/* ==================== グローバルスタイル ==================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --bg-primary: #ffffff;
    --bg-secondary: #f3f4f6;
    --border-color: #e5e7eb;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --radius: 12px;
    --radius-sm: 8px;
}

body {
    font-family: 'Noto Sans JP', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

/* ==================== ログインページ ==================== */
.login-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

.login-box {
    background: var(--bg-primary);
    padding: 40px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 440px;
    animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.login-header {
    text-align: center;
    margin-bottom: 30px;
}

.login-header h1 {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.login-header p {
    font-size: 14px;
    color: var(--text-secondary);
}

/* ==================== フォーム ==================== */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.form-control {
    width: 100%;
    padding: 12px 16px;
    font-size: 14px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    transition: all 0.2s;
    font-family: inherit;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.error-text {
    display: block;
    color: var(--danger-color);
    font-size: 12px;
    margin-top: 6px;
}

/* ==================== ボタン ==================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    font-size: 14px;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
    font-family: inherit;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    box-shadow: 0 4px 6px -1px rgba(102, 126, 234, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 15px -3px rgba(102, 126, 234, 0.4);
}

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

.btn-block {
    width: 100%;
}

/* ==================== アラート ==================== */
.alert {
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    margin-bottom: 20px;
    font-size: 14px;
    border-left: 4px solid;
}

.alert-success {
    background-color: #d1fae5;
    border-color: var(--success-color);
    color: #065f46;
}

.alert-error {
    background-color: #fee2e2;
    border-color: var(--danger-color);
    color: #991b1b;
}

.alert-warning {
    background-color: #fef3c7;
    border-color: var(--warning-color);
    color: #92400e;
}

/* ==================== ログインフッター ==================== */
.login-footer {
    margin-top: 24px;
    text-align: center;
    font-size: 14px;
    color: var(--text-secondary);
}

.login-footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.login-footer a:hover {
    text-decoration: underline;
}

/* ==================== レスポンシブ ==================== */
@media (max-width: 768px) {
    .login-box {
        padding: 30px 20px;
    }
    
    .login-header h1 {
        font-size: 20px;
    }
}