:root {
    --primary-color: #2563EB; /* Deep Blue */
    --primary-hover: #1D4ED8;
    --secondary-color: #64748B;
    --secondary-hover: #475569;
    --danger-color: #EF4444;
    --danger-hover: #DC2626;
    --success-color: #10B981;
    --background-color: #F8FAFC; /* Soft light background */
    --card-bg: #FFFFFF;
    --text-main: #1E293B;
    --text-muted: #64748B;
    --border-color: #E2E8F0;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 18px; /* Rounded corners as requested */
    
    --snake-head: #2563EB;
    --snake-body: #60A5FA;
    --food-color: #EF4444;
    --board-bg: #F1F5F9;
    --grid-line: #E2E8F0;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', sans-serif;
}

body {
    background-color: var(--background-color);
    color: var(--text-main);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Header */
.header {
    background-color: var(--card-bg);
    padding: 1.25rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 100;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.logo i {
    font-size: 1.75rem;
}

.nav ul {
    list-style: none;
    display: flex;
    gap: 2.5rem;
}

.nav a {
    text-decoration: none;
    color: var(--text-muted);
    font-weight: 500;
    transition: color 0.2s ease;
}

.nav a:hover, .nav a.active {
    color: var(--primary-color);
}

.header-contact {
    display: flex;
    gap: 1.5rem;
}

.contact-link {
    text-decoration: none;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.2s ease;
}

.contact-link:hover {
    color: var(--primary-color);
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 2rem 1rem;
}

/* Game Container */
.game-container {
    background-color: var(--card-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    padding: 2.5rem;
    max-width: 650px;
    width: 100%;
}

/* Game Header */
.game-header {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.score-card {
    display: flex;
    justify-content: space-between;
    gap: 1.5rem;
}

.score-box {
    flex: 1;
    background-color: var(--background-color);
    padding: 1.25rem;
    border-radius: var(--radius-md);
    text-align: center;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    border: 1px solid var(--border-color);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.score-box:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.score-label {
    font-size: 0.875rem;
    color: var(--text-muted);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.score-value {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    line-height: 1;
}

.score-box.high-score .score-value {
    color: var(--text-main);
}

/* Game Controls Top */
.game-controls-top {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.2s ease;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn:active:not(:disabled) {
    transform: scale(0.97);
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}
.btn-primary:hover:not(:disabled) {
    background-color: var(--primary-hover);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.btn-secondary {
    background-color: var(--secondary-color);
    color: white;
}
.btn-secondary:hover:not(:disabled) {
    background-color: var(--secondary-hover);
}

.btn-danger {
    background-color: white;
    color: var(--danger-color);
    border: 1px solid var(--danger-color);
}
.btn-danger:hover:not(:disabled) {
    background-color: var(--danger-color);
    color: white;
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.1rem;
}

/* Game Board */
.game-board-wrapper {
    position: relative;
    width: 100%;
    aspect-ratio: 1 / 1;
    background-color: var(--board-bg);
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 2px solid var(--border-color);
    margin-bottom: 2rem;
    display: flex;
    justify-content: center;
    align-items: center;
}

canvas {
    display: block;
    width: 100%;
    height: 100%;
}

/* Overlays */
.game-over-screen, .pause-screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(8px);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 1.5rem;
    z-index: 10;
    border-radius: var(--radius-md);
    opacity: 1;
    transition: opacity 0.3s ease;
}

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

.game-over-screen h2 {
    font-size: 2.5rem;
    color: var(--text-main);
    margin: 0;
}

.pause-screen h2 {
    font-size: 2.5rem;
    color: var(--text-main);
    margin: 0;
}

.game-over-screen p {
    font-size: 1.25rem;
    color: var(--text-muted);
}
.game-over-screen p span {
    color: var(--primary-color);
    font-weight: 700;
    font-size: 1.5rem;
}

/* Mobile Controls */
.mobile-controls {
    display: none;
    justify-content: center;
    margin-bottom: 1.5rem;
}

.d-pad {
    display: grid;
    grid-template-columns: repeat(3, 70px);
    grid-template-rows: repeat(3, 70px);
    gap: 0.5rem;
}

.d-pad-btn {
    background-color: var(--background-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    font-size: 1.75rem;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: all 0.15s ease;
    user-select: none;
}

.d-pad-btn:active {
    background-color: var(--primary-color);
    color: white;
    transform: scale(0.92);
}

.d-pad-btn.up { grid-column: 2; grid-row: 1; }
.d-pad-btn.left { grid-column: 1; grid-row: 2; }
.d-pad-btn.right { grid-column: 3; grid-row: 2; }
.d-pad-btn.down { grid-column: 2; grid-row: 3; }

/* Instructions */
.game-instructions {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.95rem;
}
.game-instructions i {
    margin-right: 0.35rem;
}

/* Footer */
.footer {
    background-color: var(--card-bg);
    padding: 2rem;
    text-align: center;
    border-top: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.text-danger {
    color: var(--danger-color);
}

.footer-contact {
    display: flex;
    justify-content: center;
    gap: 2rem;
    font-size: 0.95rem;
}

.footer-contact a {
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.2s ease;
}

.footer-contact a:hover {
    color: var(--primary-color);
}

/* Score Animation Class */
@keyframes pop {
    0% { transform: scale(1); }
    50% { transform: scale(1.15); color: var(--primary-hover); }
    100% { transform: scale(1); }
}

.score-pop {
    animation: pop 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}