:root {
    --sr-black: #050505;
    --sr-green: #33ff00;
    --sr-amber: #ffb000;
    --sr-red: #ff003c;
    --sr-dim: #1a1a1a;
    --sr-font: 'Courier New', Courier, monospace;
}

/* --- CONTENEDOR PRINCIPAL --- */
.sr-container {
    background-color: var(--sr-black);
    color: var(--sr-green);
    font-family: var(--sr-font);
    position: relative;
    width: 100%;
    min-height: 600px;
    overflow: hidden;
    padding: 20px;
    border: 2px solid #333;
    box-sizing: border-box;
}

/* --- EFECTOS CRT & SCANLINES --- */
.sr-scanlines {
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background: linear-gradient(to bottom, rgba(255,255,255,0), rgba(255,255,255,0) 50%, rgba(0,0,0,0.2) 50%, rgba(0,0,0,0.2));
    background-size: 100% 4px;
    pointer-events: none;
    z-index: 10;
}

.sr-crt-overlay {
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background: radial-gradient(circle, rgba(18, 16, 16, 0) 50%, rgba(0,0,0,0.25) 100%);
    pointer-events: none;
    z-index: 11;
    animation: flicker 0.15s infinite;
}

@keyframes flicker {
    0% { opacity: 0.97; }
    50% { opacity: 0.99; }
    100% { opacity: 0.96; }
}

/* --- UI ELEMENTS (Botones e Inputs) --- */
.sr-btn {
    background: transparent;
    border: 1px solid var(--sr-green);
    color: var(--sr-green);
    padding: 10px 20px;
    cursor: pointer;
    font-family: var(--sr-font);
    text-transform: uppercase;
    transition: all 0.2s;
    font-weight: bold;
}

.sr-btn:hover {
    background: var(--sr-green);
    color: var(--sr-black);
    box-shadow: 0 0 10px var(--sr-green);
}

input {
    font-family: var(--sr-font);
}

/* --- ESTRUCTURA DE PANTALLAS --- */
.sr-login, .sr-intro, .sr-hub, .sr-terminal, .sr-challenge-menu {
    display: none;
    height: 100%;
}
.sr-visible { display: block; animation: fade-in 0.5s; }

@keyframes fade-in {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* --- PANTALLA: HUB / ESCRITORIO --- */
.sr-hub-header {
    margin-bottom: 20px;
    border-bottom: 1px solid var(--sr-dim);
    padding-bottom: 10px;
}

.sr-narrative-box {
    margin-top: 25px; 
    border: 1px solid #333; 
    background: rgba(0,0,0,0.5); 
    padding: 15px; 
    color: #aaa; 
    font-style: italic; 
    font-size: 0.95rem; 
    line-height: 1.4;
}

.sr-folder-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
    gap: 20px;
    margin-top: 30px;
}

.sr-folder {
    border: 1px dashed var(--sr-green);
    padding: 20px;
    text-align: center;
    cursor: pointer;
    opacity: 0.5;
    transition: all 0.3s;
}

.sr-folder:hover { opacity: 0.8; }
.sr-folder.unlocked { opacity: 1; border-style: solid; box-shadow: 0 0 5px var(--sr-green) inset; }
.sr-folder.completed { border-color: var(--sr-amber); color: var(--sr-amber); text-decoration: line-through; opacity: 0.6; }
.sr-folder.locked { cursor: not-allowed; border-color: #333; color: #333; }

.sr-folder-icon { font-size: 2rem; margin-bottom: 10px; display: block; }

/* --- PANTALLA: MENÚ DE SELECCIÓN DE DESAFÍO --- */
.sr-challenge-menu {
    text-align: center;
    padding-top: 20px;
}

.sr-challenge-grid {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-top: 40px;
    flex-wrap: wrap; /* Permite que los botones bajen si hay muchos */
}

.sr-challenge-btn {
    background: rgba(0, 255, 0, 0.05);
    border: 2px solid var(--sr-green);
    color: var(--sr-green);
    padding: 15px;
    width: 200px;
    height: 120px;
    cursor: pointer;
    font-family: var(--sr-font);
    font-size: 1.1rem;
    transition: all 0.3s;
    text-transform: uppercase;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.sr-challenge-btn:hover {
    background: var(--sr-green);
    color: var(--sr-black);
    box-shadow: 0 0 20px var(--sr-green);
    transform: scale(1.05);
}

/* --- PANTALLA: TERMINAL DE CHAT --- */
.sr-terminal {
    display: flex;
    flex-direction: column;
    height: 550px; /* Altura fija para mantener el input abajo */
}

.sr-terminal-output {
    flex-grow: 1;
    overflow-y: auto;
    border-bottom: 1px solid #333;
    margin-bottom: 10px;
    padding: 10px;
    background: rgba(0,0,0,0.3);
    
    /* CRÍTICO PARA SUDOKU Y ASCII: Mantiene formato y fuente */
    white-space: pre-wrap;
    font-family: 'Courier New', Courier, monospace; 
}

/* Scrollbar personalizado */
.sr-terminal-output::-webkit-scrollbar { width: 8px; }
.sr-terminal-output::-webkit-scrollbar-track { background: #000; }
.sr-terminal-output::-webkit-scrollbar-thumb { background: #333; border: 1px solid var(--sr-green); }

.sr-input-area {
    display: flex;
    padding: 10px;
    border: 1px solid #333;
    align-items: center;
}

#sr-chat-input {
    flex-grow: 1;
    background: transparent;
    border: none;
    color: var(--sr-green);
    font-family: var(--sr-font);
    font-size: 1.1rem;
    outline: none;
    padding-left: 10px;
}

/* --- ESTILOS ESPECIALES: ASCII ART & GLITCH --- */
/* Aplica al <pre> o <code> generado por el desafío ASCII */
.sr-terminal-output span.sr-ascii-block, 
.sr-terminal-output pre {
    display: block;
    font-family: 'Courier New', Courier, monospace;
    line-height: 1.0; /* Apretado para dibujos ASCII */
    color: var(--sr-amber);
    text-shadow: 2px 0 var(--sr-red), -1px 0 blue;
    animation: glitch-skew 4s infinite linear alternate-reverse;
    margin: 20px 0;
    overflow-x: hidden;
    font-size: 0.85rem; 
}

@keyframes glitch-skew {
    0% { transform: skew(0deg); opacity: 1; }
    20% { transform: skew(-1deg); opacity: 0.95; }
    40% { transform: skew(0.5deg); opacity: 1; }
    60% { transform: skew(0deg); opacity: 1; }
    80% { transform: skew(2deg); opacity: 0.9; }
    100% { transform: skew(0deg); opacity: 1; }
}

/* --- UTILIDADES --- */
.sr-text-red { color: var(--sr-red); text-shadow: 0 0 5px var(--sr-red); }
.sr-blink { animation: blink 1s infinite; }

@keyframes blink {
    50% { opacity: 0; }
}

/* Responsive */
@media (max-width: 600px) {
    .sr-folder-grid { grid-template-columns: repeat(2, 1fr); }
    .sr-challenge-btn { width: 100%; height: 80px; }
}