:root {
  --primary: #4361ee;
  --primary-hover: #3a53d0;
  --secondary: #6c757d;
  --bg-color: #f8f9fa;
  --panel-bg: #ffffff;
  --text-main: #333333;
  --text-muted: #6c757d;
  --border-color: #dee2e6;
  --danger: #ef233c;
  --radius: 8px;
}

* { box-sizing: border-box; margin: 0; padding: 0; font-family: "Helvetica Neue", Arial, sans-serif; }

body { background-color: var(--bg-color); color: var(--text-main); padding: 20px; }
.app-container { max-width: 1200px; margin: 0 auto; }

.header {
  display: flex; justify-content: space-between; align-items: center;
  margin-bottom: 20px; padding: 15px 20px;
  background: var(--panel-bg); border-radius: var(--radius);
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.header h1 { font-size: 1.5rem; color: var(--primary); }

.main-content { display: grid; grid-template-columns: 1fr 1.5fr; gap: 20px; }
section { background: var(--panel-bg); padding: 20px; border-radius: var(--radius); box-shadow: 0 2px 10px rgba(0,0,0,0.05); }
h2 { font-size: 1.1rem; margin-bottom: 15px; padding-bottom: 10px; border-bottom: 2px solid var(--bg-color); }

.form-group { margin-bottom: 15px; }
.form-row { display: flex; gap: 15px; }
.form-row .form-group { flex: 1; min-width: 0; }

label { display: block; font-size: 0.9rem; font-weight: bold; margin-bottom: 5px; }
.required { color: var(--danger); }

input[type="text"], input[type="date"], select, textarea {
  width: 100%; padding: 10px; border: 1px solid var(--border-color);
  border-radius: 4px; font-size: 1rem; transition: border-color 0.2s;
}
input:focus, select:focus, textarea:focus { outline: none; border-color: var(--primary); }

/* 単元追加エリアのスタイリング */
.unit-input-group { margin-bottom: 5px; }
.add-unit-area { display: flex; gap: 5px; }
.add-unit-area input { font-size: 0.85rem; padding: 6px; }
.btn-secondary { background: var(--secondary); color: white; padding: 6px 12px; font-size: 0.85rem; white-space: nowrap; }

.char-count { text-align: right; font-size: 0.85rem; color: var(--text-muted); margin-top: 5px; }

.quick-phrases { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin-bottom: 20px; font-size: 0.85rem; }
.phrase-btn { background: #e9ecef; border: none; padding: 5px 10px; border-radius: 20px; cursor: pointer; color: var(--text-main); }
.phrase-btn:hover { background: #dee2e6; }

.form-actions { display: flex; justify-content: flex-end; gap: 10px; }
.btn { padding: 10px 20px; border-radius: 4px; font-weight: bold; cursor: pointer; border: none; transition: opacity 0.2s; }
.btn:hover { opacity: 0.9; }
.btn-primary { background: var(--primary); color: white; }
.btn-outline { background: transparent; border: 1px solid var(--primary); color: var(--primary); }
.btn-text { background: transparent; color: var(--text-muted); }

.search-bar { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 15px; }
.search-bar > * { flex: 1; min-width: 150px; }

.table-container { overflow-x: auto; max-height: 500px; overflow-y: auto; }
table { width: 100%; border-collapse: collapse; }
th, td { padding: 12px; text-align: left; border-bottom: 1px solid var(--border-color); font-size: 0.95rem; }
th { background: var(--bg-color); position: sticky; top: 0; z-index: 1; }

.action-links button { background: none; border: none; cursor: pointer; margin-right: 10px; font-size: 0.9rem; }
.edit-link { color: var(--primary); }
.delete-link { color: var(--danger); }

.badge-tag { font-size: 0.8rem; background: #e9ecef; padding: 3px 8px; border-radius: 12px; display: inline-block; margin-top: 4px;}
.badge-subject { font-size: 0.8rem; background: #e0f7fa; color: #006064; padding: 3px 8px; border-radius: 4px; display: inline-block; font-weight: bold;}

.toast { position: fixed; bottom: 20px; right: 20px; background: #333; color: white; padding: 12px 24px; border-radius: 4px; box-shadow: 0 4px 12px rgba(0,0,0,0.15); opacity: 0; visibility: hidden; transition: all 0.3s ease; z-index: 1000; }
.toast.show { opacity: 1; visibility: visible; bottom: 30px; }

@media (max-width: 768px) {
  .main-content { grid-template-columns: 1fr; }
}