/* Temas de lectura: claro (base), oscuro y sepia. */
html[data-theme="dark"]{filter:invert(1) hue-rotate(180deg) contrast(.92);background:#f7f5ef}
html[data-theme="dark"] img,
html[data-theme="dark"] video,
html[data-theme="dark"] iframe,
html[data-theme="dark"] .pt-footer{filter:invert(1) hue-rotate(180deg)}
html[data-theme="dark"] .pt-footer img{filter:none}
html[data-theme="dark"] .pt-theme-menu .sw{filter:invert(1) hue-rotate(180deg)}
html[data-theme="dark"] *,html[data-theme="dark"] *::before,html[data-theme="dark"] *::after{box-shadow:none!important;text-shadow:none!important}
html[data-theme="dark"] .pt-dd,html[data-theme="dark"] .pt-dialog,html[data-theme="dark"] .search-results,html[data-theme="dark"] .pt-theme-menu{outline:1px solid rgba(0,0,0,.18)}
html[data-theme="sepia"]{filter:sepia(.32) saturate(1.08) brightness(.97) contrast(.98);background:#f7f5ef}

/* Selector de tema. */
.pt-theme{position:relative}
.pt-theme-btn{width:40px;height:40px;display:grid;place-items:center;border:1px solid #ddd6ca;border-radius:10px;background:#fffefa;color:#4a443e;cursor:pointer;transition:border-color .18s}
.pt-theme-btn:hover{border-color:#b9ab98}
.pt-theme-btn svg{width:18px;height:18px;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}
.pt-theme-menu{position:absolute;right:0;top:calc(100% + 10px);z-index:70;width:220px;margin:0;padding:6px;list-style:none;border:1px solid #e2dace;border-radius:14px;background:#fffefa;box-shadow:0 24px 50px -24px rgba(40,30,20,.45);font-family:"DM Sans",Arial,sans-serif}
.pt-theme-menu[hidden]{display:none}
.pt-theme-menu p{margin:6px 10px 6px;color:#7d756b;font-size:11px;font-weight:700;letter-spacing:.12em;text-transform:uppercase}
.pt-theme-menu button{width:100%;display:flex;align-items:center;gap:12px;padding:9px 10px;border:0;border-radius:9px;background:none;color:#211e1b;font:500 14px "DM Sans",Arial,sans-serif;text-align:left;cursor:pointer}
.pt-theme-menu button:hover{background:#f4eee5}
.pt-theme-menu button[aria-checked="true"]{background:#f1e1d9;color:#7d2c26;font-weight:600}
.pt-theme-menu button[aria-checked="true"]::after{content:"✓";margin-left:auto}
.pt-theme-menu .sw{width:22px;height:22px;flex:none;border-radius:50%;border:1px solid rgba(0,0,0,.15)}
.sw-auto{background:linear-gradient(135deg,#f7f5ef 50%,#1c1916 50%)}.sw-light{background:#f7f5ef}.sw-dark{background:#1c1916}.sw-sepia{background:#efe2c8}
@media(max-width:900px){.pt-theme-btn{width:40px}}