html {
    --brand-green: hsl(162, 87%, 21%);
    --dark-green: hsl(162, 88%, 30%);
    --medium-green: hsl(162, 73%, 46%);
    --text-color: hsl(210, 11%, 15%);
    --gray: hsl(210, 7%, 56%);
    --light-gray: hsl(210, 17%, 95%);
    --extra-light-gray: hsl(210, 17%, 98%);
    --white: hsl(0, 0%, 100%);
    --red: hsl(342, 63%, 46%);
    box-sizing: border-box;
    color: var(--text-color);
}

*,
*::before,
*::after {
    box-sizing: inherit;
}

body {
    margin: 0;
    /* font-family: Helvetica, Arial, sans-serif; */
    font-family: Roboto, sans-serif;
    line-height: 1.4;
    letter-spacing: 0.01em;
    background-color: var(--extra-light-gray);
}

h1,
h2,
h3,
h4 {
    font-family: Sansita, serif;
    letter-spacing: 0.03em;
}

a {
    color: var(--medium-green);
}

a:visited {
    color: var(--brand-green);
}

a:hover {
    color: var(--brand-green);
}

a:active {
    color: var(--red);
}

.nav-container {
    background-color: var(--medium-green);
}

.nav-container__inner {
    display: flex;
    justify-content: space-between;
    max-width: 1080px;
    margin: 0 auto;
    padding: 0.625em 0;
}

.home-link {
    color: var(--text-color);
    font-size: 1.6rem;
    font-family: Sansita, serif;
    font-weight: bold;
    letter-spacing: 0.03em;
    text-decoration: none;
}

.top-nav {
    display: flex;
    list-style-type: none;
    margin: 0;
}

.top-nav>li+li {
    margin-left: 0.625em;
}

.top-nav a {
    display: block;
    padding: 0.3em 1.25em;
    color: var(--white);
    background: var(--brand-green);
    text-decoration: none;
    border-radius: 3px;
}

.top-nav a:hover {
    background-color: var(--dark-green);
}

.top-nav__featured>a {
    color: var(--brand-green);
    background-color: var(--white);
}

.top-nav__featured>a:hover {
    color: var(--medium-green);
    background-color: var(--white);
}

.hero {
    background: url(collaboration.jpg) no-repeat;
    background-size: cover;
    margin-bottom: 2.5rem;
}

.hero__inner {
    max-width: 1080px;
    margin: 0 auto;
    padding: 5.5625em 12.5em 12.5em 0;
    text-align: right;
}

.hero h2 {
    font-size: 1.95rem;
    margin-top: 0;
    margin-bottom: 0.625rem;
    letter-spacing: -0.02em;
}

.button {
    display: inline-block;
    padding: 0.4em 1em;
    color: var(--brand-green);
    border: 2px solid var(--brand-green);
    border-radius: 0.2em;
    text-decoration: none;
    font-size: 1rem;
}

.button:hover {
    background-color: var(--dark-green);
    color: var(--white);
}

.button--cta {
    padding: 0.6em 1em;
    background-color: var(--brand-green);
    color: var(--white);
    border: none;
}

.container {
    margin: 0 auto;
    max-width: 1080px;
}

.tile-row {
    display: flex;
}

.tile-row>* {
    flex: 1;
}

.tile-row>*+* {
    margin-left: 1.5625em;
}

.tile {
    background-color: var(--white);
    border-radius: 0.3em;
    padding: 1.5625em;
}

.tile>h4 {
    margin-bottom: 1.5em;
}

.page-footer {
    margin-top: 3em;
    padding: 1em 0;
    background-color: var(--light-gray);
    color: var(--gray);
}

.page-footer__inner {
    margin: 0 auto;
    max-width: 1080px;
    text-align: center;
    font-size: 0.8rem;
}

p {
    margin-top: 1.5em;
    margin-bottom: 1.5em;
}

.tag-list {
    list-style: none;
    padding-left: 0;
}

.tag-list>li {
    display: inline;
    padding: 0.3rem 0.5rem;
    font-size: 0.8rem;
    border-radius: 0.2rem;
    background-color: var(--light-gray);
    line-height: 2.6;
}

.case-study-wrapper {
    display: flex;
    justify-content: space-between;
    gap: 20px; /* 调整案例之间的间距 */
}

.case-study-item {
    flex: 1;
    max-width: calc(33.33% - 14px); /* 确保每个案例占据大约三分之一的宽度 */
}