:root {
  --blue-900: #0b2f5c;
  --blue-700: #124a8d;
  --blue-600: #1565c0;
  --blue-500: #1e88e5;
  --blue-100: #e3f0fd;
  --blue-50: #f4f9fe;
  --white: #ffffff;
  --gray-700: #4a5568;
  --red: #d32f2f;
  --green: #2e7d32;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  font-family: "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic",
    "Meiryo", sans-serif;
  background: linear-gradient(180deg, var(--blue-900) 0%, var(--blue-600) 100%);
  color: var(--gray-700);
  min-height: 100vh;
}

.app {
  width: 100%;
  max-width: 800px;
  margin: 0 auto;
  padding: 16px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.header {
  text-align: center;
  color: var(--white);
  padding: 24px 8px 16px;
}

.header h1 {
  margin: 0;
  font-size: 1.6rem;
  line-height: 1.4;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.card {
  background: var(--white);
  border-radius: 16px;
  padding: 24px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
  flex: 1;
}

.hidden {
  display: none !important;
}

.lead {
  text-align: center;
  font-size: 1.05rem;
  line-height: 1.7;
  margin: 8px 0 24px;
}

.btn {
  display: block;
  width: 100%;
  padding: 14px 20px;
  font-size: 1rem;
  font-weight: 700;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  transition: transform 0.1s ease, opacity 0.2s ease;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--blue-600);
  color: var(--white);
}

.btn-primary:hover {
  background: var(--blue-700);
}

.btn-secondary {
  background: var(--blue-100);
  color: var(--blue-700);
  margin-top: 16px;
}

.btn-secondary:hover {
  background: #d5e8fb;
}

/* ログイン画面 */
.login-logo {
  text-align: center;
  font-size: 3rem;
  line-height: 1;
  margin-bottom: 12px;
}

#login-form {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

#login-form input[type="text"],
#login-form input[type="password"] {
  width: 100%;
  padding: 14px 16px;
  font-size: 1rem;
  border: 2px solid var(--blue-100);
  border-radius: 10px;
  outline: none;
  font-family: inherit;
}

#login-form input[type="text"]:focus,
#login-form input[type="password"]:focus {
  border-color: var(--blue-500);
}

/* チーム選択画面 */
.team-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.team-btn {
  margin: 0;
}

.progress {
  text-align: center;
  color: var(--blue-600);
  font-weight: 700;
  margin-bottom: 16px;
  font-size: 0.95rem;
}

.question-box {
  background: var(--blue-50);
  border: 2px solid var(--blue-100);
  border-radius: 12px;
  text-align: center;
  padding: 28px 16px;
  margin-bottom: 24px;
}

.team-name {
  margin: 0 0 8px;
  color: var(--blue-700);
  font-weight: 700;
  font-size: 1.1rem;
}

.number-label {
  margin: 0;
  color: var(--gray-700);
  font-size: 0.9rem;
}

.number {
  margin: 4px 0 0;
  color: var(--blue-900);
  font-weight: 800;
  font-size: 3.5rem;
  line-height: 1;
}

#answer-form {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

#answer-input {
  width: 100%;
  padding: 14px 16px;
  font-size: 1rem;
  border: 2px solid var(--blue-100);
  border-radius: 10px;
  outline: none;
}

#answer-input:focus {
  border-color: var(--blue-500);
}

.result-box {
  margin-top: 20px;
  text-align: center;
  padding: 20px 16px;
  border-radius: 10px;
  background: var(--blue-50);
}

.result-text {
  font-size: 1.05rem;
  font-weight: 700;
  margin: 0;
  line-height: 1.6;
}

.result-text.correct {
  color: var(--green);
}

.result-text.incorrect {
  color: var(--red);
}

.score {
  text-align: center;
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--blue-700);
  margin: 8px 0 28px;
}

.footer {
  text-align: center;
  color: var(--blue-100);
  font-size: 0.8rem;
  padding: 16px 0 8px;
}

/* スマホでは全幅表示 */
@media (max-width: 480px) {
  .app {
    padding: 12px;
  }

  .header h1 {
    font-size: 1.3rem;
  }

  .card {
    padding: 18px;
    border-radius: 12px;
  }

  .number {
    font-size: 2.8rem;
  }
}