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

body {
  background-color: #f0f2f5;
  padding: 40px 20px;
  display: flex;
  justify-content: center;
}

.contact-container {
  background-color: #ffffff;
  max-width: 550px;
  width: 100%;
  padding: 40px;
  position: relative;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  min-height: 800px;
}

.close-button {
  position: absolute;
  top: 15px;
  right: 15px;
  background: none;
  border: 1px solid #ccc;
  font-size: 24px;
  cursor: pointer;
  width: 32px;
  height: 32px;
  line-height: 28px;
}

.form-title {
  font-size: 28px;
  margin-bottom: 25px;
}

/* --- タブ機能 --- */
.tab-menu {
  display: flex;
  border-bottom: 1px solid #ddd;
  margin-bottom: 25px;
}

.tab-item {
  font-size: 12px;
  font-weight: bold;
  padding-bottom: 8px;
  margin-right: 30px;
  color: #888;
  cursor: pointer;
  border-bottom: 3px solid transparent;
}

.tab-item.active {
  color: #000;
  border-bottom: 3px solid #000;
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
}

/* --- INSTRUCTIONS --- */
.btn-cta-online {
  width: 100%;
  background-color: #ffcc4d;
  border: none;
  padding: 15px;
  font-weight: bold;
  font-size: 14px;
  margin-bottom: 30px;
  cursor: pointer;
}

.notice-text {
  font-size: 13px;
  line-height: 1.6;
  margin-bottom: 25px;
}

.accordion-list {
  border-top: 1px solid #eee;
}

.accordion-item {
  border-bottom: 1px solid #eee;
}

.accordion-header {
  padding: 15px 0;
  font-size: 13px;
  font-weight: bold;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
}

.accordion-body {
  display: none;
  padding: 0 0 20px 0;
  font-size: 13px;
  line-height: 1.6;
  color: #555;
}

.accordion-item.active .accordion-body {
  display: block;
}

.accordion-item.active .fa-chevron-down {
  transform: rotate(180deg);
}

/* --- FORM --- */
.form-group { margin-bottom: 20px; }
label { display: block; font-size: 13px; font-weight: bold; margin-bottom: 5px; }
input, textarea { width: 100%; padding: 10px; border: 1px solid #888; font-size: 14px; outline: none; }
.reference-box { background: #f2f2f2; padding: 15px; font-size: 13px; margin: 20px 0; }
.form-actions { display: flex; justify-content: space-between; align-items: center; }
.btn-send { background: #ffcc4d; border: none; padding: 12px 30px; font-weight: bold; cursor: pointer; }
.btn-clear { background: none; border: none; text-decoration: underline; cursor: pointer; font-weight: bold; }

/* ★追加：エラー時の入力欄のスタイル（送信ボタンを押した時に判定されます） */
input:invalid:focus,
textarea:invalid:focus {
  border-color: #ff4d4d;
  box-shadow: 0 0 5px rgba(255, 77, 77, 0.3);
}

/* --- 送信状態メッセージボックス --- */
.form-message-box {
  padding: 15px;
  margin-bottom: 25px;
  font-size: 13px;
  font-weight: bold;
  border-left: 4px solid;
}
.form-message-box.success {
  background-color: #e6f4ea;
  color: #137333;
  border-color: #137333;
}
.form-message-box.error {
  background-color: #fce8e6;
  color: #c5221f;
  border-color: #c5221f;
}