* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    font-family: Arial, Helvetica, sans-serif;
    color: #16324f;
    background:
        radial-gradient(circle at top, rgba(255, 255, 255, 0.9), rgba(255, 255, 255, 0.4) 35%, transparent 60%),
        linear-gradient(180deg, #dff2ff 0%, #eef8ff 55%, #f7fcff 100%);
}

.page-shell {
    width: min(900px, calc(100% - 32px));
    margin: 0 auto;
    padding: 48px 0 56px;
}

.card {
    background: rgba(255, 255, 255, 0.78);
    border: 1px solid rgba(104, 168, 214, 0.35);
    border-radius: 20px;
    box-shadow: 0 18px 40px rgba(78, 129, 166, 0.14);
    backdrop-filter: blur(8px);
}

.hero {
    padding: 32px;
    text-align: center;
    margin-bottom: 20px;
}

.eyebrow {
    margin: 0 0 10px;
    font-size: 0.85rem;
    letter-spacing: 0.22em;
    text-transform: uppercase;
    color: #4f8fc2;
    font-weight: 700;
}

h1,
h2,
p,
ul,
ol {
    margin-top: 0;
}

h1 {
    margin-bottom: 12px;
    font-size: clamp(2.3rem, 4vw, 3.4rem);
    line-height: 1.05;
    color: #0f2f4a;
}

.subtitle {
    margin: 0 auto;
    max-width: 62ch;
    font-size: 1.05rem;
    line-height: 1.7;
    color: #335a77;
}

.content-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 18px;
}

.content-grid .card {
    padding: 24px;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 10;
    background: rgba(255, 255, 255, 0.9);
    border-bottom: 1px solid rgba(104, 168, 214, 0.24);
    backdrop-filter: blur(12px);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    width: min(900px, calc(100% - 32px));
    margin: 0 auto;
    padding: 18px 0;
}

.brand {
    font-weight: 700;
    color: #0f2f4a;
    text-decoration: none;
    font-size: 1.05rem;
}

.site-nav {
    display: flex;
    gap: 32px;
    align-items: center;
}

.site-nav a {
    color: #16324f;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    padding: 8px 12px;
    border-bottom: 2px solid transparent;
    transition: all 0.3s ease;
    position: relative;
}

.site-nav a:hover {
    color: #4f8fc2;
    border-bottom-color: #4f8fc2;
}

.site-nav a.active {
    color: #4f8fc2;
    border-bottom-color: #4f8fc2;
}

@media (max-width: 640px) {
    .header-inner {
        flex-direction: column;
        align-items: flex-start;
    }
}

h2 {
    margin-bottom: 14px;
    font-size: 1.35rem;
    color: #1f5f8b;
}

ul,
ol {
    padding-left: 20px;
    margin-bottom: 0;
    color: #274b63;
}

li+li {
    margin-top: 10px;
}

@media (max-width: 640px) {
    .page-shell {
        width: min(100% - 20px, 900px);
        padding: 20px 0 28px;
    }

    .hero,
    .content-grid .card {
        padding: 20px;
    }
}