*,:after,:before{box-sizing:border-box;margin:0;padding:0}:root{--color-primary:#2563eb;--color-primary-light:#3b82f6;--color-primary-dark:#1d4ed8;--color-primary-50:#eff6ff;--color-primary-100:#dbeafe;--color-primary-900:#1e3a5f;--color-accent:#f59e0b;--color-accent-light:#fbbf24;--color-success:#10b981;--color-warning:#f59e0b;--color-error:#ef4444;--color-info:#3b82f6;--color-bg:#f8fafc;--color-bg-card:#ffffff;--color-bg-elevated:#ffffff;--color-bg-dark:#0f172a;--color-border:#e2e8f0;--color-border-light:#f1f5f9;--color-text:#0f172a;--color-text-secondary:#64748b;--color-text-muted:#94a3b8;--color-text-inverse:#f8fafc;--font-sans:"Inter",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"PingFang SC","Microsoft YaHei",sans-serif;--font-mono:"JetBrains Mono","Fira Code",monospace;--text-xs:0.75rem;--text-sm:0.875rem;--text-base:1rem;--text-lg:1.125rem;--text-xl:1.25rem;--text-2xl:1.5rem;--text-3xl:1.875rem;--text-4xl:2.25rem;--font-normal:400;--font-medium:500;--font-semibold:600;--font-bold:700;--space-1:0.25rem;--space-2:0.5rem;--space-3:0.75rem;--space-4:1rem;--space-5:1.25rem;--space-6:1.5rem;--space-8:2rem;--space-10:2.5rem;--space-12:3rem;--space-16:4rem;--space-20:5rem;--radius-sm:0.375rem;--radius-md:0.5rem;--radius-lg:0.75rem;--radius-xl:1rem;--radius-2xl:1.5rem;--radius-full:9999px;--shadow-sm:0 1px 2px 0 rgba(0,0,0,0.05);--shadow-md:0 4px 6px -1px rgba(0,0,0,0.07),0 2px 4px -2px rgba(0,0,0,0.05);--shadow-lg:0 10px 15px -3px rgba(0,0,0,0.08),0 4px 6px -4px rgba(0,0,0,0.04);--shadow-xl:0 20px 25px -5px rgba(0,0,0,0.1),0 8px 10px -6px rgba(0,0,0,0.04);--transition-fast:150ms ease;--transition-base:250ms ease;--transition-slow:350ms ease;--max-width:1200px;--nav-height:64px}html{font-size:16px;scroll-behavior:smooth;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}body{font-family:var(--font-sans);color:var(--color-text);background-color:var(--color-bg);line-height:1.6;min-height:100vh}a{color:var(--color-primary);text-decoration:none;transition:color var(--transition-fast)}a:hover{color:var(--color-primary-dark)}.container{width:100%;max-width:var(--max-width);margin:0 auto;padding:0 var(--space-6)}.btn{display:inline-flex;align-items:center;justify-content:center;gap:var(--space-2);padding:var(--space-3) var(--space-6);border:none;border-radius:var(--radius-lg);font-family:var(--font-sans);font-size:var(--text-sm);font-weight:var(--font-semibold);cursor:pointer;transition:all var(--transition-base);white-space:nowrap;text-decoration:none;line-height:1.5}.btn:disabled{opacity:.5;cursor:not-allowed}.btn-primary{background:linear-gradient(135deg,var(--color-primary),var(--color-primary-dark));color:white;box-shadow:0 2px 8px rgba(37,99,235,.3)}.btn-primary:hover:not(:disabled){transform:translateY(-1px);box-shadow:0 4px 12px rgba(37,99,235,.4)}.btn-secondary{background:var(--color-bg-card);color:var(--color-text);border:1px solid var(--color-border)}.btn-secondary:hover:not(:disabled){background:var(--color-primary-50);border-color:var(--color-primary-light)}.btn-ghost{background:transparent;color:var(--color-text-secondary)}.btn-ghost:hover:not(:disabled){background:var(--color-primary-50);color:var(--color-primary)}.btn-lg{padding:var(--space-4) var(--space-8);font-size:var(--text-base)}.btn-sm{padding:var(--space-2) var(--space-4);font-size:var(--text-xs)}.btn-icon{width:40px;height:40px;padding:0;border-radius:var(--radius-full)}.card{background:var(--color-bg-card);border:1px solid var(--color-border-light);border-radius:var(--radius-xl);padding:var(--space-6);box-shadow:var(--shadow-sm);transition:all var(--transition-base)}.card:hover{box-shadow:var(--shadow-md)}.card-interactive:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg)}.form-group{margin-bottom:var(--space-5)}.form-label{display:block;font-size:var(--text-sm);font-weight:var(--font-medium);color:var(--color-text);margin-bottom:var(--space-2)}.form-input{width:100%;padding:var(--space-3) var(--space-4);background:var(--color-bg-card);border:1px