/* Palette lifted from the app's Theme.swift so the page and the app agree. */
:root {
  --canvas:   #F7F6F3;
  --surface:  #FFFFFF;
  --ink:      #14171D;
  --ink-soft: #6C717C;
  --rule:     #DDDBD5;
  --accent:   #3B4CC6;
  --now:      #E23A2E;
  --ahead:    rgba(20, 23, 29, 0.11);

  --display: ui-rounded, "SF Pro Rounded", -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  --body: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;

  --step--1: clamp(0.78rem, 0.76rem + 0.1vw, 0.84rem);
  --step-0:  clamp(1rem, 0.97rem + 0.15vw, 1.08rem);
  --step-1:  clamp(1.2rem, 1.13rem + 0.35vw, 1.4rem);
  --step-2:  clamp(1.6rem, 1.45rem + 0.75vw, 2.1rem);
  --step-3:  clamp(2.2rem, 1.9rem + 1.5vw, 3.2rem);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --canvas:   #0A0D13;
    --surface:  #141922;
    --ink:      #F2F4F8;
    --ink-soft: #8A91A0;
    --rule:     #232935;
    --accent:   #8291FA;
    --now:      #FF5347;
    --ahead:    rgba(242, 244, 248, 0.14);
  }
}

:root[data-theme="dark"] {
  --canvas:   #0A0D13;
  --surface:  #141922;
  --ink:      #F2F4F8;
  --ink-soft: #8A91A0;
  --rule:     #232935;
  --accent:   #8291FA;
  --now:      #FF5347;
  --ahead:    rgba(242, 244, 248, 0.14);
}

/* Language switch: one document, two languages. */
:root[data-lang="en"] [lang="zh"] { display: none; }
:root[data-lang="zh"] [lang="en"] { display: none; }

body {
  margin: 0;
  background: var(--canvas);
  color: var(--ink);
  font-family: var(--body);
  font-size: var(--step-0);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: 43rem;
  margin: 0 auto;
  padding: clamp(1.5rem, 4vw, 3.5rem) clamp(1.15rem, 5vw, 2rem) 4rem;
}

.eyebrow {
  font-family: var(--mono);
  font-size: var(--step--1);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-soft);
  margin: 0;
}

/* Masthead ------------------------------------------------------------ */

.masthead {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--rule);
}

.topline {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

h1 {
  font-family: var(--display);
  font-size: var(--step-3);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.05;
  margin: 0.35rem 0 0;
  text-wrap: balance;
}

.lede {
  margin: 0;
  color: var(--ink-soft);
  font-size: var(--step-1);
  max-width: 34ch;
  text-wrap: pretty;
}

.langs { display: flex; gap: 0.25rem; }

.langs button {
  font-family: var(--mono);
  font-size: var(--step--1);
  letter-spacing: 0.06em;
  color: var(--ink-soft);
  background: none;
  border: 1px solid var(--rule);
  border-radius: 999px;
  padding: 0.3rem 0.7rem;
  cursor: pointer;
}

.langs button[aria-pressed="true"] {
  color: var(--canvas);
  background: var(--ink);
  border-color: var(--ink);
}

.langs button:focus-visible,
a:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

#motif { display: block; width: 100%; height: auto; }

/* Contact ------------------------------------------------------------- */

.contact {
  margin: 3rem 0 0;
  padding: 1.4rem 1.5rem;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: 14px;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.contact a {
  font-family: var(--display);
  font-size: var(--step-1);
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
  word-break: break-word;
}

.contact a:hover { text-decoration: underline; }

.contact p { margin: 0; color: var(--ink-soft); font-size: var(--step--1); }

/* FAQ ----------------------------------------------------------------- */

section { margin-top: 3rem; }

section > .eyebrow { padding-bottom: 0.6rem; border-bottom: 1px solid var(--rule); }

h2 {
  font-family: var(--display);
  font-size: var(--step-2);
  font-weight: 650;
  letter-spacing: -0.015em;
  margin: 0.9rem 0 0;
  text-wrap: balance;
}

h3 {
  font-family: var(--display);
  font-size: var(--step-1);
  font-weight: 600;
  letter-spacing: -0.01em;
  margin: 2rem 0 0.4rem;
  text-wrap: balance;
}

p { margin: 0 0 0.8rem; max-width: 65ch; text-wrap: pretty; }

a { color: var(--accent); }

strong { font-weight: 620; }

kbd {
  font-family: var(--mono);
  font-size: 0.88em;
  padding: 0.1em 0.4em;
  border: 1px solid var(--rule);
  border-radius: 5px;
  background: var(--surface);
  white-space: nowrap;
}

/* Snapping diagram ---------------------------------------------------- */

figure {
  margin: 1.2rem 0 1.4rem;
  padding: 1.25rem 1.35rem 1rem;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: 14px;
}

figure svg { display: block; width: 100%; height: auto; }

figcaption {
  font-family: var(--mono);
  font-size: var(--step--1);
  color: var(--ink-soft);
  margin-top: 0.7rem;
  line-height: 1.5;
}

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 1.1rem;
  margin: 1rem 0 0.4rem;
  padding: 0;
  list-style: none;
  font-family: var(--mono);
  font-size: var(--step--1);
  color: var(--ink-soft);
}

.legend li { display: flex; align-items: center; gap: 0.45rem; }

.swatch { width: 11px; height: 11px; border-radius: 3px; flex: none; }

footer {
  margin-top: 3.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: var(--step--1);
  color: var(--ink-soft);
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 1.5rem;
}

/* Site navigation ------------------------------------------------------ */

.pills { display: flex; gap: 0.25rem; }

.pills a,
.pills button {
font-family: var(--mono);
font-size: var(--step--1);
letter-spacing: 0.06em;
color: var(--ink-soft);
background: none;
border: 1px solid var(--rule);
border-radius: 999px;
padding: 0.3rem 0.7rem;
cursor: pointer;
text-decoration: none;
white-space: nowrap;
}

.pills a[aria-current="page"],
.pills button[aria-pressed="true"] {
color: var(--canvas);
background: var(--ink);
border-color: var(--ink);
}

.pills a:hover { border-color: var(--ink-soft); }

.topline nav { display: flex; gap: 1rem; flex-wrap: wrap; }

/* Plain prose lists, used by the privacy policy ------------------------- */

.prose-list {
margin: 0 0 0.9rem;
padding-left: 1.1rem;
max-width: 65ch;
}

.prose-list li { margin-bottom: 0.3rem; }

.note {
margin: 1.5rem 0 0;
padding: 1.1rem 1.3rem;
background: var(--surface);
border: 1px solid var(--rule);
border-radius: 14px;
}

.note p:last-child { margin-bottom: 0; }