/* ==========================================================================
   Piel A · CRISTAL — vidrio luminoso, continuación directa de la portada.
   ========================================================================== */

.skin-a {
  --canvas: #fff1f4;
  --surface: #ffffff;
  --surface-2: rgba(255, 236, 241, .75);
  --glass: rgba(255, 255, 255, .62);
  --glass-strong: rgba(255, 255, 255, .82);
  --glass-line: rgba(255, 255, 255, .9);
  --line: rgba(120, 40, 60, .09);
  --text: #1d1416; --muted: #7a6a6e; --faint: #7a696d; --ink: #2a1a1f;
  /* Texto chico de color (enlaces, insignias): la misma familia, más hondo para leerse ≥ 4.5:1 sobre el vidrio */
  --brand-t: #b81a38; --ok-t: #0f6e3e; --info-t: #3443cc; --warn-t: #924305; --err-t: #ad232d;
  --shadow: 0 1px 1px rgba(245, 61, 92, .03), 0 12px 32px -8px rgba(160, 40, 70, .14);
  --r-lg: 24px; --r-xl: 30px;
  --icon-stroke: 1.75;
  --sidebar-w: 280px;
}

/* Lienzo con halos cálidos, como el hero de la portada */
.skin-a { background: radial-gradient(1200px 700px at 85% -10%, #ffd9e2 0%, transparent 60%), radial-gradient(900px 600px at -10% 110%, #ffe8d6 0%, transparent 55%), #fff1f4; background-attachment: fixed; }
.skin-a::before { content: ""; position: fixed; inset: 0; pointer-events: none; z-index: 0;
  background-image: linear-gradient(rgba(245, 61, 92, .045) 1px, transparent 1px), linear-gradient(90deg, rgba(245, 61, 92, .045) 1px, transparent 1px);
  background-size: 56px 56px; -webkit-mask-image: radial-gradient(ellipse 60% 50% at 70% 10%, #000, transparent 75%); mask-image: radial-gradient(ellipse 60% 50% at 70% 10%, #000, transparent 75%); }
.skin-a .app { position: relative; z-index: 1; }

/* Superficie de vidrio reutilizable */
.skin-a :is(.card, .kpi, .kpi-mini, .table-wrap, .course-card, .int-card, .inbox, .inbox-kpi, .ai-brief, .continue, .my-course, .news__item, .resource, .next-lesson, .week-goal, .auth__float, .bulk) {
  background: var(--glass); border: 1px solid var(--glass-line); box-shadow: var(--shadow);
  backdrop-filter: blur(22px) saturate(1.5); -webkit-backdrop-filter: blur(22px) saturate(1.5);
}
.skin-a .table-wrap { background: var(--glass-strong); }

/* ───── Barra lateral flotante de vidrio ───── */
.skin-a .sidebar { margin: 16px 0 16px 16px; height: calc(100vh - 32px); top: 16px; padding: 18px 14px 14px; border-radius: 30px;
  background: rgba(255, 255, 255, .58); border: 1px solid var(--glass-line); box-shadow: 0 20px 50px -20px rgba(160, 40, 70, .25);
  backdrop-filter: blur(26px) saturate(1.6); -webkit-backdrop-filter: blur(26px) saturate(1.6); gap: 14px; }
.skin-a .sidebar__brand { padding: 4px 8px 6px; }
.skin-a .brand-lockup { color: transparent; background: var(--grad-text); -webkit-background-clip: text; background-clip: text; }
.skin-a .brand-lockup em { color: var(--brand); background: rgba(245, 61, 92, .1); -webkit-text-fill-color: var(--brand); }
.skin-a .nav__group-label { font-size: 11px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--faint); padding: 0 12px 4px; }
.skin-a .nav__item { color: #4a3a3f; }
.skin-a .nav__item:hover { background: rgba(255, 255, 255, .75); }
.skin-a .nav__item.is-active { color: #fff; background: var(--grad); box-shadow: 0 10px 24px -8px rgba(245, 61, 92, .55), inset 0 1px 0 rgba(255, 255, 255, .35); }
.skin-a .nav__badge { color: #fff; background: var(--brand); }
.skin-a .nav__item.is-active .nav__badge { color: var(--brand); background: #fff; }
.skin-a .sidebar__status { background: rgba(255, 255, 255, .7); border: 1px solid var(--glass-line); }
.skin-a .sidebar__collapse { display: none; }

