/* Reset some default styles */
:root {
    --main-yellow: #ffc815;
    --main-yellow-2: #dbad13;
    --bg-color: #121c24;

    --header-bg: #f8f9fa;
    --section-bg: #f3f4f5;
    --footer-bg: #e9ecef;
    --header-height: 80px;

    --card-bg-gray: #f0f0f0;
    --card-title: #1e242b;
    --card-content: #60666b;

    --max-content-width: 1440px;
    --content-padding: 160px;
}

.btn-text {
    color: var(--main-yellow-2);
    font-weight: bold;
    width: fit-content;
}

.no-padding-y {
    padding-top: 0 !important;
    padding-bottom: 0 !important;
}

.header-bg {
    background-color: var(--header-bg, #f8f9fa) !important;
}

.footer-bg {
    background-color: var(--footer-bg, #f8f9fa) !important;
}

.bg-white {
    background-color: #fff !important;
}

.text-no-wrap {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.loadimage {
    background: url("/resources/loading.png") no-repeat fixed center center;
}

html,
body,
p {
    margin: 0;
    padding: 0;
    line-height: 1.8;
    font-size: 16px;
}

body {
    line-height: 2;
}

header,
section,
footer {
    padding-left: var(--content-padding, 80px);
    padding-right: var(--content-padding, 80px);
}

header {
    top: 0;
    height: var(--header-height, 80px);
    z-index: 90;
    position: sticky;
    position: -webkit-sticky;
    background-color: var(--header-bg, #f8f9fa);
}

/* 导航栏至少要 620px 的宽度才是正常的 */
@media (max-width: calc(620px + 2 * 64px)) {
    .navbar-nav {
        display: none !important;
    }

    .menu-icon {
        display: block !important;
    }
}

@media (max-width: calc(620px + 2 * 124px)) {
    :root {
        --content-padding: 32px;
    }
}

@media (min-width: calc(620px + 2 * 124px)) and (max-width: calc(620px + 2 * 200px)) {
    :root {
        --content-padding: 124px;
    }
}

section {
    padding-top: 50px;
    padding-bottom: 50px;
}

section:nth-child(odd) {
    background-color: #ffffff;
}

section:nth-child(even) {
    background-color: var(--header-bg, #f3f4f5);
}

.section-intro {
    border-left: #555 3px solid;
    padding-left: 12px;
    margin-bottom: 55px;
}

.section-intro h2 {
    line-height: 1.18;
    font-weight: 300;
    font-size: 2rem;
}

@media (min-width: 992px) {
    .section-intro h2 {
        font-size: 2.875rem;
        margin: 15px 0;
    }
}

.section-intro p {
    color: #6C737A;
}

footer {
    padding-top: 40px;
    padding-bottom: 40px;
    background-color: #e9ecef;
}

.max-width-content {
    max-width: var(--max-content-width, 1440px);
    margin: auto;
}

.columns-2 {
    display: grid;
    gap: 52px;
}

@media (min-width: calc(490px*2)) {
    .columns-2 {
        grid-template-columns: repeat(2, 1fr);
    }
}

.columns-3 {
    display: grid;
    gap: 12px;
}

@media (min-width: calc(420px*3)) {
    .columns-3 {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (min-width: calc(360px*2)) and (max-width: calc(420px*3)) {
    .columns-3 {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: calc(360px*2)) {
    .columns-3 {
        grid-template-columns: 1fr;
    }
}


.columns-4 {
    display: grid;
    gap: 8px;
}

@media (min-width: calc(350px*4)) {
    .columns-4 {
        grid-template-columns: repeat(4, 1fr);
    }
}

@media (min-width: calc(370px*3)) and (max-width: calc(350px*4)) {
    .columns-4 {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (min-width: calc(350px*2)) and (max-width: calc(370px*3)) {
    .columns-4 {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: calc(350px*2)) {
    .columns-4 {
        grid-template-columns: 1fr;
    }
}

.center {
    margin: auto;
}

.button {
    background-color: var(--card-bg-gray);
    color: black;
    padding: 10px 20px;
    text-decoration: none;
    border-radius: 5px;
    font-size: 1em;
    width: fit-content;
}

.button:hover {
    background-color: #c6c6c6;
    color: black;
    cursor: pointer;
}