:root {
    --bg-light: #f0f0f0;
    --bg-dark: #1e1e1e;
    --text-light: #333;
    --text-dark: #f0f0f0;
    --primary-light: #74ebd5;
    --primary-dark: #57c5b6;
    --card-bg-light: #fff;
    --card-bg-dark: #2c2c2c;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-light);
    color: var(--text-light);
    transition: background-color 0.3s, color 0.3s;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

body.dark {
    background-color: var(--bg-dark);
    color: var(--text-dark);
}

.container {
    background-color: var(--card-bg-light);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 8px 16px rgba(0,0,0,0.2);
    width: 100%;
    max-width: 400px;
    text-align: center;
    transition: background-color 0.3s;
}

body.dark .container {
    background-color: var(--card-bg-dark);
}

h2 {
    margin-bottom: 1rem;
}

input[type="text"],
input[type="email"],
input[type="password"],
input[type="tel"],
input[type="number"] {
    width: 100%;
    padding: 0.75rem;
    margin: 0.5rem 0;
    border: 1px solid #ccc;
    border-radius: 5px;
    background-color: inherit;
    color: inherit;
}

button {
    background-color: var(--primary-light);
    color: #fff;
    border: none;
    padding: 0.75rem 1.5rem;
    margin-top: 1rem;
    border-radius: 5px;
    cursor: pointer;
    font-weight: bold;
    transition: background-color 0.3s;
}

body.dark button {
    background-color: var(--primary-dark);
}

button:hover {
    opacity: 0.9;
}

.toggle-mode {
    margin-top: 1rem;
    font-size: 0.9rem;
    cursor: pointer;
    color: var(--primary-light);
}

body.dark .toggle-mode {
    color: var(--primary-dark);
}

.success {
    color: green;
    margin-top: 1rem;
}

.error {
    color: red;
    margin-top: 1rem;
}

a {
    color: var(--primary-light);
    text-decoration: none;
}

body.dark a {
    color: var(--primary-dark);
}

a:hover {
    text-decoration: underline;
}

@media (max-width: 500px) {
    .container {
        padding: 1rem;
    }
}