:root {
    --primary-color: #4a6fa5;
    --secondary-color: #6b8cae;
    --accent-color: #ff7e5f;
    --background-color: #f5f7fa;
    --card-color: #ffffff;
    --text-color: #333333;
    --text-light: #666666;
    --error-color: #e74c3c;
    --success-color: #2ecc71;
}

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

body {
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
    padding: 20px;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    padding: 20px;
}

h1, h2 {
    color: var(--primary-color);
    margin-bottom: 20px;
    text-align: center;
}

h2 {
    margin-bottom: 15px;
}

.card {
    background-color: var(--card-color);
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    padding: 25px;
    margin-bottom: 20px;
}

.form-group {
    margin-bottom: 15px;
}

label {
    display: block;
    margin-bottom: 5px;
    font-weight: 600;
    color: var(--primary-color);
}

input[type="text"],
input[type="number"],
input[type="password"],
textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 16px;
    transition: border 0.3s;
}

input[type="text"]:focus,
input[type="number"]:focus,
input[type="password"]:focus,
textarea:focus {
    border-color: var(--primary-color);
    outline: none;
}

textarea {
    min-height: 100px;
    resize: vertical;
}

button, .btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    width: 100%;
    transition: background-color 0.3s;
    text-align: center;
    display: block;
    text-decoration: none;
}

button:hover, .btn:hover {
    background-color: var(--secondary-color);
}

.btn.secondary {
    background-color: var(--secondary-color);
}

.btn.secondary:hover {
    background-color: #5a7a9e;
}

.alert {
    padding: 12px;
    border-radius: 5px;
    margin-bottom: 15px;
}

.alert.error {
    background-color: #fde8e8;
    color: var(--error-color);
    border: 1px solid #f5c6cb;
}

.message-box {
    background-color: #f8f9fa;
    padding: 15px;
    border-radius: 5px;
    border-left: 4px solid var(--primary-color);
    margin: 20px 0;
}

.result-box {
    background-color: #f8f9fa;
    font-family: monospace;
}

.hint {
    color: var(--text-light);
    font-size: 14px;
    margin-top: 10px;
    display: block;
}

small {
    color: var(--text-light);
    font-size: 13px;
}

@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    .card {
        padding: 15px;
    }
}