:root {
    --page: #f4f9fc;
    --surface: #ffffff;
    --surface-alt: #e8f3f8;
    --text: #294d5c;
    --muted: #5d7884;
    --line: #bfd4dd;
    --primary: #286f8f;
    --primary-strong: #205d78;
    --accent: #2f8f83;
    --focus: #b54f86;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    background: var(--page);
    color: var(--text);
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    line-height: 1.68;
}

a {
    color: var(--primary-strong);
    text-decoration-thickness: 1px;
    text-underline-offset: 3px;
}

a:hover {
    color: var(--accent);
}

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

a:focus-visible {
    outline: 3px solid var(--focus);
    outline-offset: 3px;
}

.site-header {
    background: var(--surface);
    border-bottom: 1px solid var(--line);
}

.header-inner,
.main-inner,
.footer-inner {
    width: min(1180px, calc(100% - 40px));
    margin: 0 auto;
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 28px;
    padding: 22px 0;
}

.logo {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    color: var(--primary-strong);
    font-weight: 800;
    letter-spacing: 0.08em;
    text-decoration: none;
}

.logo-mark {
    display: inline-grid;
    place-items: center;
    width: 38px;
    height: 38px;
    border: 2px solid var(--primary);
    border-radius: 10px 3px 10px 3px;
    font-size: 13px;
}

nav ul {
    display: flex;
    flex-wrap: wrap;
    justify-content: flex-end;
    gap: 8px 18px;
    margin: 0;
    padding: 0;
    list-style: none;
}

nav a {
    display: inline-block;
    padding: 7px 0;
    font-size: 14px;
    font-weight: 650;
    text-decoration: none;
    border-bottom: 2px solid transparent;
}

nav a:hover,
nav a:focus-visible {
    border-bottom-color: var(--accent);
}

main {
    padding: 56px 0 72px;
}

.hero {
    display: grid;
    grid-template-columns: minmax(0, 1.35fr) minmax(240px, 0.65fr);
    gap: 52px;
    align-items: start;
    margin-bottom: 54px;
}

.hero-copy {
    padding-top: 8px;
}

.kicker {
    margin: 0 0 12px;
    color: var(--accent);
    font-size: 13px;
    font-weight: 800;
    letter-spacing: 0.13em;
    text-transform: uppercase;
}

h1 {
    margin: 0 0 22px;
    color: var(--primary-strong);
    font-size: 40px;
    line-height: 1.13;
    letter-spacing: -0.025em;
}

h2 {
    margin: 0 0 18px;
    color: var(--primary-strong);
    font-size: 28px;
    line-height: 1.25;
    letter-spacing: -0.015em;
}

h3 {
    margin: 24px 0 10px;
    color: var(--primary);
    font-size: 20px;
    line-height: 1.3;
}

p {
    margin: 0 0 18px;
    font-size: 16px;
}

.hero-panel {
    padding: 24px;
    background: var(--surface-alt);
    border-top: 4px solid var(--accent);
    border-bottom: 1px solid var(--line);
}

.hero-panel strong {
    display: block;
    margin-bottom: 9px;
    color: var(--primary-strong);
    font-size: 18px;
}

.content-grid {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 30px 42px;
}

.content-grid > section,
.article-section {
    padding: 28px 0;
    border-top: 1px solid var(--line);
}

.content-grid > section:first-child,
.content-grid > section:nth-child(2) {
    border-top-width: 2px;
}

.topic-links {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
    margin: 20px 0 34px;
}

.topic-links a {
    display: block;
    min-height: 100%;
    padding: 18px;
    background: var(--surface);
    border: 1px solid var(--line);
    border-left: 4px solid var(--primary);
    text-decoration: none;
    font-weight: 700;
}

.topic-links a:hover {
    border-left-color: var(--accent);
    background: var(--surface-alt);
}

.signal-list {
    margin: 10px 0 20px;
    padding-left: 22px;
}

.signal-list li {
    margin-bottom: 9px;
}

.term-row {
    display: grid;
    grid-template-columns: 180px minmax(0, 1fr);
    gap: 20px;
    padding: 14px 0;
    border-bottom: 1px solid var(--line);
}

.term-row strong {
    color: var(--primary-strong);
}

.site-footer {
    background: var(--surface-alt);
    border-top: 1px solid var(--line);
}

.footer-inner {
    display: flex;
    justify-content: space-between;
    gap: 24px;
    padding: 26px 0 30px;
    color: var(--muted);
}

.footer-inner p {
    margin: 0;
    font-size: 14px;
}

.footer-inner a {
    font-weight: 700;
}

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

    nav ul {
        justify-content: flex-start;
    }

    .hero {
        grid-template-columns: 1fr;
        gap: 26px;
    }

    .topic-links {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 640px) {
    .header-inner,
    .main-inner,
    .footer-inner {
        width: min(100% - 28px, 1180px);
    }

    main {
        padding: 38px 0 54px;
    }

    h1 {
        overflow-wrap: anywhere;
    }

    .content-grid,
    .topic-links,
    .term-row {
        grid-template-columns: 1fr;
    }

    .term-row {
        gap: 5px;
    }

    .footer-inner {
        flex-direction: column;
    }
}