/*
 * FONDO Y ESTILO CRISTAL («glassy»).
 * Solo se activa con <html class="has-bg"> (fondo «Por defecto» o «Mi imagen»). Con «Color liso» la app se ve como siempre.
 *
 * Reglas de rendimiento y lectura:
 *  - Desenfoque (backdrop-filter) SOLO en pocos elementos grandes: menú lateral, barra superior, tarjetas, diálogos y ventanas emergentes.
 *  - Elementos pequeños y repetidos (indicadores, días del calendario, tarjetas de clases…): translúcidos pero SIN desenfoque.
 *  - Tablas del Journal y textos largos (clases): casi opacos y sin desenfoque, para leer bien.
 *  - Si el PC va lento, la app quita el desenfoque sola (clases glass-lite-1 / glass-lite-2 en <html>).
 */

/*
 * --glass-a = opacidad del cristal (0,12 transparente … 0,92 casi opaco). La pone la app según
 * Ajustes › Fondo › «Intensidad del cristal»; 0,40 si no se ha tocado.
 */
:root { --glass-a: 0.40; }
:root, :root[data-theme="dark"] {
  --glass-tint: 18, 20, 26;
  --glass-bg: rgba(var(--glass-tint), var(--glass-a));                                  /* tarjetas, barra */
  --glass-bg-strong: rgba(var(--glass-tint), min(0.95, calc(var(--glass-a) + 0.10)));  /* menú, diálogos */
  --glass-tile: rgba(var(--glass-tint), min(0.95, calc(var(--glass-a) + 0.30)));       /* pequeños, sin desenfoque */
  --glass-solid: rgba(10, 10, 12, 0.93);                                               /* tablas y textos largos */
  --glass-border: rgba(255, 255, 255, 0.14);
  --glass-highlight: inset 0 1px 0 rgba(255, 255, 255, 0.16);                          /* brillo del borde superior */
  --glass-sheen: linear-gradient(180deg, rgba(255, 255, 255, 0.07), rgba(255, 255, 255, 0) 45%);
  --glass-blur: blur(18px) saturate(160%) brightness(1.1);
  --glass-shadow: 0 12px 32px rgba(0, 0, 0, 0.45);
}
:root[data-theme="light"] {
  --glass-tint: 255, 255, 255;
  --glass-solid: rgba(255, 255, 255, 0.95);
  --glass-border: rgba(120, 130, 145, 0.24);
  --glass-highlight: inset 0 1px 0 rgba(255, 255, 255, 0.95);
  --glass-sheen: linear-gradient(180deg, rgba(255, 255, 255, 0.45), rgba(255, 255, 255, 0) 50%);
  --glass-blur: blur(20px) saturate(140%);
  --glass-shadow: 0 12px 32px rgba(50, 70, 100, 0.14);
}

/* ---------- capas del fondo (detrás de todo) ---------- */
#bg-layer { position: fixed; inset: 0; z-index: 0; pointer-events: none; overflow: hidden; display: none; }
.has-bg #bg-layer { display: block; }
#bg-canvas { position: absolute; inset: 0; width: 100%; height: 100%; }
/* la foto cubre toda la ventana, centrada y sin deformarse; un poco más grande para que el desenfoque no deje bordes */
#bg-image { position: absolute; inset: -30px; background-size: cover; background-position: center; background-repeat: no-repeat; }
#bg-shade { position: absolute; inset: 0; }
#bg-canvas[hidden], #bg-image[hidden], #bg-shade[hidden] { display: none; }

.has-bg body { background: transparent; }
.has-bg #app { position: relative; z-index: 1; }

/* ---------- cristal con desenfoque: pocos elementos grandes ---------- */
.has-bg #sidebar,
.has-bg #topbar,
.has-bg .card,
.has-bg .modal,
.has-bg .popover {
  background: var(--glass-sheen), var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur); backdrop-filter: var(--glass-blur);
}
.has-bg #sidebar, .has-bg .modal, .has-bg .popover { background: var(--glass-sheen), var(--glass-bg-strong); }
.has-bg #sidebar { border-right: 1px solid var(--glass-border); box-shadow: var(--glass-highlight); }
.has-bg #topbar { border-bottom: 1px solid var(--glass-border); }
.has-bg .card {
  border: 1px solid var(--glass-border);
  border-radius: 14px;
  box-shadow: var(--glass-highlight), var(--glass-shadow);
}
.has-bg .modal, .has-bg .popover { border: 1px solid var(--glass-border); box-shadow: var(--glass-highlight), var(--glass-shadow); }

/* ---------- translúcidos SIN desenfoque: elementos pequeños o que se repiten mucho ---------- */
.has-bg .kpi,
.has-bg .plan-card,
.has-bg .cal-day,
.has-bg .cal-week,
.has-bg .learn-progress,
.has-bg .learn-card,
.has-bg .learn-hit,
.has-bg .learn-nav-btn,
.has-bg .seg,
.has-bg .chart-tip {
  background: var(--glass-tile);
  border-color: var(--glass-border);
}