/* ───── Barra superior transparente ───── */
.skin-a .topbar { padding-top: 6px; }
.skin-a .topbar__search, .skin-a .seg, .skin-a .user-chip { background: var(--glass); border: 1px solid var(--glass-line); backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px); }
.skin-a .topbar .btn--icon { background: var(--glass); border: 1px solid var(--glass-line); border-radius: 50%; }
.skin-a .seg__item.is-active { background: #fff; box-shadow: 0 2px 8px rgba(160, 40, 70, .12); }
.skin-a .seg--mode .seg__item.is-active { color: #fff; background: var(--grad); }
.skin-a .page-hero__actions .btn--icon { background: var(--glass); border: 1px solid var(--glass-line); border-radius: 50%; }

/* ───── Controles ───── */
.skin-a .btn--ghost, .skin-a .btn--danger { background: rgba(255, 255, 255, .7); border: 1px solid var(--glass-line); box-shadow: 0 1px 2px rgba(160, 40, 70, .06); }
.skin-a .btn--ghost:hover { background: #fff; }
.skin-a .btn--primary:hover { box-shadow: 0 14px 30px -8px rgba(245, 61, 92, .55); }
.skin-a .tab.is-active { background: rgba(255, 255, 255, .85); box-shadow: 0 4px 14px -4px rgba(160, 40, 70, .2); }
.skin-a .tab__count { background: rgba(245, 61, 92, .1); color: var(--brand-t); }   /* --brand-t: ≥ 4.5:1 en día y noche */
.skin-a .pill { background: rgba(255, 255, 255, .6); border-color: var(--glass-line); }
.skin-a .pill.is-active, .skin-a .chip.is-active, .skin-a .int-pixel.is-active { background: var(--grad); border-color: transparent; color: #fff; }
.skin-a .chip.is-active b { color: #fff; }
.skin-a .input, .skin-a .textarea { background: rgba(255, 255, 255, .8); border-color: rgba(245, 61, 92, .12); }
.skin-a .kpi__value { background: linear-gradient(180deg, #1d1416, #4a2a33); -webkit-background-clip: text; background-clip: text; color: transparent; }
.skin-a .kpi-mini.is-active { background: rgba(255, 255, 255, .92); box-shadow: 0 0 0 2px rgba(245, 61, 92, .35), var(--shadow); }
.skin-a .kpi--context { background: linear-gradient(160deg, rgba(255, 255, 255, .7), rgba(255, 224, 232, .8)); }
.skin-a .ai-brief { background: linear-gradient(110deg, rgba(255, 255, 255, .78), rgba(255, 228, 214, .75)); }
.skin-a .table th { background: rgba(255, 241, 244, .6); }
.skin-a .table tbody tr:hover td { background: rgba(255, 241, 244, .55); }
.skin-a .course-card:hover { transform: translateY(-3px); box-shadow: 0 22px 40px -16px rgba(160, 40, 70, .3); }

/* ───── Bandeja ───── */
.skin-a .inbox { background: rgba(255, 255, 255, .55); }
.skin-a .thread.is-active { background: rgba(255, 255, 255, .9); box-shadow: 0 6px 18px -8px rgba(160, 40, 70, .25); }
.skin-a .msg--out { color: #fff; background: var(--grad); box-shadow: 0 6px 16px -8px rgba(245, 61, 92, .6); }
.skin-a .msg--out .msg__by, .skin-a .msg--out time, .skin-a .msg--out time .i { color: rgba(255, 255, 255, .85); }
.skin-a .side-card { background: rgba(255, 255, 255, .75); border: 1px solid var(--glass-line); }
.skin-a .inbox__thread { background: rgba(255, 255, 255, .35); }

