@import url("https://fonts.googleapis.com/css2?family=Libre+Baskerville:wght@400;600&family=Source+Sans+3:wght@400;600&display=swap");

:root{
    --bg: #f6f7f9;
    --surface: #ffffff;
    --text: #1b1f23;
    --muted: #4b5563;
    --accent: #1b6fff;
    --accent-dark: #1252b0;
    --border: #e5e7eb;
    --shadow: none;
}

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

body{
    margin: 0;
    background-color: var(--bg);
    color: var(--text);
    font-family: "Source Sans 3", "Segoe UI", Tahoma, sans-serif;
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

img{
    max-width: 100%;
    height: auto;
}

a{
    color: var(--accent);
    text-decoration-color: rgba(27, 111, 255, 0.4);
    text-underline-offset: 3px;
}

a:focus-visible,
button:focus-visible,
summary:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible{
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.skip-link{
    position: absolute;
    left: 12px;
    top: 12px;
    padding: 6px 10px;
    background-color: var(--surface);
    border: 1px solid var(--border);
    border-radius: 6px;
    transform: translateY(-200%);
    transition: transform 120ms ease;
}

.skip-link:focus{
    transform: translateY(0);
}

.site-header{
    background-color: var(--surface);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
}

.brand-bar{
    max-width: 1100px;
    margin: 0 auto;
    padding: 16px;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
}

.brand{
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.brand-title{
    margin: 0;
    font-family: "Libre Baskerville", "Times New Roman", serif;
    font-size: 1.2rem;
    font-weight: 600;
}

.brand-link{
    text-decoration: none;
}

.brand-tagline{
    margin: 0;
    font-size: 0.9rem;
    color: var(--muted);
}

nav{
    width: 100%;
    margin-left: 0;
}

.nav-list{
    list-style: none;
    display: flex;
    align-items: center;
    gap: 20px;
    margin: 0;
    padding: 0;
    flex-wrap: wrap;
    justify-content: flex-start;
}

.nav-link,
.nav-details summary{
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-weight: 600;
    font-size: 0.95rem;
    text-decoration: none;
    padding: 6px 4px;
    border-radius: 6px;
    color: var(--text);
}

.nav-link:hover,
.nav-link:focus-visible,
.nav-details summary:hover,
.nav-details summary:focus-visible{
    color: var(--accent);
    text-decoration: underline;
    text-decoration-thickness: 2px;
    text-underline-offset: 4px;
}

.nav-details{
    position: relative;
}

.nav-details summary{
    cursor: pointer;
    list-style: none;
}

.nav-details summary::-webkit-details-marker{
    display: none;
}

.nav-panel{
    position: absolute;
    top: calc(100% + 12px);
    left: 0;
    width: min(520px, 90vw);
    min-width: 320px;
    background-color: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    box-shadow: var(--shadow);
    padding: 16px;
    display: none;
    gap: 16px;
    z-index: 10;
}

.nav-details[open] .nav-panel{
    display: grid;
}

.nav-panel-title{
    margin: 0;
    font-size: 0.8rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--muted);
}

.nav-panel-grid{
    display: grid;
    grid-template-columns: repeat(2, minmax(160px, 1fr));
    gap: 16px;
}

.nav-panel-heading{
    margin: 0 0 8px;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--muted);
}

.nav-panel-list{
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    gap: 6px;
}

.nav-panel-list a{
    display: inline-flex;
    padding: 4px 6px;
    border-radius: 6px;
    text-decoration: none;
}

.nav-panel-list a:hover,
.nav-panel-list a:focus-visible{
    background-color: #eef4ff;
    color: var(--accent-dark);
}

main{
    max-width: 1100px;
    margin: 28px auto 64px;
    padding: 0 16px;
    flex: 1 0 auto;
}

.hero{
    display: grid;
    grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr);
    gap: 20px;
    align-items: start;
}

.hero-title{
    font-family: "Libre Baskerville", "Times New Roman", serif;
    font-size: 1.9rem;
    margin: 0 0 10px;
}

