* {
    box-sizing: border-box;
    margin: 0;
    user-select: none;
}

html,
body {
    height: 100%;
}

body {
    font-family: "Segoe UI", Arial, sans-serif;
    background: linear-gradient(135deg, #f8fafc 0%, #e0e7ef 100%);
    color: #23272f;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

header {
    padding: 32px 20px 0 20px;

    text-align: center;
}

header > h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: #2451a6;
    margin-bottom: 8px;
}

header > p {
    color: #5a6272;
    font-size: 1.1rem;
    margin-bottom: 0;
}

main {
    flex: 1;
    display: grid;
    grid-template-rows: auto auto auto;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    justify-items: center;
    align-items: center;
    padding: 32px 12vw 32px 12vw;
    min-height: 540px;
}

.diamond-parent {
    grid-column: 1 / -1;
}

.diamond-left {
    grid-column: 1;
    grid-row: 2;
}

.diamond-right {
    grid-column: 2;
    grid-row: 2;
}

.diamond-result {
    grid-column: 1 / -1;
    grid-row: 3;
    display: flex;
    align-items: center;
}

.text-area-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100%;
    height: 100%;
    background: #fff;
    border-radius: 10px;
    box-shadow: 0 2px 12px 0 rgba(36, 81, 166, 0.06);
    padding: 18px 20px 16px 20px;
    margin-bottom: 0;
}

label {
    margin-bottom: 8px;
    font-weight: 600;
    color: #2451a6;
}

.box {
    width: 1ch;
    height: 1ch;
    border-radius: 50%;
    margin-left: 6px;
    display: inline-block;
    transform: scale(1.5);
}

textarea {
    width: 100%;
    border: none;
    font-size: 1rem;
    font-family: inherit;
    color: #23272f;
    box-sizing: border-box;
    resize: none;
    outline: none;
    margin-bottom: 0;
    height: 100%;
}

#merged {
    width: 100%;
    text-align: left;
    user-select: text;
}

.Left,
.AddedFromLeft,
.RemovedFromLeft {
    background: #12d197;
}

.Right,
.AddedFromRight,
.RemovedFromRight {
    background: #8575ed;
}

.RemovedFromLeft,
.RemovedFromRight {
    text-decoration: line-through;
}

@media (max-width: 900px) {
    main {
        padding: 24px 2vw;
    }
}

@media (max-width: 768px) {
    main {
        grid-template-columns: 1fr;
        grid-template-rows: auto auto auto auto auto;
    }

    main > * {
        grid-column: 1;
    }

    .diamond-parent {
        grid-row: 1;
    }

    .diamond-left {
        grid-row: 2;
    }

    .diamond-right {
        grid-row: 3;
    }

    .diamond-result {
        grid-row: 5;
    }
}

footer {
    position: relative;
    margin-top: 32px;
    padding: 28px 0 18px 0;
    text-align: center;
    color: #5a6272;
    font-size: 1rem;
    box-shadow: 0 -4px 12px 0 rgba(28, 28, 87, 0.1),
        0 -1px 2px 0 rgba(1, 1, 3, 0.1);
}

.github-link > svg {
    position: absolute;
    color: #5a6272;
    top: 50%;
    right: 36px;
    transform: translateY(-50%);
    width: 32px;
    height: 32px;
    transition: transform 0.2s;
}

.github-link > svg:hover {
    cursor: pointer;
    transform: translateY(-50%) scale(1.15);
}