/* リセットとベーススタイル */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', 'Hiragino Sans', 'Hiragino Kaku Gothic ProN', 'Noto Sans JP', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    line-height: 1.6;
}

/* ログインコンテナ */
.login-container {
    width: 100%;
    max-width: 440px;
}

.login-box {
    background: white;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    padding: 48px 40px;
    animation: fadeInUp 0.6s ease-out;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ロゴセクション */
.logo-section {
    text-align: center;
    margin-bottom: 40px;
}

.logo-section h1 {
    font-size: 24px;
    font-weight: 700;
    color: #1a202c;
    margin-bottom: 8px;
    letter-spacing: -0.5px;
}

.subtitle {
    color: #718096;
    font-size: 14px;
    font-weight: 500;
}

/* フォーム */
.login-form {
    margin-bottom: 24px;
}

.form-group {
    margin-bottom: 24px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: #2d3748;
    font-size: 14px;
    font-weight: 600;
}

.form-control {
    width: 100%;
    padding: 12px 16px;
    font-size: 16px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    transition: all 0.2s ease;
    background: #f7fafc;
}

.form-control:focus {
    outline: none;
    border-color: #667eea;
    background: white;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.form-control::placeholder {
    color: #a0aec0;
}

/* エラーメッセージ */
.error-message {
    background: #fff5f5;
    color: #c53030;
    padding: 12px 16px;
    border-radius: 8px;
    font-size: 14px;
    margin-bottom: 20px;
    border: 1px solid #feb2b2;
    display: flex;
    align-items: center;
    animation: shake 0.4s ease;
}

.error-message::before {
    content: '⚠️';
    margin-right: 8px;
    font-size: 16px;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    10%, 30%, 50%, 70%, 90% { transform: translateX(-5px); }
    20%, 40%, 60%, 80% { transform: translateX(5px); }
}

/* ログインボタン */
.btn-login {
    width: 100%;
    padding: 14px 24px;
    font-size: 16px;
    font-weight: 600;
    color: white;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.btn-login:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.3);
}

.btn-login:active {
    transform: translateY(0);
}

.btn-login:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.button-text,
.button-loader {
    display: inline-block;
}

/* スピナー */
.spinner {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ヘルプテキスト */
.help-text {
    text-align: center;
    padding-top: 24px;
    border-top: 1px solid #e2e8f0;
}

.help-text p {
    color: #718096;
    font-size: 13px;
    line-height: 1.6;
}

/* レスポンシブ対応 */
@media (max-width: 480px) {
    .login-box {
        padding: 32px 24px;
    }

    .logo-section h1 {
        font-size: 20px;
    }

    .form-control {
        font-size: 16px; /* iOS のズーム防止 */
    }
}

/* ダークモード対応（オプション） */
@media (prefers-color-scheme: dark) {
    body {
        background: linear-gradient(135deg, #1a202c 0%, #2d3748 100%);
    }

    .login-box {
        background: #2d3748;
    }

    .logo-section h1 {
        color: #f7fafc;
    }

    .subtitle {
        color: #a0aec0;
    }

    .form-group label {
        color: #e2e8f0;
    }

    .form-control {
        background: #1a202c;
        border-color: #4a5568;
        color: #f7fafc;
    }

    .form-control:focus {
        background: #2d3748;
        border-color: #667eea;
    }

    .help-text {
        border-top-color: #4a5568;
    }

    .help-text p {
        color: #a0aec0;
    }
}