/* ============================================================
   SDDO NOTES — academic palette
   Navy text on warm cream. Serif headings, sans body.
   Single accent for links/CTAs.
   ============================================================ */

:root {
    --bg:          #FAF6EC;      /* warm cream */
    --paper:       #FFFFFF;      /* card surface */
    --ink:         #1A2440;      /* deep navy text */
    --ink-muted:   #5C6584;
    --rule:        #E5DCC1;      /* warm border */
    --accent:      #2E4374;      /* mid-navy link */
    --accent-dk:   #14213D;
    --gold:        #B8860B;      /* subtle gold for chapter markers */
    --shadow:      0 1px 2px rgba(20,33,61,.05), 0 8px 28px rgba(20,33,61,.06);
    --radius:      4px;
    --maxw:        1180px;
    --font-serif:  "EB Garamond", "Playfair Display", Georgia, "Times New Roman", serif;
    --font-sans:   "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
    --font-mono:   "JetBrains Mono", ui-monospace, "SF Mono", Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }

html, body {
    margin: 0;
    padding: 0;
    background: var(--bg);
    color: var(--ink);
    font-family: var(--font-sans);
    font-size: 17px;
    line-height: 1.65;
    -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: var(--accent); text-decoration: none; border-bottom: 1px solid transparent; transition: border-color .15s ease, color .15s ease; }
a:hover { color: var(--accent-dk); border-bottom-color: var(--accent); }

h1, h2, h3, h4 {
    font-family: var(--font-serif);
    font-weight: 600;
    letter-spacing: -0.005em;
    line-height: 1.15;
    margin: 0 0 .5em;
}
h1 { font-size: clamp(2.1rem, 4vw, 3.4rem); font-weight: 700; }
h2 { font-size: clamp(1.5rem, 2.4vw, 2.05rem); margin-top: 1.6em; }
h3 { font-size: 1.25rem; margin-top: 1.4em; }

p { margin: 0 0 1em; }
.muted { color: var(--ink-muted); }
.lead  { font-size: 1.12rem; color: var(--ink-muted); max-width: 60ch; }

.container {
    max-width: var(--maxw);
    margin: 0 auto;
    padding: 0 28px;
}

/* ---------- Header ---------- */
.masthead {
    border-bottom: 1px solid var(--rule);
    background: var(--bg);
    position: sticky;
    top: 0;
    z-index: 30;
    backdrop-filter: blur(8px);
}
.masthead-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 76px;
}
.brand {
    font-family: var(--font-serif);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--ink);
    display: flex;
    align-items: center;
    gap: 12px;
    border: none;
}
.brand:hover { color: var(--ink); border: none; }
.brand-mark {
    width: 28px; height: 28px;
    border: 1.5px solid var(--ink);
    color: var(--ink);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.04em;
    font-family: var(--font-sans);
}
.brand small {
    color: var(--ink-muted);
    font-family: var(--font-sans);
    font-size: 0.78rem;
    font-weight: 500;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    margin-left: 4px;
}
.menu {
    list-style: none;
    display: flex;
    gap: 26px;
    padding: 0;
    margin: 0;
}
.menu a {
    color: var(--ink);
    font-size: 0.92rem;
    font-weight: 500;
    border: none;
    padding-bottom: 4px;
    border-bottom: 1.5px solid transparent;
}
.menu a:hover, .menu a.active {
    border-bottom-color: var(--accent);
    color: var(--ink);
}

/* ---------- Hero ---------- */
.hero {
    padding: 80px 0 56px;
    border-bottom: 1px solid var(--rule);
}
.hero .eyebrow {
    display: inline-block;
    font-family: var(--font-sans);
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.18em;
    color: var(--gold);
    font-weight: 600;
    margin-bottom: 14px;
}
.hero h1 em { font-style: italic; color: var(--accent); }
.hero .lead { margin-top: 16px; max-width: 64ch; font-size: 1.18rem; }
.hero .meta {
    margin-top: 22px;
    font-family: var(--font-sans);
    font-size: 0.88rem;
    color: var(--ink-muted);
    display: flex;
    gap: 26px;
    flex-wrap: wrap;
}
.hero .meta strong { color: var(--ink); font-weight: 600; }

/* ---------- Section base ---------- */
section { padding: 56px 0; }
.section-head {
    display: flex;
    justify-content: space-between;
    align-items: end;
    gap: 24px;
    margin-bottom: 32px;
    flex-wrap: wrap;
    border-bottom: 1px solid var(--rule);
    padding-bottom: 18px;
}
.section-head .eyebrow {
    font-family: var(--font-sans);
    font-size: 0.74rem;
    text-transform: uppercase;
    letter-spacing: 0.18em;
    color: var(--gold);
    font-weight: 600;
    margin-bottom: 6px;
    display: block;
}
.section-head h2 { margin: 0; }
.section-head p { color: var(--ink-muted); margin: 6px 0 0; max-width: 60ch; }

/* ---------- Topic grid ---------- */
.topic-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}
.topic {
    background: var(--paper);
    border: 1px solid var(--rule);
    border-radius: var(--radius);
    padding: 26px 28px 28px;
    transition: transform .15s ease, box-shadow .15s ease, border-color .15s ease;
    display: flex;
    flex-direction: column;
    gap: 8px;
    border-left: 3px solid var(--gold);
    color: var(--ink);
}
.topic:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
    border-left-color: var(--accent);
}
.topic .num {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    color: var(--gold);
    letter-spacing: 0.1em;
    font-weight: 600;
    text-transform: uppercase;
}
.topic h3 {
    margin: 0 0 4px;
    font-family: var(--font-serif);
    font-size: 1.2rem;
}
.topic p {
    margin: 0;
    font-size: 0.92rem;
    color: var(--ink-muted);
    line-height: 1.5;
}
.topic .tags {
    margin-top: 14px;
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}
.topic .tag {
    background: var(--bg);
    border: 1px solid var(--rule);
    color: var(--ink-muted);
    padding: 3px 9px;
    border-radius: 999px;
    font-size: 0.74rem;
    font-family: var(--font-sans);
}

