* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Yu Gothic", "Meiryo", sans-serif;
  color: #292524;
}

.login-page,
.register-page {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  padding: 20px;
  align-items: center;
  background:
    linear-gradient(rgba(255, 255, 255, .25), rgba(255, 255, 255, .25)),
    url("../images/tennis_court.jpg");
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  justify-content: flex-start;
}

/* タイトル */
.system-title {
  width: 430px;
  text-align: center;
  background: rgba(255, 255, 255, .55);
  border-radius: 12px;
  margin-bottom: 20px;
}

.system-title h1 {
  font-size: 2.5rem;
  font-weight: bold;
}

.system-title p {
  font-size: 1.2rem;
  font-weight: bold;
}

/* カード  */
.login-card,
.register-card {
  width: 100%;
  max-width: 760px;
  border-radius: 10px;
  padding: 20px 70px;
}

.login-card {
  background: #fbfafc;
}

.register-card {
  background: #edf8ee;
}

.login-card h2,
.register-card h2 {
  text-align: center;
  font-size: 2rem;
  font-weight: bold;
  margin-bottom: 10px;
}

/* フォーム */
.form-group {
  margin-bottom: 10px;
}

.form-group label {
  display: block;
  margin-bottom: 10px;
  font-size: 1rem;
  font-weight: bold;
}

.form-group input {
  width: 100%;
  height: 40px;
  padding: 0 16px;
  border: 1px solid #999;
  border-radius: 2px;
  font-size: 1rem;
}

.form-group input::placeholder {
  color: #9ca3af;
}

.form-group input:focus {
  outline: none;
  border-color: #2f8f57;
}

/* ボタン */
.button-area {
  text-align: center;
  margin-top: 20px;
}

.login-button,
.register-button {
  width: 140px;
  height: 52px;
  border: none;
  border-radius: 6px;
  background: #2f8f57;
  color: #fff;
  font-size: 1.3rem;
  font-weight: bold;
  cursor: pointer;
  transition: .2s;
}

.login-button:hover,
.register-button:hover {
  background: #257347;
}

/* リンク */
.register-link,
.login-link {
  margin-top: 10px;
  text-align: center;
  font-size: .95rem;
}

.register-link a,
.login-link a {
  color: #2563eb;
  font-weight: bold;
  text-decoration: underline;
}

.register-link a:hover,
.login-link a:hover {
  color: #3b82f6;
}

.error {
  margin-top: 6px;
  color: #dc2626;
  font-size: 0.9rem;
  font-weight: bold;
}

/* 登録成功メッセージ */
.success-message {
  margin-bottom: 10px;
  padding: 10px 14px;
  background: #e8f5e9;
  border: 1px solid #81c784;
  border-radius: 8px;
  color: #2e7d32;
  font-size: 0.95rem;
  font-weight: bold;
  text-align: center;
}

/* スマートフォン対応 */
@media screen and (max-width: 768px) {

  .login-page,
  .register-page {
    justify-content: center;
  }

  .system-title {
    width: 100%;
  }

  .system-title h1 {
    font-size: 2rem;
  }

  .system-title p {
    font-size: 1rem;
  }

  .login-card {
    width: 100%;
    padding: 20px;
  }

  .login-link {
    font-size: 0.8rem;
    white-space: nowrap;
  }

  .register-link a {
    font-size: 0.8rem;
    white-space: nowrap;
  }

  .error {
    font-size: 0.75rem;
    white-space: nowrap;
  }

  .success-message {
    font-size : 0.7rem
  }
}