:root {
    --bg-deep: #020a16;
    --bg-mid: #051937;
    --neon-blue: #00f0ff;
    --neon-teal: #00ffaa;
    --neon-red: #ff3366;
    --text-main: #ffffff;
    --text-muted: #a0b0c0;
    --glass-bg: rgba(5, 20, 40, 0.6);
    --glass-border: rgba(0, 240, 255, 0.3);
    
    --bar-bg: rgba(0, 0, 0, 0.5);
    --health-color: #ff3366;
    --oxygen-color: #00f0ff;
    --gold: #ffd700;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    user-select: none;
    -webkit-user-select: none;
}

body, html {
    width: 100%;
    height: 100%;
    overflow: hidden;
    background-color: var(--bg-deep);
    font-family: 'Inter', sans-serif;
    color: var(--text-main);
}

h1, h2, h3, h4, .title-3d {
    font-family: 'Outfit', sans-serif;
}

/* Container */
#game-container {
    position: relative;
    width: 100vw;
    height: 100vh;
}

canvas {
    display: block;
    width: 100%;
    height: 100%;
    z-index: 1;
}

#ui-layer {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 10;
    pointer-events: none; /* Let clicks pass through to canvas unless over a UI element */
}

/* Screens */
.screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    background: radial-gradient(circle at center, rgba(5, 25, 55, 0.8) 0%, rgba(2, 10, 22, 0.95) 100%);
    transition: opacity 0.5s ease;
    pointer-events: auto;
}

.hidden {
    opacity: 0;
    pointer-events: none !important;
    display: none !important;
}

/* Typography & Effects */
.glow-text {
    text-shadow: 0 0 10px var(--neon-blue), 0 0 20px var(--neon-blue);
}

.text-blue { color: var(--neon-blue); }
.text-red { color: var(--neon-red); }
.text-gold { color: var(--gold); }

/* Loading Screen */
#loading-screen {
    z-index: 100;
    background: var(--bg-deep);
}
.loader-content {
    text-align: center;
}
.game-icon {
    width: 120px;
    height: 120px;
    border-radius: 25px;
    box-shadow: 0 0 30px rgba(0, 240, 255, 0.5);
    margin-bottom: 20px;
}
.pulse {
    animation: pulseGlow 2s infinite alternate;
}
@keyframes pulseGlow {
    from { box-shadow: 0 0 20px rgba(0, 240, 255, 0.3); transform: scale(1); }
    to { box-shadow: 0 0 40px rgba(0, 240, 255, 0.8); transform: scale(1.05); }
}
.loading-bar-container {
    width: 300px;
    height: 8px;
    background: var(--bar-bg);
    border-radius: 4px;
    margin: 20px auto;
    overflow: hidden;
    border: 1px solid var(--glass-border);
}
#loading-bar {
    width: 0%;
    height: 100%;
    background: linear-gradient(90deg, var(--neon-teal), var(--neon-blue));
    box-shadow: 0 0 10px var(--neon-blue);
    transition: width 0.1s linear;
}

/* Main Menu */
.menu-background {
    position: absolute;
    width: 100%;
    height: 100%;
    z-index: -1;
}
.menu-bg-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    filter: brightness(0.6) contrast(1.2);
}
.vignette {
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background: radial-gradient(circle, transparent 30%, #000000 100%);
}
.menu-content {
    text-align: center;
    animation: float 4s ease-in-out infinite;
}
@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}
.title-3d {
    font-size: 4rem;
    font-weight: 900;
    line-height: 1.1;
    margin-bottom: 40px;
    color: #fff;
    text-transform: uppercase;
    letter-spacing: 2px;
    text-shadow: 0 4px 0 #005577, 0 8px 15px rgba(0,0,0,0.5), 0 0 30px var(--neon-blue);
}
.title-3d span {
    font-size: 5rem;
    color: var(--neon-blue);
    text-shadow: 0 4px 0 #0088aa, 0 8px 15px rgba(0,0,0,0.5), 0 0 40px var(--neon-teal);
}

.menu-buttons {
    display: flex;
    flex-direction: column;
    gap: 15px;
    align-items: center;
}

/* Buttons */
.btn {
    padding: 15px 40px;
    font-size: 1.2rem;
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}
.primary-btn {
    background: linear-gradient(135deg, var(--neon-blue), var(--neon-teal));
    color: #000;
    box-shadow: 0 4px 15px rgba(0, 240, 255, 0.4);
}
.primary-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 20px rgba(0, 240, 255, 0.6), 0 0 15px var(--neon-teal);
}
.secondary-btn {
    background: var(--glass-bg);
    color: var(--neon-blue);
    border: 1px solid var(--glass-border);
    backdrop-filter: blur(5px);
}
.secondary-btn:hover {
    background: rgba(0, 240, 255, 0.2);
    transform: scale(1.05);
}