/* ---------- casi opacos, sin desenfoque: tablas del Journal y textos largos ---------- */
.has-bg .grid-wrap,
.has-bg .lesson,
.has-bg .lesson-tools,
.has-bg .boot-error {
  background: var(--glass-solid);
  border-color: var(--glass-border);
}
.has-bg .grid th, .has-bg .grid td { background-clip: padding-box; }

/* ---------- si el PC va lento: menos desenfoque ---------- */
.glass-lite-1 .card { -webkit-backdrop-filter: none; backdrop-filter: none; background: var(--glass-sheen), var(--glass-tile); }
.glass-lite-2 #sidebar, .glass-lite-2 #topbar, .glass-lite-2 .modal, .glass-lite-2 .popover {
  -webkit-backdrop-filter: none; backdrop-filter: none; background: var(--glass-sheen), var(--glass-solid);
}

/* ---------- Ajustes › Fondo ---------- */
.bg-same { margin: 4px 0 12px; }
.bg-row { margin-bottom: 12px; }
.bg-modes { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 10px; margin-bottom: 14px; }
.bg-mode { display: flex; flex-direction: column; gap: 4px; text-align: left; padding: 10px 12px; border: 2px solid var(--border); border-radius: 10px; background: var(--surface-2); color: var(--text); cursor: pointer; }
.bg-mode:hover { background: var(--color-seleccion-hover); }
.bg-mode.on { border-color: var(--color-foco); background: var(--color-seleccion); }
.bg-mode span { font-size: 12px; }
.bg-image-panel { margin-bottom: 12px; }
.bg-edit { display: grid; grid-template-columns: minmax(220px, 320px) 1fr; gap: 18px; margin-top: 12px; align-items: start; }
@media (max-width: 760px) { .bg-edit { grid-template-columns: 1fr; } }
.bg-label { font-size: 12px; color: var(--muted); margin-bottom: 4px; }
.bg-preview { position: relative; aspect-ratio: 16 / 10; border-radius: 10px; overflow: hidden; border: 1px solid var(--border); }
.bg-preview-img { position: absolute; inset: -8px; background-size: cover; background-position: center; }
.bg-preview-shade { position: absolute; inset: 0; }
.bg-preview-title { position: absolute; left: 12px; top: 10px; font-weight: 700; font-size: 15px; }
.bg-preview[data-theme="dark"] .bg-preview-title { color: #ececec; }
.bg-preview[data-theme="light"] .bg-preview-title { color: #161616; }
.bg-preview-sample { position: absolute; left: 12px; right: 12px; bottom: 12px; display: flex; flex-direction: column; gap: 2px; padding: 8px 10px; border-radius: 10px; font-size: 13px; -webkit-backdrop-filter: blur(8px); backdrop-filter: blur(8px); }
.bg-preview[data-theme="dark"] .bg-preview-sample { background: rgba(16, 16, 20, 0.58); color: #ececec; border: 1px solid rgba(255, 255, 255, 0.09); }
.bg-preview[data-theme="light"] .bg-preview-sample { background: rgba(255, 255, 255, 0.60); color: #161616; border: 1px solid rgba(0, 0, 0, 0.09); }
.bg-preview[data-theme="dark"] .bg-preview-sample span { color: #9d9d9d; }
.bg-preview[data-theme="light"] .bg-preview-sample span { color: #616161; }
.bg-slider { display: grid; grid-template-columns: 130px 1fr 52px; align-items: center; gap: 10px; margin: 6px 0; }
.bg-slider input[type=range] { width: 100%; accent-color: var(--color-acento); }
.bg-val { font-variant-numeric: tabular-nums; text-align: right; color: var(--muted); }
.bg-contrast { margin: 10px 0 0; padding: 8px 10px; border-radius: 8px; font-size: 13px; }
.bg-contrast.ok { background: var(--tp-bg); color: var(--tp-fg); }
.bg-contrast.low { background: var(--warn-bg); color: var(--warn-fg); border: 1px solid var(--warn-border); }
.bg-contrast.bad { background: var(--sl-bg); color: var(--sl-fg); }
.bg-contrast:empty { display: none; }
.bg-note { margin: 10px 0 6px; }
.bg-storage { margin-top: 4px; }
.bg-glass { margin: 4px 0 12px; padding-top: 10px; border-top: 1px solid var(--border); }
.bg-glass .bg-slider { grid-template-columns: 170px 1fr 52px; }
.bg-glass-scale { display: flex; justify-content: space-between; font-size: 11px; margin: -2px 62px 0 180px; }
@media (max-width: 760px) { .bg-glass-scale { margin-left: 0; } }
.bg-card .hint, .bg-card p.hint { color: var(--muted); font-size: 13px; font-weight: 400; margin: 6px 0; }