:root{--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light;--paper:#eef1f8;--paper-2:#fff;--ink:#18203a;--ink-soft:#5b6685;--ink-faint:#5b6478;--blueprint:#2f5fd0;--blueprint-700:#234aa8;--blueprint-soft:#9fb2e6;--good:#1f9d68;--good-bg:#e6f6ee;--good-ink:#15704a;--bad:#d6455f;--bad-bg:#fdeaed;--bad-ink:#a92e45;--warn:#b9791b;--line:#d6dded;--grid-minor:#2f5fd012;--grid-major:#2f5fd021;--radius:12px;--radius-sm:8px;--shadow:0 1px 2px #18203a0f, 0 8px 24px #18203a0f;--mono:ui-monospace, "SF Mono", "SFMono-Regular", Menlo, Consolas, "Liberation Mono", monospace;--sans:ui-sans-serif, system-ui, -apple-system, "SF Pro Text", "Hiragino Sans", "Yu Gothic UI", "Segoe UI", sans-serif}*{box-sizing:border-box}html,body{height:100%;margin:0}body{font-family:var(--sans);color:var(--ink);background-color:var(--paper);background-image:linear-gradient(var(--grid-minor) 1px, transparent 1px), linear-gradient(90deg, var(--grid-minor) 1px, transparent 1px), linear-gradient(var(--grid-major) 1px, transparent 1px), linear-gradient(90deg, var(--grid-major) 1px, transparent 1px);-webkit-font-smoothing:antialiased;background-size:8px 8px,8px 8px,64px 64px,64px 64px}#app{flex-direction:column;min-height:100%;display:flex}.topbar{border-bottom:1px solid var(--line);-webkit-backdrop-filter:blur(6px);backdrop-filter:blur(6px);z-index:10;background:#ffffffb3;align-items:center;gap:12px;padding:14px 20px;display:flex;position:sticky;top:0}.brand{letter-spacing:.02em;cursor:pointer;color:inherit;background:0 0;border:none;align-items:center;gap:10px;padding:0;font-size:1.05rem;font-weight:700;display:flex}.brand img{width:28px;height:28px}.brand small{color:var(--ink-faint);letter-spacing:0;font-weight:500}.topbar-spacer{flex:1}.crumb{min-width:0;color:var(--ink-soft);align-items:center;gap:12px;font-size:.9rem;display:flex}.crumb__back{color:var(--blueprint);flex:none;padding:8px 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h1{letter-spacing:.01em;margin:0 0 6px;font-size:1.7rem}.intro p{color:var(--ink-soft);max-width:62ch;margin:0;line-height:1.6}.track-grid{grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:16px;display:grid}.track-card{background:var(--paper-2);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);text-align:left;flex-direction:column;gap:8px;padding:16px 16px 14px;display:flex}.track-card__head{align-items:center;gap:10px;display:flex}.track-card__emoji{font-size:1.5rem;line-height:1}.track-card__title{margin:0;font-size:1.05rem;font-weight:700}.track-card__summary{color:var(--ink-soft);font-size:.9rem;line-height:1.5}.lesson-list{flex-direction:column;gap:2px;margin:2px 0 4px;display:flex}.lesson-row{text-align:left;font:inherit;color:var(--ink);cursor:pointer;background:0 0;border:0;border-radius:6px;align-items:center;gap:8px;min-height:40px;padding:6px 8px;font-size:.9rem;transition:background 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