* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: linear-gradient(135deg, var(--background-start) 0%, var(--background-end) 100%);
}

.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--overlay-bg);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.spinner {
    border: 8px solid var(--border-color);
    border-top: 8px solid var(--primary-color);
    border-radius: 50%;
    width: 60px;
    height: 60px;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.login-container {
    background: var(--surface-color);
    color: var(--text-color-primary);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 0 25px rgba(0, 245, 212, 0.1);
    width: 100%;
    max-width: 500px;
    margin: 0 1rem;
    border: 1px solid var(--border-color);
}

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

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

.login-form input {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid var(--border-color);
    border-radius: 5px;
    font-size: 1rem;
    background-color: transparent;
    color: var(--text-color-primary);
    transition: all 0.3s ease;
}

.login-form input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 245, 212, 0.25);
}

.login-btn {
    width: 100%;
    padding: 1rem;
    background: var(--primary-color);
    color: var(--text-color-inverse);
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: filter 0.3s ease, transform 0.2s ease;
}

.login-btn:hover {
    filter: brightness(1.1);
    transform: translateY(-2px);
}

.password-container {
    position: relative;
    display: flex;
    align-items: center;
}

.toggle-password {
    position: absolute;
    right: 10px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
    color: var(--text-color-secondary);
    transition: color 0.2s ease-in-out, transform 0.2s ease-in-out;
}

.toggle-password:hover {
    color: var(--primary-color);
    transform: scale(1.1);
}

.form-title {
    text-align: center;
    font-size: 1.8rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    animation: fadeIn 0.6s ease-out;
}

@keyframes fadeIn {
    0% { opacity: 0; transform: translateY(-10px); }
    100% { opacity: 1; transform: translateY(0); }
}

.error-message {
    color: var(--danger-color);
    margin-top: 1rem;
    text-align: center;
    font-weight: 500;
    display: none;
}

@media (max-width: 768px) {
    .login-container {
        max-width: 600px;
        padding: 2rem;
        margin: 1rem;
    }
    .form-title {
        font-size: 1.6rem;
    }
    .login-form input {
        font-size: 0.9rem;
        padding: 0.7rem;
    }
    .login-btn {
        font-size: 0.9rem;
        padding: 0.8rem;
    }
}

@media (max-width: 480px) {
    .login-container {
        margin: 1rem;
        padding: 1.5rem;
    }
    
    .form-title {
        font-size: 1.4rem;
    }
    .login-form input {
        font-size: 0.8rem;
        padding: 0.6rem;
    }
    .login-btn {
        font-size: 0.8rem;
        padding: 0.7rem;
    }
}