/* ===========================================================
   PersonalInvestor — design system
   =========================================================== */

:root {
  --bg: #f6f7fb;
  --bg-alt: #eef1f8;
  --card: #ffffff;
  --card-border: #e4e8f1;
  --text: #16203d;
  --text-muted: #5c6480;
  --text-faint: #8991ab;
  --navy: #12213f;
  --navy-2: #1f2a44;
  --accent: #3b5bfd;
  --accent-2: #6b86ff;
  --accent-soft: #eef1ff;
  --success: #1a9d6c;
  --success-soft: #e7f8f0;
  --warn: #c2792b;
  --warn-soft: #fbf1e4;
  --danger: #d1495b;
  --danger-soft: #fbeaec;
  --radius-lg: 18px;
  --radius-md: 12px;
  --radius-sm: 8px;
  --shadow: 0 6px 24px rgba(18, 33, 63, 0.07);
  --shadow-lg: 0 16px 48px rgba(18, 33, 63, 0.14);
  --maxw: 1180px;
  --header-h: 64px;
  color-scheme: light;
}

:root[data-theme="dark"] {
  --bg: #0b1120;
  --bg-alt: #0e1526;
  --card: #121a30;
  --card-border: #253052;
  --text: #e7eaf6;
  --text-muted: #a3acc9;
  --text-faint: #6f7996;
  --navy: #24345f;
  --navy-2: #c7d2f5;
  --accent: #7c93ff;
  --accent-2: #97a9ff;
  --accent-soft: #17204a;
  --success: #4fd39a;
  --success-soft: #103528;
  --warn: #e4a44f;
  --warn-soft: #3a2a10;
  --danger: #ef7c8b;
  --danger-soft: #3a1620;
  --shadow: 0 6px 24px rgba(0, 0, 0, 0.35);
  --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.5);
  color-scheme: dark;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0b1120;
    --bg-alt: #0e1526;
    --card: #121a30;
    --card-border: #253052;
    --text: #e7eaf6;
    --text-muted: #a3acc9;
    --text-faint: #6f7996;
    --navy: #0b1120;
    --navy-2: #16213d;
    --accent: #7c93ff;
    --accent-2: #97a9ff;
    --accent-soft: #17204a;
    --success: #4fd39a;
    --success-soft: #103528;
    --warn: #e4a44f;
    --warn-soft: #3a2a10;
    --danger: #ef7c8b;
    --danger-soft: #3a1620;
    --shadow: 0 6px 24px rgba(0, 0, 0, 0.35);
    --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.5);
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background .2s ease, color .2s ease;
}

img { max-width: 100%; }

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

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

/* ---------------- Header / Nav ---------------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  display: flex;
  align-items: center;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--card-border);
}

.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  width: 100%;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 20px;
}

.brand {
  font-weight: 800;
  font-size: 17px;
  color: var(--text);
  white-space: nowrap;
  display: flex;
  align-items: center;
  gap: 8px;
}
.brand:hover { text-decoration: none; opacity: .85; }

.main-nav {
  display: flex;
  gap: 4px;
  margin-left: 8px;
  flex: 1;
}

.main-nav a {
  color: var(--text-muted);
  font-size: 14.5px;
  font-weight: 600;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
}
.main-nav a:hover { background: var(--accent-soft); color: var(--accent); text-decoration: none; }
.main-nav a.active { color: var(--accent); background: var(--accent-soft); }

.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-left: auto;
}

.icon-btn {
  width: 38px;
  height: 38px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  border: 1px solid var(--card-border);
  background: var(--card);
  color: var(--text);
  cursor: pointer;
  font-size: 16px;
}
.icon-btn:hover { border-color: var(--accent); }

.nav-toggle { display: none; }

@media (max-width: 860px) {
  .main-nav {
    position: absolute;
    top: var(--header-h);
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--card-border);
    flex-direction: column;
    padding: 8px 24px 16px;
    display: none;
    gap: 2px;
  }
  .main-nav.open { display: flex; }
  .nav-toggle {
    display: inline-flex;
  }
}

