.othello_section {
    padding: 140px 20px 100px;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: #f6dc9f; 
    background-image: radial-gradient(rgba(218, 181, 132, 0.08) 1px, transparent 0);
    background-size: 24px 24px;
    box-sizing: border-box;
}

.othello_container {
    width: 100%;
    max-width: 800px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.othello_header_block {
    text-align: center;
    margin-bottom: 40px;
    width: 100%;
}

.othello_subtitle {
    font-family: "Noto Sans JP", sans-serif;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.25em;
    color: #8b6914;
    margin-bottom: 12px;
    text-transform: uppercase;
}

.othello_title {
    font-family: "Zen Old Mincho", serif;
    font-size: clamp(28px, 4vw, 42px);
    font-weight: 700;
    color: #1a1207;
    margin-bottom: 15px;
    letter-spacing: 0.15em;
}

.othello_decorator_line {
    width: 60px;
    height: 1px;
    background: linear-gradient(90deg, transparent, #8b6914, transparent);
    margin: 0 auto 25px;
}

.othello_desc {
    font-family: "Shippori Mincho", serif;
    font-size: clamp(13px, 2vw, 15px);
    line-height: 2.2;
    color: rgba(26, 18, 7, 0.75);
}

.othello_game_box {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100%;
    max-width: 440px;
    background: #e8cb88;
    border: 1px solid rgba(218, 181, 132, 0.3);
    padding: 35px 20px 30px;
    border-radius: 8px;
    box-shadow: 0 20px 50px rgba(26, 18, 7, 0.04);
    box-sizing: border-box;
}

.othello_info {
    font-family: "Zen Old Mincho", serif;
    font-size: 15px;
    font-weight: 700;
    color: #1a1207;
    margin-bottom: 25px;
    letter-spacing: 0.05em;
    background: rgba(218, 181, 132, 0.08);
    padding: 8px 24px;
    border-radius: 20px;
    border: 1px solid rgba(218, 181, 132, 0.15);
}

.canvas_wrapper {
    width: 100%;
    max-width: 400px;
    aspect-ratio: 1 / 1;
    display: flex;
    justify-content: center;
    align-items: center;
    margin-bottom: 25px;
}

#board {
    background-color: #477f33;
    border: 3px solid #1a1207;
    border-radius: 6px;
    box-shadow: 0 8px 24px rgba(26, 18, 7, 0.12);
    width: 100%;
    height: 100%;
    cursor: pointer;
}

.othello_controls {
    display: flex;
    gap: 16px;
    width: 100%;
}

.othello_btn {
    flex: 1;
    appearance: none;
    background: #e0cc9d;
    border: 1px solid #1a1207;
    color: #1a1207;
    font-family: "Zen Old Mincho", serif;
    font-weight: 700;
    padding: 12px 0;
    font-size: 14px;
    letter-spacing: 0.05em;
    cursor: pointer;
    border-radius: 4px;
    transition: transform 0.2s ease, background 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

.othello_btn:hover:not(:disabled) {
    background: #1a1207;
    color: #c1ad7e;
}

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

.othello_btn:disabled {
    border-color: #e0e0e0;
    color: #f0f0f0;
    background: #c1ad7e;
    cursor: not-allowed;
}