* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; margin: 0; background: #f8f9fa; color: #333; }
.nav { display: flex; background: #fff; position: sticky; top: 0; z-index: 100; box-shadow: 0 2px 10px rgba(0,0,0,0.05); }
.nav div { flex: 1; text-align: center; padding: 15px 0; cursor: pointer; transition: 0.3s; font-size: 15px; }
.nav div.active { color: #007bff; border-bottom: 3px solid #007bff; font-weight: bold; }
.container { padding: 15px; max-width: 1200px; margin: 0 auto; }
.search-container { margin-bottom: 15px; }
.search-box { width: 100%; padding: 12px 20px; border-radius: 25px; border: 1px solid #ddd; outline: none; font-size: 14px; transition: 0.3s; }
.search-box:focus { border-color: #007bff; box-shadow: 0 0 8px rgba(0,123,255,0.1); }
.file-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
@media (min-width: 768px) { .file-list { grid-template-columns: repeat(4, 1fr); } }
@media (min-width: 1024px) { .file-list { grid-template-columns: repeat(6, 1fr); } }
.file-item { background: #fff; padding: 20px 10px; border-radius: 12px; text-align: center; position: relative; cursor: pointer; border: 1px solid transparent; transition: 0.2s; }
.file-item:hover { border-color: #007bff; background: #f0f7ff; }
.pdf-badge { position: absolute; top: 5px; right: 5px; background: #ff4757; color: white; font-size: 11px; padding: 2px 7px; border-radius: 10px; font-weight: bold; }
.icon { font-size: 45px; margin-bottom: 10px; display: block; }
.name { font-size: 14px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; padding: 0 5px; }