/* Base layer.
 *
 * Most of this file exists to remove browser behaviours that give away
 * that an app is a web page: the tap flash, the callout menu on long
 * press, rubber-band scroll on the document, text selection on chrome,
 * and the 300ms-feeling double-tap zoom. An app that does all of these
 * things feels like a website no matter how it is styled. */

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

html {
  -webkit-text-size-adjust: 100%;   /* iOS: don't reflow type on rotate */
  text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: var(--t-base);
  line-height: 1.55;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overscroll-behavior-y: none;      /* no rubber-band on the document */
  text-rendering: optimizeLegibility;
}

/* Chrome is not selectable; content is. Selecting a nav label by accident
 * while scrolling is a tell that you are in a browser. */
body.is-app {
  user-select: none;
  -webkit-user-select: none;
  position: fixed;                  /* the app shell never scrolls; panes do */
  inset: 0;
  overflow: hidden;
}
.selectable, input, textarea, [contenteditable] {
  user-select: text;
  -webkit-user-select: text;
}

/* Every scrolling pane gets momentum and keeps its overscroll to itself. */
.scroll {
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior: contain;
  scrollbar-width: thin;
  scrollbar-color: var(--line-2) transparent;
}
.scroll::-webkit-scrollbar { width: 10px; height: 10px; }
.scroll::-webkit-scrollbar-thumb {
  background: var(--line-2); border-radius: var(--r-full);
  border: 3px solid transparent; background-clip: content-box;
}
.scroll::-webkit-scrollbar-track { background: transparent; }

img, svg, video, canvas { display: block; max-width: 100%; }
img { -webkit-user-drag: none; user-select: none; }

h1, h2, h3, h4 { margin: 0; font-weight: 640; line-height: 1.2; letter-spacing: -0.02em; }
h1 { font-size: var(--t-xl); }
h2 { font-size: var(--t-lg); }
h3 { font-size: var(--t-md); }
p  { margin: 0; }

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

/* ---------- focus -------------------------------------------------
 * Visible for keyboards, invisible for pointers. :focus-visible does
 * exactly this and is safe to rely on now. */
:focus { outline: none; }
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: var(--r-sm);
}

/* ---------- controls ---------------------------------------------- */
button, input, select, textarea {
  font: inherit;
  color: inherit;
}

.btn {
  -webkit-appearance: none;
  appearance: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--s-2);
  min-height: var(--tap);
  padding: 0 var(--s-5);
  border: 1px solid var(--line-2);
  border-radius: var(--r-full);
  background: var(--surface-2);
  color: var(--ink);
  font-size: var(--t-base);
  font-weight: 560;
  cursor: pointer;
  white-space: nowrap;
  transition: background var(--dur-1) var(--ease),
              border-color var(--dur-1) var(--ease),
              transform var(--dur-1) var(--ease),
              opacity var(--dur-1) var(--ease);
}
.btn:hover:not(:disabled) { background: var(--surface-3); }
/* Press feedback is a scale, not a color change -- it reads as physical
 * and it works on touch, where :hover never fires. */
.btn:active:not(:disabled) { transform: scale(.97); }
.btn:disabled { opacity: .45; cursor: not-allowed; }

.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-ink);
  font-weight: 620;
}
.btn-primary:hover:not(:disabled) { background: var(--accent-hi); border-color: var(--accent-hi); }

.btn-ghost { background: transparent; border-color: transparent; color: var(--ink-2); }
.btn-ghost:hover:not(:disabled) { background: var(--surface-2); color: var(--ink); }

.btn-lg { min-height: 54px; padding: 0 var(--s-6); font-size: var(--t-md); }
.btn-sm { min-height: 34px; padding: 0 var(--s-3); font-size: var(--t-sm); }
.btn-icon { width: var(--tap); min-height: var(--tap); padding: 0; border-radius: var(--r-full); }

.field {
  width: 100%;
  min-height: var(--tap);
  padding: var(--s-3) var(--s-4);
  background: var(--sunken);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  color: var(--ink);
  font-size: var(--t-base);
  /* 16px minimum on iOS or focusing the field zooms the viewport. The
   * app's base size is 15px, so inputs are bumped explicitly. */
  font-size: max(16px, var(--t-base));
  transition: border-color var(--dur-1) var(--ease), background var(--dur-1) var(--ease);
}
.field::placeholder { color: var(--ink-3); }
.field:focus { border-color: var(--accent); background: var(--surface); }
textarea.field { min-height: 90px; resize: vertical; line-height: 1.5; }

