:root {
    --bg-color: #f0f2f5;
    --text-color: #333;
    --cell-bg: #ffffff;
    --cell-hover: #f9f9f9;
    --accent: #ff4757; /* Red for X */
    --accent-o: #2ed573; /* Green for O */
    --shadow: 0 4px 6px rgba(0,0,0,0.1);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

.container {
    text-align: center;
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: 0 10px 25px rgba(0,0,0,0.05);
    max-width: 90vw;
}

h1 {
    margin: 0;
    font-size: 2.5rem;
    background: linear-gradient(45deg, var(--accent), var(--accent-o));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    margin-bottom: 1.5rem;
    color: #666;
}

.status {
    margin-bottom: 1rem;
    font-size: 1.2rem;
    font-weight: bold;
    min-height: 1.5rem;
}

.board {
    display: grid;
    grid-template-columns: repeat(3, 100px);
    grid-template-rows: repeat(3, 100px);
    gap: 10px;
    margin: 0 auto;
}

.cell {
    background-color: var(--cell-bg);
    border-radius: 10px;
    box-shadow: var(--shadow);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 3rem;
    cursor: pointer;
    transition: transform 0.2s, background-color 0.2s;
    user-select: none;
    /* Emoji color override hack */
    color: transparent;
    text-shadow: 0 0 0 #333;
}

.cell:hover {
    transform: scale(1.05);
    background-color: var(--cell-hover);
}

.cell.x { text-shadow: 0 0 0 var(--accent); }
.cell.o { text-shadow: 0 0 0 var(--accent-o); }

.x-text {
    color: transparent;
    text-shadow: 0 0 0 var(--accent);
}
.o-text {
    color: transparent;
    text-shadow: 0 0 0 var(--accent-o);
}

.restart-btn {
    margin-top: 2rem;
    padding: 0.8rem 2rem;
    font-size: 1rem;
    background-color: var(--text-color);
    color: white;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    transition: background-color 0.2s;
}

.restart-btn:hover {
    background-color: #555;
}

@media (max-width: 400px) {
    .board {
        grid-template-columns: repeat(3, 80px);
        grid-template-rows: repeat(3, 80px);
    }
    .cell {
        font-size: 2.5rem;
    }
}

/* Footer Controls */
.footer-controls {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 15px;
    margin-top: 1.5rem;
}

.github-btn {
    text-decoration: none;
    color: var(--text-color);
    border: 1px solid #ddd;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    transition: all 0.2s;
}

.github-btn:hover {
    background-color: #f0f0f0;
    border-color: #ccc;
}

.help-container {
    position: relative;
    cursor: pointer;
}

.help-icon {
    display: inline-flex;
    justify-content: center;
    align-items: center;
    width: 24px;
    height: 24px;
    background-color: #ddd;
    color: #666;
    border-radius: 50%;
    font-weight: bold;
    font-size: 0.9rem;
    transition: background-color 0.2s;
}

.help-container:hover .help-icon {
    background-color: #ccc;
    color: #333;
}

/* Tooltip */
.tooltip {
    visibility: hidden;
    opacity: 0;
    position: absolute;
    bottom: 140%; /* Position above the icon */
    left: 50%;
    transform: translateX(-50%);
    background-color: #333;
    color: white;
    padding: 1rem;
    border-radius: 8px;
    width: 250px;
    text-align: left;
    font-size: 0.85rem;
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
    transition: opacity 0.2s, visibility 0.2s;
    z-index: 10;
}

.tooltip::after {
    content: "";
    position: absolute;
    top: 100%;
    left: 50%;
    margin-left: -5px;
    border-width: 5px;
    border-style: solid;
    border-color: #333 transparent transparent transparent;
}

.help-container:hover .tooltip {
    visibility: visible;
    opacity: 1;
}

.tooltip h3 {
    margin-top: 0;
    margin-bottom: 0.5rem;
    font-size: 1rem;
    border-bottom: 1px solid #555;
    padding-bottom: 0.3rem;
}

.tooltip ul {
    margin: 0;
    padding-left: 1.2rem;
}

.tooltip li {
    margin-bottom: 0.3rem;
}