:root { 
    --primary: #2563eb; 
    --primary-hover: #1d4ed8;
    --error: #dc2626;
    --text: #1e293b;
    --text-light: #64748b;
    --border: #e2e8f0;
    --background: #f8fafc;
}

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

body { 
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--background);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
    line-height: 1.5;
    color: var(--text);
}

.login-container {
    background: white;
    border-radius: 16px;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    padding: 2.5rem;
    width: 100%;
    max-width: 420px;
    border: 1px solid var(--border);
}

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

.logo h1 {
    color: #1e293b;
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    margin-bottom: 0.5rem;
}

.logo p {
    color: var(--text-light);
    margin-top: 0.5rem;
    margin-bottom: 2rem;
}

.logo img {
    margin: 0 auto 1rem;
    display: block;
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text);
    font-size: 0.875rem;
    font-weight: 500;
}

.form-control {
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 0.9375rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    background-color: white;
    color: var(--text);
    transition: all 0.2s ease;
    height: 46px;
}

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

.btn {
    display: block;
    width: 100%;
    padding: 0.75rem 1rem;
    background-color: var(--primary);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    height: 46px;
    margin-top: 0.5rem;
}

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

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

.error-message {
    color: var(--error);
    font-size: 0.875rem;
    margin: -0.5rem 0 1.5rem;
    text-align: center;
    padding: 0.75rem 1rem;
    border-radius: 8px;
    background-color: #fef2f2;
    border: 1px solid #fecaca;
    animation: fadeIn 0.3s ease;
}

.back-link {
    display: block;
    text-align: center;
    margin-top: 1.5rem;
    color: var(--text-light);
    font-size: 0.875rem;
    text-decoration: none;
    transition: color 0.2s ease;
}

.back-link:hover {
    color: var(--primary);
    text-decoration: none;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Responsive adjustments */
@media (max-width: 480px) {
    .login-container {
        padding: 1.5rem;
    }
    .logo h1 {
        font-size: 1.25rem;
    }
    .logo p {
        font-size: 0.875rem;
    }
}