body {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    background-color: white;
    color: black;
    justify-content: center;
    align-items: center;
}

h1 {
    margin-bottom: 24px;
    color: black;
    font-size: 10;
    text-transform: uppercase;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
}

button {
    margin: 20px 0;
    padding: 12px 20px;
    font-size: 18px;
    font-weight: 600;
    text-transform: uppercase;
    border: 3px solid black;
    color: black;
    background-color: rgba(255, 255, 255, 0.827);
    cursor: pointer;
    transition: all 0.15s ease;
}

button:hover {
    background-color: black;
    color: white;
    border: 5px solid rgba(255, 255, 255, 0.827);
    transform: translateY(-2px);
}

button:active {
    transform: translateY(1px) scale(0.98);
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

#result {
    display: inline-block;
    font-size: 96px;
    margin-left: 12px;
    filter: drop-shadow(0 8px 20px rgba(0,0,0,0.6));
    transition: transform 0.15s ease;
}

#result:hover {
    transform: scale(1.05);
}

h2 {
    margin: 18px 0 10px;
    font-size: 14px;
    letter-spacing: 2px;
    text-transform: uppercase;
    opacity: 0.8;
}

#history {
    list-style: none;
    padding: 0;
    margin: 0 0 14px;
    width: min(360px, 90vw);
    max-height: 180px;
    overflow: auto;
    border: 1px solid rgba(255, 255, 255, 0.15);
    background-color: rgba(255, 255, 255, 0.05);
}

#history li {
    padding: 10px 12px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    display: flex;
    justify-content: space-between;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
}

#history li:last-child {
    border-bottom: none;
}

#clearBtn {
    padding: 10px 18px;
    font-size: 14px;
}