body {
    background-color: rgba(90,152,180,0.5);
}

#main {
    display: flex;
    flex-direction: column;
    border: 3px solid #5a98bd;
    border-radius: 10px;
    background: rgba(90, 152, 189, 0.4);
}

/**
 * Selection of tech tree era
 */

#tech-select-area {
    display: flex;
    flex-grow: 1;
    padding: 5px;
    border-bottom: 3px solid #5a98bd;
    text-align: center;
    align-items: center;
    position: relative;
}

#tech-select-list {
    flex: 1 0 auto;
    border: 0;
    font-size: 16px;
    text-align: center;
    background: transparent;
}

#tech-select-list option {
    text-align: center;
}

/**
 * Showing of tech tree
 */

#tech-tree {
    padding: 20px;
    overflow-x: scroll;
    position: relative;
}

#tech-tree-area {
    display: flex;
    align-items: center;
    position: relative;
}

.tech-node {
    display: flex;
    min-width: 200px;
    align-items: center;
    gap: 10px;
    padding: 10px;
    border: 3px solid #339ab4;
    border-radius: 10px;
    background-color: #c3ae7b;
}

.tech-node .icon {
    width: 50px;
    height: 50px;
}

.tech-node .title {
    flex-grow: 1;
    font-size: 18px;
    text-align: center;
}

.tech-node.selected {
    border-color: #3ea525;
    background-color: #91e252;
}

.tech-group {
    display: flex;
    flex-direction: column;
    gap: 40px;
}

/* SVG arrows */
.tech-connector {
    flex: 1 0 100px;
    align-self: stretch;
    position: relative;
}

svg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

#arrowhead {
    fill: #5a98bd;
}

.tech-connector .base .arrow {
    stroke-width: 10;
    fill: none;
    stroke: #5a98bd;
}

.tech-connector .highlight .arrow {
    stroke-width: 10;
    fill: none;
    stroke: #91e252;
}

/**
 * Showing cost
 */

#tech-tree-cost {
    display: flex;
}

#tech-tree-research-cost {
    border-right: 3px solid #5a98bd;
}

.tech-tree-cost-wrap {
    flex: 1 0 auto;
    padding: 20px;
}

.tech-tree-cost-wrap h3 {
    border-bottom: 3px solid #5a98bd;
}

#research-cost-list {
    display: flex;
    flex-direction: column;
}

.research-item-wrap, .goods-item-wrap,
.goods-item-era-wrap {
    display: flex;
    gap: 10px;
}

.goods-item-wrap {
    flex-direction: column;
    gap: 5px;
}

.research-title, .goods-title,
.goods-item-era-title {
    font-weight: bold;
}

.research-title, .goods-item-era-title {
    flex-basis: 20px;
}

.goods-title. {
    flex-basis: 110px;
}

.goods-cost-list {
    display: flex;
    gap: 50px;
    margin-top: 20px;
}