/* Panels */
.glass-panel {
    background: var(--glass-bg);
    backdrop-filter: blur(15px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 30px;
    width: 90%;
    max-width: 500px;
    box-shadow: 0 20px 50px rgba(0,0,0,0.5), inset 0 0 20px rgba(0,240,255,0.1);
}
.glass-panel h2 {
    text-align: center;
    margin-bottom: 20px;
    font-size: 2rem;
    color: var(--neon-blue);
    text-shadow: 0 0 10px var(--neon-blue);
}
.panel-footer {
    margin-top: 25px;
    display: flex;
    justify-content: center;
}

/* HUD */
#hud {
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    pointer-events: none;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    padding: 20px;
}
.hud-top {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}
.glass-card {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    padding: 10px 20px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.3);
}
.status-bars {
    display: flex;
    flex-direction: column;
    gap: 10px;
    width: 250px;
}
.bar-container {
    display: flex;
    align-items: center;
    gap: 10px;
}
.bar-icon {
    font-size: 1.5rem;
    width: 30px;
    text-align: center;
}
.bar-track {
    flex-grow: 1;
    height: 14px;
    background: var(--bar-bg);
    border-radius: 7px;
    border: 1px solid rgba(255,255,255,0.1);
    overflow: hidden;
}
.bar-fill {
    height: 100%;
    width: 100%;
    border-radius: 7px;
    transition: width 0.2s ease;
}
.health-fill {
    background: linear-gradient(90deg, #aa0000, var(--health-color));
    box-shadow: 0 0 10px var(--health-color);
}
.oxygen-fill {
    background: linear-gradient(90deg, #0055aa, var(--oxygen-color));
    box-shadow: 0 0 10px var(--oxygen-color);
}
.depth-meter {
    text-align: center;
    min-width: 120px;
}
.depth-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    letter-spacing: 1px;
}
.depth-value {
    font-size: 1.8rem;
    font-weight: 700;
    font-family: 'Outfit', sans-serif;
    color: var(--neon-teal);
    text-shadow: 0 0 10px var(--neon-teal);
}
.resource-counter {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: 700;
}

#warning-message {
    position: absolute;
    top: 25%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 2rem;
    font-weight: 900;
    color: var(--neon-red);
    text-shadow: 0 0 20px var(--neon-red);
    animation: flashWarning 1s infinite alternate;
}
@keyframes flashWarning {
    from { opacity: 0.2; transform: translate(-50%, -50%) scale(1); }
    to { opacity: 1; transform: translate(-50%, -50%) scale(1.1); }
}

/* Mobile Controls */
#mobile-controls {
    pointer-events: auto;
    display: flex;
    justify-content: flex-start;
    align-items: flex-end;
    padding: 20px;
    margin-top: auto;
}
#joystick-zone {
    width: 150px;
    height: 150px;
    position: relative;
    touch-action: none;
}
#joystick-base {
    position: absolute;
    bottom: 20px;
    left: 20px;
    width: 120px;
    height: 120px;
    background: rgba(0, 240, 255, 0.1);
    border: 2px solid rgba(0, 240, 255, 0.3);
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    backdrop-filter: blur(5px);
}
#joystick-stick {
    width: 50px;
    height: 50px;
    background: rgba(0, 240, 255, 0.6);
    border-radius: 50%;
    box-shadow: 0 0 15px var(--neon-blue);
    position: absolute;
    pointer-events: none;
}

/* Shop Items */
.shop-items {
    display: flex;
    flex-direction: column;
    gap: 15px;
    max-height: 50vh;
    overflow-y: auto;
    padding-right: 10px;
}
.shop-items::-webkit-scrollbar { width: 6px; }
.shop-items::-webkit-scrollbar-thumb { background: var(--neon-blue); border-radius: 3px; }

.shop-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(0,0,0,0.4);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 8px;
    padding: 15px;
}
.item-info h4 { color: var(--neon-teal); margin-bottom: 5px; }
.item-info p { font-size: 0.85rem; color: var(--text-muted); }
.upgrade-level { font-size: 0.8rem; font-weight: bold; color: var(--gold); margin-top: 5px; }
.buy-btn {
    padding: 8px 15px;
    font-size: 1rem;
    background: rgba(255, 215, 0, 0.2);
    color: var(--gold);
    border: 1px solid var(--gold);
}
.buy-btn:hover:not(:disabled) {
    background: var(--gold);
    color: #000;
}
.buy-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    filter: grayscale(1);
}

/* Responsive */
@media (max-width: 768px) {
    .title-3d { font-size: 2.5rem; }
    .title-3d span { font-size: 3rem; }
    .hud-top {
        flex-wrap: wrap;
        gap: 10px;
    }
    .status-bars { width: 180px; }
    .depth-value { font-size: 1.5rem; }
    .glass-panel { padding: 20px; }
}