/* ============================================================
   COMPONENTS
   ============================================================ */

/* ---- Site header ---- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(237, 230, 211, 0.92);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--line-soft);
}
.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: var(--sp-3);
  gap: var(--sp-4);
}
.wordmark {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-family: var(--font-display);
  font-size: 1.28rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--ink);
}
.wordmark__mark { width: 28px; height: 28px; flex-shrink: 0; }
.wordmark__sub {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--ink-faint);
  display: block;
  margin-top: 1px;
}

.main-nav__list {
  display: flex;
  gap: var(--sp-5);
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: var(--step--1);
}
.main-nav__list a {
  position: relative;
  padding-block: 4px;
}
.main-nav__list a::after {
  content: "";
  position: absolute;
  left: 0; right: 100%;
  bottom: -2px;
  height: 1px;
  background: var(--rust);
  transition: right var(--dur-2) var(--ease);
}
.main-nav__list a:hover::after,
.main-nav__list a[aria-current="page"]::after { right: 0; }
.main-nav__list a[aria-current="page"] { color: var(--rust-deep); }

.header-actions { display: flex; align-items: center; gap: var(--sp-3); }

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  width: 40px; height: 36px;
  cursor: pointer;
  color: var(--ink);
}

.btn-short-label { display: none; }

@media (max-width: 520px) {
  .wordmark { font-size: 1.05rem; gap: 0.5rem; }
  .wordmark__sub { display: none; }
  .site-header__inner { gap: var(--sp-2); }
}

@media (max-width: 860px) {
  .wordmark span { white-space: nowrap; }
  .main-nav { display: none; }
  .main-nav.is-open {
    display: block;
    position: absolute;
    top: 100%; left: 0; right: 0;
    background: var(--paper);
    border-bottom: 1px solid var(--line);
    padding: var(--sp-4);
  }
  .main-nav.is-open .main-nav__list {
    flex-direction: column;
    gap: var(--sp-3);
    font-size: var(--step-1);
  }
  .nav-toggle { display: block; }
  .header-actions .btn .btn-full-label { display: none; }
  .header-actions .btn .btn-short-label { display: inline; }
}

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: var(--step--1);
  padding: 0.72em 1.35em;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform var(--dur-1) var(--ease), background var(--dur-1) var(--ease), border-color var(--dur-1) var(--ease), color var(--dur-1) var(--ease), box-shadow var(--dur-1) var(--ease);
  white-space: nowrap;
}
.btn:hover { transform: translateY(-2px); box-shadow: 0 10px 22px -12px rgba(33, 29, 22, 0.4); }
.btn:active { transform: translateY(0); box-shadow: none; }

.btn--primary {
  background: var(--olive);
  color: var(--paper);
  border-color: var(--olive);
}
.btn--primary:hover { background: var(--olive-deep); border-color: var(--olive-deep); box-shadow: 0 10px 22px -10px rgba(75, 88, 66, 0.55); }

.btn--on-dark {
  background: var(--brass);
  color: var(--board);
  border-color: var(--brass);
}
.btn--on-dark:hover { background: #bd9c56; border-color: #bd9c56; box-shadow: 0 10px 22px -10px rgba(166, 134, 63, 0.55); }

.btn--ghost {
  background: transparent;
  color: var(--ink);
  border-color: var(--line);
}
.btn--ghost:hover { border-color: var(--ink); }

.btn--ghost-on-dark {
  background: transparent;
  color: var(--paper);
  border-color: var(--line-on-dark);
}
.btn--ghost-on-dark:hover { border-color: var(--paper); }

.btn--text {
  padding: 0;
  border: none;
  background: none;
  color: var(--rust-deep);
  font-weight: 600;
  border-bottom: 1px solid var(--rust-deep);
  border-radius: 0;
  padding-bottom: 2px;
}
.btn--text:hover { color: var(--rust); border-color: var(--rust); transform: none; }

/* ---- Section rhythm ---- */
.section { padding-block: var(--sp-8); }
.section--tight { padding-block: var(--sp-7); }
.section--dark { background: var(--board); color: var(--paper); }
.section--olive { background: var(--olive-deep); color: var(--paper); }
.section--rule-top { border-top: 1px solid var(--line); }
.section--dark .eyebrow { color: var(--brass); }

.hr {
  border: none;
  border-top: 1px solid var(--line);
  margin: 0;
}
.hr--on-dark { border-top-color: var(--line-on-dark); }

/* ---- Coordinate marker (used instead of 01/02/03 numbering) ---- */
.coord {
  font-family: var(--font-mono);
  font-size: var(--step--1);
  color: var(--brass);
  letter-spacing: 0.02em;
}

