:root {
  --bg: #f4f8fb;
  --surface: #ffffff;
  --text: #0f172a;
  --muted: #607089;
  --line: #dbe7ef;
  --teal: #18b7a8;
  --teal-dark: #07877a;
  --teal-light: #e9fbf8;
  --gold: #f6b84b;
  --shadow-soft: 0 18px 48px rgba(15,23,42,0.07);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { overflow-x: hidden; }
img, svg, video { max-width: 100%; }

body {
  background:
    radial-gradient(circle at 18% 10%, rgba(24,183,168,0.12), transparent 30%),
    radial-gradient(circle at 84% 0%, rgba(246,184,75,0.10), transparent 26%),
    var(--bg);
  color: var(--text);
  font-family: "SF Pro Text", -apple-system, BlinkMacSystemFont,
    "PingFang SC", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* NAV */
nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(244,248,251,0.88);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid rgba(219,231,239,0.88);
}
.nav-inner {
  width: 100%; max-width: 1180px; margin: 0 auto; padding: 0 28px;
  min-height: 64px; display: flex; align-items: center; justify-content: space-between;
  gap: 18px;
}
.nav-logo { display: flex; align-items: center; gap: 10px; text-decoration: none; min-width: 0; }
.brand-mark { width: 38px; height: 38px; border-radius: 12px; object-fit: cover; box-shadow: 0 8px 24px rgba(15,23,42,0.12); flex: 0 0 auto; }
.nav-logo img { width: 38px; height: 38px; border-radius: 12px; object-fit: cover; box-shadow: 0 8px 24px rgba(15,23,42,0.12); flex: 0 0 auto; }
.nav-logo svg { width: 38px; height: 38px; flex-shrink: 0; border-radius: 12px; box-shadow: 0 8px 24px rgba(15,23,42,0.12); }
.nav-logo-text { font-size: 22px; font-weight: 850; color: var(--text); letter-spacing: -0.01em; }
.nav-logo-text span { color: var(--teal); }
.nav-right {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 6px;
  min-width: 0;
}
.nav-link {
  color: var(--muted);
  padding: 8px 12px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 720;
  text-decoration: none;
  white-space: nowrap;
}
.nav-link:hover { background: rgba(24,183,168,0.08); color: var(--text); }
.nav-btn {
  min-height: 38px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  background: var(--teal);
  color: #fff;
  padding: 0 15px;
  font-size: 14px;
  font-weight: 850;
  text-decoration: none;
  white-space: nowrap;
  box-shadow: 0 8px 18px rgba(24,183,168,0.20);
}
.nav-back {
  font-size: 14px; font-weight: 760; color: var(--muted);
  text-decoration: none; padding: 9px 15px; border-radius: 999px;
  border: 1px solid var(--line); background: rgba(255,255,255,0.82);
  transition: color 0.15s, background 0.15s, border-color 0.15s;
  white-space: nowrap;
}
.nav-back:hover { color: var(--text); background: var(--surface); border-color: rgba(24,183,168,0.25); }

/* PAGE */
.page-wrap {
  width: 100%; max-width: 840px; margin: 0 auto; padding: 72px 32px 104px;
  min-width: 0;
}
.page-wrap * { min-width: 0; }
.page-eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  min-height: 30px; padding: 0 13px; border-radius: 999px;
  background: var(--teal-light); border: 1px solid rgba(24,183,168,0.20);
  font-size: 13px; font-weight: 850; color: var(--teal-dark); margin-bottom: 18px;
}
.page-title {
  font-size: clamp(34px, 5vw, 56px); font-weight: 900;
  line-height: 1.04; letter-spacing: -0.032em; margin-bottom: 14px;
  text-wrap: balance;
}
.page-meta { font-size: 16px; color: var(--muted); line-height: 1.75; margin-bottom: 44px; max-width: 62ch; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--teal-dark);
  font-size: 13px;
  font-weight: 850;
  margin-bottom: 14px;
}
.eyebrow::before { content: ""; width: 7px; height: 7px; border-radius: 50%; background: var(--teal); }
.section-title {
  font-size: clamp(34px, 5vw, 58px);
  line-height: 1.05;
  letter-spacing: -0.032em;
  font-weight: 900;
  color: var(--text);
  max-width: 820px;
  text-wrap: balance;
}
.section-sub {
  color: var(--muted);
  font-size: 17px;
  line-height: 1.75;
  max-width: 700px;
}

