.subject-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px;margin:30px 0}.subject-card{display:flex;align-items:flex-start;flex-direction:column;gap:16px;padding:28px;min-width:0}.subject-card h2{font-size:27px}.subject-card p{line-height:1.9;color:#687969}.subject-card .btn{margin-top:auto;width:100%}.subject-symbol{font-size:36px;color:#8ba57b}.subject-card.biology{background:#f3f6ed}.subject-card.chemistry{background:#f2f1f8}.subject-card.chemistry .btn{background:#596482;border-color:#596482}.science-note{margin-top:24px;padding:20px;border:1px solid #dddacf;border-radius:15px;background:#f5f1e6;line-height:1.9;font-size:13px}.subject-switch{display:inline-flex;align-items:center;font-size:13px;min-height:44px;white-space:nowrap;color:#526c50}.topbar{flex-wrap:wrap;gap:10px}.topbar .account-button{margin-left:auto}@media(max-width:900px){.subject-grid{grid-template-columns:1fr}.subject-card{padding:24px}.subject-card p br{display:none}.subject-card .btn{margin-top:8px}.subject-grid{margin-top:22px}.subject-switch{font-size:12px}.subject-card h2{font-size:25px}}

@media(min-width:900px){.subject-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
.subject-card.chinese .subject-symbol{color:#71805f}