/* BattAI support site — Ember Glass
   Warm amber on deep warm plum (dark) / warm cream (light). No emoji anywhere. */

:root {
  --bg: #FBF5EC;
  --bg-raised: #FFFFFF;
  --card: #FFFFFF;
  --card-border: rgba(60, 38, 18, 0.10);
  --card-shadow: 0 18px 40px -22px rgba(90, 48, 16, 0.38), 0 2px 6px -2px rgba(90, 48, 16, 0.10);
  --text: #2A1B12;
  --text-2: #6E5A49;
  --text-3: #9E8A76;
  --brand: #FF6B3D;
  --brand-soft: rgba(255, 107, 61, 0.12);
  --gold: #E8A020;
  --gold-soft: rgba(255, 194, 76, 0.18);
  --accent: #E4577C;
  --rule: rgba(60, 38, 18, 0.10);
  --glow-a: rgba(255, 178, 92, 0.55);
  --glow-b: rgba(255, 110, 147, 0.30);
  --glow-c: rgba(255, 210, 140, 0.45);
  --pill-bg: rgba(255, 255, 255, 0.72);
  --header-bg: rgba(251, 245, 236, 0.82);
  --code-bg: rgba(60, 38, 18, 0.06);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #171016;
    --bg-raised: #221419;
    --card: #2C1A1E;
    --card-border: rgba(255, 205, 170, 0.12);
    --card-shadow: 0 22px 48px -26px rgba(0, 0, 0, 0.85), 0 2px 8px -3px rgba(0, 0, 0, 0.5);
    --text: #FDEFE4;
    --text-2: #D9BCAC;
    --text-3: #A98C7E;
    --brand: #FF8A5C;
    --brand-soft: rgba(255, 138, 92, 0.16);
    --gold: #FFC24C;
    --gold-soft: rgba(255, 194, 76, 0.14);
    --accent: #FF6E93;
    --rule: rgba(255, 205, 170, 0.13);
    --glow-a: rgba(255, 138, 92, 0.30);
    --glow-b: rgba(255, 110, 147, 0.18);
    --glow-c: rgba(255, 194, 76, 0.20);
    --pill-bg: rgba(255, 255, 255, 0.06);
    --header-bg: rgba(23, 16, 22, 0.82);
    --code-bg: rgba(255, 205, 170, 0.08);
  }
}

:root[data-theme="dark"] {
  --bg: #171016;
  --bg-raised: #221419;
  --card: #2C1A1E;
  --card-border: rgba(255, 205, 170, 0.12);
  --card-shadow: 0 22px 48px -26px rgba(0, 0, 0, 0.85), 0 2px 8px -3px rgba(0, 0, 0, 0.5);
  --text: #FDEFE4;
  --text-2: #D9BCAC;
  --text-3: #A98C7E;
  --brand: #FF8A5C;
  --brand-soft: rgba(255, 138, 92, 0.16);
  --gold: #FFC24C;
  --gold-soft: rgba(255, 194, 76, 0.14);
  --accent: #FF6E93;
  --rule: rgba(255, 205, 170, 0.13);
  --glow-a: rgba(255, 138, 92, 0.30);
  --glow-b: rgba(255, 110, 147, 0.18);
  --glow-c: rgba(255, 194, 76, 0.20);
  --pill-bg: rgba(255, 255, 255, 0.06);
  --header-bg: rgba(23, 16, 22, 0.82);
  --code-bg: rgba(255, 205, 170, 0.08);
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto,
    "Helvetica Neue", Arial, "PingFang TC", "Noto Sans TC", sans-serif;
  font-size: 17px;
  line-height: 1.62;
  letter-spacing: 0.005em;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* Ambient ember glow — never a flat single colour background */
.bg {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(58rem 38rem at 12% -8%, var(--glow-a), transparent 62%),
    radial-gradient(44rem 32rem at 96% 4%, var(--glow-b), transparent 60%),
    radial-gradient(52rem 40rem at 68% 96%, var(--glow-c), transparent 64%);
  opacity: 0.9;
}

