.track-grid{grid-template-columns:1fr;gap:30px;max-width:1080px;margin:0 auto;display:grid}@media (min-width:960px){.track-grid{grid-template-columns:1fr 1fr;align-items:start;gap:50px}}.track-card{background:var(--white);border:1px solid var(--border);border-radius:var(--r-2xl);box-shadow:var(--sh-md);padding:30px 24px}@media (min-width:600px){.track-card{padding:36px 32px}}.track-card h3{letter-spacing:-.025em;margin-bottom:6px;font-size:22px;font-weight:800}.track-card h3 em{background:var(--brand-grad);color:#0000;-webkit-background-clip:text;background-clip:text;font-style:normal}.track-card .intro{color:var(--muted);margin-bottom:22px;font-size:14px;line-height:1.55}.preview-card{border:1px solid var(--border);border-radius:var(--r-2xl);background:linear-gradient(165deg,#f8fafc 0%,#fff 100%);padding:26px 24px;position:relative}.preview-tag{background:var(--ink);color:#fff;border-radius:var(--r-full);letter-spacing:.08em;text-transform:uppercase;padding:4px 12px;font-size:10.5px;font-weight:800;position:absolute;top:-10px;left:24px}.preview-card.live .preview-tag{background:var(--brand-grad);box-shadow:var(--sh-glow-red)}.preview-card-h{border-bottom:1px solid var(--border);flex-wrap:wrap;justify-content:space-between;align-items:center;gap:10px;margin-bottom:18px;padding-bottom:18px;display:flex}.preview-card-h .id{font-family:var(--f-mono);color:var(--muted);letter-spacing:.04em;margin-bottom:4px;font-size:11.5px}.preview-card-h h4{letter-spacing:-.015em;font-size:16px;font-weight:700}.explain-grid{grid-template-columns:1fr;gap:14px;max-width:1080px;margin:40px auto 0;display:grid}@media (min-width:720px){.explain-grid{grid-template-columns:repeat(3,1fr)}}.explain{background:var(--white);border:1px solid var(--border);border-radius:var(--r-lg);transition:all .25s var(--ease);padding:20px}.explain:hover{box-shadow:var(--sh-md);border-color:#0000;transform:translateY(-3px)}.explain h5{margin:12px 0 6px;font-size:14.5px;font-weight:700}.explain p{color:var(--muted);font-size:13px;line-height:1.55}.track-not-found{background:var(--brand-soft);border:1px solid var(--brand);border-radius:var(--r-lg);color:var(--brand-deep);margin-bottom:14px;padding:16px 18px;font-size:13.5px;line-height:1.55}.track-not-found strong{font-weight:700}