solid var(--color-border);border-radius:var(--radius-lg);font-family:var(--font-sans);font-size:var(--text-base);color:var(--color-text);transition:border-color var(--transition-fast),box-shadow var(--transition-fast);outline:none}.form-input:focus{border-color:var(--color-primary);box-shadow:0 0 0 3px rgba(37,99,235,.1)}.form-input::placeholder{color:var(--color-text-muted)}.form-error{font-size:var(--text-sm);color:var(--color-error);margin-top:var(--space-1)}.badge{display:inline-flex;align-items:center;padding:var(--space-1) var(--space-3);border-radius:var(--radius-full);font-size:var(--text-xs);font-weight:var(--font-semibold)}.badge-primary{background:var(--color-primary-100);color:var(--color-primary-dark)}.badge-success{background:#d1fae5;color:#065f46}.badge-warning{background:#fef3c7;color:#92400e}.badge-error{background:#fee2e2;color:#991b1b}.score-circle{display:flex;align-items:center;justify-content:center;width:80px;height:80px;border-radius:var(--radius-full);background:linear-gradient(135deg,var(--color-primary-50),var(--color-primary-100));border:3px solid var(--color-primary);font-size:var(--text-2xl);font-weight:var(--font-bold);color:var(--color-primary-dark)}.spinner{width:24px;height:24px;border:3px solid var(--color-border);border-top-color:var(--color-primary);border-radius:var(--radius-full);animation:spin .6s linear infinite}@keyframes spin{to{transform:rotate(1turn)}}.loading-overlay{position:fixed;inset:0;background:rgba(255,255,255,.8);-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);display:flex;flex-direction:column;align-items:center;justify-content:center;gap:var(--space-4);z-index:50}.navbar{position:-webkit-sticky;position:sticky;top:0;height:var(--nav-height);background:rgba(255,255,255,.85);-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);border-bottom:1px solid var(--color-border-light);z-index:40}.navbar-inner{max-width:var(--max-width);margin:0 auto;padding:0 var(--space-6);height:100%;justify-content:space-between}.navbar-brand,.navbar-inner{display:flex;align-items:center}.navbar-brand{gap:var(--space-3);font-size:var(--text-lg);font-weight:var(--font-bold);color:var(--color-text)}.navbar-brand img{width:36px;height:36px;border-radius:var(--radius-full)}.navbar-links{gap:var(--space-2)}.hero,.navbar-links{display:flex;align-items:center}.hero{min-height:calc(100vh - var(--nav-height));flex-direction:column;justify-content:center;text-align:center;padding:var(--space-16) var(--space-6);background:linear-gradient(180deg,var(--color-primary-50) 0,var(--color-bg) 100%)}.hero-logo{width:120px;height:120px;border-radius:var(--radius-2xl);box-shadow:var(--shadow-xl);margin-bottom:var(--space-8);animation:float 3s ease-in-out infinite}@keyframes float{0%,to{transform:translateY(0)}50%{transform:translateY(-10px)}}.hero h1{font-size:var(--text-4xl);font-weight:var(--font-bold);color:var(--color-text);margin-bottom:var(--space-4);line-height:1.2}.hero p{font-size:var(--text-lg);color:var(--color-text-secondary);max-width:600px;margin-bottom:var(--space-8)}.hero-actions{gap:var(--space-4);flex-wrap:wrap}.auth-page,.hero-actions{display:flex;justify-content:center}.auth-page{min-height:calc(100vh - var(--nav-height));align-items:center;padding:var(--space-8) var(--space-6)}.auth-card{width:100%;max-width:420px}.auth-card h1{font-size:var(--text-2xl);font-weight:var(--font-bold);margin-bottom:var(--space-2)}.auth-card .subtitle{color:var(--color-text-secondary);margin-bottom:var(--space-8)}.auth-footer{text-align:center;margin-top:var(--space-6);color:var(--color-text-secondary);font-size:var(--text-sm)}.dashboard-header{padding:var(--space-8) 0}.dashboard-header