/* ============================================================
   Maria K — Models in finance, made understandable.
   Minimal, editorial personal-brand site. One stylesheet, no build.

   Structure:
     1. Tokens            5. Sections & layout
     2. Base              6. Credentials
     3. Header + nav      7. Topic / simple lists
     4. Hero              8. Notes, footer, responsive
   ============================================================ */

/* 1. TOKENS ------------------------------------------------- */
:root {
  --bg:        #f7f9fb;
  --bg-soft:   #eef2f6;
  --bg-elev:   #ffffff;
  --fg:        #10151b;
  --fg-soft:   #3a4553;
  --muted:     #74808d;
  --line:      #d7dee5;
  --line-soft: #e6ebf0;
  --accent:    #234b6d;
  --accent-ink:#173650;

  --maxw:   760px;
  --maxw-wide: 940px;
  --pad:    clamp(20px, 5vw, 32px);

  --sans:  "Inter", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, "Times New Roman", serif;
}
:root[data-theme="dark"] {
  --bg:        #0b0f14;
  --bg-soft:   #111820;
  --bg-elev:   #151d26;
  --fg:        #eef2f6;
  --fg-soft:   #c2cbd4;
  --muted:     #8f98a3;
  --line:      #25313d;
  --line-soft: #1a242f;
  --accent:    #8fb8d8;
  --accent-ink:#b7d4ea;
}

/* 2. BASE --------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0; background: var(--bg); color: var(--fg);
  font-family: var(--sans); font-size: 17px; line-height: 1.65;
  -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility;
  transition: background .3s ease, color .3s ease;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
h1, h2, h3, h4 { margin: 0; font-family: var(--serif); font-weight: 600; line-height: 1.2; }
p { margin: 0; }
::selection { background: var(--accent); color: var(--bg); }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding-left: var(--pad); padding-right: var(--pad); }
.wrap-wide { max-width: var(--maxw-wide); margin: 0 auto; padding-left: var(--pad); padding-right: var(--pad); }

/* 3. HEADER + NAV ------------------------------------------- */
.site-header {
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--bg) 90%, transparent);
  backdrop-filter: saturate(140%) blur(8px);
  position: sticky; top: 0; z-index: 20;
}
.header-inner {
  max-width: var(--maxw-wide); margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  gap: 20px; min-height: 62px; padding: 0 var(--pad);
}
.logo {
  font-family: var(--serif); font-weight: 600; font-size: 1.15rem;
  letter-spacing: .01em; color: var(--fg); white-space: nowrap;
}
.nav-links { display: flex; gap: 28px; list-style: none; margin: 0; padding: 0; }
.nav-links a {
  font-size: 13.5px; letter-spacing: .01em; font-weight: 500;
  color: var(--fg-soft); padding: 4px 0;
  border-bottom: 1.5px solid transparent; transition: color .18s;
}
.nav-links a:hover { color: var(--fg); }
.nav-links a[aria-current="page"] { color: var(--fg); border-bottom-color: var(--accent); }

.header-utils { display: flex; align-items: center; gap: 10px; }
.icon-btn {
  display: inline-grid; place-items: center; width: 34px; height: 34px;
  border: 1px solid var(--line); border-radius: 8px; background: transparent;
  color: var(--fg-soft); cursor: pointer; transition: color .18s, border-color .18s;
}
.icon-btn:hover { color: var(--fg); border-color: var(--muted); }
.icon-btn svg { fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; width: 17px; height: 17px; }
.theme-toggle .icon-moon { display: none; }
:root[data-theme="dark"] .theme-toggle .icon-sun { display: none; }
:root[data-theme="dark"] .theme-toggle .icon-moon { display: block; }
.menu-toggle { display: none; }

.mobile-nav[hidden] { display: none; }
.mobile-nav {
  display: flex; flex-direction: column; border-bottom: 1px solid var(--line);
  padding: 4px var(--pad) 12px; background: var(--bg);
}
.mobile-nav a {
  padding: 12px 2px; font-size: 15px; font-weight: 500;
  color: var(--fg-soft); border-bottom: 1px solid var(--line-soft);
}
.mobile-nav a:last-child { border-bottom: 0; }
.mobile-nav a[aria-current="page"] { color: var(--fg); }

/* 4. HERO --------------------------------------------------- */
.expert-hero {
  max-width: var(--maxw-wide); margin: 0 auto;
  padding: clamp(56px, 10vw, 104px) var(--pad) clamp(40px, 7vw, 72px);
  display: grid; grid-template-columns: minmax(0, 1fr) 230px;
  gap: clamp(32px, 5vw, 60px); align-items: start;
}
.hero-portrait { margin: 0; }
.hero-portrait img {
  width: 100%; aspect-ratio: 4/5; object-fit: cover;
  border-radius: 14px; border: 1px solid var(--line);
}
@media (max-width: 720px) {
  .expert-hero { grid-template-columns: 1fr; gap: 0; }
  .hero-portrait { order: -1; width: 132px; margin-bottom: 30px; }
}
.hero-kicker {
  font-size: 12.5px; letter-spacing: .16em; text-transform: uppercase;
  color: var(--muted); font-weight: 600; margin-bottom: 22px;
}
.expert-hero h1 {
  font-size: clamp(2.1rem, 5.2vw, 3.15rem); line-height: 1.08;
  letter-spacing: -.01em; max-width: 16ch;
}
.hero-para {
  color: var(--fg-soft); font-size: 1.15rem; margin-top: 24px; max-width: 54ch;
}
.hero-credentials {
  margin-top: 26px; padding-top: 22px; border-top: 1px solid var(--line);
  font-size: .98rem; color: var(--fg); font-weight: 500;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }
.hero-note { margin-top: 22px; font-size: .92rem; color: var(--muted); max-width: 52ch; }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 12px 22px; border-radius: 9px;
  font-size: .95rem; font-weight: 600; letter-spacing: .01em;
  border: 1px solid var(--accent); background: var(--accent); color: var(--bg);
  cursor: pointer; transition: background .18s, border-color .18s, color .18s;
}
.btn:hover { background: var(--accent-ink); border-color: var(--accent-ink); }
:root[data-theme="dark"] .btn { color: #0b0f14; }
.btn-outline {
  background: transparent; color: var(--fg); border-color: var(--line);
}
.btn-outline:hover { background: transparent; border-color: var(--fg); color: var(--fg); }

