/* リセットとベーススタイル */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

/* メインコンテナ */
.container {
    max-width: 800px;
    margin: 0 auto;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    padding: 40px;
    backdrop-filter: blur(10px);
}

/* ヘッダー */
h1 {
    text-align: center;
    color: #2c3e50;
    margin-bottom: 40px;
    font-size: 2.5rem;
    font-weight: 300;
    position: relative;
}

h1::after {
    content: '';
    display: block;
    width: 60px;
    height: 3px;
    background: linear-gradient(135deg, #667eea, #764ba2);
    margin: 15px auto;
    border-radius: 2px;
}

h2 {
    font-size: 1.1rem;
    font-weight: 600;
    color: #2c3e50;
    margin-bottom: 10px;
    display: block;
}

textarea {
    width: 100%;
    min-height: 120px;
    padding: 15px;
    border: 2px solid #e1e8ed;
    border-radius: 10px;
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
    font-size: 14px;
    line-height: 1.5;
    resize: vertical;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
    background: #fafbfc;
}

section {
    margin-bottom: 30px;
}


textarea:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
    background: white;
}

.button-group {
    display: flex;
    gap: 10px;
    margin: 15px 0;
    flex-wrap: wrap;
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(102, 126, 234, 0.3);
}


.btn-primary {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
}

.btn-secondary {
    background: #f8f9fa;
    color: #6c757d;
    border: 1px solid #dee2e6;
}

.btn-copy {
    background: #28a745;
    color: white;
}