body {
    background-color: #f4f4f0; /* 生成り紙 */
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    color: #2b2b2b;
}

/* SVG Filter Definition: 滲み（Bleed） */
.ink-bleed {
    filter: url('#bleed');
}

/* Input Styles */
.ink-field {
    width: 100%;
    background: transparent;
    border: none;
    border-bottom: 2px solid #ccc;
    outline: none;
    font-family: 'Dancing Script', cursive; /* 筆記体 */
    font-size: 3rem;
    color: #1a237e; /* インクブルー */
    padding: 10px 0;
    transition: border-color 0.3s;
    line-height: 1.5;
}

.ink-field:focus {
    border-bottom-color: #1a237e;
}

.ink-field::placeholder {
    color: #ccc;
    font-family: 'Shippori Mincho', serif;
    font-size: 1.5rem;
    opacity: 0.5;
}

/* カーソルの色変更 */
.ink-field {
    caret-color: #1a237e;
}