:root {
    --keyboard-width: 600px;
    --keyboard-bg: #23272f;
    --keyboard-key-bg: linear-gradient(180deg, #3a3f4b 0%, #23272f 100%);
    --keyboard-key-hover: #4caf50;
    --keyboard-key-active: #388e3c;
    --keyboard-key-shadow: 0 2px 8px rgba(0,0,0,0.18);
    --keyboard-key-radius: 12px;
    --keyboard-key-font: 'Segoe UI', Arial, sans-serif;
    --keyboard-key-font-size: 1.5rem;
    --keyboard-key-font-size-lg: 2.2rem;
    --keyboard-gap: 10px;
    --keyboard-padding: 20px;
}

.numpad {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--keyboard-gap);
    background: var(--keyboard-bg);
    position: absolute;
    padding: var(--keyboard-padding);
    border-radius: 18px;
    box-shadow: 0 4px 24px rgba(0,0,0,0.25);
    z-index: 1000000;
    height: auto;
    min-width: 320px;
    max-width: 400px;
    width: 100%;
    bottom: 2vh;
    left: 0;
    right: 0;
    margin: 0 auto;
    transform: none;
}

.hidden_keyboard {
    display: none !important;
    visibility: hidden;
    z-index: -1000000;
}

.keyboard {
    display: grid;
    grid-template-columns: repeat(11, 1fr);
    gap: var(--keyboard-gap);
    background: var(--keyboard-bg);
    position: absolute;
    padding: var(--keyboard-padding);
    border-radius: 18px;
    box-shadow: 0 4px 24px rgba(0,0,0,0.25);
    z-index: 1000000;
    width: var(--keyboard-width);
    min-width: 400px;
    max-width: 98vw;
    bottom: 2vh;
    left: 0;
    right: 0;
    margin: 0 auto;
    transform: none;
}

.keyboard button, .numpad button {
    font-family: var(--keyboard-key-font);
    font-size: var(--keyboard-key-font-size-lg);
    font-weight: 600;
    color: #fff;
    background: var(--keyboard-key-bg);
    border: none;
    border-radius: var(--keyboard-key-radius);
    box-shadow: var(--keyboard-key-shadow);
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 60px;
    min-width: 0;
    transition: background 0.15s, box-shadow 0.15s, transform 0.08s;
    outline: none;
    user-select: none;
    margin: 0;
    padding: 0;
}

.keyboard button {
    font-size: var(--keyboard-key-font-size);
}

.keyboard button:active, .numpad button:active {
    background: var(--keyboard-key-active);
    transform: scale(0.97);
}

.keyboard button:hover, .numpad button:hover, .keyboard button:focus, .numpad button:focus {
    background: var(--keyboard-key-hover);
    color: #fff;
    box-shadow: 0 6px 24px rgba(76,175,80,0.18);
}

.keyboard button[style*="grid-column"], .numpad button[style*="grid-column"] {
    font-size: 1.3rem !important;
    font-weight: 700;
    background: #e53935;
    color: #fff;
    letter-spacing: 1px;
}

.keyboard button:last-child, .numpad button:last-child {
    border-bottom-right-radius: var(--keyboard-key-radius);
}

.keyboard button:first-child, .numpad button:first-child {
    border-top-left-radius: var(--keyboard-key-radius);
}

@media (max-width: 700px) {
    :root {
        --keyboard-width: 98vw;
        --keyboard-key-font-size: 1.1rem;
        --keyboard-key-font-size-lg: 1.5rem;
    }
    .keyboard, .numpad {
        min-width: 0;
        max-width: 100vw;
        padding: 10px;
    }
    .keyboard button, .numpad button {
        min-height: 44px;
    }
}