/* ---------------- Buttons ---------------- */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 15px;
  border: 1px solid transparent;
  cursor: pointer;
}
.btn:hover { text-decoration: none; }

.btn-primary {
  background: var(--navy);
  color: #fff;
}
.btn-primary:hover { background: var(--accent); }

.btn-ghost {
  background: transparent;
  border-color: var(--card-border);
  color: var(--text);
}
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }

.btn-sm { padding: 8px 14px; font-size: 13.5px; }

/* ---------------- Hero ---------------- */

.hero {
  padding: 72px 0 56px;
  background:
    radial-gradient(1100px 500px at 15% -10%, color-mix(in srgb, var(--accent) 16%, transparent), transparent 60%),
    radial-gradient(900px 500px at 100% 0%, color-mix(in srgb, var(--accent) 10%, transparent), transparent 60%);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 6px 14px;
  border-radius: 999px;
  margin-bottom: 20px;
}

h1.hero-title {
  font-size: clamp(32px, 5vw, 54px);
  line-height: 1.08;
  letter-spacing: -0.02em;
  margin: 0 0 20px;
  max-width: 900px;
  font-weight: 800;
}

.hero-sub {
  font-size: clamp(17px, 2vw, 20px);
  color: var(--text-muted);
  max-width: 720px;
  margin: 0 0 32px;
}

.hero-cta { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 48px; }

.hero-quote {
  font-size: 19px;
  font-style: italic;
  color: var(--text);
  border-left: 3px solid var(--accent);
  padding: 4px 0 4px 18px;
  max-width: 780px;
  margin: 0 0 40px;
}

/* ---------------- Stats bar ---------------- */

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}
@media (max-width: 800px) { .stats-grid { grid-template-columns: repeat(2, 1fr); } }

.stat-card {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 20px;
  box-shadow: var(--shadow);
}
.stat-value {
  font-size: 26px;
  font-weight: 800;
  color: var(--navy-2);
}
.stat-label {
  font-size: 13.5px;
  color: var(--text-muted);
  margin-top: 4px;
}
.stat-src { font-size: 11.5px; color: var(--text-faint); margin-top: 6px; }

/* ---------------- Sections ---------------- */

section.section { padding: 64px 0; }
section.section.alt { background: var(--bg-alt); }
section.section.tight { padding: 40px 0; }

.section-head { max-width: 720px; margin: 0 0 40px; }
.section-kicker {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .05em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 10px;
}
.section-title {
  font-size: clamp(24px, 3vw, 34px);
  font-weight: 800;
  letter-spacing: -0.01em;
  margin: 0 0 12px;
}
.section-desc { color: var(--text-muted); font-size: 16px; }

/* ---------------- Cards / grids ---------------- */

.card {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow);
}

.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
@media (max-width: 900px) { .grid-3 { grid-template-columns: 1fr; } .grid-2 { grid-template-columns: 1fr; } }

.pain-card .num {
  display: inline-flex;
  width: 34px; height: 34px;
  align-items: center; justify-content: center;
  background: var(--danger-soft);
  color: var(--danger);
  border-radius: 999px;
  font-weight: 800;
  font-size: 14px;
  margin-bottom: 14px;
}
.pain-card h3 { margin: 0 0 8px; font-size: 18px; }
.pain-card p { margin: 0; color: var(--text-muted); font-size: 14.5px; }

.feature-card .icon { font-size: 26px; margin-bottom: 10px; display: block; }
.feature-card h4 { margin: 0 0 6px; font-size: 16px; }
.feature-card p { margin: 0; color: var(--text-muted); font-size: 14px; }

.doc-card {
  display: block;
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 26px;
  box-shadow: var(--shadow);
  transition: transform .15s ease, box-shadow .15s ease, border-color .15s ease;
}
.doc-card:hover { text-decoration: none; transform: translateY(-3px); box-shadow: var(--shadow-lg); border-color: var(--accent); }
.doc-card .tag {
  display: inline-block;
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: .03em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 4px 10px;
  border-radius: 999px;
  margin-bottom: 14px;
}
.doc-card h3 { margin: 0 0 8px; font-size: 19px; }
.doc-card p { margin: 0 0 16px; color: var(--text-muted); font-size: 14.5px; }
.doc-card .meta { font-size: 12.5px; color: var(--text-faint); display: flex; gap: 14px; }
.doc-card .go { margin-top: 14px; font-weight: 700; font-size: 14px; color: var(--accent); }

