:root {
    --bg-gradient-top: #1a0b2e;
    --bg-gradient-bottom: #0f0518;
    --text-color: #f8fafc;
    --brand-glow: #00f3ff;
    
    --board-bg: #221538;
    --board-border: #35225c;
    
    --tile-face: #3d2b5e;
    --tile-base: #201338;
    
    --tile-active-face: #00f3ff;
    --tile-active-base: #0088cc;
    --tile-active-glow: rgba(0, 243, 255, 0.6);
    
    --tile-error-face: #ff2a6d;
    --tile-error-base: #990f38;
    --tile-error-glow: rgba(255, 42, 109, 0.6);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

body {
    background: linear-gradient(135deg, var(--bg-gradient-top), var(--bg-gradient-bottom));
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: flex-start; 
    min-height: 100vh;
    overflow-x: hidden;
    overflow-y: auto; 
    padding: 2rem 1rem;
    touch-action: manipulation; 
}

#game-wrapper {
    width: 100%;
    max-width: 800px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

header {
    width: 100%;
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    align-items: center; 
}

.brand-title {
    font-size: 2.2rem;
    font-weight: 900;
    color: var(--text-color);
    text-transform: uppercase;
    letter-spacing: 2px;
    text-align: center;
    width: 100%;
    text-shadow: 0 0 10px var(--brand-glow), 0 0 20px var(--brand-glow);
}

.header-controls {
    display: flex;
    justify-content: space-between; 
    align-items: center;
    width: 100%;
    gap: 1rem;
}

.stats-bar {
    display: flex;
    justify-content: space-around;
    width: 100%;
    background: var(--board-bg);
    padding: 1rem;
    border-radius: 12px;
    font-size: 1.25rem;
    font-weight: bold;
    border: 3px solid var(--board-border);
    box-shadow: 0 8px 0 var(--tile-base), 0 15px 20px rgba(0,0,0,0.5);
    flex-wrap: wrap;
    gap: 0.5rem;
}

.stat { text-transform: uppercase; letter-spacing: 1px; }
.stat span { color: var(--brand-glow); }

#board-container {
    position: relative;
    width: 100%;
    max-width: 600px;
    aspect-ratio: 1 / 1; 
    margin-top: 1rem;
}

#grid-board {
    display: grid;
    grid-template-columns: repeat(var(--grid-size, 3), 1fr);
    grid-template-rows: repeat(var(--grid-size, 3), 1fr);
    gap: 12px;
    width: 100%;
    height: 100%;
    background-color: var(--board-bg);
    padding: 15px;
    border-radius: 16px;
    border: 3px solid var(--board-border);
    box-shadow: 0 12px 0 var(--tile-base), 0 20px 30px rgba(0,0,0,0.7);
}

.tile {
    background-color: var(--tile-face);
    border-radius: 10px;
    cursor: pointer;
    box-shadow: 0 8px 0 var(--tile-base);
    /* Removed color transitions: This ensures it turns OFF immediately when clicked */
    transition: transform 0.1s ease;
}

.tile:active { 
    transform: translateY(8px);
    box-shadow: 0 0 0 var(--tile-base);
}

.tile.active-node {
    background-color: var(--tile-active-face);
    box-shadow: 0 8px 0 var(--tile-active-base), 0 0 25px var(--tile-active-glow);
}

.tile.active-node:active {
    transform: translateY(8px);
    box-shadow: 0 0 0 var(--tile-active-base), 0 0 15px var(--tile-active-glow);
}

.tile.error-node {
    background-color: var(--tile-error-face);
    box-shadow: 0 8px 0 var(--tile-error-base), 0 0 25px var(--tile-error-glow);
}

/* OVERLAYS & MENUS */
#overlay-menu, #paused-screen {
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(15, 5, 24, 0.95);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    border-radius: 16px;
    text-align: center;
    padding: 2rem;
    visibility: hidden;
    opacity: 0;
    transition: opacity 0.3s ease;
    z-index: 10;
    backdrop-filter: blur(5px);
}

#overlay-menu.active, #paused-screen.active {
    visibility: visible;
    opacity: 1;
}

#intro-screen {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: 100%;
}

#intro-title {
    font-size: 3.5rem;
    color: var(--text-color);
    text-shadow: 0 0 20px var(--brand-glow);
    text-transform: uppercase;
    opacity: 0;
    transition: opacity 1s ease;
    position: absolute;
    text-align: center;
}

