:root {
    --ink: #0f172a;
    --muted: #475569;
    --line: #e2e8f0;
    --paper: #ffffff;
    --surface: #ffffff;
    --primary: #1e293b;
    --accent: #7c2d12;
    --accent-soft: #fef3c7;
    --shadow: rgba(15, 23, 42, 0.08);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    background: var(--paper);
    color: var(--ink);
    font-family: Inter, system-ui, sans-serif;
    line-height: 1.6;
}

a {
    color: inherit;
}

.container {
    width: min(1120px, calc(100% - 4rem));
    margin: 0 auto;
}

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

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 2.25rem 0;
}

.brand {
    font-family: "Playfair Display", serif;
    font-size: 1.75rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    text-decoration: none;
}

.brand span {
    color: var(--accent);
    font-weight: 500;
}

.nav {
    display: flex;
    gap: 2rem;
    font-size: 0.95rem;
}

.nav a {
    color: var(--muted);
    text-decoration: none;
}

.nav a:hover {
    color: var(--ink);
}

.hero {
    padding: 5rem 0 2rem;
}

.hero-content {
    max-width: 1120px;
}

.eyebrow {
    margin: 0 0 1rem;
    color: var(--accent);
    font-size: 0.9rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

h1,
h2,
h3,
p {
    margin-top: 0;
}

h1 {
    max-width: 760px;
    margin-bottom: 1.75rem;
    font-family: "Playfair Display", serif;
    font-size: 3rem;
    font-weight: 600;
    line-height: 1.15;
}

.lead {
    max-width: 690px;
    color: var(--muted);
    font-size: 1.05rem;
}

.section {
    width: min(1120px, calc(100% - 4rem));
    margin: 0 auto;
    padding: 4rem 0;
}

.section-heading {
    max-width: 680px;
    margin-bottom: 2.5rem;
}

.section-heading h2 {
    font-family: "Playfair Display", serif;
    font-size: 2rem;
    font-weight: 600;
}

.section-heading p,
article p {
    color: var(--muted);
}

.grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 3rem;
}

article {
    min-height: 120px;
    padding: 0;
    background: transparent;
    border: 0;
    border-radius: 0;
}

article h3 {
    color: var(--primary);
    font-weight: 500;
}

.subjects-section {
    padding-top: 1rem;
}

.study-panel {
    position: relative;
    padding: 1.25rem 1.35rem 1.5rem;
    background: var(--surface);
    border: 1px solid #d5d7db;
    box-shadow: 0 10px 24px var(--shadow);
}

.study-panel::before {
    content: "";
    position: absolute;
    top: 1.25rem;
    bottom: auto;
    left: -1px;
    width: 6px;
    height: 38px;
    background: #f2a234;
}

.study-title {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1rem;
}

.study-title h2 {
    margin: 0;
    padding-left: 0.15rem;
    font-size: 1.65rem;
    font-weight: 400;
}

.study-source {
    margin: 1.5rem 0 0;
    padding-top: 1rem;
    color: var(--muted);
    border-top: 1px solid var(--line);
    font-size: 0.85rem;
}

.course-group {
    margin-top: 0.85rem;
    border-top: 1px solid var(--line);
}

.course-group:first-of-type {
    border-top: 0;
}

.course-group summary {
    cursor: pointer;
    padding: 0.95rem 0;
    font-size: 1.15rem;
    font-weight: 700;
    list-style-position: outside;
}

.course-group summary::marker {
    color: #c8cbd0;
}

.course-link {
    display: grid;
    grid-template-columns: 6rem minmax(0, 1fr);
    gap: 0.85rem;
    padding: 0.6rem 0 0.6rem 1.35rem;
    color: var(--ink);
    text-decoration: none;
    border-radius: 4px;
}

.course-link:hover,
.course-link:focus {
    background: #f8fafc;
    color: var(--accent);
    outline: none;
}

.course-link strong {
    color: var(--primary);
}

.course-link span {
    color: var(--muted);
}

.course-link:hover span,
.course-link:focus span {
    color: var(--accent);
}

.active-subject strong {
    color: var(--accent);
}

.site-footer {
    padding: 2.5rem 0;
    color: var(--muted);
    border-top: 1px solid var(--line);
    font-size: 0.85rem;
}

.site-footer p {
    margin: 0;
}

@media (max-width: 760px) {
    .container,
    .section {
        width: min(100% - 2rem, 1120px);
    }

    .header-inner {
        align-items: flex-start;
        flex-direction: column;
        padding: 1.4rem 0;
    }

    .nav {
        flex-wrap: wrap;
        gap: 1rem;
    }

    h1 {
        font-size: 2.4rem;
    }

    .grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .study-panel {
        padding: 1rem;
    }

    .course-link {
        grid-template-columns: 1fr;
        gap: 0.1rem;
        padding-left: 1rem;
    }
}