/* ───── Alumno e inicio de sesión ───── */
.skin-a .continue { background: linear-gradient(120deg, rgba(255, 255, 255, .8), rgba(255, 231, 238, .75)); }
.skin-a .auth__brand { background: radial-gradient(700px 500px at 20% 10%, #ffd0db, transparent 60%), radial-gradient(600px 500px at 90% 90%, #ffe0c9, transparent 60%), #ffeef2; }
.skin-a .auth__brand h1 { color: #1d1416; }
.skin-a .auth__form-side { background: rgba(255, 255, 255, .6); backdrop-filter: blur(20px); }

/* ───── Móvil: barra inferior de vidrio flotante + hoja inferior ───── */
@media (max-width: 1100px) {
  .skin-a .sidebar { margin: 0; top: 0; height: 100vh; border-radius: 0 30px 30px 0; background: rgba(255, 246, 248, .94); }
}
@media (max-width: 767px) {
  .skin-a .topbar { background: rgba(255, 241, 244, .7); backdrop-filter: blur(18px); -webkit-backdrop-filter: blur(18px); padding-top: 0; }
  .skin-a .topbar .topbar__menu { display: none; }
  .skin-a .tabbar { position: fixed; z-index: 40; left: 14px; right: 14px; bottom: 14px; height: 68px; padding: 8px; gap: 4px; border-radius: 26px;
    background: rgba(255, 255, 255, .72); border: 1px solid var(--glass-line); box-shadow: 0 18px 40px -12px rgba(160, 40, 70, .35);
    backdrop-filter: blur(24px) saturate(1.6); -webkit-backdrop-filter: blur(24px) saturate(1.6); }
  .skin-a .tabbar__fab { display: none; }
  .skin-a .tabbar__item { position: relative; flex: 1; display: grid; place-items: center; gap: 2px; align-content: center; border-radius: 18px; font-size: 10.5px; font-weight: 600; color: var(--muted); }
  .skin-a .tabbar__item .i { width: 22px; height: 22px; }
  .skin-a .tabbar__item.is-active { color: #fff; background: var(--grad); box-shadow: 0 8px 18px -8px rgba(245, 61, 92, .7); }
  .skin-a .tabbar__badge { position: absolute; top: 4px; right: calc(50% - 22px); min-width: 17px; height: 17px; border-radius: 9px; display: grid; place-items: center; font-style: normal; font-size: 10px; font-weight: 800; color: #fff; background: var(--brand); box-shadow: 0 0 0 2px #fff; }
  /* Menú «Más»: hoja inferior con mosaico */
  .skin-a .sidebar { inset: auto 0 0 0; width: 100%; height: auto; max-height: 86vh; border-radius: 30px 30px 0 0; transform: translateY(105%); padding: 14px 16px 24px; }
  .skin-a .sidebar.is-open { transform: none; }
  .skin-a .sidebar__top::before { content: ""; position: absolute; top: 8px; left: 50%; width: 42px; height: 5px; margin-left: -21px; border-radius: 3px; background: rgba(120, 40, 60, .18); }
  .skin-a .nav__group { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 8px; }
  .skin-a .nav__group-label { grid-column: 1 / -1; padding: 6px 4px 0; }
  .skin-a .nav__item { flex-direction: column; justify-content: center; gap: 6px; min-height: 84px; padding: 10px 4px; background: rgba(255, 255, 255, .8); border: 1px solid var(--glass-line); font-size: 12px; text-align: center; }
  .skin-a .nav__label { white-space: normal; line-height: 1.2; }
  .skin-a .nav__badge { position: absolute; top: 8px; right: 8px; }
  .skin-a .sidebar__foot .sidebar__status { display: none; }
  .skin-a .table tr { background: var(--glass-strong); border: 1px solid var(--glass-line); box-shadow: var(--shadow); }
  .skin-a .inbox__list .threads { padding: 0 var(--pad); }
  .skin-a .is-thread .inbox__thread { background: #fff7f9; }
  .skin-a .auth__brand { background: radial-gradient(500px 300px at 20% 0%, #ffd0db, transparent 70%), #fff1f4; }
}