#intro-title.visible { opacity: 1; }

#tutorial-container {
    position: relative;
    width: 280px;
    height: 350px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.tutorial-text {
    font-size: 1.5rem; 
    font-weight: bold; 
    color: #cbd5e1;
    margin-bottom: 1.5rem;
    text-align: center;
    min-height: 60px;
}

.tutorial-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
    width: 200px;
    height: 200px;
    background: var(--board-bg);
    padding: 10px;
    border-radius: 12px;
    border: 2px solid var(--board-border);
}

.t-tile {
    background-color: var(--tile-face);
    border-radius: 8px;
    box-shadow: 0 6px 0 var(--tile-base);
}

.t-tile.sim-active {
    background-color: var(--tile-active-face);
    box-shadow: 0 6px 0 var(--tile-active-base), 0 0 15px var(--tile-active-glow);
}

.t-tile.sim-click {
    transform: translateY(6px);
    box-shadow: 0 0 0 var(--tile-active-base);
}

#tutorial-cursor {
    position: absolute;
    z-index: 20;
    opacity: 0;
    pointer-events: none;
    transition: top 0.8s ease, left 0.8s ease, opacity 0.5s ease;
    transform-origin: top left;
}

#tutorial-cursor.visible { opacity: 1; }
#tutorial-cursor.clicking { transform: scale(0.85); transition: transform 0.1s; }


#game-over-screen h2, #paused-screen h2 {
    font-size: 2.8rem;
    margin-bottom: 1rem;
    color: var(--text-color);
    text-shadow: 0 0 15px var(--brand-glow);
    text-transform: uppercase;
}

.paused-subtext {
    font-size: 1.5rem; 
    font-weight: bold; 
    color: #cbd5e1;
}

.final-stats {
    background: var(--board-bg);
    padding: 1.5rem;
    border-radius: 12px;
    border: 2px solid var(--board-border);
    margin-bottom: 2rem;
}

.final-score-text {
    font-size: 1.3rem;
    color: #cbd5e1;
    margin: 0.5rem 0;
    font-weight: bold;
}

.final-score-text span { color: var(--brand-glow); font-size: 1.5rem; }

/* 3D BUTTONS */
.btn-3d {
    color: #fff;
    border: none;
    border-radius: 8px;
    font-weight: 900;
    text-transform: uppercase;
    cursor: pointer;
    transition: transform 0.1s ease, box-shadow 0.1s ease;
    text-align: center;
}

.btn-3d:active { transform: translateY(6px); }

.primary-btn {
    background-color: var(--tile-active-face);
    color: #000;
    padding: 1.25rem 3rem;
    font-size: 1.5rem;
    box-shadow: 0 6px 0 var(--tile-active-base), 0 0 15px var(--tile-active-glow);
    margin-top: 1rem;
}
.primary-btn:active { box-shadow: 0 0 0 var(--tile-active-base); }

.small-btn {
    background-color: var(--tile-face);
    padding: 0.75rem 1.25rem;
    font-size: 1rem;
    box-shadow: 0 4px 0 var(--tile-base);
}
.small-btn:active { box-shadow: 0 0 0 var(--tile-base); transform: translateY(4px); }

.secondary-btn {
    background-color: #475569;
    box-shadow: 0 4px 0 #1e293b;
}
.secondary-btn:active { box-shadow: 0 0 0 #1e293b; }

/* RESPONSIVE DESIGN */
@media (max-width: 600px) {
    .brand-title { font-size: 1.6rem; }
    .header-controls { flex-direction: column; } 
    .btn-3d.small-btn { width: 100%; } 
    .stats-bar { font-size: 1rem; padding: 0.75rem; }
    .btn-3d.primary-btn { padding: 1rem 2rem; font-size: 1.2rem; }
    #intro-title { font-size: 2rem; }
    .tutorial-text { font-size: 1.2rem; }
}

@media (max-height: 600px) and (orientation: landscape) {
    #game-wrapper {
        flex-direction: row;
        align-items: flex-start;
        gap: 2rem;
    }
    header { width: 300px; position: sticky; top: 2rem; }
    .header-controls { flex-direction: column; align-items: stretch; }
    .stats-bar { flex-direction: column; align-items: center; }
    #board-container { margin-top: 0; }
    #tutorial-container { transform: scale(0.8); }
}