:root {
    /* Colors */
    --primary-bg: #e0e7ff;
    --secondary-bg: #c4b5fd;
    --container-bg: #ffffff;
    --text-primary: #1f2937;
    --text-secondary: #4b5563;
    --error-color: #dc2626;
    --border-color: #e5e7eb;
    --input-bg: #f9fafb;
    --accent-primary: #8b5cf6;
    --accent-secondary: #a78bfa;
    --shadow-color: rgba(0, 0, 0, 0.15);
    --accent-shadow: rgba(139, 92, 246, 0.1);
    --accent-hover-shadow: rgba(139, 92, 246, 0.4);

    /* Sizes */
    --container-padding: 40px;
    --container-max-width: 450px;
    --border-radius: 20px;
    --input-padding: 12px;
    --button-padding: 12px;
    --font-size-base: 1rem;
    --font-size-small: 0.875rem;
    --font-size-xsmall: 0.75rem;
    --font-size-title: 2rem;
    --margin-base: 20px;
    --shadow-spread: 40px;
}

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

body {
    font-family: 'Roboto', sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.login-container {
    background: white;
    padding: 2.5rem;
    border-radius: 15px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 500px;
    margin: 2rem;
}

.login-container h2 {
    font-family: 'Playfair Display', serif;
    color: #2c3e50;
    text-align: center;
    margin-bottom: 2rem;
    font-size: 2rem;
}

.input-group {
    margin-bottom: 1.5rem;
    position: relative;
}

.input-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: #34495e;
    font-weight: 500;
}

.input-group input {
    width: 100%;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.input-group input:focus {
    border-color: #4a90e2;
    outline: none;
    box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.1);
}

.password-toggle {
    position: absolute;
    right: 12px;
    top: 40px;
    cursor: pointer;
    user-select: none;
    opacity: 0.7;
    transition: opacity 0.3s ease;
}

.password-toggle:hover {
    opacity: 1;
}

button {
    width: 100%;
    padding: 14px;
    background: #4a90e2;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

button:hover {
    background: #357abd;
}

.error {
    color: #e74c3c;
    font-size: 0.9rem;
    margin-top: 0.5rem;
    display: none;
}

.error-message {
    background-color: #fde8e8;
    color: #e74c3c;
    padding: 12px;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
    border: 1px solid #fbd5d5;
}

.success-message {
    background-color: #e8f5e9;
    color: #2e7d32;
    padding: 12px;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
    border: 1px solid #c8e6c9;
}

.signup-link {
    text-align: center;
    margin-top: 1.5rem;
    color: #7f8c8d;
}

.signup-link a {
    color: #4a90e2;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.signup-link a:hover {
    color: #357abd;
    text-decoration: underline;
}

/* Responsive Design */
@media (max-width: 600px) {
    .login-container {
        margin: 1rem;
        padding: 1.5rem;
    }

    .login-container h2 {
        font-size: 1.75rem;
    }

    .input-group input {
        padding: 10px;
    }
}

@media (max-width: 400px) {
    .login-container {
        padding: calc(var(--container-padding) / 2.67);
    }

    .login-container h2 {
        font-size: calc(var(--font-size-title) * 0.625);
    }

    .input-group label {
        font-size: var(--font-size-xsmall);
    }

    .error {
        font-size: var(--font-size-xsmall);
    }

    .signup-link {
        font-size: var(--font-size-xsmall);
    }
}