.label {
  display: block;
  font-size: var(--t-xs);
  font-weight: 600;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin-bottom: var(--s-2);
}

/* ---------- helpers ---------------------------------------------- */
.row { display: flex; align-items: center; gap: var(--s-3); }
.col { display: flex; flex-direction: column; gap: var(--s-3); }
.grow { flex: 1 1 auto; min-width: 0; }
.wrap { flex-wrap: wrap; }
.center { align-items: center; justify-content: center; }
.muted { color: var(--ink-2); }
.dim { color: var(--ink-3); }
.small { font-size: var(--t-sm); }
.xs { font-size: var(--t-xs); }
.mono { font-family: var(--mono); font-size: .92em; }
.hidden { display: none !important; }
.nowrap { white-space: nowrap; }
.truncate { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

.pill {
  display: inline-flex; align-items: center; gap: var(--s-1);
  padding: 3px var(--s-3);
  border-radius: var(--r-full);
  background: var(--surface-3);
  font-size: var(--t-xs); font-weight: 600;
  color: var(--ink-2);
  white-space: nowrap;
}
.pill-accent { background: var(--accent-wash); color: var(--accent); border: 1px solid var(--accent-line); }
.pill-ok  { background: rgba(75,168,113,.14); color: var(--ok); }
.pill-err { background: var(--err-wash); color: var(--err); }

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: var(--s-5);
}

hr.rule { border: 0; border-top: 1px solid var(--line); margin: var(--s-5) 0; }

/* Respect the OS setting. Someone who turns motion off gets no motion. */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ---------- shared header ----------
 * .brand and .brand-tail live HERE, not in app.css: both pages use them,
 * and keeping them app-only meant the landing page drew a brand whose
 * mark was invisible because it never loaded that stylesheet. */
.brand {
  display: inline-flex; align-items: baseline;
  font-weight: 720; letter-spacing: -.03em; font-size: var(--t-md);
  color: var(--ink); text-decoration: none;
}
.brand:hover { text-decoration: none; }
.brand-tail { color: var(--accent); }

 * The brand and the cross-link between surfaces look and behave the
 * same on the landing page and in the app; only the page's own actions
 * differ. See js/chrome.js. */
.brand-slot { display: flex; align-items: center; gap: var(--s-4); min-width: 0; }
.brand-slot .brand { flex: none; }

/* THE header. One bar, the same height, brand and blur on both pages;
   each page puts its own actions on the right (Source / Open app on
   the landing page, Home / About / Process in the app). The app's used
   to be 52px and the landing page's 60px, with the brand at two
   weights, so crossing between them read as two products. */
.appbar {
  position: sticky; top: 0; z-index: 40;
  padding-top: var(--safe-t);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur-2) var(--ease);
}
.appbar.stuck, body.is-app .appbar { border-bottom-color: var(--line); }
.appbar-row {
  display: flex; align-items: center; gap: var(--s-3);
  height: 60px;
  padding: 0 max(var(--gutter), var(--safe-r)) 0 max(var(--gutter), var(--safe-l));
}
.appbar .brand { font-weight: 700; font-size: var(--t-base); }
.appbar-actions { display: flex; align-items: center; gap: var(--s-2); margin-left: auto; }

/* Hidden on a phone: an action the bar has no room for there. */
.hide-sm { display: none; }
@media (min-width: 620px) { .hide-sm { display: inline-flex; } }

/* A small uppercase label above a heading: "Step 2 of 4", a section's
   name. Shared because both pages count steps. */
.eyebrow {
  display: inline-block;
  font-size: var(--t-xs); font-weight: 700;
  letter-spacing: .09em; text-transform: uppercase;
  color: var(--accent);
}

.appbar-x {
  display: inline-flex; align-items: center;
  height: 32px; padding: 0 var(--s-3);
  border-radius: var(--r-full);
  border: 1px solid var(--line);
  color: var(--ink-2);
  font-size: var(--t-sm); font-weight: 560;
  text-decoration: none;
  white-space: nowrap;
  transition: background var(--dur-1) var(--ease), color var(--dur-1) var(--ease),
              border-color var(--dur-1) var(--ease);
}
.appbar-x:hover { background: var(--surface-2); color: var(--ink); border-color: var(--line-2); text-decoration: none; }
.appbar-x:active { transform: scale(.97); }

/* On a phone the app's header has to hold the brand, the cross-link and
   two actions. The cross-link is the one that can lose its label. */
@media (max-width: 520px) {
  body.is-app .appbar-x { padding: 0 var(--s-2); font-size: var(--t-xs); }
}