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

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --primary-color-rgba-10: rgba(37, 99, 235, 0.1);
    --success-color: #10b981;
    --success-color-rgba-10: rgba(16, 185, 129, 0.1);
    --success-color-rgba-30: rgba(16, 185, 129, 0.3);
    --error-color: #ef4444;
    --error-color-rgba-10: rgba(239, 68, 68, 0.1);
    --error-color-rgba-30: rgba(239, 68, 68, 0.3);
    --warning-color: #f59e0b;
    --warning-color-rgba-10: rgba(245, 158, 11, 0.1);
    --warning-color-rgba-30: rgba(245, 158, 11, 0.3);
    --info-color: #3b82f6;
    --info-color-rgba-10: rgba(59, 130, 246, 0.1);
    --info-color-rgba-30: rgba(59, 130, 246, 0.3);
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
    --bg-light: #f9fafb;
    --bg-white: #ffffff;
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-header: linear-gradient(135deg, #10b981 0%, #059669 100%);
    --gradient-brand: linear-gradient(135deg, #06b6d4 0%, #764ba2 100%);
    --gradient-accent: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 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);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--gradient-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    color: var(--text-primary);
    line-height: 1.6;
}

.site-header {
    background: var(--bg-white);
    padding: 1.5rem 2rem;
    box-shadow: var(--shadow-sm);
    display: flex;
    align-items: center;
    gap: 1rem;
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    color: var(--text-primary);
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: var(--gradient-primary);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.25rem;
}

.brand-name {
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--gradient-header);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.5px;
}

.main-container {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem 1rem;
}

.auth-box {
    background: var(--bg-white);
    border-radius: 12px;
    box-shadow: var(--shadow-xl);
    max-width: 450px;
    width: 100%;
    overflow: hidden;
    position: relative;
}

.auth-box::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-accent);
}

.auth-header {
    background: var(--gradient-header);
    padding: 2rem;
    text-align: center;
    color: white;
    border-bottom: 2px solid rgba(255, 255, 255, 0.2);
}

.auth-header h1 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.auth-header p {
    font-size: 0.95rem;
    opacity: 0.95;
}

.auth-content {
    padding: 2rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.form-label .required {
    color: var(--error-color);
    margin-left: 2px;
}

.form-input {
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    transition: all 0.2s;
    background: var(--bg-white);
    color: var(--text-primary);
}

.form-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-color-rgba-10);
}

.form-input.error {
    border-color: var(--error-color);
}

.form-input.error:focus {
    box-shadow: 0 0 0 3px var(--error-color-rgba-10);
}

.checkbox-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.checkbox-group input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: var(--primary-color);
}

.checkbox-group label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    cursor: pointer;
}

.btn-primary {
    width: 100%;
    padding: 0.875rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    color: white;
    background: var(--gradient-accent);
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

.btn-primary:active:not(:disabled) {
    transform: translateY(0);
}

.btn-primary:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.nav-links {
    margin-top: 1.5rem;
    text-align: center;
}

.nav-link {
    color: var(--primary-color);
    text-decoration: none;
    font-size: 0.875rem;
    transition: color 0.2s;
}

.nav-link:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

.form-error {
    display: block;
    font-size: 0.875rem;
    margin-top: 0.5rem;
    color: var(--error-color);
}

.form-error--form-level {
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    background: var(--error-color-rgba-10);
    border: 1px solid var(--error-color-rgba-30);
}

.form-error--success {
    color: var(--success-color);
    background: var(--success-color-rgba-10);
    border-color: var(--success-color-rgba-30);
}

.form-error--error {
    color: var(--error-color);
    background: var(--error-color-rgba-10);
    border-color: var(--error-color-rgba-30);
}

.form-error--info {
    color: var(--info-color);
    background: var(--info-color-rgba-10);
    border-color: var(--info-color-rgba-30);
}

.form-error--warning {
    color: var(--warning-color);
    background: var(--warning-color-rgba-10);
    border-color: var(--warning-color-rgba-30);
}

[data-auth-error] {
    display: none;
}

[data-auth-error].visible {
    display: block;
}

.site-footer {
    background: var(--bg-white);
    padding: 1.5rem 2rem;
    text-align: center;
    font-size: 0.875rem;
    color: var(--text-secondary);
    border-top: 1px solid var(--border-color);
}

@media (max-width: 640px) {
    .site-header {
        padding: 1rem 1.5rem;
    }

    .brand-name {
        font-size: 1.25rem;
    }

    .logo-icon {
        width: 36px;
        height: 36px;
    }

    .auth-header {
        padding: 1.5rem;
    }

    .auth-header h1 {
        font-size: 1.5rem;
    }

    .auth-content {
        padding: 1.5rem;
    }

    .main-container {
        padding: 1rem;
    }
}