.mysql-page{height:100%}:root{--bg:#f6f7fb;--surface:#fff;--ink:#1e2235;--ink-soft:#5b6178;--ink-faint:#9aa0b4;--line:#e6e8f0;--line-soft:#eef0f6;--brand:#5b5ef5;--brand-soft:#eeeffd;--brand-deep:#4043d8;--accent:#0fb9a6;--accent-soft:#e2f7f4;--amber:#f59e0b;--amber-soft:#fef3e0;--rose:#f0546b;--rose-soft:#fde8ec;--code-bg:#1b1e36;--code-ink:#e9ebff;--shadow:0 1px 3px rgba(28,32,60,.06),0 6px 24px rgba(28,32,60,.06);--radius:14px;--mono:"SF Mono","JetBrains Mono","Fira Code",Menlo,Consolas,monospace;--sans:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif}*{box-sizing:border-box;margin:0;padding:0}html,body{height:100%}body{font-family:var(--sans);background:var(--bg);color:var(--ink);line-height:1.7;font-size:15px;-webkit-font-smoothing:antialiased}::-webkit-scrollbar{width:9px;height:9px}::-webkit-scrollbar-thumb{background:#d2d6e4;border-radius:6px}::-webkit-scrollbar-thumb:hover{background:#b8bdcf}.app{display:grid;grid-template-columns:282px 1fr;height:100vh;overflow:hidden}@media(max-width:860px){.app{grid-template-columns:1fr}}.sidebar{background:var(--surface);border-right:1px solid var(--line);overflow:hidden;display:flex;flex-direction:column}.brand{padding:22px 22px 16px;border-bottom:1px solid var(--line-soft)}.brand h1{font-size:18px;font-weight:800;letter-spacing:-.3px;display:flex;align-items:center;gap:8px}.brand .logo{width:30px;height:30px;border-radius:8px;background:linear-gradient(135deg,var(--brand),var(--accent));display:flex;align-items:center;justify-content:center;color:#fff;font-size:13px;font-weight:800;flex-shrink:0}.brand p{font-size:12px;color:var(--ink-faint);margin-top:4px}.progress-wrap{padding:14px 22px;border-bottom:1px solid var(--line-soft)}.progress-bar{height:7px;background:var(--line);border-radius:4px;overflow:hidden}.progress-bar>div{height:100%;background:linear-gradient(90deg,var(--brand),var(--accent));border-radius:4px;transition:width .4s;width:0}.progress-text{font-size:11px;color:var(--ink-faint);margin-top:6px;display:flex;justify-content:space-between}.nav{flex:1;overflow-y:auto;padding:10px 12px 30px;scrollbar-width:none}.nav::-webkit-scrollbar{display:none}.nav:after{content:"";position:sticky;bottom:0;left:0;right:0;display:block;height:28px;margin:0 -12px -30px;background:linear-gradient(to bottom,transparent,var(--surface));pointer-events:none}.nav-section-header{display:flex;align-items:center;justify-content:space-between;padding:8px 10px;border-radius:9px;cursor:pointer;-webkit-user-select:none;-moz-user-select:none;user-select:none;transition:background .15s;margin:2px 0}.nav-section-header:hover{background:var(--line-soft)}.nav-section-title{font-size:11px;font-weight:700;color:var(--ink-faint);text-transform:uppercase;letter-spacing:.6px}.nav-section-arrow{font-size:10px;color:var(--ink-faint);transition:transform .25s;flex-shrink:0;margin-left:6px}.nav-section-header.collapsed .nav-section-arrow{transform:rotate(-90deg)}.nav-section-children{display:grid;grid-template-rows:1fr;transition:grid-template-rows .25s ease,opacity .2s ease;overflow:hidden}.nav-section-children.collapsed{grid-template-rows:0fr;opacity:0}.nav-section-children>div{min-height:0}.nav-item{display:flex;align-items:center;gap:10px;padding:8px 10px;border-radius:9px;cursor:pointer;font-size:13.5px;color:var(--ink-soft);transition:all .15s;-webkit-user-select:none;-moz-user-select:none;user-select:none}.nav-item:hover{background:var(--brand-soft);color:var(--brand-deep)}.nav-item.active{background:var(--brand);color:#fff;font-weight:600;box-shadow:0 3px 10px #5b5ef54d}.nav-item .num{width:22px;height:22px;border-radius:6px;background:var(--line);display:flex;align-items:center;justify-content:center;font-size:11px;font-weight:700;flex-shrink:0}.nav-item.active .num{background:#ffffff40}.nav-item.done .num{background:var(--accent);color:#fff}.main{overflow-y:auto;position:relative}.topbar{position:sticky;top:0;z-index:20;background:#f6f7fbd9;backdrop-filter:blur(12px);border-bottom:1px solid var(--line);padding:12px 36px;display:flex;align-items:center;justify-content:space-between;gap:16px}.topbar .crumb{font-size:13px;color:var(--ink-faint)}.topbar .crumb b{color:var(--ink);font-weight:600}.btn{border:none;background:var(--surface);border:1px solid var(--line);border-radius:9px;padding:8px 14px;font-size:13px;font-weight:600;color:var(--ink-soft);cursor:pointer;transition:all .15s;font-family:var(--sans);display:inline-flex;align-items:center;gap:6px}.btn-accent{border-color:var(--accent);color:var(--accent)}.btn-brand{background:var(--brand);color:#fff;border-color:var(--brand)}.btn:hover{border-color:var(--brand);color:var(--brand)}.content{max-width:860px;margin:0 auto;padding:30px 36px 140px}.lesson-head{margin-bottom:24px}.lesson-tag{display:inline-flex;align-items:center;font-size:11px;font-weight:700;color:var(--brand);background:var(--brand-soft);padding:4px 11px;border-radius:20px;letter-spacing:.4px}.lesson-head h2{font-size:28px;font-weight:800;letter-spacing:-.6px;margin:12px 0 6px;line-height:1.25}.lesson-head .sub{font-size:15px;color:var(--ink-soft)}.prose p{margin:13px 0;color:var(--ink-soft)}.prose p strong{color:var(--ink);font-weight:650}.prose h3{font-size:18px;font-weight:700;margin:26px 0 8px;color:var(--ink);letter-spacing:-.2px}.prose ul,.prose ol{margin:10px 0 10px 22px;color:var(--ink-soft)}.prose li{margin:5px 0}.prose code{font-family:var(--mono);font-size:13px;background:var(--brand-soft);color:var(--brand-deep);padding:1px 6px;border-radius:5px}.callout{border-radius:12px;padding:14px 17px;margin:16px 0;font-size:14px;display:flex;gap:12px;border:1px solid}.callout .ico{flex-shrink:0;font-size:16px;line-height:1.7}.callout.tip{background:var(--accent-soft);border-color:#bfeae3}.callout.warn{background:var(--amber-soft);border-color:#fde3b5}.callout.note{background:var(--brand-soft);border-color:#d6d8fb}.callout .body{color:var(--ink-soft)}.callout .body strong{color:var(--ink)}.code-block{background:var(--code-bg);border-radius:12px;overflow:hidden;margin:16px 0;box-shadow:var(--shadow)}.code-block .code-head{display:flex;align-items:center;justify-content:space-between;padding:8px 14px;background:#ffffff0d;border-bottom:1px solid rgba(255,255,255,.06)}.code-block .code-head .label{font-size:11px;color:#8a8fcf;font-weight:600;letter-spacing:.5px;font-family:var(--mono)}.code-actions{display:flex;gap:6px}.code-actions button{background:#ffffff14;border:none;color:#c5c9f0;font-size:11.5px;font-weight:600;padding:5px 11px;border-radius:6px;cursor:pointer;transition:all .15s;font-family:var(--sans)}.code-actions button:hover{background:#ffffff29;color:#fff}.code-actions button.run{background:var(--accent);color:#fff}.code-actions