.wrap { width: 100%; max-width: 62rem; margin: 0 auto; padding: 0 1.25rem; }

/* Header */
header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--header-bg);
  backdrop-filter: saturate(180%) blur(18px);
  -webkit-backdrop-filter: saturate(180%) blur(18px);
  border-bottom: 1px solid var(--rule);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 3.75rem;
  flex-wrap: wrap;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 700;
  letter-spacing: -0.015em;
  color: var(--text);
  text-decoration: none;
  font-size: 1.05rem;
}

.brand img {
  width: 2rem;
  height: 2rem;
  border-radius: 0.5rem;
  box-shadow: 0 4px 12px -6px rgba(120, 60, 20, 0.6);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  flex-wrap: wrap;
}

.nav-links a {
  color: var(--text-2);
  text-decoration: none;
  font-size: 0.94rem;
  font-weight: 550;
  padding: 0.4rem 0.7rem;
  border-radius: 0.6rem;
  transition: color 0.18s ease, background 0.18s ease;
}

.nav-links a:hover { color: var(--brand); background: var(--brand-soft); }
.nav-links a[aria-current="page"] { color: var(--brand); background: var(--brand-soft); }

/* Hero */
.hero { padding: 3.4rem 0 1.6rem; text-align: center; }

.hero .app-icon {
  width: 5.5rem;
  height: 5.5rem;
  border-radius: 1.35rem;
  box-shadow: 0 26px 50px -26px rgba(150, 70, 20, 0.75), 0 0 0 1px var(--card-border);
  margin-bottom: 1.1rem;
}

.eyebrow {
  display: inline-block;
  font-size: 0.76rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--brand);
  margin-bottom: 0.7rem;
}

h1 {
  font-size: clamp(2rem, 6vw, 2.9rem);
  line-height: 1.12;
  letter-spacing: -0.028em;
  margin: 0 0 0.7rem;
  font-weight: 760;
}

.tagline {
  font-size: clamp(1.05rem, 2.6vw, 1.22rem);
  color: var(--text-2);
  max-width: 40rem;
  margin: 0 auto 1.3rem;
}

.badges { display: flex; flex-wrap: wrap; gap: 0.5rem; justify-content: center; }

.pill {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: var(--pill-bg);
  border: 1px solid var(--card-border);
  color: var(--text-2);
  border-radius: 999px;
  padding: 0.34rem 0.85rem;
  font-size: 0.84rem;
  font-weight: 560;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.pill .mark { width: 0.45rem; height: 0.45rem; border-radius: 2px; background: var(--gold); transform: rotate(45deg); flex: none; }

/* Sections */
section { padding: 1.6rem 0; }

.section-head { margin-bottom: 1.3rem; }
.section-head h2 { margin: 0 0 0.35rem; }
.section-head p { margin: 0; color: var(--text-2); max-width: 44rem; }

h2 {
  font-size: clamp(1.35rem, 3.4vw, 1.72rem);
  letter-spacing: -0.02em;
  line-height: 1.25;
  margin: 0 0 0.6rem;
  font-weight: 720;
}

h3 {
  font-size: 1.06rem;
  letter-spacing: -0.01em;
  margin: 0 0 0.35rem;
  font-weight: 660;
}

p { margin: 0 0 0.9rem; }
p:last-child { margin-bottom: 0; }

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

/* Cards */
.card {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: 1.15rem;
  padding: 1.4rem 1.5rem;
  box-shadow: var(--card-shadow);
}

.grid { display: grid; gap: 0.9rem; grid-template-columns: repeat(auto-fit, minmax(16rem, 1fr)); }

.feature h3 { display: flex; align-items: center; gap: 0.55rem; }
.feature p { color: var(--text-2); font-size: 0.96rem; margin: 0; }

.glyph {
  width: 2rem;
  height: 2rem;
  border-radius: 0.6rem;
  flex: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--gold-soft);
  border: 1px solid var(--card-border);
}

.glyph svg { width: 1.05rem; height: 1.05rem; stroke: var(--brand); fill: none; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }

/* FAQ */
.faq { display: grid; gap: 0.7rem; }

details {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: 1rem;
  box-shadow: var(--card-shadow);
  overflow: hidden;
}

summary {
  cursor: pointer;
  list-style: none;
  padding: 1.05rem 3rem 1.05rem 1.3rem;
  font-weight: 640;
  font-size: 1.01rem;
  letter-spacing: -0.01em;
  position: relative;
  color: var(--text);
}

summary::-webkit-details-marker { display: none; }

summary::after {
  content: "";
  position: absolute;
  right: 1.3rem;
  top: 1.42rem;
  width: 0.55rem;
  height: 0.55rem;
  border-right: 2px solid var(--brand);
  border-bottom: 2px solid var(--brand);
  transform: rotate(45deg);
  transition: transform 0.22s ease;
}

details[open] summary::after { transform: rotate(-135deg); }
details[open] summary { color: var(--brand); }

.answer { padding: 0 1.3rem 1.25rem; color: var(--text-2); font-size: 0.97rem; }
.answer p { margin-bottom: 0.75rem; }
.answer ol, .answer ul { margin: 0 0 0.75rem; padding-left: 1.15rem; }
.answer li { margin-bottom: 0.35rem; }
.answer strong { color: var(--text); font-weight: 640; }

code, .mono {
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.88em;
  background: var(--code-bg);
  padding: 0.12em 0.4em;
  border-radius: 0.35rem;
}

/* Steps */
.steps { counter-reset: step; display: grid; gap: 0.7rem; margin: 0; padding: 0; list-style: none; }

.steps li {
  counter-increment: step;
  position: relative;
  padding-left: 2.4rem;
  color: var(--text-2);
  font-size: 0.97rem;
}

.steps li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: -0.1rem;
  width: 1.65rem;
  height: 1.65rem;
  border-radius: 0.55rem;
  background: var(--brand-soft);
  border: 1px solid var(--card-border);
  color: var(--brand);
  font-size: 0.82rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Contact */
.contact-card { text-align: center; }

.mail {
  display: inline-block;
  font-size: clamp(1.02rem, 3.2vw, 1.3rem);
  font-weight: 680;
  letter-spacing: -0.01em;
  color: var(--brand);
  word-break: break-all;
  margin: 0.2rem 0 0.7rem;
}

/* Legal document */
.doc { max-width: 48rem; }
.doc .card { padding: 1.7rem 1.6rem; }
.doc h2 { margin-top: 2rem; padding-top: 1.3rem; border-top: 1px solid var(--rule); }
.doc h2:first-of-type { margin-top: 0; padding-top: 0; border-top: none; }
.doc p, .doc li { color: var(--text-2); }
.doc strong { color: var(--text); font-weight: 640; }
.doc ul { padding-left: 1.15rem; margin: 0 0 0.9rem; }
.doc li { margin-bottom: 0.4rem; }

.updated { color: var(--text-3); font-size: 0.88rem; margin: 0 0 0.4rem; }

.callout {
  background: var(--gold-soft);
  border: 1px solid var(--card-border);
  border-radius: 0.9rem;
  padding: 1rem 1.15rem;
  margin: 0 0 1.2rem;
}

.callout p { margin: 0; color: var(--text); font-weight: 560; }

table { width: 100%; border-collapse: collapse; font-size: 0.94rem; margin: 0 0 1rem; }
.table-scroll { overflow-x: auto; -webkit-overflow-scrolling: touch; }
th, td { text-align: left; padding: 0.6rem 0.7rem; border-bottom: 1px solid var(--rule); vertical-align: top; }
th { color: var(--text); font-weight: 640; font-size: 0.82rem; letter-spacing: 0.05em; text-transform: uppercase; }
td { color: var(--text-2); }

/* Footer */
footer {
  margin-top: 2.5rem;
  padding: 2rem 0 3rem;
  border-top: 1px solid var(--rule);
  color: var(--text-3);
  font-size: 0.88rem;
}

.foot { display: flex; flex-wrap: wrap; gap: 0.75rem 1.25rem; align-items: center; justify-content: space-between; }
.foot nav { display: flex; gap: 1rem; flex-wrap: wrap; }
.foot a { color: var(--text-2); }

@media (max-width: 30rem) {
  body { font-size: 16px; }
  .card { padding: 1.2rem 1.15rem; }
  .doc .card { padding: 1.3rem 1.15rem; }
  summary { padding: 0.95rem 2.6rem 0.95rem 1.05rem; }
  .answer { padding: 0 1.05rem 1.1rem; }
  .hero { padding: 2.4rem 0 1.2rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}