/* PROSE */
.prose {
  background: rgba(255,255,255,0.72);
  border: 1px solid rgba(219,231,239,0.86);
  border-radius: 24px;
  padding: 30px;
  box-shadow: 0 14px 42px rgba(15,23,42,0.04);
}
.prose h2 {
  font-size: 20px; font-weight: 850; color: var(--text);
  margin: 38px 0 12px; padding-top: 34px;
  border-top: 1px solid var(--line);
  letter-spacing: -0.01em;
}
.prose h2:first-child { border-top: none; margin-top: 0; padding-top: 0; }
.prose p { font-size: 15px; color: var(--muted); line-height: 1.82; margin-bottom: 14px; }
.prose ul { padding-left: 20px; margin-bottom: 14px; }
.prose ul li { font-size: 15px; color: var(--muted); line-height: 1.82; margin-bottom: 6px; }
.prose strong { color: var(--text); font-weight: 780; }
.prose a { color: var(--teal-dark); font-weight: 760; }

/* HIGHLIGHT BOX */
.info-box {
  background: var(--teal-light); border: 1px solid rgba(24,183,168,0.22);
  border-radius: 16px; padding: 18px 20px; margin: 20px 0;
}
.info-box p { margin: 0; color: var(--teal-dark) !important; font-size: 14px !important; }

.rk-icon-token {
  width: 44px;
  height: 44px;
  border-radius: 14px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--teal-dark);
  background: linear-gradient(145deg, #effffb, #d6f5ee);
  border: 1px solid rgba(24,183,168,0.20);
  box-shadow: 0 10px 22px rgba(15,23,42,0.06), inset 0 1px 0 rgba(255,255,255,0.85);
  flex: 0 0 auto;
}
.rk-icon-token svg {
  width: 22px;
  height: 22px;
  stroke: currentColor;
}
.rk-icon-token.small {
  width: 28px;
  height: 28px;
  border-radius: 10px;
}
.rk-icon-token.small svg {
  width: 15px;
  height: 15px;
}
.rk-icon-token.gold {
  color: #9a6707;
  background: linear-gradient(145deg, #fff8e6, #ffe7ad);
  border-color: rgba(246,184,75,0.38);
}

.assistant-cue {
  display: grid;
  grid-template-columns: 86px minmax(0, 1fr);
  gap: 18px;
  align-items: center;
  margin: -20px 0 34px;
  padding: 18px 20px;
  border-radius: 24px;
  border: 1px solid rgba(24,183,168,0.18);
  background:
    linear-gradient(135deg, rgba(255,255,255,0.92), rgba(235,250,247,0.88));
  box-shadow: 0 18px 46px rgba(15,23,42,0.06);
}
.assistant-cue img {
  width: 86px;
  height: 86px;
  object-fit: contain;
  filter: drop-shadow(0 12px 18px rgba(15,23,42,0.12));
}
.assistant-cue > div {
  min-width: 0;
}
.assistant-cue strong {
  display: block;
  font-size: 18px;
  line-height: 1.25;
  color: var(--text);
  margin-bottom: 5px;
}
.assistant-cue p {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.65;
  margin: 0;
  overflow-wrap: anywhere;
}

.brand-image-icon {
  width: 64px;
  height: 64px;
  display: block;
  object-fit: contain;
  filter: drop-shadow(0 12px 18px rgba(15,23,42,0.10));
}

.contact-card-icon.brand-image-icon {
  display: block;
}

.support-shortcuts {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
  margin: -14px 0 38px;
}

