solid var(--gray-200);background:var(--gray-50);padding:12px;font-size:.875rem;resize:vertical;transition:border-color var(--transition-fast)}.feedback-textarea:focus{outline:none;border-color:var(--brand-400);box-shadow:0 0 0 3px rgba(99,102,241,.1)}.loading-text{font-size:.85rem;color:var(--gray-400);font-style:italic;margin-top:8px}.sidebar-card{padding:20px;background:#fff;border:1px solid var(--gray-200);border-radius:var(--radius-lg);box-shadow:var(--shadow-xs)}.sidebar-card h4{margin:0 0 10px;font-size:.88rem;font-weight:700;color:var(--gray-800)}.sidebar-card p{margin:0 0 14px;font-size:.85rem;color:var(--gray-500);line-height:1.55}.question-nav-card{max-height:320px;overflow-y:auto}.question-nav-grid{display:grid;grid-template-columns:repeat(5,1fr);grid-gap:6px;gap:6px}.nav-dot{display:flex;align-items:center;justify-content:center;width:36px;height:36px;border-radius:var(--radius-sm);background:var(--gray-100);color:var(--gray-500);font-size:.78rem;font-weight:600;text-decoration:none;transition:all var(--transition-fast)}.nav-dot:hover{background:var(--gray-200);text-decoration:none;color:var(--gray-700)}.nav-dot.answered{background:var(--brand-50);color:var(--brand-600)}.nav-dot.correct{background:var(--success-50);color:var(--success-600)}.nav-dot.wrong{background:var(--danger-50);color:var(--danger-600)}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border:none;border-radius:var(--radius-sm);font-weight:600;font-size:.875rem;cursor:pointer;transition:all var(--transition-fast);text-decoration:none}.btn-primary{padding:12px 24px;color:#fff;background:var(--brand-600);box-shadow:var(--shadow-xs)}.btn-primary:hover{background:var(--brand-700);box-shadow:var(--shadow-sm);color:#fff;text-decoration:none}.btn-primary:disabled{opacity:.5;cursor:not-allowed}.btn-lg{padding:14px 28px;font-size:.95rem}.btn-ghost{padding:10px 16px;border:1px solid var(--gray-200);background:#fff;color:var(--gray-700)}.btn-ghost:hover{background:var(--gray-50);border-color:var(--gray-300);text-decoration:none;color:var(--gray-700)}.btn-sm{padding:7px 12px;font-size:.82rem}.full-width{width:100%;text-align:center}.empty-state{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:12px;padding:64px 24px;text-align:center;color:var(--gray-500)}.empty-state.error{color:var(--danger-600);background:var(--danger-50);border-radius:var(--radius-lg);padding:32px 24px}.empty-state svg{color:var(--gray-300)}.spinner{width:32px;height:32px;border:3px solid var(--gray-200);border-top-color:var(--brand-500);border-radius:50%;animation:spin .7s linear infinite}@keyframes spin{to{transform:rotate(1turn)}}.ad-shell{padding:12px;background:var(--gray-50);border:1px solid var(--gray-100);border-radius:var(--radius-lg)}.ad-label{margin:0 0 8px;text-transform:uppercase;letter-spacing:.08em;color:var(--gray-400);font-size:.62rem;font-weight:600}.cookie-banner{position:fixed;z-index:50;left:24px;right:24px;bottom:24px;padding:20px 24px;border-radius:var(--radius-lg);background:var(--gray-900);color:#fff;display:flex;justify-content:space-between;gap:24px;align-items:center;box-shadow:var(--shadow-xl)}.cookie-banner strong{font-size:.9rem}.cookie-banner p{margin:4px 0 0;font-size:.82rem;color:var(--gray-400);line-height:1.5}.cookie-actions{display:flex;gap:10px;flex-shrink:0}.cookie-actions .btn-ghost{color:var(--gray-300);border-color:var(--gray-700);background:transparent}.cookie-actions .btn-ghost:hover{background:var(--gray-800)}.cookie-actions .btn-primary{background:var(--brand-500)}.interstitial-backdrop{position:fixed;inset:0;z-index:60;background:rgba(17,24,39,.55);-webkit-backdrop-filter:blur(6px);backdrop-filter:blur(6px);display:grid;place-items:center;padding:24px}.interstitial-card{width:min(520px,100%);padding:36px;text-align:center;background:#fff;border-radius:var(--radius-xl);box-shadow:var(--shadow-xl)}.interstitial-card .eyebrow{margin:0;text-transform:uppercase;letter-spacing:.1em;color:var(--brand-500);font-size:.7rem;font-weight:700}.interstitial-card h3{margin:8px 0 4px;font-size:1.2rem;font-weight:700}.interstitial-card p{color:var(--gray-500);font-size:.9rem;margin-bottom:20px}.scroll-top-btn{position:fixed;bottom:24px;right:24px;z-index:30;width:44px;height:44px;display:flex;align-items:center;justify-content:center;border-radius:var(--radius-full);background:var(--brand-600);color:#fff;border:none;box-shadow:var(--shadow-lg);cursor:pointer;transition:all var(--transition-fast)}.scroll-top-btn:hover{background:var(--brand-700);transform:translateY(-2px)}.site-footer{border-top:1px solid var(--gray-200);background:#fff;margin-top:0}.footer-inner{max-width:1200px;margin:0 auto;padding:48px 24px 24px;display:grid;grid-template-columns:2fr 1fr 1fr;grid-gap:40px;gap:40px}.footer-logo{font-weight:800;font-size:1.1rem;color:var(--gray-900)}.footer-desc{margin:8px 0 0;font-size:.85rem;color:var(--gray-500);line-height:1.6;max-width:320px}.footer-nav h4{margin:0 0 12px;font-size:.8rem;font-weight:700;color:var(--gray-800);text-transform:uppercase;letter-spacing:.06em}.footer-nav ul{list-style:none;margin:0;padding:0}.footer-nav li{margin-bottom:8px}.footer-nav a{color:var(--gray-500);font-size:.85rem;transition:color var(--transition-fast)}.footer-nav a:hover{color:var(--brand-600)}.footer-bottom{max-width:1200px;margin:0 auto;padding:16px 24px;border-top:1px solid var(--gray-100)}.footer-bottom p{margin:0;font-size:.78rem;color:var(--gray-400);text-align:center}.legal-page{max-width:720px;margin:32px auto;padding:40px;background:#fff;border:1px solid var(--gray-200);border-radius:var(--radius-lg);box-shadow:var(--shadow-sm)}.legal-page h1{font-size:1.8rem;font-weight:800;margin-bottom:24px}.legal-page p{color:var(--gray-600);line-height:1.8;margin-bottom:16px}@media (max-width:1024px){.exam-layout{grid-template-columns:1fr}.exam-sidebar{position:static;display:grid;grid-template-columns:repeat(2,1fr);grid-gap:16px;gap:16px;order:-1}}@media (max-width:768px){.navbar-toggle{display:block}.navbar-links{display:none;position:absolute;top:60px;left:0;right:0;background:#fff;border-bottom:1px solid var(--gray-200);flex-direction:column;padding:8px;box-shadow:var(--shadow-md)}.navbar-links.open{display:flex}.navbar-links a{padding:12px 16px}.hero{padding:40px 0 44px}.hero h1{font-size:1.8rem}.stats-grid{grid-template-columns:1fr;margin-top:-24px}.section-header{flex-direction:column;gap:16px}.search-box,.search-box input{width:100%}.footer-inner,.howto-grid,.subject-grid{grid-template-columns:1fr}.footer-inner{gap:24px;padding:32px 24px 16px}.exam-hero-row{flex-direction:column;align-items:flex-start}.exam-sidebar{grid-template-columns:1fr}.exam-card{flex-direction:column;align-items:flex-start}.exam-card-action{align-self:flex-end}.subject-hero-content{flex-direction:column;gap:12px}.results-summary{flex-wrap:wrap;gap:12px}.results-percent{margin-left:0}.cookie-banner{flex-direction:column;align-items:stretch;left:12px;right:12px;bottom:12px}.container{padding:0 16px}.legal-page{padding:24px;margin:16px auto}.question-card{padding:18px}}@media (max-width:480px){.stats-grid{gap:12px}.stat-card{padding:16px}.hero-features{gap:8px}.hero-feature{font-size:.75rem;padding:6px 10px}}