/* === Tesis Sahil — Academic stylesheet === */

:root {
    --color-bg: #fafaf7;
    --color-paper: #ffffff;
    --color-ink: #1a1a1a;
    --color-ink-soft: #4a4a4a;
    --color-muted: #888;
    --color-accent: #2c5f2d;
    --color-accent-soft: #97bc62;
    --color-border: #e5e5e0;
    --color-citation: #1d4e89;

    --font-serif: 'Crimson Pro', 'Georgia', serif;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

    --max-width: 760px;
    --max-width-wide: 980px;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-serif);
    font-size: 19px;
    line-height: 1.75;
    color: var(--color-ink);
    background: var(--color-bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* === Header === */
.site-header {
    background: var(--color-paper);
    border-bottom: 1px solid var(--color-border);
    padding: 16px 0;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(8px);
}

.site-header .container {
    max-width: var(--max-width-wide);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.brand {
    font-family: var(--font-sans);
    font-weight: 700;
    font-size: 18px;
    color: var(--color-accent);
    text-decoration: none;
    letter-spacing: -0.01em;
}

.site-nav {
    display: flex;
    gap: 24px;
}

.site-nav a {
    font-family: var(--font-sans);
    font-size: 15px;
    color: var(--color-ink-soft);
    text-decoration: none;
    transition: color 0.15s;
}

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

/* === Hero === */
.hero {
    padding: 80px 0 40px;
    text-align: center;
    border-bottom: 1px solid var(--color-border);
    margin-bottom: 48px;
}

.hero h1 {
    font-family: var(--font-serif);
    font-size: 32px;
    line-height: 1.3;
    font-weight: 600;
    letter-spacing: -0.01em;
    max-width: 700px;
    margin: 0 auto 24px;
    color: var(--color-ink);
}

.hero-meta {
    font-family: var(--font-sans);
    font-size: 15px;
    color: var(--color-ink-soft);
    line-height: 1.7;
}

/* === Chapter list === */
.chapter-list {
    margin-bottom: 80px;
}

.chapter-list h2 {
    font-family: var(--font-sans);
    font-size: 13px;
    font-weight: 600;
    color: var(--color-muted);
    letter-spacing: 0.12em;
    text-transform: uppercase;
    margin-bottom: 16px;
}

.chapter-list ul {
    list-style: none;
    border-top: 1px solid var(--color-border);
}

.chapter-list li {
    border-bottom: 1px solid var(--color-border);
}

.chapter-list a,
.chapter-list li.disabled {
    display: flex;
    align-items: baseline;
    gap: 24px;
    padding: 18px 0;
    text-decoration: none;
    color: var(--color-ink);
    transition: padding 0.2s;
}

.chapter-list a:hover {
    padding-left: 12px;
    color: var(--color-accent);
}

.chapter-list li.disabled {
    color: var(--color-muted);
    cursor: not-allowed;
}

.chapter-num {
    font-family: var(--font-sans);
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.08em;
    color: var(--color-accent);
    min-width: 70px;
}

.chapter-list li.disabled .chapter-num {
    color: var(--color-muted);
}

.chapter-title {
    font-size: 20px;
    font-weight: 500;
}

/* === Chapter content === */
.chapter-header {
    padding: 64px 0 40px;
    border-bottom: 1px solid var(--color-border);
    margin-bottom: 48px;
    text-align: center;
}

.chapter-header .label {
    font-family: var(--font-sans);
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--color-accent);
    margin-bottom: 8px;
}

.chapter-header h1 {
    font-family: var(--font-serif);
    font-size: 36px;
    font-weight: 600;
    line-height: 1.25;
    color: var(--color-ink);
    letter-spacing: -0.01em;
}

.section h2 {
    font-family: var(--font-sans);
    font-size: 16px;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--color-accent);
    margin: 48px 0 20px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--color-accent);
}

.section h3 {
    font-family: var(--font-serif);
    font-size: 22px;
    font-weight: 600;
    margin: 32px 0 12px;
    color: var(--color-ink);
}

.section ol.problem-list {
    margin: 16px 0 28px 0;
    padding-left: 32px;
    list-style: decimal;
}

.section ol.problem-list > li {
    margin-bottom: 16px;
    padding-left: 8px;
    text-align: justify;
    line-height: 1.75;
    hyphens: auto;
}

.section ol.problem-list > li::marker {
    color: var(--color-accent);
    font-weight: 700;
}