h1{font-size:var(--text-3xl);font-weight:var(--font-bold)}.dashboard-header .greeting{color:var(--color-text-secondary);margin-top:var(--space-2)}.quota-cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));grid-gap:var(--space-6);gap:var(--space-6);margin-bottom:var(--space-8)}.quota-card{display:flex;align-items:center;gap:var(--space-5)}.quota-card .quota-info h3{font-size:var(--text-lg);font-weight:var(--font-semibold);margin-bottom:var(--space-1)}.quota-card .quota-remaining{font-size:var(--text-3xl);font-weight:var(--font-bold);color:var(--color-primary)}.practice-page{max-width:800px;margin:0 auto;padding:var(--space-8) var(--space-6)}.topic-card{margin-bottom:var(--space-8)}.topic-card h2{font-size:var(--text-xl);font-weight:var(--font-semibold);margin-bottom:var(--space-3)}.question-text{font-size:var(--text-lg);color:var(--color-text);padding:var(--space-5);background:var(--color-primary-50);border-left:4px solid var(--color-primary);border-radius:0 var(--radius-md) var(--radius-md) 0;margin-bottom:var(--space-6)}.recorder{display:flex;flex-direction:column;align-items:center;gap:var(--space-4);padding:var(--space-8);border:2px dashed var(--color-border);border-radius:var(--radius-xl);transition:border-color var(--transition-base)}.recorder.recording{border-color:var(--color-error);background:#fef2f2}.record-btn{width:80px;height:80px;border-radius:var(--radius-full);border:none;background:linear-gradient(135deg,var(--color-error),#dc2626);color:white;font-size:var(--text-2xl);cursor:pointer;transition:all var(--transition-base);box-shadow:0 4px 15px rgba(239,68,68,.3);display:flex;align-items:center;justify-content:center}.record-btn:hover{transform:scale(1.05)}.record-btn.recording{animation:pulse 1.5s ease-in-out infinite}@keyframes pulse{0%,to{box-shadow:0 0 0 0 rgba(239,68,68,.4)}50%{box-shadow:0 0 0 15px rgba(239,68,68,0)}}.result-page{max-width:900px;margin:0 auto;padding:var(--space-8) var(--space-6)}.result-header{text-align:center;margin-bottom:var(--space-8)}.score-overview{display:flex;align-items:center;justify-content:center;gap:var(--space-8);flex-wrap:wrap;margin-bottom:var(--space-8)}.score-breakdown{display:grid;grid-template-columns:repeat(2,1fr);grid-gap:var(--space-4);gap:var(--space-4)}.score-item{display:flex;justify-content:space-between;align-items:center;padding:var(--space-3) var(--space-4);background:var(--color-bg);border-radius:var(--radius-md)}.score-item .label{font-size:var(--text-sm);color:var(--color-text-secondary)}.score-item .value{font-weight:var(--font-bold);color:var(--color-primary)}.feedback-section{margin-bottom:var(--space-8)}.feedback-section h3{font-size:var(--text-lg);font-weight:var(--font-semibold);margin-bottom:var(--space-4);display:flex;align-items:center;gap:var(--space-2)}.feedback-list{list-style:none}.feedback-list li{padding:var(--space-3) var(--space-4);border-left:3px solid var(--color-border);margin-bottom:var(--space-3);font-size:var(--text-sm);line-height:1.7;color:var(--color-text-secondary)}.feedback-list.strengths li{border-left-color:var(--color-success)}.feedback-list.improvements li{border-left-color:var(--color-warning)}.sample-answer{background:linear-gradient(135deg,var(--color-primary-50),#f0f9ff);border:1px solid var(--color-primary-100);border-radius:var(--radius-xl);padding:var(--space-6)}.sample-answer h3{margin-bottom:var(--space-4)}.sample-answer p{line-height:1.8;color:var(--color-text)}@media (max-width:768px){:root{--nav-height:56px}.hero h1{font-size:var(--text-3xl)}.hero-logo{width:80px;height:80px}.quota-cards,.score-breakdown{grid-template-columns:1fr}.score-overview{flex-direction:column}.navbar-links .btn span.desktop-only{display:none}}@media (max-width:480px){.hero h1{font-size:var(--text-2xl)}.hero-actions{flex-direction:column;width:100%}.hero-actions .btn{width:100%}}