/* 전체 배경 및 폰트 설정 */
body {
    font-family: 'Malgun Gothic', 'Apple SD Gothic Neo', sans-serif;
    background-color: #f0fdf4; /* 편안한 연두색 배경 */
    color: #333;
    display: flex;
    justify-content: center;
    padding: 20px;
    margin: 0;
}

/* 메인 화면 컨테이너 */
.container {
    background: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
    max-width: 800px;
    width: 100%;
    text-align: center;
}

header h1 {
    color: #166534;
    margin-bottom: 10px;
}

header p {
    color: #64748b;
    margin-top: 0;
    margin-bottom: 20px;
}

/* 설정 영역 스타일 */
.controls {
    background: #f8fafc;
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 30px;
    text-align: left;
    border: 1px solid #e2e8f0;
}

.input-group, .config-group {
    margin-bottom: 15px;
}

label {
    display: inline-block;
    font-weight: bold;
    margin-bottom: 8px;
    color: #475569;
    font-size: 0.95rem;
}

textarea {
    width: 100%;
    padding: 10px;
    border: 1px solid #cbd5e1;
    border-radius: 6px;
    resize: vertical;
    font-family: inherit;
    box-sizing: border-box;
}

.config-group input {
    width: 60px;
    padding: 8px;
    margin-right: 20px;
    text-align: center;
    border: 1px solid #cbd5e1;
    border-radius: 6px;
}

button {
    width: 100%;
    padding: 15px;
    background-color: #22c55e;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: bold;
    cursor: pointer;
    transition: background 0.2s;
}

button:hover {
    background-color: #16a34a;
}

/* 교실 및 책상 영역 스타일 */
.classroom {
    border: 2px solid #e2e8f0;
    padding: 30px 20px;
    border-radius: 12px;
    background: #ffffff;
}

.teacher-desk {
    width: 150px;
    margin: 0 auto 40px auto;
    padding: 12px;
    background-color: #475569;
    color: white;
    font-weight: bold;
    font-size: 1.1rem;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.seating-grid {
    display: grid;
    gap: 15px;
    justify-content: center;
}

/* 개별 학생 책상 */
.desk {
    background-color: #fef3c7; /* 따뜻한 나무색 */
    border: 2px solid #f59e0b;
    border-radius: 8px;
    padding: 15px 5px;
    min-width: 80px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 1.05rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    word-break: keep-all;
}

/* 남는 빈자리 */
.empty-desk {
    background-color: #f1f5f9;
    border: 2px dashed #cbd5e1;
    color: #94a3b8;
    box-shadow: none;
}