/* =========================================
   VARIABLES & DESIGN SYSTEM
   ========================================= */
:root {
    --bg-main: #ffffff;
    --bg-accent: #f5f7fa;
    --text-main: #1a1a1a;
    --text-muted: #666666;
    --accent: #000000;
    --accent-hover: #333333;
    --error: #ff3b30;
    --glass: rgba(255, 255, 255, 0.85);
    --shadow-sm: 0 10px 30px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 20px 40px rgba(0, 0, 0, 0.12);
    --transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
}

/* =========================================
   RESET & BASE LAYOUT
   ========================================= */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Alegreya Sans', sans-serif;
}

body, html {
    height: 100%;
    width: 100%;
    overflow: hidden; /* Mantiene la app contenida */
    background-color: var(--bg-main);
    color: var(--text-main);
}

/* Sistema de Capas SPA */
.view-layer {
    position: fixed;
    inset: 0;
    width: 100vw;
    height: 100vh;
    display: none;
    opacity: 0;
    transition: opacity 0.5s ease;
    z-index: 1;
}

.view-layer.active {
    display: flex;
    opacity: 1;
    z-index: 10;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

/* =========================================
   LOGIN (Auth Screen)
   ========================================= */
#auth-screen {
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    justify-content: center;
    align-items: center;
}

.login-box {
    background: var(--glass);
    backdrop-filter: blur(15px);
    padding: 60px 45px;
    border-radius: 24px;
    box-shadow: var(--shadow-sm);
    text-align: center;
    max-width: 420px;
    width: 90%;
}

.logo-placeholder {
    font-size: 12px;
    font-weight: 800;
    letter-spacing: 6px;
    margin-bottom: 25px;
    text-transform: uppercase;
}

.input-group {
    position: relative;
    margin-bottom: 20px;
}

.input-group i {
    position: absolute;
    left: 18px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
}

.input-group input {
    width: 100%;
    padding: 16px 16px 16px 50px;
    border: 1px solid rgba(0,0,0,0.08);
    border-radius: 12px;
    font-size: 16px;
    transition: var(--transition);
}

.input-group input:focus {
    outline: none;
    border-color: var(--accent);
    background: #fff;
}

.btn-primary {
    width: 100%;
    padding: 16px;
    background: var(--accent);
    color: white;
    border: none;
    border-radius: 12px;
    font-weight: 700;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 12px;
    transition: var(--transition);
}

.btn-primary:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

/* =========================================
   HUB (Catálogo)
   ========================================= */
#hub-screen {
    background: var(--bg-accent);
    flex-direction: column;
    overflow-y: auto;
    padding: 80px 40px;
}

.hub-wrapper {
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

.hub-header {
    margin-bottom: 60px;
}

.hub-header h2 {
    font-size: 42px;
    letter-spacing: -1.5px;
    margin-bottom: 10px;
}

.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 35px;
}

.pres-card {
    background: #fff;
    border: none;
    border-radius: 20px;
    overflow: hidden;
    cursor: pointer;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    text-align: left;
}

.pres-card:hover {
    transform: translateY(-12px);
    box-shadow: var(--shadow-lg);
}

.card-thumb {
    height: 180px;
    background-size: cover;
    background-position: center;
    position: relative;
    background-color: #eee;
}

.badge {
    position: absolute;
    top: 15px;
    right: 15px;
    background: var(--accent);
    color: white;
    padding: 5px 14px;
    border-radius: 30px;
    font-size: 11px;
    font-weight: 800;
}

.card-body {
    padding: 30px;
}

.card-body h3 {
    font-size: 22px;
    margin-bottom: 8px;
}

.card-body p {
    color: var(--text-muted);
    font-size: 15px;
    margin-bottom: 20px;
}

.card-meta {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 12px;
    font-weight: 700;
    color: var(--text-muted);
    border-top: 1px solid #f0f0f0;
    padding-top: 15px;
    text-transform: uppercase;
}

/* =========================================
   VISOR FULLSCREEN (Sin Parches)
   ========================================= */
#viewer-screen {
    background-color: #000;
    z-index: 1000;
}

.iframe-wrapper {
    width: 100vw;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

#presentation-frame {
    width: 100%;
    height: 100%;
    border: none;
    background: #000;
}

/* Botón Cerrar Flotante Premium */
.btn-close-viewer {
    position: fixed;
    top: 25px;
    right: 25px;
    z-index: 1100;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: white;
    padding: 12px 22px;
    border-radius: 50px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 10px;
    transition: var(--transition);
}

.btn-close-viewer:hover {
    background: var(--error);
    transform: scale(1.05);
    box-shadow: 0 10px 20px rgba(0,0,0,0.3);
}

.btn-icon {
    background: none;
    border: none;
    font-size: 20px;
    cursor: pointer;
    transition: var(--transition);
}

.btn-icon:hover {
    transform: scale(1.2);
    color: var(--error);
}