*,:before,:after{box-sizing:border-box}body{background:var(--color-background);color:var(--color-text);margin:0;font-family:system-ui,-apple-system,Segoe UI,sans-serif;line-height:1.5}.container{max-width:960px;margin:0 auto;padding:24px 16px}.narrow{max-width:440px}.stack{flex-direction:column;gap:12px;display:flex}.row{flex-wrap:wrap;gap:12px;display:flex}.muted{color:var(--color-text-muted)}.grow{flex:240px;min-width:0}.card{background:var(--color-surface);border:1px solid var(--color-border);border-radius:10px;padding:16px}.error{color:var(--color-danger)}.notice{background:var(--color-surface);border-left:4px solid var(--color-primary);padding:8px 12px}input{font:inherit;border:1px solid var(--color-border-strong);background:var(--color-background);color:var(--color-text);border-radius:6px;padding:10px 12px}input[aria-invalid=true]{border-color:var(--color-danger)}button{font:inherit;background:var(--color-primary);color:var(--color-on-primary);cursor:pointer;border:0;border-radius:6px;padding:10px 16px}button:disabled{opacity:.6;cursor:progress}button.secondary{background:var(--color-surface);color:var(--color-text);border:1px solid var(--color-border-strong)}button.danger{background:var(--color-danger);color:var(--color-on-danger)}button.link{color:var(--color-primary);background:0 0;padding:0;text-decoration:underline}:focus-visible{outline:3px solid var(--color-primary);outline-offset:2px}fieldset{border:0;margin:0;padding:0}textarea,select{font:inherit;border:1px solid var(--color-border-strong);background:var(--color-background);color:var(--color-text);border-radius:6px;padding:10px 12px}textarea[aria-invalid=true],select[aria-invalid=true]{border-color:var(--color-danger)}table.list{border-collapse:collapse;width:100%}table.list th,table.list td{text-align:left;border-bottom:1px solid var(--color-border);padding:8px}.articles{padding:0;list-style:none}.narrow-article{max-width:720px}.article-body h2,.article-body h3{margin-bottom:4px}.facts{grid-template-columns:max-content 1fr;gap:4px 16px;display:grid}.facts dt{font-weight:600}.facts dd{margin:0}.diff{white-space:pre-wrap;padding:0;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;list-style:none}.diff-added{background:color-mix(in srgb, var(--color-success) 15%, transparent)}.diff-removed{background:color-mix(in srgb, var(--color-danger) 15%, transparent);text-decoration:line-through}.visually-hidden{clip-path:inset(50%);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}a.button{background:var(--color-primary);color:var(--color-on-primary);border-radius:6px;padding:10px 16px;text-decoration:none;display:inline-block}.course-progress{gap:4px}.course-progress progress{width:100%;max-width:320px;accent-color:var(--color-primary)}.chat-layout{grid-template-columns:minmax(200px,260px) minmax(0,1fr);align-items:start;gap:24px;display:grid}@media (max-width:720px){.chat-layout{grid-template-columns:minmax(0,1fr)}}.chat-thread-list,.chat-messages,.chat-source-list{margin:0;padding:0;list-style:none}.chat-thread a[aria-current=page]{font-weight:600}.chat-question{background:color-mix(in srgb, var(--color-primary) 12%, var(--color-surface));white-space:pre-wrap;overflow-wrap:anywhere;border-radius:10px;align-self:flex-end;max-width:85%;padding:12px 16px}.chat-answer{overflow-wrap:anywhere}.chat-ai-label{color:var(--color-text-muted);margin:0;font-size:.875rem;font-weight:600}.chat-conversation textarea{resize:vertical;width:100%}.skip-link{z-index:100;background:var(--color-background);color:var(--color-text);padding:10px 16px;position:fixed;top:8px;left:16px;transform:translateY(calc(-100% - 16px))}.skip-link:focus{transform:translateY(0)}.studio-navigation a{align-items:center;min-height:44px;display:inline-flex}.studio-navigation a[aria-current]{text-underline-offset:.2em;font-weight:700;text-decoration-thickness:.15em}