:root{--color-primary: #ff006e;--color-primary-dark: #ff4d88;--bg-page: #ffffff;--bg-card: #ffffff;--bg-surface: #f8f8f8;--text-primary: #000000;--text-secondary: #333333;--text-tertiary: #666666;--color-success: #00b856;--color-success-dark: #34d399;--color-warning: #ff9f1c;--color-warning-dark: #fbbf24;--color-error: #ff3b30;--color-error-dark: #f87171;--border-question: #ff006e;--border-solution: #00b856;--color-accent: #ffbe0b;--color-secondary: #00f5ff;--border-default: #000000;--mastery-pink: #ff006e;--mastery-cyan: #00f5ff;--mastery-yellow: #ffbe0b;--mastery-green: #00b856;--mastery-blue: #2563eb;--mastery-purple: #8b5cf6;--mastery-orange: #ff9f1c;--mastery-indigo: #6366f1;--mastery-unmastered: var(--color-error);--mastery-fuzzy: var(--color-warning);--mastery-mastered: var(--color-success);--font-title: "SimHei", "Microsoft YaHei", "Noto Sans SC", sans-serif;--font-body: "SimSun", "宋体", "Noto Serif SC", serif;--font-mono: "Courier New", "Consolas", monospace;--font-math: "KaTeX_Main", "Times New Roman", serif;--space-xs: 8px;--space-sm: 16px;--space-md: 24px;--space-lg: 32px;--space-xl: 48px;--space-2xl: 64px;--border-width: 3px;--border-solid: 3px solid #000000;--radius-none: 0px;--shadow-card: 4px 4px 0px 0px #000000;--shadow-card-hover: 2px 2px 0px 0px #000000;--shadow-card-active: 0px 0px 0px 0px #000000;--shadow-modal: 6px 6px 0px 0px #000000;--shadow-nav: 0px 3px 0px 0px #000000;--sidebar-w: 200px;--content-max: 800px;--max-width: 1440px;--bg-question: #fff0f3;--bg-solution: #f0fff4;--bg-user-msg: #ffe0eb;--bg-ai-msg: #e0ffff}[data-theme=dark]{--color-primary: #ff4d88;--bg-page: #0a0a0a;--bg-card: #1a1a1a;--bg-surface: #141414;--text-primary: #ffffff;--text-secondary: #cccccc;--text-tertiary: #888888;--color-success: #34d399;--color-warning: #fbbf24;--color-error: #f87171;--border-question: #ff4d88;--border-solution: #34d399;--color-accent: #fcd34d;--color-secondary: #22d3ee;--border-default: #ffffff;--shadow-card: 4px 4px 0px 0px #ffffff;--shadow-card-hover: 2px 2px 0px 0px #ffffff;--shadow-modal: 6px 6px 0px 0px #ffffff;--shadow-nav: 0px 3px 0px 0px #ffffff;--bg-question: #2a1118;--bg-solution: #0f2417;--bg-user-msg: #3a1726;--bg-ai-msg: #0e2a2a}*{box-sizing:border-box;margin:0;padding:0}html,body,#root{height:100%}body{font-family:var(--font-body);background:var(--bg-page);color:var(--text-primary);font-size:15px;line-height:1.5;-webkit-font-smoothing:antialiased}h1,h2,h3,h4,h5,.font-title{font-family:var(--font-title);font-weight:900;letter-spacing:.5px}code,pre,.font-mono{font-family:var(--font-mono)}a{color:var(--color-primary);text-decoration:none}button{font-family:var(--font-title);cursor:pointer}.btn{display:inline-flex;align-items:center;gap:var(--space-xs);padding:var(--space-sm) var(--space-md);border:var(--border-solid);border-radius:var(--radius-none);font-family:var(--font-title);font-weight:800;font-size:14px;background:#fff;color:#000;box-shadow:var(--shadow-card);transition:background .3s steps(1),color .3s steps(1),box-shadow .3s steps(1),transform .3s steps(1);-webkit-user-select:none;user-select:none}.btn:hover{background:var(--color-accent);color:#000}.btn:active{box-shadow:var(--shadow-card-active);transform:translate(2px,2px)}.btn:disabled,.btn[disabled]{opacity:.5;cursor:not-allowed;box-shadow:var(--shadow-card);transform:none}.btn-primary{background:var(--color-primary);color:#fff;border-color:var(--border-default)}.btn-primary:hover{background:var(--color-primary);color:#fff;filter:brightness(1.08)}.btn-secondary{background:#fff;color:#000}.btn-danger{background:var(--color-error);color:#fff}.btn-danger:hover{background:var(--color-error);color:#fff;filter:brightness(1.08)}.btn-sm{padding:var(--space-xs) var(--space-sm);font-size:12px;box-shadow:2px 2px 0 0 var(--border-default)}.btn-loading{position:relative}.spinner-square{display:inline-block;width:12px;height:12px;border:2px solid currentColor;animation:spin90 .7s steps(4) infinite}@keyframes spin90{to{transform:rotate(360deg)}}.nb-card{background:var(--bg-card);border:var(--border-solid);border-radius:var(--radius-none);box-shadow:var(--shadow-card);padding:var(--space-md)}.nb-card:hover{box-shadow:var(--shadow-card-hover)}.nb-input,.nb-select,.nb-textarea{width:100%;padding:var(--space-sm);border:var(--border-solid);border-radius:var(--radius-none);background:#fff;color:var(--text-primary);font-family:var(--font-body);font-size:15px;outline:none}.nb-input:focus,.nb-select:focus,.nb-textarea:focus{border:3px solid var(--color-primary)}.nb-textarea{resize:vertical;min-height:96px}.nb-badge{display:inline-flex;align-items:center;gap:4px;padding:2px