/* ---------- Article (topic detail page) ---------- */
.article {
    display: grid;
    grid-template-columns: 1fr minmax(0, 720px) 1fr;
    padding: 64px 0 100px;
    gap: 36px;
}
.article > .body { grid-column: 2; }
.article > aside {
    grid-column: 3;
    position: sticky;
    top: 100px;
    align-self: start;
    padding-left: 24px;
    border-left: 1px solid var(--rule);
    font-size: 0.92rem;
}
.article > aside h4 {
    font-family: var(--font-sans);
    font-size: 0.74rem;
    text-transform: uppercase;
    letter-spacing: 0.14em;
    color: var(--ink-muted);
    margin: 0 0 12px;
}
.article > aside ul { list-style: none; padding: 0; margin: 0 0 24px; }
.article > aside li { margin: 6px 0; }
.article > aside a { color: var(--ink-muted); border: none; }
.article > aside a:hover { color: var(--accent); }

.article .body p,
.article .body li {
    font-family: var(--font-serif);
    font-size: 1.16rem;
    line-height: 1.7;
}
.article .body ul, .article .body ol { padding-left: 22px; margin: 0 0 1.2em; }
.article .body li { margin: 0.3em 0; }

.article .num-eyebrow {
    font-family: var(--font-mono);
    font-size: 0.82rem;
    color: var(--gold);
    letter-spacing: 0.14em;
    text-transform: uppercase;
    font-weight: 600;
    margin-bottom: 8px;
    display: block;
}
.article h1 { margin: 0 0 16px; }
.article .body > .lead {
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 1.25rem;
    color: var(--ink-muted);
    margin-bottom: 32px;
    padding-bottom: 24px;
    border-bottom: 1px solid var(--rule);
}

blockquote {
    border-left: 3px solid var(--gold);
    margin: 24px 0;
    padding: 8px 22px;
    color: var(--ink);
    font-style: italic;
    font-family: var(--font-serif);
}

/* ---------- Source / PDF link ---------- */
.source-strip {
    background: var(--paper);
    border: 1px solid var(--rule);
    border-radius: var(--radius);
    padding: 20px 24px;
    margin: 32px 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 18px;
    flex-wrap: wrap;
}
.source-strip .label {
    font-family: var(--font-sans);
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--ink-muted);
    font-weight: 600;
}
.source-strip .title {
    font-family: var(--font-serif);
    font-size: 1.08rem;
    color: var(--ink);
    margin: 2px 0 0;
}
.btn {
    display: inline-block;
    padding: 10px 20px;
    border-radius: var(--radius);
    border: 1px solid var(--ink);
    background: var(--ink);
    color: #fff;
    font-family: var(--font-sans);
    font-weight: 500;
    font-size: 0.92rem;
    cursor: pointer;
}
.btn:hover { background: var(--accent-dk); color: #fff; border-color: var(--accent-dk); }
.btn-ghost { background: transparent; color: var(--ink); }
.btn-ghost:hover { background: var(--ink); color: #fff; }

/* ---------- Code ---------- */
pre, code {
    font-family: var(--font-mono);
    font-size: 0.86rem;
}
.article .body code {
    background: rgba(46, 67, 116, 0.08);
    color: var(--accent-dk);
    padding: 2px 6px;
    border-radius: 3px;
    font-size: 0.88em;
}
pre {
    background: var(--ink);
    color: #EDEDED;
    padding: 22px 24px;
    border-radius: var(--radius);
    overflow-x: auto;
    line-height: 1.6;
    margin: 20px 0;
    font-size: 0.84rem;
}
pre code { background: none; color: inherit; padding: 0; }

/* ---------- Reading list ---------- */
.book-list { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 20px; }
.book {
    background: var(--paper);
    border: 1px solid var(--rule);
    border-radius: var(--radius);
    padding: 26px;
    color: var(--ink);
}
.book h3 { margin: 0 0 4px; font-size: 1.1rem; }
.book .author { color: var(--ink-muted); font-size: 0.9rem; font-family: var(--font-sans); margin-bottom: 14px; }
.book p { font-size: 0.95rem; color: var(--ink); margin: 0 0 16px; }
.book a { font-family: var(--font-sans); font-weight: 500; font-size: 0.9rem; }

/* ---------- Footer ---------- */
.colophon {
    border-top: 1px solid var(--rule);
    padding: 40px 0;
    color: var(--ink-muted);
    font-size: 0.88rem;
}
.colophon .container { display: flex; justify-content: space-between; gap: 20px; flex-wrap: wrap; }

/* ---------- Mobile ---------- */
@media (max-width: 900px) {
    .article { grid-template-columns: 1fr; padding: 36px 0 64px; }
    .article > .body, .article > aside { grid-column: 1; }
    .article > aside {
        position: static; padding-left: 0; padding-top: 24px;
        border-left: none; border-top: 1px solid var(--rule); margin-top: 32px;
    }
    .menu { display: none; }
    section { padding: 36px 0; }
}