:root{
  --bg:#fafafa;
  --card:#fff;
  --accent:#1976d2;
  --font: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

*{box-sizing:border-box;font-family:var(--font);}

body{margin:0;background:var(--bg);color:#111}
.topbar{display:flex;align-items:center;justify-content:space-between;padding:10px 12px;background:var(--accent);color:#fff}
.topbar h1{margin:0;font-size:18px}
.fab{position:fixed;bottom:18px;right:18px;width:56px;height:56px;border-radius:50%;background:var(--accent);color:#fff;border:none;font-size:26px}
.fab.small{width:44px;height:44px;right:80px;bottom:18px}
.subjects-list{display:flex;flex-direction:column;gap:10px;padding:12px}
.subject-tile{display:flex;align-items:center;justify-content:space-between;background:var(--card);padding:10px;border-radius:8px;box-shadow:0 1px 4px rgba(0,0,0,.08)}
.subject-icon{font-size:28px;margin-left:8px}
.subject-name{flex:1;text-align:right;padding-right:8px;font-weight:600}
.subject-view{padding:12px}
.hidden{display:none}
.tabs{display:flex;gap:6px;margin-bottom:12px}
.tab{flex:1;padding:10px;border-radius:8px;border:none;color:#fff;font-weight:700}
.tab[disabled]{opacity:.6}
.tab-content{min-height:200px;background:var(--card);padding:12px;border-radius:8px;box-shadow:0 1px 6px rgba(0,0,0,.05)}
.note-card{background:#f8f8f8;padding:10px;border-radius:6px;margin-bottom:8px;cursor:pointer}
.pdf-item, .audio-item, .img-grid{margin-bottom:8px}
.img-grid{display:flex;flex-wrap:wrap;gap:6px}
.img-grid img{width:100px;height:100px;object-fit:cover;border-radius:6px;cursor:pointer}
.fullscreen-img{position:fixed;inset:0;background:rgba(0,0,0,.9);display:flex;align-items:center;justify-content:center}
.fullscreen-img img{max-width:98%;max-height:98%}
.delete-subject{background:transparent;border:none;font-size:18px;cursor:pointer}