:root{--bg:#fafbfc;--surface:#fff;--surface-2:#e8f0fe;--border:#e3e6eb;--text:#1a1d22;--text-dim:#6b7280;--accent:#4a90d9}*{box-sizing:border-box}body{background:var(--bg);color:var(--text);min-height:100vh;margin:0;padding:48px 24px 96px;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,PingFang TC,Noto Sans TC,sans-serif}#app{max-width:720px;margin:0 auto}.hero{margin-bottom:48px}.hero h1{letter-spacing:-.02em;margin:0;font-size:40px}.hero .subtitle{color:var(--text-dim);margin:8px 0 0;font-size:16px}.groups{flex-direction:column;gap:32px;display:flex}.group-title{text-transform:uppercase;letter-spacing:.08em;color:var(--text-dim);margin:0 0 12px;font-size:13px;font-weight:600}.course-list{flex-direction:column;gap:8px;margin:0;padding:0;list-style:none;display:flex}.course-link{background:var(--surface);border:1px solid var(--border);color:inherit;border-radius:10px;grid-template-columns:auto 1fr auto;align-items:baseline;gap:16px;padding:14px 18px;text-decoration:none;transition:background .12s,border-color .12s,box-shadow .12s,transform .12s;display:grid;box-shadow:0 1px 2px #0f172a0a}.course-link:hover{background:var(--surface-2);border-color:var(--accent);box-shadow:0 2px 8px #4a90d92e}.course-link:active{transform:translateY(1px)}.course-slug{color:var(--accent);min-width:64px;font-family:SF Mono,Fira Code,ui-monospace,monospace;font-size:13px}.course-title{font-size:15px}.course-meta{color:var(--text-dim);font-size:12px}.empty{background:var(--surface);border:1px dashed var(--border);color:var(--text-dim);border-radius:10px;padding:24px}code{background:var(--surface-2);border-radius:4px;padding:1px 6px;font-family:SF Mono,Fira Code,ui-monospace,monospace;font-size:.9em}