/* ---------------- Diagram frame (always light so mermaid stays legible) ---------------- */

.diagram-frame {
  background: #ffffff;
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 20px;
  overflow-x: auto;
  box-shadow: var(--shadow);
}
.diagram-frame .mermaid { display: flex; justify-content: center; min-width: max-content; margin: 0 auto; }
.diagram-caption { text-align: center; font-size: 13px; color: var(--text-muted); margin-top: 10px; }

/* ---------------- Footer ---------------- */

.site-footer {
  border-top: 1px solid var(--card-border);
  padding: 40px 0;
  background: var(--bg-alt);
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}
.footer-links { display: flex; gap: 18px; flex-wrap: wrap; }
.footer-links a { color: var(--text-muted); font-size: 14px; font-weight: 600; }
.footer-note { color: var(--text-faint); font-size: 13px; max-width: 620px; }

/* ===========================================================
   Document pages (full markdown render)
   =========================================================== */

.doc-hero {
  padding: 36px 0 28px;
  border-bottom: 1px solid var(--card-border);
  background: var(--bg-alt);
}
.doc-hero .doc-tag {
  font-size: 12.5px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .04em;
  color: var(--accent);
  margin-bottom: 8px;
}
.doc-hero h1 { font-size: clamp(24px, 3.4vw, 36px); margin: 0 0 10px; font-weight: 800; }
.doc-hero .doc-desc { color: var(--text-muted); font-size: 15.5px; max-width: 760px; margin: 0 0 16px; }
.doc-hero .doc-links { display: flex; gap: 10px; flex-wrap: wrap; }

.doc-layout {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 40px 24px 100px;
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 48px;
  align-items: start;
  min-width: 0;
}
@media (max-width: 980px) {
  .doc-layout { grid-template-columns: minmax(0, 1fr); }
}

.doc-layout main,
.markdown-body {
  min-width: 0;
}

.toc-wrap { position: sticky; top: calc(var(--header-h) + 24px); }
.toc-title { font-size: 12px; font-weight: 800; text-transform: uppercase; letter-spacing: .05em; color: var(--text-faint); margin-bottom: 12px; }
.toc-list { list-style: none; margin: 0; padding: 0; max-height: calc(100vh - var(--header-h) - 100px); overflow-y: auto; }
.toc-list li { margin: 0; }
.toc-list a {
  display: block;
  padding: 6px 0 6px 12px;
  border-left: 2px solid var(--card-border);
  color: var(--text-muted);
  font-size: 13.5px;
  line-height: 1.4;
}
.toc-list a.lvl3 { padding-left: 24px; font-size: 12.8px; }
.toc-list a:hover { color: var(--accent); text-decoration: none; }
.toc-list a.active { color: var(--accent); border-left-color: var(--accent); font-weight: 600; }

@media (max-width: 980px) {
  .toc-wrap { position: static; margin-bottom: 8px; }
  .toc-list { max-height: 260px; border: 1px solid var(--card-border); border-radius: var(--radius-md); padding: 12px; background: var(--card); }
  .toc-list a { border-left: none; padding-left: 8px; }
}

.doc-loading { color: var(--text-muted); padding: 40px 0; }

/* markdown-body: full rendered content styling */
.markdown-body { font-size: 16px; color: var(--text); max-width: 100%; }
.markdown-body > *:first-child { margin-top: 0; }

.markdown-body h1 { font-size: 30px; font-weight: 800; margin: 44px 0 18px; scroll-margin-top: calc(var(--header-h) + 16px); }
.markdown-body h2 {
  font-size: 24px; font-weight: 800; margin: 48px 0 16px;
  padding-top: 8px; border-top: 1px solid var(--card-border);
  scroll-margin-top: calc(var(--header-h) + 16px);
}
.markdown-body h1 + h2, .markdown-body > h2:first-of-type { border-top: none; padding-top: 0; }
.markdown-body h3 { font-size: 19px; font-weight: 700; margin: 30px 0 12px; scroll-margin-top: calc(var(--header-h) + 16px); color: var(--navy-2); }
:root[data-theme="dark"] .markdown-body h3 { color: var(--text); }
.markdown-body h4 { font-size: 16px; font-weight: 700; margin: 22px 0 10px; }