/* ---- Pull quote ---- */
.pull-quote {
  border-left: 2px solid var(--rust);
  padding-left: var(--sp-4);
  font-family: var(--font-display);
  font-size: var(--step-2);
  font-style: italic;
  font-weight: 500;
  line-height: 1.35;
  color: var(--ink);
  max-width: 34ch;
}

/* ---- Cards ---- */
.card {
  background: var(--paper-dim);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: var(--sp-5);
}

.card--path {
  background: var(--paper);
  border: 1px solid var(--line);
  padding: var(--sp-6) var(--sp-5);
  display: flex;
  flex-direction: column;
  gap: var(--sp-3);
  position: relative;
  overflow: hidden;
  transition: transform var(--dur-1) var(--ease), box-shadow var(--dur-1) var(--ease);
}
.card--path::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background: var(--olive);
  transition: height var(--dur-1) var(--ease);
}
.card--path.is-rust::before { background: var(--rust); }
.card--path:hover {
  transform: translateY(-3px);
  box-shadow: 0 18px 36px -20px rgba(33, 29, 22, 0.35);
}
.card--path:hover::before { height: 5px; }

/* ---- Board diagram (rendered via Lichess's board-image export) ---- */
.board-diagram {
  display: block;
  width: 100%;
  height: auto;
  border-radius: calc(var(--radius-md) - 2px);
  filter: drop-shadow(0 6px 16px rgba(28, 15, 5, 0.25));
}

/* ---- Article / blog cards ---- */
.post-card {
  display: grid;
  gap: var(--sp-2);
  padding-block: var(--sp-5);
  border-top: 1px solid var(--line);
}
.post-card:first-child { border-top: none; }
.post-card__meta {
  font-family: var(--font-mono);
  font-size: var(--step--1);
  color: var(--ink-faint);
  display: flex;
  gap: var(--sp-3);
  flex-wrap: wrap;
}
.post-card__title {
  font-size: var(--step-2);
}
.post-card__title a { transition: color var(--dur-1) var(--ease); }
.post-card__title a:hover { color: var(--rust-deep); }
.post-card__excerpt { color: var(--ink-soft); max-width: 62ch; }
.tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--olive-deep);
  background: var(--olive-pale);
  padding: 0.2em 0.55em;
  border-radius: 2px;
}

/* ---- Footer ---- */
.site-footer {
  background: var(--board);
  color: var(--paper-dim);
  padding-block: var(--sp-7) var(--sp-5);
}
.site-footer a:hover { color: var(--brass); }
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: var(--sp-6);
}
.footer-grid h3 {
  font-family: var(--font-mono);
  font-size: var(--step--1);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--brass);
  margin-bottom: var(--sp-3);
  font-weight: 500;
}
.footer-grid ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.6em; font-size: var(--step--1); }
.footer-bottom {
  margin-top: var(--sp-6);
  padding-top: var(--sp-4);
  border-top: 1px solid var(--line-on-dark);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--sp-2);
  font-size: 0.8rem;
  color: var(--ink-faint);
}
@media (max-width: 760px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

/* ---- Skip helpers ---- */
/* Progressive enhancement: content is fully visible by default so it can
   never get stuck hidden (slow JS, JS errors, no JS). The ".js-reveal"
   class is added by main.js only once it's actually ready to manage the
   animation, and only that scoped state ever sets opacity to 0. */
.js-reveal .reveal {
  opacity: 0;
  transform: translateY(14px);
  /* --stagger-i is set by main.js per sibling group, so rows of cards settle
     in left-to-right instead of popping in as one flat block. */
  transition: opacity var(--dur-3) var(--ease) calc(var(--stagger-i, 0) * 70ms),
              transform var(--dur-3) var(--ease) calc(var(--stagger-i, 0) * 70ms);
}
.js-reveal .reveal.is-visible { opacity: 1; transform: translateY(0); }
@media (prefers-reduced-motion: reduce) {
  .js-reveal .reveal { opacity: 1; transform: none; transition: none; }
}

/* ---- Scroll progress bar ---- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--olive), var(--rust));
  z-index: 600;
  transition: width 80ms linear;
}
@media (prefers-reduced-motion: reduce) {
  .scroll-progress { display: none; }
}

/* ---- Breadcrumbs (article pages) ---- */
.breadcrumbs {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--ink-faint);
  display: flex;
  gap: 0.5em;
  flex-wrap: wrap;
}
.breadcrumbs a:hover { color: var(--rust-deep); }