:root {
  --bg: #f7f8f9;
  --text: #111827;
  --muted: #6b7280;
  --border: #e5e7eb;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --danger: #dc2626;
  --radius: 12px;
  --shadow: 0 8px 24px rgba(0,0,0,.08);
}

/* =====================
   Reset
   ===================== */
*,
*::before,
*::after {
  box-sizing: border-box;   /* ← padding込みで幅を計算 */
}

body.auth-body {
  background: var(--bg);
}

.auth-page {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  padding: 80px 16px 24px;
}

.auth-card {
  width: 100%;
  max-width: 420px;
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 32px;

  display: flex;
  flex-direction: column;
  justify-content: flex-start;
}

.auth-title {
  font-size: 22px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 12px;
}

form {
  margin-top: 8px;
}

.form-group {
  margin-bottom: 14px;
}

.form-group label {
  display: block;
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 6px;
}

/* 入力フィールド */
.auth-card input[type="text"],
.auth-card input[type="email"],
.auth-card input[type="password"] {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 16px;
  background: #fff;
}

.auth-card input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37,99,235,.2);
}

/* ボタン */
.btn {
  width: 100%;
  padding: 12px 16px;
  border-radius: 10px;
  border: none;
  cursor: pointer;
  font-weight: 700;
  font-size: 16px;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}
.btn-primary:hover { background: var(--primary-hover); }

/* 補助テキスト */
.helper {
  margin-top: 12px;
  font-size: 14px;
  text-align: center;
  color: var(--muted);
}
.helper a { color: var(--text); text-decoration: underline; }

/* エラー */
.errorlist, .field-errors {
  margin: 10px 0;
  padding: 10px 12px;
  background: #fef2f2;
  border: 1px solid #fecaca;
  color: var(--danger);
  border-radius: 8px;
  font-size: 14px;
}

/* =====================
   レスポンシブ調整
   ===================== */

/* SP: 画面幅の80%、余白小さめ */
@media (max-width: 767px) {
  .auth-card {
    width: 80%;
    margin: 0 auto;
    padding: 20px;
  }
  .form-group {
    margin-bottom: 10px;
  }
  .btn {
    padding: 10px 14px;
    font-size: 15px;
  }
  .auth-title {
    font-size: 20px;
    margin-bottom: 10px;
  }
}

/* PC: 余白広め */
@media (min-width: 768px) {
  .auth-page {
    padding: 100px 32px;
    justify-content: flex-start;
  }
  .auth-card {
    padding: 40px;
  }
}