:root {
  color-scheme: light;
  --ink: #202124;
  --muted: #5f6368;
  --line: #dfe3e8;
  --soft: #f5f7fa;
  --blue: #1a73e8;
  --blue-strong: #0b57d0;
  --blue-soft: #e8f0fe;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }

.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;
}

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background: #fff;
}

button,
input,
select,
textarea { font: inherit; }

a { color: var(--blue-strong); }

.help-header {
  position: sticky;
  top: 0;
  z-index: 10;
  min-height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 10px 24px;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, .94);
  backdrop-filter: blur(12px);
}

.help-brand {
  display: inline-flex;
  align-items: center;
  min-width: 0;
  color: var(--ink);
  text-decoration: none;
}

.help-brand img {
  width: auto;
  max-width: 168px;
  height: 42px;
  object-fit: contain;
}

.help-header nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.help-header nav a {
  min-height: 38px;
  display: inline-flex;
  align-items: center;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--ink);
  text-decoration: none;
}

.help-header nav a.primary {
  border-color: var(--blue);
  color: #fff;
  background: var(--blue);
}

.help-header nav a[data-help-language] {
  width: 40px;
  min-width: 40px;
  padding: 0;
}

.help-header nav a[data-help-language] img {
  width: 27px;
  height: 27px;
  display: block;
}

.help-main {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
  padding: 56px 0 80px;
}

.help-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(280px, .75fr);
  align-items: center;
  gap: 44px;
  padding: 44px;
  border-radius: 18px;
  background: linear-gradient(135deg, #f7faff 0%, #e8f1ff 48%, #d9e7ff 100%);
}

.help-eyebrow {
  display: block;
  color: var(--blue-strong);
  font-size: 13px;
  font-weight: 700;
}

.help-hero h1 {
  margin: 10px 0 12px;
  font-size: clamp(34px, 5vw, 56px);
  line-height: 1.1;
  letter-spacing: -.025em;
}

.help-hero p {
  max-width: 680px;
  margin: 0;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.7;
}

.help-hero-visual {
  min-height: 220px;
  display: grid;
  place-items: center;
}

.help-hero-visual img {
  width: min(100%, 360px);
  height: auto;
  display: block;
  border-radius: 14px;
  mix-blend-mode: multiply;
}

.quick-links {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin: 22px 0 42px;
}

.quick-links a {
  min-height: 80px;
  display: grid;
  align-content: center;
  gap: 4px;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: 10px;
  color: var(--ink);
  text-decoration: none;
}

.quick-links a:hover { border-color: #aecbfa; background: #f8fbff; }
.quick-links strong { font-size: 15px; }
.quick-links small { color: var(--muted); line-height: 1.4; }

.guide-layout {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 42px;
  align-items: start;
}

.guide-toc {
  position: sticky;
  top: 84px;
  display: grid;
  gap: 4px;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
}

.guide-toc a {
  padding: 9px 10px;
  border-radius: 7px;
  color: var(--muted);
  font-size: 13px;
  text-decoration: none;
}

.guide-toc a:hover { color: var(--blue-strong); background: var(--blue-soft); }

.guide-content { min-width: 0; }

.guide-section {
  scroll-margin-top: 92px;
  padding: 34px 0;
  border-bottom: 1px solid var(--line);
}

.guide-section:first-child { padding-top: 0; }
.guide-section:last-child { border-bottom: 0; }

.guide-section h2 {
  margin: 0 0 10px;
  font-size: 27px;
}

.guide-section > p {
  margin: 0 0 20px;
  color: var(--muted);
  line-height: 1.7;
}

.instruction-list {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: guide-step;
}

.instruction-list li {
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  gap: 10px;
  align-items: start;
  line-height: 1.65;
  counter-increment: guide-step;
}

.instruction-list li::before {
  content: counter(guide-step);
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  color: var(--blue-strong);
  background: var(--blue-soft);
  font-size: 12px;
  font-weight: 700;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.feature-card {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
}

.feature-card strong { display: block; margin-bottom: 6px; }
.feature-card p { margin: 0; color: var(--muted); font-size: 14px; line-height: 1.6; }

.flow-visual {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
  margin: 20px 0;
  padding: 24px;
  border-radius: 12px;
  background: var(--soft);
}

