/* =====================================================================
   layout.css — page structure: header, sections, grids, footer
   ===================================================================== */

.container {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding-left: var(--gutter);
  padding-right: var(--gutter);
}

/* ---------- Header ---------- */
.site-header {
  position: fixed; top: 0; left: 0; right: 0;
  z-index: 50;
  height: var(--header-h);
  transition: background-color 0.4s ease, border-color 0.4s ease, box-shadow 0.4s ease;
  border-bottom: 1px solid transparent;
}
.site-header.is-scrolled {
  background: rgba(244, 239, 230, 0.75);
  border-bottom-color: var(--line);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  backdrop-filter: saturate(160%) blur(14px);
}
[data-theme="dark"] .site-header.is-scrolled { background: rgba(14, 13, 11, 0.7); }

.nav {
  height: 100%;
  display: flex; align-items: center; justify-content: space-between; gap: 1.5rem;
}

.brand {
  display: inline-flex; align-items: center; gap: 0.75rem;
  text-decoration: none; font-weight: 500;
}
.brand-mark {
  display: inline-grid; place-items: center;
  width: 38px; height: 38px; border-radius: 12px;
  background: var(--ink); color: var(--bg);
  font-family: var(--font-display); font-size: 0.95rem; font-weight: 600; letter-spacing: 0.02em;
  transition: transform 0.4s var(--ease), background-color 0.3s;
}
.brand:hover .brand-mark { background: var(--accent); color: var(--accent-ink); transform: rotate(-6deg); }
.brand-name { font-size: 0.95rem; }
@media (max-width: 480px) { .brand-name { display: none; } }

.nav-links {
  display: flex; gap: 0.25rem;
  font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.12em; text-transform: uppercase;
}
.nav-links a {
  position: relative; display: block; padding: 0.5rem 0.75rem;
  text-decoration: none; color: var(--ink-2);
  transition: color 0.25s;
}
.nav-links a::after {
  content: ""; position: absolute; left: 0.75rem; right: 0.75rem; bottom: 0.2rem; height: 1px;
  background: var(--accent);
  transform: scaleX(0); transform-origin: left;
  transition: transform 0.35s var(--ease);
}
.nav-links a:hover, .nav-links a.is-active { color: var(--ink); }
.nav-links a:hover::after, .nav-links a.is-active::after { transform: scaleX(1); }

.nav-actions { display: flex; align-items: center; gap: 0.5rem; }

.icon-btn {
  display: inline-grid; place-items: center;
  width: 40px; height: 40px; border-radius: 999px;
  border: 1px solid var(--line-strong);
  color: var(--ink);
  transition: background-color 0.25s, border-color 0.25s, transform 0.3s var(--ease);
}
.icon-btn:hover { background: var(--accent-soft); border-color: var(--line-strong); transform: translateY(-1px); }
.icon-btn .icon { width: 18px; height: 18px; }

.theme-toggle .icon-moon, [data-theme="dark"] .theme-toggle .icon-sun { display: none; }
[data-theme="dark"] .theme-toggle .icon-moon { display: block; }

.nav-toggle { display: none; }
.nav-toggle .icon-close, .nav-open .nav-toggle .icon-menu { display: none; }
.nav-open .nav-toggle .icon-close { display: block; }

/* Mobile menu */
@media (max-width: 800px) {
  .nav-toggle { display: inline-grid; }
  .nav-links {
    position: fixed; top: var(--header-h); left: 0; right: 0; bottom: 0;
    flex-direction: column; justify-content: center; gap: 0.25rem;
    padding: 2rem var(--gutter);
    background: var(--bg);
    opacity: 0; visibility: hidden; transform: translateY(-8px);
    transition: opacity 0.3s ease, transform 0.4s var(--ease), visibility 0s linear 0.4s;
  }
  .nav-open .nav-links { opacity: 1; visibility: visible; transform: none; transition-delay: 0s; }
  .nav-open .site-header { background: var(--bg); border-bottom-color: var(--line); }
  .nav-links a {
    padding: 0.9rem 0;
    font-family: var(--font-display); font-size: clamp(2rem, 8vw, 3rem); letter-spacing: -0.02em; text-transform: none;
    border-bottom: 1px solid var(--line);
  }
  .nav-links a::after { display: none; }
  .nav-open { overflow: hidden; }
}

/* ---------- Sections ---------- */
.section { padding: var(--section-gap) 0 0; }
.section:last-of-type { padding-bottom: var(--section-gap); }

.section-head { margin-bottom: clamp(2rem, 5vw, 3.25rem); }
.section-num {
  display: inline-flex; align-items: center; gap: 0.75rem;
  margin-bottom: 1rem;
  color: var(--accent);
}
.section-num::after { content: ""; width: 2.5rem; height: 1px; background: currentColor; opacity: 0.6; }

/* About */
.about-grid {
  display: grid; grid-template-columns: 1fr; gap: 3rem;
  align-items: start;
}
@media (min-width: 860px) {
  .about-grid { grid-template-columns: minmax(0, 7fr) minmax(0, 4fr); gap: clamp(3rem, 6vw, 6rem); }
  .about-side { position: sticky; top: calc(var(--header-h) + 2rem); }
}

/* Experience timeline */
.timeline { border-top: 1px solid var(--line); }

/* Projects */
.projects-grid {
  display: grid; gap: 1.25rem;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 300px), 1fr));
}

/* Skills */
.skills-grid {
  display: grid; gap: 2.5rem 3rem;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 260px), 1fr));
}

/* Education */
.edu-grid { display: grid; grid-template-columns: 1fr; gap: 3rem; align-items: start; }
@media (min-width: 860px) { .edu-grid { grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); gap: 5rem; } }

/* ---------- Footer ---------- */
.site-footer { border-top: 1px solid var(--line); padding: 2.5rem 0 3rem; }
.footer-inner { display: flex; justify-content: space-between; align-items: flex-end; gap: 2rem; flex-wrap: wrap; }
.footer-note { margin: 0.35rem 0 0; font-size: 0.9rem; color: var(--ink-2); }
.to-top { display: inline-flex; align-items: center; gap: 0.5rem; text-decoration: none; color: var(--ink-2); }
.to-top .icon-up { transform: rotate(180deg); transition: transform 0.3s var(--ease); }
.to-top:hover { color: var(--ink); }
.to-top:hover .icon-up { transform: rotate(180deg) translateY(3px); }