body {
    font-family: 'Helvetica Neue', Arial, sans-serif;
    background-color: #f0f4f8;
    margin: 0;
    padding: 20px;
    color: #333;
}
.back-btn {
    padding: 10px 20px;
    background-color: #4CAF50; /* 緑色（お好みの色に変えてください） */
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    margin: 10px;
    transition: background-color 0.3s;
}

.back-btn:hover {
    background-color: #45a049; /* ホバー時の色 */
}

.header {
    text-align: center;
    margin-bottom: 50px;
}

.header h1 {
    color: #2c3e50;
    font-size: 2.5rem;
}

.header p {
    color: #7f8c8d;
}

.container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    max-width: 1000px;
    margin: 0 auto;
}

.card {
    background: white;
    padding: 30px 20px;
    border-radius: 20px;
    box-shadow: 0 10px 20px rgba(0,0,0,0.05);
    text-align: left;
    cursor: pointer;
    transition: transform 0.3s ease;
    position: relative;
    overflow: hidden;

}
.card a{
    text-decoration: none;
}

.card:hover {
    transform: translateY(-10px);
}

.card-number {
    font-size: 3rem;
    font-weight: bold;
    color: #e0e6ed;
    position: absolute;
    top: 10px;
    right: 20px;
}

.card h3 {
    margin-top: 20px;
    font-size: 1.2rem;
}

.card p {
    color: #6c5ce7;
    font-size: 0.9rem;
    font-weight: bold;
}

/* モーダルスタイル */
.modal {
    display: none;
    position: fixed;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background: rgba(0,0,0,0.5);
    z-index: 1000;
}

.modal-content {
    background: white;
    margin: 5% auto;
    padding: 30px;
    width: 80%;
    max-width: 700px;
    border-radius: 15px;
    position: relative;
    animation: slideDown 0.4s ease;
}

@keyframes slideDown {
    from { transform: translateY(-50px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.close {
    position: absolute;
    right: 20px; top: 10px;
    font-size: 28px; cursor: pointer;
}

.code-box {
    background: #1e1e1e;
    color: #dcdcdc;
    padding: 15px;
    border-radius: 8px;
    font-family: 'Courier New', monospace;
    margin: 15px 0;
    white-space: pre-wrap;
}

.result-box {
    background: #f8f9fa;
    border-left: 5px solid #6c5ce7;
    padding: 10px 15px;
    margin-top: 10px;
}
.section-box {
    max-width: 800px;
    margin: 40px auto;
    padding: 24px;
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.08);
  }
  
  .slide-viewer {
    text-align: center;
  }
  
  .slide-viewer img {
    width: 100%;
    max-width: 600px;
    max-height: 400px;
    object-fit: contain;
    border-radius: 8px;
    background: #fff;
  }
  
  .slide-controls {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 16px;
    margin-top: 16px;
  }

  .btn-primary {
    background: var(--accent-color);
    background: #F7DF1E;
    font-size: larger;
    border-radius: 7px;
    margin: 5px;
    padding: 10px 16px;
    border: none;
    text-decoration: none;
}
/*practise*/
/* 練習場全体のカード */
.editor-card {
    background: #fff;
    border-radius: 15px;
    padding: 25px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
}

/* コード入力画面（黒い部分） */
#code-editor {
    width: 100%;
    height: 180px;
    background: #1e1e1e;
    color: #9cdcfe;
    border-radius: 10px;
    padding: 15px;
    font-family: 'Consolas', monospace;
    font-size: 15px;
    border: none;
    margin-bottom: 15px;
    resize: none;
}

/* ボタンのデザイン */
.button-group {
    margin-bottom: 15px;
}

.btn-run {
    background: #6c5ce7; /* 紫色 */
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 6px;
    cursor: pointer;
    font-weight: bold;
}

.btn-clear {
    background: #e0e0e0;
    border: none;
    padding: 10px 20px;
    border-radius: 6px;
    cursor: pointer;
    margin-left: 10px;
}

/* コンソール（答えが出る場所） */
.console-panel {
    border: 1px solid #e0e0e0;
    border-radius: 10px;
    padding: 15px;
    background: #fafafa;
}

.output-area {
    margin-top: 10px;
    font-family: monospace;
    white-space: pre-wrap;
    color: #333;
    min-height: 50px;
}

#output {
    margin-top: 10px;
    font-family: monospace;
    color: #2d3436;
    white-space: pre-wrap;
}