.flow-visual span {
  position: relative;
  min-height: 72px;
  display: grid;
  place-items: center;
  padding: 12px;
  border: 1px solid #c8daf8;
  border-radius: 9px;
  color: var(--blue-strong);
  background: #fff;
  text-align: center;
  font-weight: 600;
}

.flow-visual span:not(:last-child)::after {
  content: "→";
  position: absolute;
  right: -19px;
  color: #7baaf7;
}

.support-search {
  width: min(720px, 100%);
  margin-top: 24px;
}

.support-search input {
  width: 100%;
  min-height: 48px;
  padding: 0 16px;
  border: 1px solid var(--line);
  border-radius: 10px;
  color: var(--ink);
  background: #fff;
}

.faq-list {
  display: grid;
  gap: 10px;
  margin-top: 24px;
}

.faq-section-title {
  margin: 22px 0 2px;
  font-size: 22px;
}

.faq-section-title:first-child { margin-top: 0; }

.faq-list details {
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
}

.faq-list summary {
  padding: 18px 48px 18px 18px;
  cursor: pointer;
  font-weight: 600;
}

.faq-answer {
  padding: 0 18px 18px;
  color: var(--muted);
  line-height: 1.7;
}

.faq-answer p { margin: 0 0 8px; }
.faq-answer p:last-child { margin-bottom: 0; }
.faq-list details[hidden] { display: none; }

.feedback-wrap {
  display: grid;
  grid-template-columns: minmax(0, .75fr) minmax(340px, 1.25fr);
  gap: 32px;
  margin-top: 54px;
  padding: 32px;
  border-radius: 16px;
  background: var(--soft);
}

.feedback-copy h2 { margin: 0 0 10px; font-size: 27px; }
.feedback-copy p { margin: 0; color: var(--muted); line-height: 1.7; }

.feedback-form {
  display: grid;
  gap: 13px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fff;
}

.feedback-form label { display: grid; gap: 6px; font-size: 13px; font-weight: 600; }
.feedback-form input,
.feedback-form select,
.feedback-form textarea {
  width: 100%;
  min-height: 42px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--ink);
  background: #fff;
}

.feedback-form textarea { min-height: 130px; resize: vertical; line-height: 1.55; }
.feedback-form button { min-height: 42px; border: 0; border-radius: 8px; color: #fff; background: var(--blue); font-weight: 600; }
.feedback-form button:disabled { opacity: .55; }
.feedback-status { min-height: 20px; margin: 0; color: var(--muted); font-size: 13px; }
.feedback-status.success { color: #137333; }
.feedback-status.error { color: #b3261e; }
.feedback-honeypot { position: absolute !important; left: -9999px !important; }

.help-footer {
  padding: 24px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  background: var(--soft);
  text-align: center;
  font-size: 12px;
}

@media (max-width: 760px) {
  .help-header { flex-wrap: wrap; padding: 8px 12px; }
  .help-brand img { max-width: 118px; height: 36px; }
  .help-header nav { max-width: 100%; overflow-x: auto; }
  .help-header nav a { min-height: 36px; padding: 0 9px; font-size: 12px; }
  .help-header nav a[data-help-language] { padding: 0; }
  .help-main { width: min(100% - 24px, 1180px); padding-top: 24px; }
  .help-hero { grid-template-columns: 1fr; gap: 18px; padding: 28px 22px; }
  .help-hero-visual { min-height: 150px; }
  .quick-links { grid-template-columns: 1fr; margin-bottom: 30px; }
  .guide-layout { grid-template-columns: 1fr; gap: 20px; }
  .guide-toc { position: static; grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .feature-grid { grid-template-columns: 1fr; }
  .flow-visual { grid-template-columns: 1fr; gap: 22px; }
  .flow-visual span:not(:last-child)::after { right: auto; bottom: -20px; content: "↓"; }
  .feedback-wrap { grid-template-columns: 1fr; gap: 20px; padding: 22px 14px; }
  .feedback-form { padding: 16px; }
}

@media (max-width:680px) {
 .help-hero { padding:24px 20px; gap:12px; }
 .help-hero-visual { min-height:0; height:88px; }
 .help-hero-visual img { width:auto; max-width:100%; height:88px; object-fit:contain; }
 .help-hero h1 { font-size:28px; line-height:1.3; }
}