.primer-app{--pr-bg:#fafaf7;--pr-surface:#fff;--pr-ink:#1a1a1a;--pr-ink-2:#4a4a4a;--pr-ink-3:#6e6e6e;--pr-ink-4:#a0a0a0;--pr-line:#ebe9e4;--pr-line-2:#d8d6d0;--pr-accent:#a6192e;--pr-accent-soft:#f7eaec;--pr-good:#228b22;--pr-radius:12px;background:var(--pr-bg);color:var(--pr-ink);letter-spacing:-.005em;font-family:Inter,Noto Sans SC,-apple-system,system-ui,sans-serif}.primer-container{max-width:720px;margin:0 auto;padding:48px 24px 80px}.primer-header{text-align:center;margin-bottom:36px}.primer-eyebrow{letter-spacing:.18em;color:var(--pr-ink-3);text-transform:uppercase;margin-bottom:12px;font-size:11px}.primer-title{margin:0 0 14px;font-family:Instrument Serif,Noto Serif SC,Georgia,serif;font-size:40px;line-height:1.15}.primer-lead{color:var(--pr-ink-2);max-width:560px;margin:0 auto;font-size:15px;line-height:1.7}.pr-option{background:var(--pr-surface);border:1px solid var(--pr-line);border-radius:var(--pr-radius);color:inherit;margin-bottom:14px;padding:24px;text-decoration:none;transition:all .15s;display:block}.pr-option:hover{border-color:var(--pr-accent);transform:translateY(-1px);box-shadow:0 4px 14px #0000000a}.pr-option-tag{letter-spacing:.08em;text-transform:uppercase;border-radius:4px;margin-bottom:10px;padding:3px 8px;font-size:10.5px;font-weight:600;display:inline-block}.pr-option-tag.beginner{color:#b08000;background:#fff7e0}.pr-option-tag.medium{color:#0050b3;background:#e6f2ff}.pr-option-tag.expert{color:#4a4a4a;background:#f0f0f0}.pr-option-title{margin:0 0 8px;font-family:Instrument Serif,Noto Serif SC,Georgia,serif;font-size:22px}.pr-option-desc{color:var(--pr-ink-2);font-size:13.5px;line-height:1.6}.pr-option-meta{color:var(--pr-ink-4);margin-top:10px;font-family:JetBrains Mono,ui-monospace,monospace;font-size:12px}.pr-card-stage{min-height:480px;position:relative}.pr-card{background:var(--pr-surface);border:1px solid var(--pr-line);border-radius:var(--pr-radius);padding:36px 32px}.pr-card-num{letter-spacing:.16em;color:var(--pr-ink-3);text-transform:uppercase;margin-bottom:14px;font-family:JetBrains Mono,ui-monospace,monospace;font-size:11px}.pr-card-title{margin:0 0 18px;font-family:Instrument Serif,Noto Serif SC,Georgia,serif;font-size:30px;line-height:1.2}.pr-card h3{color:var(--pr-ink);margin:18px 0 6px;font-size:14px;font-weight:700}.pr-card p{color:var(--pr-ink-2);margin:0 0 8px;font-size:14.5px;line-height:1.75}.pr-card ul{color:var(--pr-ink-2);margin:4px 0 12px;padding-left:18px;font-size:14px;line-height:1.7}.pr-card li{margin-bottom:4px}.pr-card-callout{background:var(--pr-bg);border-left:3px solid var(--pr-accent);color:var(--pr-ink-2);margin:18px 0;padding:12px 16px;font-size:13.5px;line-height:1.7}.pr-progress{gap:5px;margin:20px 0 14px;display:flex}.pr-progress-dot{background:var(--pr-line);border-radius:2px;flex:1;height:4px;transition:background .2s}.pr-progress-dot.active{background:var(--pr-accent)}.pr-progress-dot.passed{background:var(--pr-ink-3)}.pr-nav{justify-content:space-between;align-items:center;margin-top:24px;display:flex}.pr-btn{cursor:pointer;border:none;border-radius:999px;align-items:center;gap:6px;padding:10px 18px;font-size:13px;font-weight:600;text-decoration:none;transition:all .15s;display:inline-flex}.pr-btn-primary{background:var(--pr-accent);color:#fff}.pr-btn-primary:hover{background:#7a1322}.pr-btn-ghost{color:var(--pr-ink-2);background:0 0}.pr-btn-ghost:hover{color:var(--pr-ink)}.pr-btn:disabled{opacity:.4;cursor:not-allowed}.pr-term{background:var(--pr-accent-soft);color:var(--pr-accent);border-radius:4px;padding:1px 