.subject-menu{position:relative;color:#827a91;font-size:13px;font-weight:650}
.subject-menu summary{cursor:pointer;list-style:none;white-space:nowrap}
.subject-menu summary::after{content:' ▾';font-size:10px}
.subject-menu summary::-webkit-details-marker{display:none}
.subject-menu[open] summary{color:var(--purple)}
#subject-navigation{position:absolute;top:34px;left:-15px;min-width:215px;padding:8px;background:white;border:1px solid var(--line);border-radius:13px;box-shadow:0 12px 30px #29253f15}
#subject-navigation a{display:block;padding:10px 12px;border-radius:8px}
#subject-navigation a:hover{background:var(--lavender)}
.subject-card.vietnamese{background:#eaf4fb;border-color:#dcebf4}
.vietnamese .subject-icon{background:#cee5f6;color:#3b77a3;transform:rotate(-4deg)}
.vietnamese .subject-meta{color:#3b77a3}
.subject-card.nature{background:#edf5e8;border-color:#dfead7}
.nature .subject-icon{background:#d6e8c8;color:#587b42;transform:rotate(4deg)}
.nature .subject-meta{color:#587b42}
.subject-card h3{font-size:21px;letter-spacing:-.025em}
.brand img{object-fit:contain;flex-shrink:0}
@media(min-width:851px){.learning-grid:has(> :nth-child(4):last-child){grid-template-columns:repeat(4,1fr)}.learning-grid:has(> :nth-child(4):last-child) .topic-top{align-items:start}.learning-grid:has(> :nth-child(4):last-child) .topic-emoji{width:35px;height:35px;font-size:18px;flex-shrink:0}}
@media(max-width:850px){#subject-navigation{position:static;margin-top:12px;box-shadow:none;min-width:205px}.subject-menu{font-size:12px}}
@media(max-width:600px){.subject-card h3{font-size:20px}.brand small{letter-spacing:.8px}}