var(--space-xs);border:2px solid var(--border-default);border-radius:var(--radius-none);font-family:var(--font-title);font-size:12px;font-weight:700;background:#fff;color:#000}.nb-badge-accent{background:var(--color-accent)}.nb-badge-subject{background:var(--color-secondary);border-color:var(--border-default)}.row{display:flex;align-items:center}.col{display:flex;flex-direction:column}.gap-xs{gap:var(--space-xs)}.gap-sm{gap:var(--space-sm)}.gap-md{gap:var(--space-md)}.gap-lg{gap:var(--space-lg)}.spread{justify-content:space-between}.wrap{flex-wrap:wrap}.muted{color:var(--text-tertiary)}.secondary{color:var(--text-secondary)}.text-center{text-align:center}.full{width:100%}@keyframes flash{0%{opacity:1}to{opacity:0}}.flash-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#fff;z-index:9999;pointer-events:none;animation:flash .1s steps(1) forwards}.toast{position:fixed;bottom:var(--space-xl);left:50%;transform:translate(-50%);background:var(--bg-card);border:var(--border-solid);box-shadow:var(--shadow-card);padding:var(--space-sm) var(--space-md);font-family:var(--font-title);font-weight:800;z-index:10000}@media (max-width: 900px){.admin-grid{grid-template-columns:1fr!important}}.nav-item svg{flex-shrink:0}.error-card{position:relative;background:var(--bg-card);border:var(--border-solid);border-radius:var(--radius-none);box-shadow:var(--shadow-card);padding:var(--space-md);padding-left:calc(var(--space-md) + 6px);transition:box-shadow .3s steps(1)}.error-card:hover{box-shadow:var(--shadow-card-hover)}.error-card__bar{position:absolute;left:0;top:0;bottom:0;width:6px;background:var(--mastery-unmastered)}.error-card__head{display:flex;align-items:center;gap:var(--space-xs);margin-bottom:var(--space-sm)}.error-card__date{margin-left:auto;font-family:var(--font-mono);font-size:12px;color:var(--text-tertiary)}.error-card__q{border-left:4px solid var(--border-question);background:var(--bg-question);padding:var(--space-sm);margin-bottom:var(--space-sm)}.error-card__s{border-left:4px solid var(--border-solution);background:var(--bg-solution);padding:var(--space-sm);max-height:0;overflow:hidden;transition:max-height .2s steps(5)}.error-card__s.open{max-height:1200px}.error-card__footer{display:flex;align-items:center;gap:var(--space-sm);margin-top:var(--space-sm);flex-wrap:wrap}.mastery-dots{display:inline-flex;gap:4px}.mastery-dot{width:18px;height:18px;border:2px solid #000;border-radius:0;cursor:pointer;padding:0}.mastery-dot.sel{outline:3px solid #000;outline-offset:1px}.asym-layout{display:grid;grid-template-columns:var(--sidebar-w) 1fr;gap:var(--space-lg);max-width:var(--max-width);margin:0 auto;padding:var(--space-xl);align-items:start}.sidebar{position:sticky;top:var(--space-xl);border:var(--border-solid);background:var(--bg-surface);box-shadow:var(--shadow-card);padding:var(--space-md)}.content-area{max-width:var(--content-max);margin-left:40px}@media (max-width: 1024px){.asym-layout{grid-template-columns:1fr;padding:var(--space-md)}.sidebar{position:static}.content-area{margin-left:0}}.error-stream{display:flex;flex-direction:column;gap:var(--space-md)}.error-stream>*:nth-child(odd){margin-left:0}.error-stream>*:nth-child(2n){margin-left:24px}.topnav{display:flex;align-items:center;gap:var(--space-md);border-bottom:var(--border-solid);box-shadow:var(--shadow-nav);padding:var(--space-sm) var(--space-xl);background:var(--bg-page);position:sticky;top:0;z-index:50}.logo{font-family:var(--font-title);font-weight:900;font-size:22px;border-bottom:4px solid var(--color-primary)}.nav-item{font-family:var(--font-title);font-weight:800;font-size:14px;padding:8px 12px;border:2px solid var(--border-default);border-left:4px solid transparent;background:#fff;color:#000;text-decoration:none;box-shadow:2px 2px 0 0 var(--border-default)}.nav-item:hover{background:var(--color-accent)}.nav-active{border-left:4px solid var(--color-primary);background:var(--bg-surface)}.review-stage{min-height:100vh;background:var(--bg-page);padding:var(--space-xl);display:flex;flex-direction:column}.review-card{width:70%;margin-left:60px;border:var(--border-solid);box-shadow:var(--shadow-card);background:var(--bg-card);padding:var(--space-lg)}.modal-mask{position:fixed;top:0;right:0;bottom:0;left:0;background:#00000059;display:flex;align-items:center;justify-content:center;z-index:200}.modal{background:var(--bg-card);border:var(--border-solid);box-shadow:var(--shadow-modal);padding:var(--space-lg);min-width:320px;max-width:90vw}.dots:after{content:"▌▌▌";font-family:var(--font-mono);animation:dotblink .9s steps(3) infinite}@keyframes dotblink{0%{opacity:1}50%{opacity:.2}to{opacity:1}}