/* ==========================================================================
   layout.css - shell, header, mobile nav, footer, scene scaffolding
   Breakpoints (plan section 2): 1100 / 860 / 600
   ========================================================================== */

/* ------------------------------------------------------------- 1. shell -- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* -------------------------------------------------- 2. scene scaffolding - */
.scene {
  position: relative;
  width: 100%;
  padding-block: var(--scene-pad);
}

.work-root {
  position: relative;
  width: 100%;
}

/* ---------------------------------------------- 3. header (post-hero) ---- */
/* Hidden while the hero owns the screen: it slides down after the hero. */
.site-header {
  position: fixed;
  inset-inline: 0;
  top: 0;
  z-index: var(--z-header);
  visibility: hidden;
  background-color: var(--bg-deep);
  border-bottom: 1px solid var(--line);
  transform: translateY(-110%);
  transition:
    transform var(--dur-mid) var(--ease-out),
    visibility 0s linear var(--dur-mid);
}

.site-header.is-visible {
  visibility: visible;
  transform: translateY(0);
  transition:
    transform var(--dur-mid) var(--ease-out),
    visibility 0s linear 0s;
}

.site-header__inner {
  display: flex;
  align-items: center;
  gap: var(--sp-5);
  height: var(--header-h);
}

.brand {
  font-family: var(--font-display);
  font-size: 1.25rem;
  letter-spacing: var(--tracking-wide);
  color: var(--text);
  text-decoration: none;
}

.brand::after {
  content: "";
  display: inline-block;
  width: 0.4em;
  height: 0.4em;
  margin-inline-start: 0.35em;
  border-radius: var(--r-pill);
  background-color: var(--gold);
  vertical-align: middle;
}

.nav {
  margin-inline-start: auto;
}

.nav__list {
  display: flex;
  align-items: center;
  gap: var(--sp-6);
}

.nav__link {
  position: relative;
  display: inline-block;
  padding-block: var(--sp-2);
  color: var(--text-muted);
  font-size: var(--fs-sm);
  font-weight: 600;
  letter-spacing: var(--tracking-wide);
  text-decoration: none;
  transition: color var(--dur-fast) var(--ease-out);
}

.nav__link::after {
  content: "";
  position: absolute;
  inset-inline: 0;
  bottom: 0;
  height: 1px;
  background-color: var(--gold);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--dur-mid) var(--ease-out);
}

.nav__link:hover,
.nav__link:focus-visible {
  color: var(--text);
}

.nav__link:hover::after {
  transform: scaleX(1);
}

/* hamburger: shown from 860px down */
.nav-toggle {
  display: none;
  margin-inline-start: auto;
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  place-items: center;
}

.nav-toggle__bars {
  display: grid;
  gap: 5px;
  width: 20px;
}

.nav-toggle__bars i {
  display: block;
  height: 2px;
  background-color: var(--text);
  transition: transform var(--dur-fast) var(--ease-out), opacity var(--dur-fast) var(--ease-out);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ------------------------------------------- 4. mobile nav (flat list) --- */
.mobile-nav {
  position: fixed;
  inset-inline: 0;
  top: var(--header-h);
  z-index: var(--z-mobile);
  background-color: var(--bg-panel);
  border-bottom: 1px solid var(--line);
  animation: rp-nav-in var(--dur-mid) var(--ease-out);
}

.mobile-nav__list {
  display: flex;
  flex-direction: column;
  padding-block: var(--sp-3);
}

.mobile-nav__list a {
  display: block;
  padding: var(--sp-4) 0;
  border-bottom: 1px solid var(--line);
  color: var(--text);
  font-family: var(--font-display);
  font-size: var(--fs-h3);
  text-decoration: none;
}

.mobile-nav__list li:last-child a {
  border-bottom: 0;
}

.mobile-nav__list a:hover {
  color: var(--gold-bright);
}

@keyframes rp-nav-in {
  from {
    opacity: 0;
    transform: translateY(-8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* --------------------------------------------------------- 5. footer ----- */
.site-footer {
  position: relative;
  border-top: 1px solid var(--line);
  background-color: var(--bg-deep);
  padding-block: var(--sp-6);
}

.site-footer__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-4);
}

.site-footer__copy {
  color: var(--text-muted);
  font-size: var(--fs-sm);
}

.site-footer__top {
  padding: var(--sp-2) var(--sp-5);
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  color: var(--text);
  font-size: var(--fs-sm);
  font-weight: 600;
  transition:
    border-color var(--dur-fast) var(--ease-out),
    color var(--dur-fast) var(--ease-out);
}

.site-footer__top:hover {
  border-color: var(--gold);
  color: var(--gold-bright);
}

/* ------------------------------------------------------ 6. breakpoints --- */
@media (max-width: 1100px) {
  .nav__list {
    gap: var(--sp-5);
  }
}

@media (max-width: 860px) {
  .nav {
    display: none;
  }

  .nav-toggle {
    display: grid;
  }

  .site-footer__inner {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 600px) {
  .site-header__inner {
    gap: var(--sp-3);
  }

  .brand {
    font-size: 1.0625rem;
  }
}