.lede{
    margin: 0 0 14px;
    color: var(--muted);
    font-size: 1.02rem;
}

.button-row{
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.button{
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 8px 14px;
    border-radius: 8px;
    border: 1px solid var(--accent);
    background-color: var(--accent);
    color: #fff;
    text-decoration: none;
    font-weight: 600;
}

.button.secondary{
    background-color: transparent;
    color: var(--accent);
}

.card{
    background-color: var(--surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 18px;
}

.section{
    margin-top: 40px;
}

.section-title{
    font-family: "Libre Baskerville", "Times New Roman", serif;
    margin: 0 0 12px;
    font-size: 1.3rem;
}

.section-note{
    margin: 0 0 18px;
    color: var(--muted);
}

.index-grid{
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 16px;
}

.index-list{
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    gap: 6px;
}

.fact-label{
    font-weight: 700;
}

.keywords-list{
    display: flex;
    flex-wrap: wrap;
    gap: 10px 14px;
}

.index-list a{
    text-decoration: none;
    padding: 4px 6px;
    border-radius: 6px;
}

.index-list a:hover,
.index-list a:focus-visible{
    background-color: #eef4ff;
    color: var(--accent-dark);
}

.content{
    display: grid;
    gap: 20px;
    max-width: 900px;
    margin: 0 auto;
}

footer{
    border-top: 1px solid var(--border);
    background-color: var(--surface);
    padding: 10px 12px;
}

.footer-inner{
    max-width: 1100px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    gap: 10px;
    flex-wrap: wrap;
    color: var(--muted);
}

.footer-nav{
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
}

form{
    display: grid;
    gap: 16px;
}

fieldset{
    border: 1px solid var(--border);
    padding: 16px;
    border-radius: 10px;
}

legend{
    padding: 0 6px;
    font-weight: 600;
}

label{
    display: block;
    margin-bottom: 6px;
    font-weight: 600;
}

input,
select,
textarea{
    width: 100%;
    padding: 10px;
    border-radius: 8px;
    border: 1px solid var(--border);
    font-family: inherit;
}

button{
    padding: 10px 16px;
    border-radius: 8px;
    border: 1px solid var(--accent-dark);
    background-color: var(--accent);
    color: #fff;
    font-weight: 600;
    cursor: pointer;
}

@media (max-width: 900px){
    .brand-bar{
        flex-direction: column;
        align-items: flex-start;
    }

    nav{
        margin-left: 0;
    }

    .hero{
        grid-template-columns: 1fr;
    }

    .nav-panel{
        position: static;
        min-width: 100%;
        box-shadow: none;
    }
}

@media (max-width: 768px){
    .brand-bar{
        gap: 14px;
    }

    .brand-title{
        font-size: 1.1rem;
    }

    .nav-list{
        flex-wrap: wrap;
        gap: 12px 16px;
    }

    .hero-title{
        font-size: 1.55rem;
    }

    .section-title{
        font-size: 1.15rem;
    }

    .index-grid{
        grid-template-columns: 1fr;
    }
}

@media (max-width: 600px){
    body{
        line-height: 1.55;
    }

    .brand-tagline{
        font-size: 0.85rem;
    }

    .nav-link,
    .nav-details summary{
        padding: 4px 2px;
        font-size: 0.92rem;
    }

    .hero-title{
        font-size: 1.4rem;
    }

    .lede{
        font-size: 0.98rem;
    }

    .button-row{
        flex-direction: column;
        align-items: flex-start;
    }

    .button{
        width: 100%;
        justify-content: center;
    }

    .card{
        padding: 16px;
    }

    .footer-inner{
        flex-direction: column;
        align-items: flex-start;
    }
}

@media (max-width: 400px){
    main{
        margin: 20px auto 48px;
    }

    .hero-title{
        font-size: 1.25rem;
    }

    .nav-panel{
        padding: 12px;
    }

    .footer-nav{
        gap: 10px;
    }
}