/* ───── Modo noche ───── */
.theme-dark .skin-a {
  --canvas: #140a0e; --text: #f7eef0; --muted: #b29ea4; --faint: #a08b92; --ink: #fff;
  --brand-t: #ff6b84; --ok-t: #3fc483; --info-t: #8b97ff; --warn-t: #f0a040; --err-t: #ff7378;
  --glass: rgba(42, 22, 30, .55); --glass-strong: rgba(48, 26, 34, .75); --glass-line: rgba(255, 255, 255, .08);
  --surface: #241419; --surface-2: rgba(255, 255, 255, .06); --line: rgba(255, 255, 255, .08);
  --shadow: 0 16px 40px -12px rgba(0, 0, 0, .5);
  color-scheme: dark;   /* barras de desplazamiento, reproductores de audio y controles nativos en oscuro */
  background: radial-gradient(1000px 600px at 85% -10%, rgba(245, 61, 92, .28), transparent 60%), radial-gradient(800px 600px at -10% 110%, rgba(252, 173, 103, .14), transparent 55%), #140a0e;
}
.theme-dark .skin-a .sidebar { background: rgba(36, 18, 25, .7); }
.theme-dark .skin-a .nav__item { color: #d9c7cc; }
.theme-dark .skin-a .nav__item:hover { background: rgba(255, 255, 255, .06); }
.theme-dark .skin-a .kpi__value { background: linear-gradient(180deg, #fff, #f3c9d2); -webkit-background-clip: text; background-clip: text; }
.theme-dark .skin-a :is(.seg__item.is-active, .tab.is-active, .thread.is-active, .kpi-mini.is-active) { background: rgba(255, 255, 255, .1); color: #fff; }
.theme-dark .skin-a :is(.btn--ghost, .btn--danger, .pill, .input, .textarea, .sidebar__status, .side-card) { background: rgba(255, 255, 255, .06); border-color: rgba(255, 255, 255, .08); }
.theme-dark .skin-a .table th { background: rgba(255, 255, 255, .03); }
.theme-dark .skin-a .table tbody tr:hover td { background: rgba(255, 255, 255, .04); }
.theme-dark .skin-a :is(.ai-brief, .kpi--context, .continue) { background: linear-gradient(120deg, rgba(60, 26, 38, .75), rgba(70, 36, 30, .6)); }
.theme-dark .skin-a .inbox__thread { background: rgba(0, 0, 0, .15); }
.theme-dark .skin-a .chip.is-active { color: #fff; }
.theme-dark .skin-a .topbar { background: transparent; }
@media (max-width: 767px) {
  .theme-dark .skin-a .tabbar { background: rgba(40, 20, 28, .78); }
  .theme-dark .skin-a .topbar { background: rgba(20, 10, 14, .7); }
}
.theme-dark .skin-a .seg--mode .seg__item.is-active { color: #fff; background: var(--grad); }

/* ───── Plataforma: ajustes de la piel Cristal ───── */
.skin-a .search-inline { background: var(--glass); border-color: var(--glass-line); backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px); }
.skin-a .user-menu__panel, .skin-a .palette__box { background: rgba(255, 255, 255, .92); border-color: var(--glass-line); backdrop-filter: blur(24px) saturate(1.5); -webkit-backdrop-filter: blur(24px) saturate(1.5); }
.skin-a .empty__icon { box-shadow: 0 14px 30px -10px rgba(245, 61, 92, .55), inset 0 1px 0 rgba(255, 255, 255, .35); }
.theme-dark .skin-a .user-menu__panel, .theme-dark .skin-a .palette__box { background: rgba(36, 18, 25, .92); }
.theme-dark .skin-a .search-inline { background: rgba(255, 255, 255, .06); border-color: rgba(255, 255, 255, .08); }
.theme-dark .skin-a .toast { background: #2b1a20; border: 1px solid rgba(255, 255, 255, .08); }
.theme-dark .skin-a .auth__form-side { background: rgba(20, 10, 14, .55); }
.theme-dark .skin-a .auth__brand { background: radial-gradient(700px 500px at 20% 10%, rgba(245, 61, 92, .35), transparent 60%), radial-gradient(600px 500px at 90% 90%, rgba(252, 173, 103, .18), transparent 60%), #1a0e12; }
.theme-dark .skin-a .auth__brand h1 { color: #fff; }