.section h4 {
    font-family: var(--font-serif);
    font-size: 18px;
    font-weight: 600;
    margin: 24px 0 8px;
    color: var(--color-ink);
}

.chapter-intro {
    font-size: 17px;
    color: var(--color-ink-soft);
    line-height: 1.7;
    margin-top: 16px;
    text-align: justify;
}

.table-wrap {
    overflow-x: auto;
    margin: 20px 0 28px;
    border: 1px solid var(--color-border);
    border-radius: 6px;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    font-family: var(--font-sans);
    font-size: 14.5px;
    line-height: 1.6;
}

.data-table thead {
    background: #f3f5f1;
}

.data-table th {
    text-align: left;
    padding: 12px 14px;
    font-weight: 600;
    color: var(--color-ink);
    border-bottom: 2px solid var(--color-accent);
}

.data-table td {
    padding: 11px 14px;
    border-bottom: 1px solid var(--color-border);
    vertical-align: top;
    color: var(--color-ink-soft);
}

.data-table tr:last-child td {
    border-bottom: none;
}

.data-table tr:nth-child(even) {
    background: #fafaf7;
}

.formula {
    margin: 18px 0 24px;
    padding: 16px 20px;
    background: #f3f5f1;
    border-left: 3px solid var(--color-accent);
    border-radius: 0 6px 6px 0;
    font-family: var(--font-serif);
    font-size: 18px;
    color: var(--color-ink);
    text-align: center;
}

.formula p {
    margin: 0;
    text-align: center;
}

.chapter-header .chapter-subtitle {
    font-size: 16px;
    color: var(--color-ink-soft);
    font-style: italic;
    margin-top: 12px;
    line-height: 1.6;
}

.bibliography {
    list-style: decimal;
    padding-left: 32px;
    margin: 24px 0;
}

.bibliography li {
    padding: 12px 0 12px 8px;
    margin-bottom: 4px;
    line-height: 1.65;
    text-indent: 0;
    border-bottom: 1px solid var(--color-border);
    font-size: 17px;
}

.bibliography li:last-child {
    border-bottom: none;
}

.bibliography li a {
    color: var(--color-citation);
    text-decoration: none;
    word-break: break-all;
}

.bibliography li a:hover {
    text-decoration: underline;
}

.ref-meta {
    margin-top: 32px;
    padding: 16px 20px;
    background: #f3f5f1;
    border-left: 3px solid var(--color-accent);
    border-radius: 4px;
    font-size: 15px;
    color: var(--color-ink-soft);
    line-height: 1.6;
}

.ref-meta strong {
    color: var(--color-accent);
}

/* === Sidebar TOC === */
/* Default: sidebar hidden, toggle visible (mobile-first) */
.toc-sidebar {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    width: 280px;
    max-width: 85vw;
    padding: 80px 16px 24px 24px;
    background: var(--color-paper);
    border-right: 1px solid var(--color-border);
    overflow-y: auto;
    z-index: 150;
    transform: translateX(-100%);
    transition: transform 0.25s ease;
    box-shadow: 4px 0 16px rgba(0, 0, 0, 0.12);
    scrollbar-width: thin;
    scrollbar-color: var(--color-border) transparent;
}

.toc-sidebar.open {
    transform: translateX(0);
}

.toc-sidebar::-webkit-scrollbar {
    width: 4px;
}

.toc-sidebar::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: 2px;
}

.toc-toggle {
    position: fixed;
    bottom: 24px;
    left: 24px;
    z-index: 200;
    background: var(--color-accent);
    color: white;
    border: none;
    border-radius: 24px;
    padding: 12px 20px;
    font-family: var(--font-sans);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.18);
    display: block;
}

.toc-toggle.active {
    background: #1f4720;
}

.toc-title {
    font-family: var(--font-sans);
    font-size: 11px;
    font-weight: 700;
    color: var(--color-muted);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 14px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--color-border);
}

.toc-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.toc-item a {
    display: block;
    font-family: var(--font-sans);
    font-size: 13.5px;
    line-height: 1.45;
    padding: 7px 12px 7px 14px;
    color: var(--color-ink-soft);
    text-decoration: none;
    border-left: 2px solid transparent;
    margin-left: -2px;
    transition: color 0.15s, border-color 0.15s, background 0.15s;
}

.toc-item a:hover {
    color: var(--color-accent);
    background: rgba(44, 95, 45, 0.05);
}

