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8px;border-radius:100px}.topic-name{font-family:var(--font-display);font-size:17px;font-weight:600;margin-bottom:4px}.topic-hint{font-size:13px;color:var(--ink-soft);margin-bottom:14px;line-height:1.4}.mastery-track{height:5px;border-radius:3px;background:var(--paper-line);overflow:hidden;margin-bottom:8px}.mastery-fill{height:100%;background:var(--teal);border-radius:3px;transition:width .3s ease}.topic-meta{font-family:var(--font-mono);font-size:11px;color:var(--ink-soft)}.question-view{max-width:640px;margin:0 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var(--paper-line)}.explanation-label{font-family:var(--font-mono);font-size:11px;text-transform:uppercase;letter-spacing:.08em;color:var(--ink-soft);margin-bottom:6px}.explanation p{line-height:1.55;margin:0 0 18px}.btn{display:inline-flex;align-items:center;gap:8px;font-family:var(--font-body);font-weight:600;font-size:14px;border-radius:8px;padding:11px 18px;cursor:pointer;border:none}.btn--primary{background:var(--ink);color:var(--paper)}.btn--primary:hover{background:var(--gold)}.btn--ghost{background:transparent;border:1px solid var(--paper-line);color:var(--ink)}.footer{margin-top:56px;padding-top:20px;border-top:1px solid var(--paper-line);font-size:12px;color:var(--ink-soft);text-align:center}@media (max-width: 560px){.header{flex-direction:column;align-items:flex-start}.stats-strip{align-self:stretch;justify-content:space-between}}.ap-shell-nav{display:flex;align-items:center;justify-content:space-between;padding:12px 24px;background:#16233b;border-bottom:1px solid #2a3a58;position:sticky;top:0;z-index:100}.ap-shell-brand{display:flex;align-items:center;gap:10px}.ap-shell-stamp{width:28px;height:28px;border-radius:50%;border:1.5px solid #b4841e;box-shadow:0 0 0 3px #16233b,0 0 0 4px #b4841e;display:flex;align-items:center;justify-content:center;color:#b4841e}.ap-shell-word{font-family:Fraunces,serif;font-weight:600;font-size:16px;color:#faf7f1}.ap-shell-tabs{display:flex;gap:6px}.ap-shell-tab{font-family:IBM Plex Mono,monospace;font-size:12px;padding:8px 14px;border-radius:100px;border:1px solid transparent;background:transparent;color:#9aa7bf;cursor:pointer}.ap-shell-tab:hover{color:#faf7f1}.ap-shell-tab.active{background:#faf7f1;color:#16233b;font-weight:600}@media (max-width: 480px){.ap-shell-nav{flex-direction:column;align-items:flex-start;gap:10px}}:root{--ink: #16233b;--ink-soft: #5b6a85;--paper: #faf7f1;--paper-line: #e7e0d2;--gold: #b4841e;--teal: #2c6b68;--font-display: "Fraunces", serif;--font-body: "Inter", system-ui, sans-serif;--font-mono: "IBM Plex Mono", monospace}*{box-sizing:border-box}html,body,#root{height:100%}body{margin:0;background:var(--paper);background-image:radial-gradient(circle at 1px 1px,var(--paper-line) 1px,transparent 0);background-size:28px 28px;color:var(--ink);font-family:var(--font-body);-webkit-font-smoothing:antialiased}*:focus-visible{outline:2px solid var(--gold);outline-offset:2px}@media (prefers-reduced-motion: reduce){*{animation-duration:.001ms!important;transition-duration:.001ms!important}}button{font-family:inherit}