7px;font-size:.92em;font-weight:600;display:inline-block}.pr-back-link{color:var(--pr-ink-3);align-items:center;gap:4px;margin-bottom:24px;font-size:12px;text-decoration:none;display:inline-flex}.pr-back-link:hover{color:var(--pr-ink)}.pr-quiz-q{background:var(--pr-surface);border:1px solid var(--pr-line);border-radius:var(--pr-radius);margin-bottom:14px;padding:24px}.pr-quiz-num{color:var(--pr-ink-3);letter-spacing:.1em;margin-bottom:8px;font-family:JetBrains Mono,ui-monospace,monospace;font-size:11px}.pr-quiz-text{color:var(--pr-ink);margin-bottom:14px;font-size:16px;font-weight:600}.pr-quiz-opt{text-align:left;border:1.5px solid var(--pr-line);width:100%;color:var(--pr-ink-2);cursor:pointer;background:#fff;border-radius:8px;margin-bottom:6px;padding:10px 14px;font-size:14px;transition:all .12s;display:block}.pr-quiz-opt:hover{border-color:var(--pr-accent);color:var(--pr-ink)}.pr-quiz-opt.selected{border-color:var(--pr-accent);background:var(--pr-accent-soft);color:var(--pr-accent)}.pr-explain{background:var(--pr-surface);border:1px solid var(--pr-line);border-radius:var(--pr-radius);margin-bottom:16px;padding:28px 28px 24px}.primer-bubble-btn{z-index:50;background:var(--pr-ink);color:#fff;cursor:pointer;border:none;border-radius:999px;align-items:center;gap:7px;padding:11px 18px;font-size:13px;font-weight:600;transition:transform .15s,background .15s;display:inline-flex;position:fixed;bottom:20px;right:20px;box-shadow:0 6px 24px #0000002e}.primer-bubble-btn:hover{background:var(--pr-accent);transform:translateY(-1px)}.primer-bubble-dot{background:#5fffa0;border-radius:50%;width:6px;height:6px;animation:2s ease-in-out infinite pr-pulse;display:inline-block}@keyframes pr-pulse{0%,to{opacity:1}50%{opacity:.4}}.primer-chat-overlay{z-index:100;background:#0000002e;justify-content:flex-end;display:flex;position:fixed;inset:0}.primer-chat-panel{background:var(--pr-surface);flex-direction:column;width:420px;max-width:100vw;height:100vh;display:flex;box-shadow:-4px 0 24px #0000001a}.primer-chat-header{border-bottom:1px solid var(--pr-line);background:var(--pr-bg);justify-content:space-between;align-items:flex-start;padding:18px 20px 14px;display:flex}.primer-chat-body{flex-direction:column;flex:1;gap:10px;padding:16px 20px;display:flex;overflow-y:auto}.primer-chat-msg{white-space:pre-wrap;word-break:break-word;border-radius:14px;max-width:88%;padding:10px 14px;font-size:13.5px;line-height:1.65}.primer-chat-msg.user{background:var(--pr-accent);color:#fff;border-bottom-right-radius:4px;align-self:flex-end}.primer-chat-msg.ai{background:var(--pr-bg);color:var(--pr-ink-2);border-bottom-left-radius:4px;align-self:flex-start}.primer-chat-input-wrap{border-top:1px solid var(--pr-line);background:var(--pr-surface);align-items:flex-end;gap:8px;padding:12px;display:flex}.primer-chat-input{border:1.5px solid var(--pr-line);resize:none;background:var(--pr-bg);border-radius:12px;flex:1;max-height:100px;padding:10px 14px;font-family:inherit;font-size:13.5px}.primer-chat-input:focus{border-color:var(--pr-accent);background:#fff;outline:none}.primer-chat-send{background:var(--pr-ink);color:#fff;cursor:pointer;border:none;border-radius:12px;padding:10px 16px;font-size:13px;font-weight:600;transition:background .15s}.primer-chat-send:hover:not(:disabled){background:var(--pr-accent)}.primer-chat-send:disabled{opacity:.4;cursor:not-allowed}@media (max-width:640px){.primer-chat-panel{width:100%}}.pr-explain-eyebrow{letter-spacing:.16em;color:var(--pr-accent);text-transform:uppercase;margin-bottom:10px;font-family:JetBrains Mono,ui-monospace,monospace;font-size:11px}