*{box-sizing:border-box}
:root{
  --bg:#f1dfcc; --card:#f3e7db; --ink:#362639; --muted:#6a5164; --border:#e0cec1;
  --accent:#c79ad7; --accent-2:#7c3aed; --shadow: rgba(0,0,0,.08);
}
html,body{height:100%}
body{margin:0; font-family:system-ui,-apple-system,Segoe UI,Roboto,Ubuntu; background:var(--bg); color:var(--ink); display:flex; flex-direction:column}
.app-header{background:#e8d3e8; padding:14px 16px; border-bottom:1px solid var(--border); position:sticky; top:0; z-index:5; display:flex; align-items:center; gap:12px}
.app-header h1{margin:0; font-size:20px}
.app-header .back{color:var(--ink); text-decoration:none; font-size:20px; padding:4px 8px; border-radius:10px; border:1px solid transparent}
.app-header .back:hover{border-color:var(--border); background:#f6ebf6}
.app-footer{padding:10px 16px; border-top:1px solid var(--border); text-align:center; color:var(--muted); background:#f3e7db}

.container{max-width:960px; margin:0 auto; width:100%; padding:16px}
.subtitle{margin:0 0 12px}
.grid{display:grid; grid-template-columns:repeat(auto-fill,minmax(200px,1fr)); gap:14px}
.card{background:linear-gradient(135deg,#d7c4ff,#c9a4e8); color:#2a2139; border:1px solid var(--border); border-radius:18px; padding:18px; box-shadow:0 10px 20px var(--shadow); text-decoration:none; display:flex; flex-direction:column; gap:10px}
.card .icon{font-size:28px}
.card.subject{color:#fff; font-weight:700; font-size:18px}
.card.s1{background:linear-gradient(135deg,#6ea8ff,#7c9fff)}
.card.s2{background:linear-gradient(135deg,#28b487,#2dd4bf)}
.card.s3{background:linear-gradient(135deg,#ff8c42,#ff6f3c)}
.card.s4{background:linear-gradient(135deg,#b04cff,#7c3aed)}
.card.s5{background:linear-gradient(135deg,#9a6b4f,#84562f)}
.card.s6{background:linear-gradient(135deg,#808b96,#5c677d)}

.tabs{display:flex; gap:8px; padding:10px 16px; border-bottom:1px solid var(--border); background:#e8d3e8; position:sticky; top:54px; z-index:4}
.tab-btn{background:#f3e7db; color:var(--muted); border:1px solid var(--border); padding:8px 12px; border-radius:12px; cursor:pointer}
.tab-btn.active{color:var(--ink); border-color:var(--accent-2); box-shadow:0 0 0 2px rgba(124,58,237,.1)}

.toolbar{display:flex; gap:8px; justify-content:flex-end; margin-bottom:12px}
.primary{background:linear-gradient(135deg,var(--accent),var(--accent-2)); border:none; color:white; padding:10px 14px; border-radius:12px; cursor:pointer; font-weight:700}
.ghost{background:transparent; color:var(--ink); border:1px solid var(--border); padding:8px 12px; border-radius:12px; cursor:pointer}
.file-input{position:relative; overflow:hidden}
.file-input input{position:absolute; inset:0; opacity:0; cursor:pointer}

.tab{display:none}
.tab.active{display:block}

.cards{list-style:none; margin:0; padding:0; display:grid; grid-template-columns:repeat(auto-fill,minmax(260px,1fr)); gap:12px}
.item{background:var(--card); border:1px solid var(--border); border-radius:16px; padding:12px; box-shadow:0 10px 20px var(--shadow)}
.item h4{margin:0 0 6px; font-size:16px}
.item .meta{color:var(--muted); font-size:12px}
.item .actions{display:flex; gap:8px; margin-top:10px}
.btn{border:1px solid var(--border); background:transparent; padding:6px 10px; border-radius:10px; cursor:pointer}
.btn.danger{border-color:#d66; color:#a00}

.empty{color:var(--muted); text-align:center; margin-top:24px}
.muted{color:var(--muted)}

.dialog{border:none; border-radius:16px; padding:0; max-width:520px; width:95%}
.dialog::backdrop{background:rgba(0,0,0,.4)}
dialog form{padding:16px}
label{display:block; margin-bottom:10px; color:var(--muted)}
input[type=text], textarea{
  width:100%; border:1px solid var(--border); background:#fff8f0; color:var(--ink); padding:10px; border-radius:12px; outline:none;
}

.viewer{margin-top:16px; background:#fff; border:1px solid var(--border); border-radius:12px; padding:10px; min-height:160px}
.viewer iframe, .viewer object, .viewer img, .viewer audio{width:100%}
audio{margin-top:8px}