* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Hiragino Sans', 'Hiragino Kaku Gothic ProN', Meiryo, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.container {
    background: white;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    max-width: 900px;
    width: 100%;
    padding: 40px;
}

header {
    text-align: center;
    margin-bottom: 40px;
}

h1 {
    color: #333;
    font-size: 2rem;
    margin-bottom: 8px;
}

.subtitle {
    color: #666;
    font-size: 0.95rem;
}

.conversion-area {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 20px;
    align-items: start;
}

.input-section,
.output-section {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

label {
    font-weight: 600;
    color: #444;
    font-size: 0.9rem;
}

textarea {
    width: 100%;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    resize: vertical;
    transition: border-color 0.3s;
}

textarea:focus {
    outline: none;
    border-color: #667eea;
}

#output-text {
    background-color: #f9f9f9;
}

.arrow {
    font-size: 2rem;
    color: #667eea;
    align-self: center;
    font-weight: bold;
}

.copy-button {
    background: #667eea;
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
}

.copy-button:hover {
    background: #5568d3;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.copy-button:active {
    transform: translateY(0);
}

.copy-button.copied {
    background: #48bb78;
}

.info {
    margin-top: 30px;
    text-align: center;
    padding: 16px;
    background: #f0f4ff;
    border-radius: 8px;
}

.info p {
    color: #555;
    font-size: 0.9rem;
}

@media (max-width: 768px) {
    .container {
        padding: 24px;
    }

    h1 {
        font-size: 1.5rem;
    }

    .conversion-area {
        grid-template-columns: 1fr;
        gap: 24px;
    }

    .arrow {
        transform: rotate(90deg);
        justify-self: center;
    }
}


footer {
            margin-top: 30px;
            text-align: center;
            font-size: 14px;
            color: #777;
        }

    #bmc-container {
    position: fixed;
    bottom: 32px;
    right: 100px;
    display: flex;
    align-items: center;
    gap: 8px;
    z-index: 9999;
  }

  #floating-message {
    background: #fff8ee;
    color: #333;
    padding: 10px 14px;
    border-radius: 10px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.15);
    font-family: sans-serif;
    font-size: 14px;
    opacity: 1;
    transition: opacity 1s ease-out;
    animation: fadein 1s ease-in-out;
  }

  @keyframes fadein {
    0% { opacity: 0; transform: translateY(10px); }
    100% { opacity: 1; transform: translateY(0); }
  }