:root {
    --bg-color: #f4f7f9;
    --card-bg-color: #ffffff;
    --text-color: #333;
    --primary-color: #007bff;
    --border-color: #ccc;
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

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

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
}

.container {
    max-width: 680px;
    width: 100%;
    margin: 0 auto;
}

h1 {
    text-align: center;
    color: #222;
    margin-bottom: 30px;
    font-size: 2rem;
    font-weight: 600;
}

h2 {
    color: #444;
    margin-bottom: 20px;
    font-size: 1.5rem;
    font-weight: 500;
    border-bottom: 1px solid #eee;
    padding-bottom: 10px;
}

.card {
    background-color: var(--card-bg-color);
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    padding: 25px;
    margin-bottom: 30px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
}

.input-group {
    margin-bottom: 20px;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: #555;
}

input[type="text"], 
input[type="number"] {
    padding: 10px 15px;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    font-size: 1rem;
    width: 100%;
    transition: border-color 0.2s, box-shadow 0.2s;
}

input[type="text"]:focus, 
input[type="number"]:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.15);
}

.checkbox-group {
    display: flex;
    align-items: center;
    margin-bottom: 12px;
}

.checkbox-group input[type="checkbox"] {
    margin-right: 10px;
    width: 18px;
    height: 18px;
    accent-color: var(--primary-color);
}

.checkbox-group label {
    cursor: pointer;
    user-select: none;
}

button {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 18px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    width: 100%;
    margin-top: 10px;
    transition: background-color 0.2s;
}

button:hover {
    background-color: #0056b3;
}

.password-container {
    position: relative;
    margin-bottom: 20px;
}

.password-container input {
    padding-right: 50px;
}

#copyBtn {
    position: absolute;
    right: 0;
    top: 0;
    bottom: 0;
    background: transparent;
    color: #777;
    width: 50px;
    margin: 0;
    border: none;
    border-radius: 0 6px 6px 0;
    transition: background-color 0.2s;
}

#copyBtn:hover {
    background-color: #f0f0f0;
}

.icon {
    font-size: 1.2rem;
}

.strength-meter {
    height: 10px;
    background-color: #e9ecef;
    border-radius: 5px;
    margin: 20px 0 10px;
    overflow: hidden;
}

.strength-bar {
    height: 100%;
    width: 0%;
    transition: width 0.4s ease, background-color 0.4s ease;
}

#strengthText {
    font-size: 0.9rem;
    font-weight: 500;
    text-align: center;
    margin-bottom: 15px;
    color: #666;
}

.suggestions-container {
    margin-top: 20px;
}

.suggestion-item {
    padding: 10px;
    background-color: #f8f9fa;
    border-left: 3px solid var(--primary-color);
    border-radius: 0 4px 4px 0;
    margin-bottom: 8px;
    font-size: 0.95rem;
}

.very-weak { background-color: #e74c3c; }
.weak { background-color: #f39c12; }
.medium { background-color: #f1c40f; }
.strong { background-color: #27ae60; }
.very-strong { background-color: #2ecc71; }

@media (max-width: 600px) {
    body {
        padding: 10px;
        align-items: flex-start;
    }
    
    .card {
        padding: 20px;
    }
    
    h1 {
        font-size: 1.8rem;
    }
}