/* 5. SECTIONS ----------------------------------------------- */
.section {
  max-width: var(--maxw); margin: 0 auto;
  padding: clamp(40px, 7vw, 64px) var(--pad);
  border-top: 1px solid var(--line-soft);
}
.section h2 {
  font-size: clamp(1.5rem, 3vw, 1.9rem); letter-spacing: -.01em;
}
.section-lead {
  color: var(--fg-soft); font-size: 1.08rem; margin-top: 14px; max-width: 60ch;
}
.section-cta { margin-top: 30px; display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }

/* Simple page intro (interior pages) */
.page-head {
  max-width: var(--maxw); margin: 0 auto;
  padding: clamp(52px, 9vw, 88px) var(--pad) clamp(24px, 4vw, 40px);
}
.page-head .hero-kicker { margin-bottom: 18px; }
.page-head h1 { font-size: clamp(2rem, 4.6vw, 2.8rem); letter-spacing: -.01em; max-width: 20ch; }
.page-head .lead { color: var(--fg-soft); font-size: 1.12rem; margin-top: 18px; max-width: 58ch; }
.page-head--portrait {
  max-width: var(--maxw-wide); display: grid;
  grid-template-columns: minmax(0, 1fr) 200px;
  gap: clamp(28px, 4vw, 52px); align-items: start;
}
@media (max-width: 720px) {
  .page-head--portrait { grid-template-columns: 1fr; gap: 0; }
  .page-head--portrait .hero-portrait { order: -1; width: 124px; margin-bottom: 26px; }
}

/* 6. CREDENTIALS -------------------------------------------- */
.credential-list { margin-top: 34px; }
.credential-row {
  padding: 24px 0; border-top: 1px solid var(--line-soft);
}
.credential-row:first-child { border-top: 0; padding-top: 8px; }
.credential-row h3 { font-size: 1.2rem; }
.credential-row p { color: var(--fg-soft); margin-top: 8px; font-size: 1rem; max-width: 62ch; }

/* 7. TOPIC LIST --------------------------------------------- */
.topic-list { margin-top: 34px; }
.topic-row {
  display: block; padding: 26px 0; border-top: 1px solid var(--line-soft);
  transition: border-color .18s;
}
.topic-row:first-child { border-top: 0; }
.topic-label {
  font-size: 11.5px; letter-spacing: .14em; text-transform: uppercase;
  color: var(--muted); font-weight: 600;
}
.topic-row h3 {
  font-size: 1.32rem; margin-top: 10px; letter-spacing: -.005em;
  transition: color .18s;
}
a.topic-row:hover h3 { color: var(--accent); }
.topic-row p { color: var(--fg-soft); margin-top: 8px; font-size: 1.02rem; max-width: 64ch; }

/* 8. SIMPLE LIST -------------------------------------------- */
.simple-list { list-style: none; margin: 28px 0 0; padding: 0; }
.simple-list li {
  padding: 14px 0; border-top: 1px solid var(--line-soft);
  color: var(--fg-soft); font-size: 1.04rem;
}
.simple-list li:first-child { border-top: 0; }

/* Inline text links (about "Find me", CTAs) */
.link-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }
.text-link {
  color: var(--accent); font-weight: 600; border-bottom: 1px solid transparent;
  transition: border-color .18s;
}
.text-link:hover { border-bottom-color: var(--accent); }

/* Notes / disclaimers */
.note-box {
  margin-top: 34px; padding: 18px 20px; border: 1px solid var(--line);
  border-radius: 10px; background: var(--bg-soft);
  color: var(--fg-soft); font-size: .95rem;
}
.disclaimer {
  color: var(--muted); font-size: .88rem; margin-top: 6px;
}

/* FOOTER ---------------------------------------------------- */
.site-footer { border-top: 1px solid var(--line); background: var(--bg-soft); margin-top: clamp(48px, 8vw, 80px); }
.footer-inner {
  max-width: var(--maxw-wide); margin: 0 auto;
  padding: 44px var(--pad) 22px;
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 18px;
}
.footer-inner .logo { font-size: 1.05rem; }
.footer-nav { display: flex; flex-wrap: wrap; gap: 20px; }
.footer-nav a { font-size: 13.5px; color: var(--fg-soft); font-weight: 500; transition: color .18s; }
.footer-nav a:hover { color: var(--fg); }
.footer-meta {
  max-width: var(--maxw-wide); margin: 0 auto;
  padding: 16px var(--pad) 34px; border-top: 1px solid var(--line-soft);
  color: var(--muted); font-size: 13px;
}
.footer-meta p { margin: 0; }
.footer-meta .disclaimer { margin-top: 4px; }

/* RESPONSIVE ------------------------------------------------ */
@media (max-width: 720px) {
  .nav-links { display: none; }
  .menu-toggle { display: inline-grid; }
  .footer-inner { flex-direction: column; align-items: flex-start; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}