/* ==========================================================================
   Base: reset, type, the app frame (screens, navigation bar, tab bar).
   ========================================================================== */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  height: 100%;
}

body {
  margin: 0;
  height: 100%;
  overflow: hidden;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: var(--fs-body);
  line-height: var(--lh-body);
  letter-spacing: -0.004em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
  overscroll-behavior: none;
}

button,
input,
textarea,
select {
  font: inherit;
  color: inherit;
  letter-spacing: inherit;
}

button {
  cursor: pointer;
  background: none;
  border: 0;
  padding: 0;
  margin: 0;
  -webkit-user-select: none;
  user-select: none;
}

a {
  color: var(--accent-text);
  text-decoration: none;
}

img,
svg {
  display: block;
}

h1, h2, h3, h4, p {
  margin: 0;
}

[hidden] {
  display: none !important;
}

:focus {
  outline: none;
}

:focus-visible {
  box-shadow: var(--focus-ring);
  border-radius: var(--r-sm);
}

/* ---- Type helpers ---------------------------------------------------------- */

.t-display { font: 700 var(--fs-display)/var(--lh-display) var(--font-display); letter-spacing: var(--tracking-tight); }
.t-largetitle { font: 700 var(--fs-largetitle)/var(--lh-largetitle) var(--font-display); letter-spacing: var(--tracking-tight); }
.t-title1 { font: 700 var(--fs-title1)/var(--lh-title1) var(--font-display); letter-spacing: var(--tracking-tight); }
.t-title2 { font: 700 var(--fs-title2)/var(--lh-title2) var(--font-display); letter-spacing: var(--tracking-snug); }
.t-title3 { font: 600 var(--fs-title3)/var(--lh-title3) var(--font-display); letter-spacing: var(--tracking-snug); }
.t-headline { font: 600 var(--fs-headline)/var(--lh-headline) var(--font); letter-spacing: -0.01em; }
.t-body { font: 400 var(--fs-body)/var(--lh-body) var(--font); }
.t-callout { font: 400 var(--fs-callout)/var(--lh-callout) var(--font); }
.t-subhead { font: 400 var(--fs-subhead)/var(--lh-subhead) var(--font); }
.t-footnote { font: 400 var(--fs-footnote)/var(--lh-footnote) var(--font); }
.t-caption { font: 500 var(--fs-caption)/var(--lh-caption) var(--font); letter-spacing: 0.01em; }
.t-eyebrow {
  font: 600 var(--fs-footnote)/var(--lh-footnote) var(--font);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-3);
}
.t-2 { color: var(--text-2); }
.t-3 { color: var(--text-3); }
.t-num { font-variant-numeric: tabular-nums; }
.t-strong { font-weight: 600; }
.t-clamp { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; min-width: 0; }

/* ---- App frame --------------------------------------------------------------- */

#app {
  position: fixed;
  inset: 0;
  overflow: hidden;
  background: var(--bg);
}

.stack {
  position: absolute;
  inset: 0;
  overflow: hidden;
  isolation: isolate;
}

.screen {
  position: absolute;
  inset: 0;
  overflow-x: hidden;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior-y: contain;
  background: var(--bg);
  padding-bottom: calc(var(--tabbar-h) + var(--safe-b) + 28px);
  will-change: transform;
  contain: layout paint;
}

.screen[inert] {
  pointer-events: none;
}

/* The dimming layer used while a screen slides over another. */
.screen-dim {
  position: fixed;
  inset: 0;
  background: #000;
  opacity: 0;
  pointer-events: none;
  z-index: 40;
}

.screen-inner {
  max-width: var(--content-max);
  margin: 0 auto;
  padding-left: var(--safe-l);
  padding-right: var(--safe-r);
}

/* ---- Navigation bar (iOS large-title pattern) -------------------------------- */

.navbar {
  position: sticky;
  top: 0;
  z-index: 20;
  height: calc(var(--navbar-h) + var(--safe-t));
  padding: var(--safe-t) 6px 0;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  background: transparent;
  border-bottom: 0.5px solid transparent;
  transition: background-color var(--dur-fast) ease, border-color var(--dur-fast) ease;
}

.navbar.is-scrolled,
.navbar.is-solid {
  background: var(--bar-bg);
  -webkit-backdrop-filter: var(--bar-blur);
  backdrop-filter: var(--bar-blur);
  border-bottom-color: var(--separator);
}

