/* Study surfaces inherit the active world's paper, ink, type and accent. */
.study-dialog { width:min(780px,calc(100vw - 20px)); max-height:92dvh; overflow:auto; padding:18px; border:1px solid var(--n84); border-radius:var(--r-soft); color:var(--ink); background:var(--paper); font:inherit; }
.study-dialog > header { display:flex; justify-content:space-between; align-items:center; gap:12px; }
.study-dialog h2 { margin:0 0 12px; font:inherit; font-size:1.3em; font-weight:700; }
.study-dialog button, .study-dialog select { min-height:42px; padding:8px 12px; color:var(--ink); background:var(--paper); border:1px solid var(--n84); border-radius:var(--r-soft); font:inherit; cursor:pointer; }
.study-dialog button:hover, .study-dialog button:focus-visible { border-color:var(--accent-ui); outline:2px solid var(--accent-ui); outline-offset:2px; }
.study-dialog button:disabled { opacity:.55; cursor:default; }
.study-dialog label { display:grid; gap:5px; margin:8px 0; }
.study-dialog input, .study-dialog textarea { min-width:0; width:100%; padding:9px; border:1px solid var(--n84); border-radius:var(--r-soft); color:var(--ink); background:var(--paper); font:inherit; box-sizing:border-box; }
.study-dialog input[type="checkbox"] { width: 20px; height: 20px; accent-color: var(--pen); }
.study-actions { display:flex; flex-wrap:wrap; gap:8px; margin:12px 0; align-items:center; }
.study-actions[hidden] { display:none; }
.study-card-list { padding-left:24px; }
.study-card-list > li, .study-library-list > article { border-bottom:1px solid var(--n84); padding:12px 0; }
.study-library-list { max-height:60dvh; overflow:auto; }
.study-library-list > div { display:flex; justify-content:space-between; gap:12px; padding:8px 0; }
.study-dialog .study-card-face { display:block; width:100%; min-height:240px; max-height:50dvh; overflow:auto; text-align:center; box-shadow:var(--shadow-lift); background:color-mix(in oklab,var(--paper) 94%,var(--accent-ui))!important; }
.study-card-face .flashcard-item { margin:14px 8px; }
.study-card-face img { max-width:100%; max-height:250px; object-fit:contain; }
.study-card-face .flashcard-math { overflow:auto; }
.board-object[data-kind="deck"] { overflow:visible; padding:12px; min-width:240px; min-height:210px; }
.board-object[data-kind="deck"] > .object-body { width:100%; height:100%; }
.study-deck-stack { position:relative; isolation:isolate; display:flex; flex-direction:column; gap:6px; width:100%; height:100%; box-sizing:border-box; padding:10px; color:var(--ink); background:var(--paper); border:2px solid var(--accent-ui); border-radius:var(--r-soft); box-shadow:var(--shadow-lift); font:inherit; line-height:1.4; text-align:center; }
.study-deck-stack::before, .study-deck-stack::after { content:""; position:absolute; inset:0; z-index:-1; border:1px solid var(--accent-ui); border-radius:inherit; background:var(--paper); transform:translate(5px,5px) rotate(1deg); }
.study-deck-stack::before { transform:translate(9px,9px) rotate(2deg); }
.study-deck-title { font-size:1em; overflow:hidden; text-overflow:ellipsis; white-space:nowrap; flex-shrink:0; }
.study-deck-face { flex:1; min-height:36px; overflow:auto; padding:8px; cursor:pointer; overflow-wrap:anywhere; }
.study-deck-face img { max-width:100%; max-height:180px; object-fit:contain; }
.study-deck-face .flashcard-math { overflow:auto; }
.study-deck-actions { display:flex; gap:6px; align-items:center; justify-content:space-between; flex-shrink:0; }
.study-deck-actions button { min-height:36px; padding:4px 8px; color:var(--ink); background:var(--paper); border:1px solid var(--n84); border-radius:var(--r-soft); font:inherit; font-size:.8em; cursor:pointer; }
.study-deck-actions button:disabled { opacity:.5; cursor:default; }
.study-deck-face:focus-visible, .study-deck-actions button:focus-visible { outline:2px solid var(--accent-ui); outline-offset:2px; }
.study-eyebrow { color:var(--muted); font-size:.8em; }
.study-timer-chip { color:var(--ink); background:var(--paper); border:1px solid var(--n84); border-radius:var(--r-soft); font:inherit; font-variant-numeric:tabular-nums; white-space:nowrap; min-height:32px; padding:4px 8px; }
@media(max-width:600px) { .study-dialog { padding:12px; } .study-actions button { flex:1 1 auto; } .study-dialog .study-card-face { min-height:210px; } }
@media print { .study-timer-chip { display:none!important; } }
.study-timer-alert:not([hidden]) { position: fixed; z-index: 90; left: 12px; right: 12px; top: max(12px, env(safe-area-inset-top)); width: fit-content; max-width: calc(100% - 24px); margin: auto; display: flex; flex-wrap: wrap; align-items: center; gap: 8px; padding: 10px 12px; color: var(--ink); background: var(--paper); border: 2px solid var(--pen); border-radius: var(--r-soft,10px); box-shadow: var(--shadow-lift); }
.study-timer-alert button { min-height: 44px; padding: 6px 10px; color: var(--ink); background: var(--sheet); border: 1px solid var(--line); border-radius: var(--r-tight,6px); }
.study-timer-complete { outline: 2px solid var(--pen); outline-offset: 2px; }
@media print { .study-timer-alert { display: none !important; } }