/* ============================================================
   Base: reset, typography (Inter), layout primitives, header, footer.
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  font-size: var(--fs-base);
  line-height: 1.6;
  color: var(--color-text-primary);
  background-color: var(--color-canvas);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  font-feature-settings: "cv02", "cv03", "cv04", "cv11";
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* --- Headings --- */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: var(--fw-bold);
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--color-text-primary);
}
h1 { font-size: var(--fs-2xl); letter-spacing: -0.03em; }
h2 { font-size: var(--fs-xl); }
h3 { font-size: var(--fs-lg); letter-spacing: -0.015em; }
h4 { font-size: var(--fs-md); }

p { color: var(--color-text-primary); }
strong, b { font-weight: var(--fw-semibold); }

a { color: var(--color-accent); text-decoration: none; transition: color var(--t-fast); }
a:hover { color: var(--color-accent-dim); }

small { font-size: var(--fs-sm); }
img, svg { max-width: 100%; display: block; }

::selection { background: var(--color-accent-soft); color: var(--color-accent-dim); }

/* --- Helpers --- */
.muted { color: var(--color-text-secondary); }
.dim { color: var(--color-text-muted); }
.mono { font-variant-numeric: tabular-nums; letter-spacing: -0.01em; }
.eyebrow {
  display: inline-block;
  font-size: var(--fs-xs);
  font-weight: var(--fw-semibold);
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--color-accent);
}
.material-icons { vertical-align: middle; font-size: 1.25em; line-height: 1; }

/* --- Layout --- */
.container { width: 100%; max-width: var(--maxw); margin-inline: auto; padding-inline: var(--space-6); }
.container-narrow { max-width: var(--maxw-narrow); }
.container-wide { max-width: var(--maxw-wide); }
.stack > * + * { margin-top: var(--space-4); }
.stack-lg > * + * { margin-top: var(--space-6); }
.row { display: flex; gap: var(--space-3); align-items: center; }
.row-between { display: flex; gap: var(--space-4); align-items: center; justify-content: space-between; flex-wrap: wrap; }
.grow { flex: 1 1 auto; min-width: 0; }
.center { text-align: center; }
.section { padding-block: var(--space-16); }
.section-sm { padding-block: var(--space-10); }
main { flex: 1 1 auto; }

/* --- App header --- */
.appbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--color-border);
}
.appbar__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  gap: var(--space-4);
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-display);
  font-weight: var(--fw-extra);
  font-size: 1.3rem;
  letter-spacing: -0.03em;
  color: var(--color-text-primary);
}
.brand:hover { color: var(--color-text-primary); }
.brand__mark {
  display: inline-grid;
  place-items: center;
  width: 30px; height: 30px;
  border-radius: 8px;
  background: var(--color-accent);
  color: #fff;
  font-size: 1.1rem;
}
.appbar__nav { display: flex; align-items: center; gap: var(--space-2); }
.navlink {
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--color-text-secondary);
}
.navlink:hover { color: var(--color-text-primary); background: var(--color-surface-3); }
.navlink.is-active { color: var(--color-accent); }

/* mobile menu toggle */
.nav-toggle { display: none; }

/* --- Footer --- */
.footer {
  margin-top: auto;
  border-top: 1px solid var(--color-border);
  background: var(--color-bg);
  padding-block: var(--space-8);
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
}
.footer .container { display: flex; justify-content: space-between; flex-wrap: wrap; gap: var(--space-4); align-items: center; }

/* --- Focus & motion --- */
:focus-visible { outline: 2px solid var(--color-accent); outline-offset: 2px; border-radius: 4px; }
[x-cloak] { display: none !important; }
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; scroll-behavior: auto !important; }
}

/* --- Visibility utilities (work with the screen store too) --- */
.hide-mobile { }
.only-mobile { display: none !important; }
@media (max-width: 767px) {
  .hide-mobile { display: none !important; }
  .only-mobile { display: revert !important; }
  .container { padding-inline: var(--space-4); }
  .section { padding-block: var(--space-12); }
  .nav-toggle {
    display: inline-grid; place-items: center;
    width: 40px; height: 40px; border-radius: var(--radius-sm);
    border: 1px solid var(--color-border); background: var(--color-surface);
    color: var(--color-text-primary); cursor: pointer;
  }
  .appbar__nav--links {
    position: absolute; left: 0; right: 0; top: var(--header-h);
    flex-direction: column; align-items: stretch; gap: var(--space-1);
    background: var(--color-bg); border-bottom: 1px solid var(--color-border);
    padding: var(--space-3) var(--space-4) var(--space-4);
    box-shadow: var(--shadow-md);
  }
  .appbar__nav--links .navlink, .appbar__nav--links .btn { width: 100%; justify-content: center; }
}

/* --- Dev resolution badge --- */
.resbadge {
  position: fixed; bottom: 12px; left: 12px; z-index: 200;
  font-family: var(--font-mono); font-variant-numeric: tabular-nums;
  font-size: 0.7rem; font-weight: var(--fw-medium);
  background: var(--color-text-primary); color: #fff;
  border-radius: var(--radius-pill); padding: 5px 11px;
  box-shadow: var(--shadow-md); pointer-events: none; opacity: 0.85;
}
@media (max-width: 767px) { .resbadge { bottom: 76px; } }