.markdown-body p { margin: 0 0 16px; color: var(--text); }
.markdown-body strong { font-weight: 700; }
.markdown-body ul, .markdown-body ol { margin: 0 0 16px; padding-left: 22px; }
.markdown-body li { margin: 6px 0; }
.markdown-body hr { border: none; border-top: 1px solid var(--card-border); margin: 40px 0; }

.markdown-body blockquote {
  margin: 0 0 20px;
  padding: 14px 18px;
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--text);
  font-size: 15px;
}
.markdown-body blockquote p:last-child { margin-bottom: 0; }

.markdown-body a { font-weight: 600; }

.markdown-body code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  background: var(--accent-soft);
  color: var(--navy-2);
  padding: 2px 6px;
  border-radius: 5px;
  font-size: 0.88em;
}
:root[data-theme="dark"] .markdown-body code { color: var(--accent-2); }

.markdown-body pre {
  background: var(--navy);
  color: #e7eaf6;
  padding: 16px 18px;
  border-radius: var(--radius-md);
  overflow-x: auto;
  margin: 0 0 20px;
}
.markdown-body pre code { background: none; color: inherit; padding: 0; font-size: 13.5px; }

.markdown-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 0 0 24px;
  font-size: 14.2px;
  display: block;
  overflow-x: auto;
}
.markdown-body th, .markdown-body td {
  border: 1px solid var(--card-border);
  padding: 10px 12px;
  text-align: left;
  vertical-align: top;
}
.markdown-body th {
  background: var(--bg-alt);
  font-weight: 700;
  white-space: nowrap;
}
.markdown-body tr:nth-child(even) td { background: color-mix(in srgb, var(--bg-alt) 55%, transparent); }

/* mermaid diagrams inside markdown body */
.markdown-body .mermaid-frame {
  background: #ffffff;
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 20px;
  margin: 0 0 24px;
  overflow-x: auto;
}
.markdown-body .mermaid-frame .mermaid { display: flex; justify-content: center; min-width: max-content; margin: 0 auto; }

/* Belt-and-suspenders: force white text on dark "pillar" nodes (mermaid
   classDef color can be dropped by some browsers' handling of JS-injected
   !important rules — an external stylesheet rule is more reliable). */
.diagram-frame .pillar tspan,
.diagram-frame .pillar span,
.markdown-body .mermaid-frame .pillar tspan,
.markdown-body .mermaid-frame .pillar span {
  fill: #ffffff !important;
  color: #ffffff !important;
}

.doc-footnote {
  margin-top: 60px;
  padding-top: 24px;
  border-top: 1px solid var(--card-border);
  color: var(--text-faint);
  font-size: 13px;
  font-style: italic;
}

.doc-pagenav {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-top: 40px;
  flex-wrap: wrap;
}
.doc-pagenav a {
  flex: 1;
  min-width: 220px;
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  background: var(--card);
  color: var(--text);
  font-weight: 600;
  font-size: 14px;
}
.doc-pagenav a:hover { border-color: var(--accent); text-decoration: none; }
.doc-pagenav .dir { display: block; font-size: 11.5px; color: var(--text-faint); text-transform: uppercase; letter-spacing: .04em; margin-bottom: 4px; font-weight: 700; }

.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 44px; height: 44px;
  border-radius: 999px;
  background: var(--navy);
  color: #fff;
  display: none;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
  cursor: pointer;
  z-index: 90;
  border: none;
  font-size: 18px;
}
.back-to-top.show { display: inline-flex; }

/* generic utility */
.badge {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 999px;
  background: var(--success-soft);
  color: var(--success);
}
.badge.warn { background: var(--warn-soft); color: var(--warn); }