:root {
    --indigo-50: #eef2ff;
    --indigo-100: #e0e7ff;
    --indigo-200: #c7d2fe;
    --indigo-400: #818cf8;
    --indigo-500: #6366f1;
    --indigo-600: #4f46e5;
    --indigo-700: #4338ca;
    --indigo-800: #3730a3;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    --white: #ffffff;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: linear-gradient(135deg, var(--indigo-600) 0%, var(--indigo-800) 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

.login-container {
    background: var(--white);
    padding: 2.5rem;
    border-radius: 1rem;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    width: 100%;
    max-width: 420px;
}

.logo {
    text-align: center;
    margin-bottom: 2rem;
}

.logo-mark {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 3.5rem;
    height: 3.5rem;
    background: linear-gradient(135deg, var(--indigo-600) 0%, var(--indigo-500) 100%);
    color: var(--white);
    font-size: 1.75rem;
    font-weight: 800;
    border-radius: 0.75rem;
    margin-bottom: 1rem;
}

.logo h1 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 0.25rem;
}

.logo p {
    color: var(--gray-500);
    font-size: 0.9375rem;
}

.form-group {
    margin-bottom: 1.25rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    font-size: 0.875rem;
    color: var(--gray-700);
}

.form-group input {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 1px solid var(--gray-300);
    border-radius: 0.5rem;
    font-size: 1rem;
    font-family: inherit;
    color: var(--gray-900);
    background: var(--white);
    transition: all 0.2s;
}

.form-group input:focus {
    outline: none;
    border-color: var(--indigo-500);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-group input::placeholder {
    color: var(--gray-400);
}

.btn-primary {
    width: 100%;
    background: var(--indigo-600);
    color: var(--white);
    padding: 0.875rem 1.5rem;
    border: none;
    border-radius: 0.5rem;
    font-size: 1rem;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: all 0.2s;
    margin-top: 0.5rem;
}

.btn-primary:hover {
    background: var(--indigo-700);
    transform: translateY(-1px);
}

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

.alert {
    padding: 1rem;
    margin-bottom: 1.25rem;
    border-radius: 0.5rem;
    font-size: 0.9375rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.alert-error {
    background: #fef2f2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

.alert-success {
    background: #ecfdf5;
    color: #065f46;
    border: 1px solid #a7f3d0;
}

.back-link {
    display: block;
    text-align: center;
    margin-top: 1.5rem;
    color: var(--indigo-600);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9375rem;
    transition: color 0.2s;
}

.back-link:hover {
    color: var(--indigo-700);
}

@media (max-width: 480px) {
    .login-container {
        padding: 1.5rem;
    }
}