.navbar-side {
  display: flex;
  align-items: center;
  min-width: 0;
}

.navbar-side.end {
  justify-content: flex-end;
  gap: 2px;
}

.navbar-title {
  font: 600 var(--fs-headline)/var(--lh-headline) var(--font);
  letter-spacing: -0.01em;
  text-align: center;
  max-width: 62vw;
  opacity: 0;
  transform: translate3d(0, 6px, 0);
  transition: opacity var(--dur-fast) ease, transform var(--dur-base) var(--ease-out);
}

.navbar.is-scrolled .navbar-title,
.navbar.show-title .navbar-title {
  opacity: 1;
  transform: none;
}

.large-title {
  padding: 2px var(--gutter) 6px;
}

.large-title h1 {
  font: 700 var(--fs-largetitle)/var(--lh-largetitle) var(--font-display);
  letter-spacing: var(--tracking-tight);
}

.large-title p {
  margin-top: 2px;
  color: var(--text-2);
  font: 400 var(--fs-subhead)/var(--lh-subhead) var(--font);
}

/* Back button: chevron + label, the iOS way. */
.nav-back {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  height: 44px;
  padding: 0 8px 0 2px;
  color: var(--accent-text);
  font: 400 var(--fs-body)/1 var(--font);
  border-radius: var(--r-sm);
  transition: opacity var(--dur-fast) ease;
}

.nav-back svg {
  width: 26px;
  height: 26px;
  stroke-width: 2.2;
}

.nav-back:active {
  opacity: 0.45;
}

/* ---- Tab bar --------------------------------------------------------------- */

.tabbar {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 30;
  height: calc(var(--tabbar-h) + var(--safe-b));
  padding: 0 calc(var(--safe-r) + 4px) var(--safe-b) calc(var(--safe-l) + 4px);
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  background: var(--bar-bg);
  -webkit-backdrop-filter: var(--bar-blur);
  backdrop-filter: var(--bar-blur);
  border-top: 0.5px solid var(--separator);
}

.tab {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 3px;
  padding-top: 4px;
  color: var(--text-3);
  font: 500 10.5px/1 var(--font);
  letter-spacing: 0.01em;
  transition: color var(--dur-fast) ease;
}

.tab svg {
  width: 25px;
  height: 25px;
  stroke-width: 1.7;
  transition: transform var(--dur-press) var(--ease-out);
}

.tab:active svg {
  transform: scale(0.88);
}

.tab[aria-current="page"] {
  color: var(--accent-text);
}

.tab[aria-current="page"] svg {
  stroke-width: 2;
}

.tab-badge {
  position: absolute;
  top: 5px;
  left: calc(50% + 8px);
  min-width: 17px;
  height: 17px;
  padding: 0 5px;
  border-radius: var(--r-pill);
  background: var(--hot-dot);
  color: #fff;
  font: 600 11px/17px var(--font);
  text-align: center;
  font-variant-numeric: tabular-nums;
}

/* ---- Sections inside screens ------------------------------------------------ */

.section {
  padding: 0 var(--gutter);
  margin-top: var(--s-6);
}

.section:first-child {
  margin-top: var(--s-3);
}

.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--s-3);
  padding: 0 4px var(--s-2);
}

.section-head h2 {
  font: 600 var(--fs-title3)/var(--lh-title3) var(--font-display);
  letter-spacing: var(--tracking-snug);
}

.section-head .t-eyebrow {
  padding-left: 0;
}

.section-note {
  padding: var(--s-2) 4px 0;
  color: var(--text-3);
  font: 400 var(--fs-footnote)/var(--lh-footnote) var(--font);
}

/* ---- One-time entrance (first render of a screen only) ---------------------- */

@keyframes rise {
  from {
    opacity: 0;
    transform: translate3d(0, 10px, 0);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

.enter > * {
  animation: rise 420ms var(--ease-out) both;
  animation-delay: calc(var(--i, 0) * 38ms);
}

/* ---- Wide screens (laptop): keep a calm centred column ---------------------- */

@media (min-width: 760px) {
  :root {
    --gutter: 28px;
  }
  .tabbar {
    left: 50%;
    right: auto;
    width: 480px;
    margin-left: -240px;
    bottom: 16px;
    height: var(--tabbar-h);
    padding-bottom: 0;
    border: 0.5px solid var(--separator);
    border-radius: var(--r-xl);
  }
  .screen {
    padding-bottom: calc(var(--tabbar-h) + 48px);
  }
}

/* ---- Reduced motion: keep fades, drop movement ----------------------------- */

@media (prefers-reduced-motion: reduce) {
  .enter > * {
    animation-name: fade-only;
  }
  @keyframes fade-only {
    from { opacity: 0; }
    to { opacity: 1; }
  }
  .navbar-title {
    transform: none !important;
  }
}