.support-shortcut {
  min-width: 0;
  min-height: 110px;
  display: grid;
  align-content: center;
  justify-items: center;
  gap: 8px;
  padding: 16px 12px;
  border: 1px solid rgba(219,231,239,0.9);
  border-radius: 18px;
  background: rgba(255,255,255,0.74);
  color: var(--text);
  text-align: center;
  text-decoration: none;
  box-shadow: 0 12px 30px rgba(15,23,42,0.04);
}

.support-shortcut:hover {
  border-color: rgba(24,183,168,0.28);
  background: #ffffff;
}

.support-shortcut img {
  width: 46px;
  height: 46px;
  object-fit: contain;
  filter: drop-shadow(0 8px 12px rgba(15,23,42,0.08));
}

.support-shortcut span {
  font-size: 13px;
  font-weight: 820;
  line-height: 1.25;
}

/* FOOTER */
footer {
  background: rgba(255,255,255,0.82); border-top: 1px solid var(--line);
}
.footer-top {
  max-width: 1180px; margin: 0 auto; padding: 54px 28px 44px;
  display: grid; grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px; align-items: start;
}
.footer-brand-logo {
  display: flex; align-items: center; gap: 10px;
  text-decoration: none; margin-bottom: 14px;
}
.footer-brand-logo img { width: 30px; height: 30px; border-radius: 9px; object-fit: cover; box-shadow: none; }
.footer-brand-logo svg { width: 30px; height: 30px; border-radius: 9px; }
.footer-brand-name { font-size: 16px; font-weight: 850; color: var(--text); letter-spacing: -0.01em; }
.footer-brand-name span { color: var(--teal); }
.footer-tagline { font-size: 13px; color: var(--muted); line-height: 1.7; max-width: 24em; }
.footer-col h4 {
  font-size: 12px; font-weight: 850; text-transform: none;
  letter-spacing: 0; color: #8a9aad; margin-bottom: 16px;
}
.footer-col ul { list-style: none; }
.footer-col ul li { margin-bottom: 10px; }
.footer-col ul li a {
  font-size: 14px; color: var(--muted); text-decoration: none;
  font-weight: 650; transition: color 0.15s;
}
.footer-col ul li a:hover { color: var(--text); }
.footer-bottom {
  border-top: 1px solid var(--line); max-width: 1180px;
  margin: 0 auto; padding: 18px 28px;
  display: flex; justify-content: space-between; align-items: center;
  flex-wrap: wrap; gap: 8px;
}
.footer-copy { font-size: 12px; color: #a8b7c5; }
.footer-domain { font-size: 12px; color: #a8b7c5; font-weight: 650; }

@media (max-width: 900px) { .footer-top { grid-template-columns: 1fr 1fr; gap: 28px; } }
@media (max-width: 640px) {
  .nav-inner { padding: 0 14px; min-height: 60px; gap: 8px; }
  .nav-logo { gap: 8px; }
  .nav-logo-text { font-size: 19px; }
  .brand-mark, .nav-logo img, .nav-logo svg { width: 34px; height: 34px; border-radius: 10px; }
  .nav-right { margin-left: auto; gap: 8px; }
  .nav-link { display: none; }
  .nav-btn { display: none; }
  .nav-back {
    width: 36px;
    height: 36px;
    padding: 0;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 0;
    margin-left: auto;
    margin-right: 48px;
  }
  .nav-back::before {
    content: "←";
    font-size: 17px;
    line-height: 1;
  }
  .page-wrap { padding: 54px 20px 78px; }
  .page-title { font-size: 38px; }
  .assistant-cue {
    width: calc(100vw - 40px);
    max-width: calc(100vw - 40px);
    grid-template-columns: 66px minmax(0, 1fr);
    gap: 14px;
    margin: -20px 0 28px;
    padding: 16px;
    border-radius: 20px;
  }
  .assistant-cue img {
    width: 66px;
    height: 66px;
  }
  .assistant-cue strong { font-size: 16px; }
  .support-shortcuts { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .support-shortcut { min-height: 96px; }
  .prose { padding: 22px; border-radius: 20px; }
  .footer-top { grid-template-columns: 1fr; padding: 40px 20px 30px; }
  .footer-bottom { padding: 15px 20px; }
}