:root {
    --bg-color: #f3f4f6;
    --card-bg: #ffffff;
    --text-color: #1f2937;
    --muted-text: #6b7280;
    --border-color: #d1d5db;
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --success-color: #10b981;
    --success-hover: #059669;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    padding: 20px;
    box-sizing: border-box;
}

.container {
    background-color: var(--card-bg);
    border-radius: 12px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    padding: 30px;
    max-width: 500px;
    width: 100%;
    text-align: center;
}

h1 {
    font-size: 2em;
    margin-bottom: 25px;
    color: var(--primary-color);
}

.password-display {
    display: flex;
    margin-bottom: 25px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    background-color: var(--bg-color);
}

#passwordOutput {
    flex-grow: 1;
    padding: 15px;
    font-size: 1.2em;
    font-family: monospace;
    background-color: var(--bg-color);
    border: none;
    color: var(--text-color);
    cursor: text;
    user-select: all;
    text-align: center;
    min-width: 0; /* Allows shrinking on small screens */
}

#copyButton {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 10px 15px;
    cursor: pointer;
    font-size: 1em;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.2s ease-in-out;
}

#copyButton:hover {
    background-color: var(--primary-hover);
}

#copyButton.copied {
    background-color: var(--success-color);
}

#copyButton.copied:hover {
    background-color: var(--success-hover);
}

#copyButton svg {
    width: 20px;
    height: 20px;
}

.controls {
    text-align: left;
}

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

.control-group label {
    display: block;
    margin-bottom: 10px;
    font-weight: 600;
    font-size: 1.1em;
}

input[type="range"] {
    width: 100%;
    -webkit-appearance: none;
    height: 8px;
    background: var(--border-color);
    outline: none;
    border-radius: 5px;
    transition: opacity 0.2s;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: grab;
    transition: background-color 0.2s ease-in-out;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

input[type="range"]::-webkit-slider-thumb:hover {
    background: var(--primary-hover);
}

input[type="range"]:active::-webkit-slider-thumb {
    cursor: grabbing;
}

button:not(#copyButton) {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 25px;
    border-radius: 8px;
    font-size: 1.1em;
    cursor: pointer;
    width: 100%;
    transition: background-color 0.2s ease-in-out, transform 0.1s ease-in-out;
}

button:not(#copyButton):hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
}

button:not(#copyButton):active {
    transform: translateY(0);
}

.footer {
    margin-top: 30px;
    font-size: 0.9em;
    color: var(--muted-text);
}

.footer p {
    margin-bottom: 5px;
}

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

.footer a:hover {
    text-decoration: underline;
}

/* For browsers that don't support modern range styling */
@media screen and (-webkit-min-device-pixel-ratio:0) {
    input[type="range"] {
        height: 8px;
    }
}