/* Rendimiento en celulares: el vidrio se queda en la estructura (barras y menús);
   el contenido usa superficie sólida translúcida, sin desenfoque. */
@media (max-width: 767px) {
  .skin-a :is(.card, .kpi, .kpi-mini, .table-wrap, .course-card, .int-card, .inbox, .inbox-kpi, .ai-brief, .continue, .my-course, .news__item, .resource, .next-lesson, .week-goal, .table tr) {
    backdrop-filter: none; -webkit-backdrop-filter: none; background: rgba(255, 255, 255, .86);
  }
  .theme-dark .skin-a :is(.card, .kpi, .kpi-mini, .table-wrap, .course-card, .int-card, .inbox, .inbox-kpi, .ai-brief, .continue, .my-course, .news__item, .resource, .next-lesson, .week-goal, .table tr) {
    background: rgba(40, 22, 30, .9);
  }
  .skin-a::before { display: none; }
}
@media (prefers-reduced-transparency: reduce) {
  .skin-a :is(.card, .kpi, .sidebar, .tabbar, .topbar__search, .seg, .user-chip) { backdrop-filter: none; -webkit-backdrop-filter: none; background: var(--surface); }
}
/* Chat abierto en móvil: pantalla completa y opaca, sin ver la bandeja detrás. */
@media (max-width: 767px) {
  .skin-a .inbox.is-hilo .inbox__thread,
  .theme-dark .skin-a .inbox.is-hilo .inbox__thread { background: var(--canvas); }
}
/* Menú de usuario: fondo sólido para que se lea sobre cualquier tarjeta. */
.skin-a .user-menu__panel { background: rgba(255, 255, 255, .97); }
.theme-dark .skin-a .user-menu__panel { background: rgba(32, 20, 25, .97); }
/* Menú «Más» en móvil con modo noche: mosaicos oscuros. */
@media (max-width: 767px) {
  .theme-dark .skin-a .nav__item { background: rgba(255, 255, 255, .05); border-color: rgba(255, 255, 255, .08); }
  .theme-dark .skin-a .nav__item.is-active { background: var(--grad); color: #fff; }
}

/* ───── QA 024 ───── */
/* Tonos de texto chico con contraste AA (el rosa y el rojo de marca no llegan a 4.5:1 sobre fondo claro). */
.skin-a { --brand-txt: #c41c42; --err-txt: #c2272d; }
.theme-dark .skin-a { --brand-txt: #ff6b80; --err-txt: #ff6b6f; }
.skin-a .nav__group-label { color: var(--muted); }
.skin-a :is(.nav__badge, .tabbar__badge) { background: #cf1f45; }   /* blanco sobre #cf1f45: 5.3:1 (sobre --brand no llega a 4.5) */
.skin-a .nav__item.is-active .nav__badge { color: #cf1f45; background: #fff; }
/* Barra superior: transparente arriba; al bajar, vidrio para que nada (video, avisos) pase por detrás sin fondo. */
.skin-a .topbar { transition: background-color .2s ease, box-shadow .2s ease; }
.skin-a .topbar.is-scrolled { background: rgba(255, 241, 244, .8); backdrop-filter: blur(18px) saturate(1.4); -webkit-backdrop-filter: blur(18px) saturate(1.4); box-shadow: 0 1px 0 var(--line); }
.theme-dark .skin-a .topbar.is-scrolled { background: rgba(20, 10, 14, .8); }
@media (prefers-reduced-transparency: reduce) {
  .skin-a .topbar.is-scrolled { backdrop-filter: none; -webkit-backdrop-filter: none; background: var(--canvas); }
}