button.run:hover{background:#0aa392}.code-block pre{margin:0;padding:14px 16px;overflow-x:auto;font-family:var(--mono);font-size:13.5px;line-height:1.65;color:var(--code-ink)}.code-body{display:flex;background:var(--code-bg)}.code-body .line-numbers{flex-shrink:0;padding:14px 12px 14px 16px;text-align:right;-webkit-user-select:none;-moz-user-select:none;user-select:none;border-right:1px solid rgba(255,255,255,.07);background:#0000001f}.code-body .line-numbers .ln{display:block;font-family:var(--mono);font-size:12.5px;line-height:1.65;color:#5b5f8a}.code-body pre{flex:1;margin:0;padding:14px 16px;overflow-x:auto;font-family:var(--mono);font-size:13.5px;line-height:1.65;color:var(--code-ink)}.result-wrap{margin:0 0 16px;border:1px solid var(--line);border-radius:12px;overflow:hidden;background:var(--surface)}.result-head{padding:8px 14px;background:var(--line-soft);font-size:11.5px;font-weight:700;color:var(--ink-faint);letter-spacing:.4px;display:flex;justify-content:space-between;align-items:center;position:sticky;top:0;z-index:5}.badge{font-size:10px;padding:2px 8px;border-radius:10px;font-weight:700}.badge.err{background:var(--rose);color:#fff}.badge.ok{background:var(--accent);color:#fff}.badge.info{background:var(--brand);color:#fff}.result-table{width:100%;border-collapse:collapse;font-size:13px}.result-table th{background:var(--line-soft);text-align:left;padding:8px 13px;font-weight:700;color:var(--ink);border-bottom:1px solid var(--line);font-size:12px;white-space:nowrap}.result-table td{padding:7px 13px;border-bottom:1px solid var(--line-soft);color:var(--ink-soft)}.result-table tr:last-child td{border-bottom:none}.result-table td.null{color:var(--ink-faint);font-style:italic}.result-table tr:hover td{background:var(--brand-soft)}.result-msg{padding:13px 16px;font-size:13.5px;font-family:var(--mono);color:var(--ink-soft)}.result-msg.err{color:var(--rose)}.quiz{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:20px 22px;margin:24px 0;box-shadow:var(--shadow)}.quiz-head{display:flex;align-items:center;gap:8px;margin-bottom:12px}.qtag{font-size:11px;font-weight:700;color:#fff;background:var(--brand);padding:3px 10px;border-radius:20px;letter-spacing:.4px}.quiz-q{font-size:15px;color:var(--ink);margin-bottom:13px;font-weight:500}.quiz-opts{display:flex;flex-direction:column;gap:9px}.quiz-opt{display:flex;align-items:center;gap:11px;padding:10px 14px;border:1.5px solid var(--line);border-radius:10px;cursor:pointer;transition:all .15s;font-size:14px;color:var(--ink-soft)}.quiz-opt:hover{border-color:var(--brand);background:var(--brand-soft)}.quiz-opt .letter{width:24px;height:24px;border-radius:7px;background:var(--line);display:flex;align-items:center;justify-content:center;font-size:12px;font-weight:700;flex-shrink:0;color:var(--ink-soft)}.quiz-opt.correct{border-color:var(--accent);background:var(--accent-soft);color:var(--ink);font-weight:600}.quiz-opt.correct .letter{background:var(--accent);color:#fff}.quiz-opt.wrong{border-color:var(--rose);background:var(--rose-soft);color:var(--ink)}.quiz-opt.wrong .letter{background:var(--rose);color:#fff}.quiz-opt.disabled{cursor:default;pointer-events:none}.quiz-explain{margin-top:12px;padding:12px 14px;border-radius:10px;font-size:13.5px;display:none;line-height:1.6}.quiz-explain.show{display:block;animation:fade .3s}.quiz-explain.right{background:var(--accent-soft);color:#0a8a7a;border:1px solid #bfeae3}.quiz-explain.wrong{background:var(--rose-soft);color:#c43a52;border:1px solid #f6cdd3}@keyframes fade{0%{opacity:0;transform:translateY(4px)}to{opacity:1;transform:translateY(0)}}.lesson-nav{display:flex;justify-content:space-between;gap:12px;margin-top:32px}.lesson-nav .btn{flex:1;justify-content:center;padding:11px 16px}.dock{position:fixed;bottom:0;right:0;width:calc(100% - 282px);background:var(--surface);border-top:1px solid var(--line);box-shadow:0 -6px 24px #1c203c14;z-index:30;transition:transform .35s cubic-bezier(.4,0,.2,1)}.dock.collapsed{transform:translateY(calc(100% - 46px))}.dock-toggle{height:46px;display:flex;align-items:center;justify-content:space-between;padding:0 24px;cursor:pointer;-webkit-user-select:none;-moz-user-select:none;user-select:none}.dock-toggle .t-label{font-size:13px;font-weight:700;color:var(--ink);display:flex;align-items:center;gap:8px}.dock-toggle .dot{width:8px;height:8px;border-radius:50%;background:var(--accent)}.dock-toggle .t-actions{display:flex;gap:8px;align-items:center;font-size:11px;color:var(--ink-faint)}.chev{transition:transform .35s;color:var(--ink-faint)}.dock.collapsed .chev{transform:rotate(180deg)}.dock-body{height:320px;display:flex;gap:1px;background:var(--line);overflow:hidden}.dock-editor{flex:1;background:var(--code-bg);display:flex;flex-direction:column}.dock-editor textarea{flex:1;background:transparent;border:none;color:var(--code-ink);font-family:var(--mono);font-size:13.5px;line-height:1.7;padding:14px 16px;resize:none;outline:none;-moz-tab-size:2;-o-tab-size:2;tab-size:2;white-space:pre;overflow:auto}.dock-editor textarea::-moz-placeholder{color:#5b5f8a}.dock-editor textarea::placeholder{color:#5b5f8a}.dock-result{flex:1.1;background:var(--surface);overflow:auto;display:flex;flex-direction:column}@media(max-width:860px){.dock{width:100%}.dock-body{flex-direction:column;height:420px}}.schema-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:10px;margin:14px 0}.schema-card{background:var(--surface);border:1px solid var(--line);border-radius:11px;padding:12px 14px;cursor:pointer;transition:all .15s}.schema-card:hover{border-color:var(--brand);box-shadow:var(--shadow)}.schema-card .tn{font-size:13px;font-weight:700;color:var(--brand-deep);font-family:var(--mono)}.schema-card .tc{font-size:11px;color:var(--ink-faint);margin-top:3px}.schema-detail{background:var(--code-bg);border-radius:11px;padding:15px 17px;margin:12px 0;font-family:var(--mono);font-size:12.5px;color:var(--code-ink);white-space:pre;overflow-x:auto;line-height:1.6}.table-pill{display:inline-block;font-family:var(--mono);font-size:12px;background:var(--brand-soft);color:var(--brand-deep);padding:1px 7px;border-radius:5px;font-weight:600}.cmp-table{width:100%;border-collapse:collapse;margin:14px 0;font-size:13.5px}.cmp-table th{background:var(--line-soft);padding:9px;border:1px solid var(--line);text-align:left}.cmp-table td{padding:9px;border:1px solid var(--line);color:var(--ink-soft)}.toast{position:fixed;top:20px;left:50%;transform:translate(-50%);background:var(--ink);color:#fff;padding:10px 20px;border-radius:10px;font-size:13px;z-index:100;opacity:0;transition:opacity .3s;pointer-events:none}.toast.show{opacity:1}.toast.ok{background:var(--accent)}.toast.err{background:var(--rose)}