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

.container {
    width: 100vw;
    height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: start;
    gap: 20px;
    padding-top: 20px;
}

.input-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

.input-section > p {
    color: red;
    display: none;
}

.url-input {
    padding: 8px 12px;
    border: 1px solid #ccc;
    border-radius: 4px;
    width: 400px;
}

.display-btn {
    padding: 8px 16px;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

.grid-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-template-rows: 1fr 1fr;
    column-gap: 40px;
    max-width: 1200px;
    min-height: 400px;
}

.image-cell {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    padding-top: 10px;
}

.image {
    width: 100%;
    height: auto;
    border-radius: 10px;
}

.btn-group {
    display: flex;
    gap: 10px;
    justify-content: center;
    width: 100%;
}

.btn-group .btn-flip {
    width: 40px;
    height: 40px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 20px;
    text-align: center;
    line-height: 40px;
    background-color: #007bff;
    color: white;
    border-radius: 4px;
}

.flip-box {
    background-color: transparent;
    width: 100%;
    height: 100%;
    perspective: 1000px;
}

.flip-inner {
    width: 100%;
    height: 100%;
    text-align: center;
    transition: transform 0.8s;
    transform-style: preserve-3d;
}