.toc-item a.active {
    color: var(--color-accent);
    border-left-color: var(--color-accent);
    font-weight: 600;
    background: rgba(44, 95, 45, 0.07);
}

.toc-level-3 a {
    padding-left: 28px;
    font-size: 12.5px;
    color: var(--color-muted);
}

.toc-level-3 a.active {
    color: var(--color-accent);
}

/* Desktop: sidebar always visible, content shifted */
@media (min-width: 1101px) {
    .toc-sidebar {
        top: 65px;
        max-width: 280px;
        transform: none;
        box-shadow: none;
        padding-top: 24px;
    }

    .toc-toggle {
        display: none;
    }

    body.has-toc main.container {
        max-width: 1080px;
        margin-left: 0;
        margin-right: auto;
        padding-left: 304px;
        padding-right: 24px;
    }

    body.has-toc .site-header .container {
        max-width: none;
        padding-left: 304px;
        padding-right: 24px;
    }
}

@media print {
    .toc-sidebar, .toc-toggle {
        display: none !important;
    }

    body.has-toc main.container,
    body.has-toc .site-header .container {
        padding-left: 24px;
    }
}

.section p {
    margin-bottom: 20px;
    text-align: justify;
    text-indent: 0;
    hyphens: auto;
}

.section p + p {
    text-indent: 2em;
}

.section strong {
    font-weight: 700;
    color: var(--color-ink);
}

/* === In-text citations === */
.cite {
    color: var(--color-citation);
    font-style: italic;
    font-size: 0.95em;
    cursor: help;
    border-bottom: 1px dotted var(--color-citation);
    transition: background 0.15s;
}

.cite:hover {
    background: rgba(29, 78, 137, 0.08);
}

/* === Quote / penegasan judul === */
.title-callout {
    margin: 32px 0;
    padding: 24px 28px;
    background: linear-gradient(135deg, rgba(44, 95, 45, 0.06), rgba(151, 188, 98, 0.04));
    border-left: 4px solid var(--color-accent);
    border-radius: 4px;
    font-style: italic;
    font-size: 20px;
    line-height: 1.6;
    color: var(--color-ink);
}

/* === Daftar pustaka === */
.bibliography {
    list-style: none;
    margin-top: 24px;
}

.bibliography li {
    padding: 14px 0;
    padding-left: 2em;
    text-indent: -2em;
    border-bottom: 1px solid var(--color-border);
    font-size: 17px;
    line-height: 1.6;
}

.bibliography li:last-child {
    border-bottom: none;
}

.bibliography em {
    font-style: italic;
}

.bibliography a {
    color: var(--color-citation);
    text-decoration: none;
    word-break: break-all;
}

.bibliography a:hover {
    text-decoration: underline;
}

/* === Navigation prev/next === */
.chapter-nav {
    display: flex;
    justify-content: space-between;
    gap: 16px;
    margin: 64px 0 32px;
    padding: 24px 0;
    border-top: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
}

.chapter-nav a {
    font-family: var(--font-sans);
    font-size: 14px;
    color: var(--color-ink-soft);
    text-decoration: none;
    padding: 8px 16px;
    border: 1px solid var(--color-border);
    border-radius: 6px;
    transition: all 0.15s;
}

.chapter-nav a:hover {
    background: var(--color-accent);
    color: white;
    border-color: var(--color-accent);
}

/* === Footer === */
.site-footer {
    margin-top: 80px;
    padding: 32px 0;
    border-top: 1px solid var(--color-border);
    background: var(--color-paper);
    font-family: var(--font-sans);
    font-size: 14px;
    text-align: center;
    color: var(--color-ink-soft);
}

.site-footer .muted {
    color: var(--color-muted);
    font-size: 12px;
    margin-top: 4px;
}

/* === Responsive === */
@media (max-width: 640px) {
    body { font-size: 17px; }
    .hero { padding: 48px 0 32px; }
    .hero h1 { font-size: 24px; }
    .chapter-header { padding: 40px 0 24px; }
    .chapter-header h1 { font-size: 26px; }
    .site-nav { gap: 16px; }
    .site-nav a { font-size: 13px; }
    .chapter-list a, .chapter-list li.disabled {
        flex-direction: column;
        gap: 4px;
    }
    .chapter-title { font-size: 18px; }
}

/* === Print === */
@media print {
    .site-header, .site-footer, .chapter-nav { display: none; }
    body { font-size: 12pt; background: white; }
    .container { max-width: 100%; }
    .section p { text-align: justify; }
}