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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #1a1a1a 0%, #2d2d2d 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.login-container {
    background: #ffffff;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 15px 35px rgba(0,0,0,0.3);
    width: 100%;
    max-width: 400px;
    border: 1px solid #e0e0e0;
}

.logo-placeholder {
    text-align: center;
    margin-bottom: 2rem;
    padding: 1rem;
    background: #f5f5f5;
    border-radius: 8px;
    border: 2px dashed #ccc;
}

.logo-placeholder h1 {
    color: #333;
    font-size: 1.8rem;
    margin-bottom: 0.5rem;
}

.logo-placeholder p {
    color: #666;
    font-size: 0.9rem;
}

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

label {
    display: block;
    margin-bottom: 0.5rem;
    color: #333;
    font-weight: 500;
}

input[type="text"], input[type="password"] {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid #e0e0e0;
    border-radius: 6px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

input[type="text"]:focus, input[type="password"]:focus {
    outline: none;
    border-color: #333;
}

.btn {
    width: 100%;
    padding: 0.75rem;
    background: #333;
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    cursor: pointer;
    transition: background 0.3s ease;
}

.btn:hover {
    background: #555;
}

.error {
    background: #ffe6e6;
    color: #d63031;
    padding: 0.75rem;
    border-radius: 6px;
    margin-bottom: 1rem;
    border: 1px solid #fab1a0;
}

.success {
    background: #e6ffe6;
    color: #00b894;
    padding: 0.75rem;
    border-radius: 6px;
    margin-bottom: 1rem;
    border: 1px solid #81ecec;
}

.demo-info {
    margin-top: 1.5rem;
    padding: 1rem;
    background: #f8f9fa;
    border-radius: 6px;
    border-left: 4px solid #333;
}

.demo-info h4 {
    color: #333;
    margin-bottom: 0.5rem;
}

.demo-info p {
    color: #666;
    font-size: 0.9rem;
    margin-bottom: 0.25rem;
}