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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

.container {
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(10px);
    padding: 2.5rem;
    border-radius: 24px;
    box-shadow: 0 25px 50px rgba(0,0,0,0.15);
    max-width: 420px;
    width: 100%;
    text-align: center;
}

h1 { 
    background: linear-gradient(45deg, #667eea, #764ba2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.5rem;
    font-size: 2rem;
}

p { color: #666; margin-bottom: 2rem; font-size: 0.95rem; }

.controls { margin-bottom: 2rem; }
.controls label { 
    display: flex; align-items: center; justify-content: center; gap: 0.75rem; 
    margin-bottom: 1.5rem; font-size: 1.1rem;
}
#length { width: 100%; height: 8px; cursor: pointer; }
#lengthValue { font-weight: bold; color: #667eea; min-width: 2ch; }

.checkboxes { display: flex; flex-direction: column; gap: 0.75rem; }
.checkboxes label { justify-content: flex-start; font-size: 1rem; }

button {
    background: linear-gradient(45deg, #667eea, #764ba2);
    color: white;
    border: none;
    padding: 1rem 1.5rem;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    margin: 0.25rem;
}

button:hover { transform: translateY(-2px); box-shadow: 0 10px 25px rgba(102,126,234,0.4); }

.output { margin: 2rem 0; }
#password {
    width: 100%; padding: 1.25rem; font-family: 'Courier New', monospace;
    font-size: 1.4rem; letter-spacing: 2px; text-align: center;
    border: 3px solid #e5e7eb; border-radius: 12px; background: #f9fafb;
    transition: all 0.3s ease; margin-bottom: 1rem;
}
#password:focus { outline: none; border-color: #667eea; }

.buttons { display: flex; gap: 0.5rem; justify-content: center; }

.strength {
    padding: 0.75rem; border-radius: 10px;
    font-weight: 600; font-size: 1.1rem;
}

.strong { background: rgba(34,197,94,0.2); color: #16a34a; }
.medium { background: rgba(251,191,36,0.2); color: #d97706; }
.weak { background: rgba(239,68,68,0.2); color: #dc2626; }

@media (max-width: 480px) {
    .container { padding: 2rem 1.5rem; margin: 1rem; }
    h1 { font-size: 1.6rem; }
}