:root {
    --primary-color: #3b82f6;
    --primary-dark: #2563eb;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --light-bg: #f8fafc;
    --card-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --gradient-bg: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

body {
    background: var(--gradient-bg);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    min-height: 100vh;
}

.login-container {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border-radius: 20px;
    box-shadow: var(--card-shadow);
    border: 1px solid rgba(255, 255, 255, 0.2);
    overflow: hidden;
    max-width: 450px;
    margin: auto;
}

.login-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 2rem;
    text-align: center;
    position: relative;
}

.login-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="50" cy="50" r="1" fill="rgba(255,255,255,0.1)"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    opacity: 0.1;
}

.login-header h1 {
    font-size: 1.75rem;
    font-weight: 700;
    margin: 0;
    position: relative;
    z-index: 1;
}

.login-header p {
    margin: 0.5rem 0 0 0;
    opacity: 0.9;
    font-size: 0.95rem;
    position: relative;
    z-index: 1;
}

.login-body {
    padding: 2rem;
}

.form-floating {
    position: relative;
    margin-bottom: 1.5rem;
}

.form-floating input {
    height: 58px;
    padding: 1rem 1rem 0.5rem;
    border: 2px solid #e2e8f0;
    border-radius: 12px;
    font-size: 1rem;
    transition: all 0.3s ease;
    background: #fafbfc;
}

.form-floating input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
    background: white;
    outline: none;
}

.form-floating label {
    padding: 1rem;
    color: var(--secondary-color);
    font-weight: 500;
    transition: all 0.3s ease;
}

.password-toggle {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--secondary-color);
    cursor: pointer;
    padding: 8px;
    border-radius: 6px;
    transition: all 0.2s ease;
    z-index: 10;
}

.password-toggle:hover {
    background: rgba(59, 130, 246, 0.1);
    color: var(--primary-color);
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    border: none;
    border-radius: 12px;
    padding: 0.875rem 2rem;
    font-weight: 600;
    font-size: 1rem;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px -5px rgba(59, 130, 246, 0.4);
}

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

.btn-primary .spinner-border {
    width: 1rem;
    height: 1rem;
    margin-right: 0.5rem;
}

.alert {
    border: none;
    border-radius: 12px;
    padding: 1rem 1.25rem;
    margin-bottom: 1.5rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    animation: slideDown 0.3s ease;
}

.alert-success {
    background: rgba(16, 185, 129, 0.1);
    color: #065f46;
    border-left: 4px solid var(--success-color);
}

.alert-danger {
    background: rgba(239, 68, 68, 0.1);
    color: #991b1b;
    border-left: 4px solid var(--danger-color);
}

.form-check {
    margin: 1.5rem 0;
}

.form-check-input:checked {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.form-check-label {
    font-weight: 500;
    color: var(--secondary-color);
}

.forgot-password {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9rem;
    transition: all 0.2s ease;
}

.forgot-password:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

.is-invalid {
    border-color: var(--danger-color) !important;
    background: rgba(239, 68, 68, 0.05);
}

.invalid-feedback {
    color: var(--danger-color);
    font-size: 0.875rem;
    font-weight: 500;
    margin-top: 0.5rem;
    display: block;
}

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

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

.login-container {
    animation: fadeIn 0.6s ease;
}

@media (max-width: 768px) {
    .login-container {
        margin: 1rem;
        border-radius: 16px;
    }
    
    .login-header, .login-body {
        padding: 1.5rem;
    }
}

/* Loading state */
.btn-loading {
    pointer-events: none;
    opacity: 0.7;
}