/* ===== HTX Skill Hub — design tokens (matches www.htx.com) ===== */
:root {
  --Background-L1: #ffffff;
  --Background-L2: #f6f6f6;
  --Background-L3: #f3f3f3;
  --Background-L1-dim: #fafafa;
  --Text-L1: #000000;
  --Text-L2: #595959;
  --Text-L3: #8c8c8c;
  --Text-L4: #b3b3b3;
  --Border-L1: #dddddd;
  --Border-L2: #ebebeb;
  --Functional-Blue: #007fff;
  --Functional-Blue-dark: #0173e5;
  --Functional-Green: #07b067;
  --Functional-Red: #f24966;
  --Functional-Orange: #fe8731;
  --radius-card: 16px;
  --radius-section: 24px;
  --radius-sm: 8px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--Background-L1);
  color: var(--Text-L1);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB',
               'Microsoft YaHei', sans-serif;
  font-size: 14px;
  line-height: 1.5;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--Functional-Blue); text-decoration: none; }
a:hover { color: var(--Functional-Blue-dark); }

code, pre {
  font-family: 'SF Mono', 'Consolas', 'Menlo', monospace;
  font-size: 13px;
}
code {
  background: var(--Background-L2);
  padding: 2px 6px;
  border-radius: 4px;
  color: var(--Text-L1);
}

/* ===== HTX main-site nav (black bar, mirrors www.htx.com) ===== */
.htx-nav {
  background: #000;
  height: 56px;
  display: flex; align-items: center;
  border-bottom: 1px solid #1a1a1a;
}
.htx-nav-inner {
  width: 100%;
  padding: 0 24px;
  display: flex; align-items: center; gap: 16px;
  color: #fff;
}
.htx-nav-logo {
  display: flex; align-items: center; gap: 6px;
  color: #fff; font-size: 18px; font-weight: 700;
  flex-shrink: 0;
}
.htx-nav-logo:hover { color: #fff; }
.htx-nav-logo-flame {
  width: 22px; height: 22px;
  background: linear-gradient(135deg, #ff7a30 0%, #ff3b30 100%);
  border-radius: 50% 50% 50% 0;
  transform: rotate(-10deg);
  flex-shrink: 0;
}
.htx-nav-menu {
  display: flex; align-items: center; gap: 6px;
  margin-left: 12px;
  flex-shrink: 0;
}
.htx-nav-menu a {
  display: flex; align-items: center; gap: 4px;
  padding: 8px 12px;
  font-size: 14px;
  color: #d8d8d8;
  white-space: nowrap;
  border-radius: 4px;
}
.htx-nav-menu a i {
  display: inline-block;
  width: 0; height: 0;
  border-left: 4px solid transparent;
  border-right: 4px solid transparent;
  border-top: 4px solid #888;
  margin-left: 2px;
}
.htx-nav-menu a:hover { color: #fff; background: #1a1a1a; }
.htx-nav-search {
  flex: 1;
  max-width: 360px;
  height: 36px;
  padding: 0 14px;
  background: #1a1a1a;
  border-radius: 6px;
  display: flex; align-items: center; gap: 8px;
  color: #888;
  font-size: 13px;
  margin-left: auto;
}
.htx-nav-search-icon { font-size: 13px; opacity: 0.6; }
.htx-nav-actions {
  display: flex; align-items: center; gap: 14px;
  flex-shrink: 0;
}
.htx-nav-login { color: #fff; font-size: 14px; }
.htx-nav-login:hover { color: var(--Functional-Blue); }
.htx-nav-register {
  background: var(--Functional-Blue);
  color: #fff; font-size: 14px; font-weight: 500;
  padding: 7px 18px;
  border-radius: 6px;
}
.htx-nav-register:hover { background: var(--Functional-Blue-dark); color: #fff; }
.htx-nav-icon {
  color: #aaa; font-size: 16px;
  cursor: pointer;
  padding: 4px;
}
.htx-nav-icon:hover { color: #fff; }

/* ===== Hero ===== */
.hero {
  position: relative;
  padding: 90px 16px 200px;
  text-align: center;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  bottom: 0; left: 50%;
  transform: translateX(-50%);
  width: 1921px; height: 425px;
  background: radial-gradient(ellipse at center, rgba(0, 127, 255, 0.08) 0%, transparent 60%);
  pointer-events: none;
  z-index: 0;
}
.hero-inner {
  position: relative;
  z-index: 1;
  display: flex; flex-direction: column; align-items: center;
  gap: 16px;
  max-width: 1200px; margin: 0 auto;
}
.hero h1 {
  margin: 0;
  font-size: 72px;
  font-weight: 700;
  line-height: 1.213em;
  color: var(--Text-L1);
  letter-spacing: -1px;
}
.hero h1 .accent { color: var(--Functional-Blue); }
.hero .subtitle {
  margin: 0;
  font-size: 18px;
  line-height: 1.7;
  color: var(--Text-L2);
  max-width: 920px;
  font-weight: 400;
}

/* ===== Skill capability area ===== */
.skill-capability-area {
  max-width: 1200px;
  margin: -30px auto 120px;
  padding: 48px 40px;
  border: 1px solid var(--Border-L2);
  border-radius: var(--radius-section);
  background: var(--Background-L1);
  position: relative;
  z-index: 1;
  display: flex; flex-direction: column;
  gap: 32px;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.04);
}

/* Filter tabs */
.filter-bar {
  display: flex; gap: 8px; align-items: center;
  flex-wrap: wrap;
}
.filter-tab {
  padding: 7px 16px;
  border-radius: 99px;
  font-size: 13px; font-weight: 500;
  background: var(--Background-L2);
  border: 1px solid transparent;
  color: var(--Text-L2);
  cursor: pointer;
  transition: all 0.15s;
  font-family: inherit;
}
.filter-tab:hover {
  color: var(--Text-L1);
  background: var(--Background-L3);
}
.filter-tab.active {
  background: var(--Functional-Blue);
  color: #fff;
}
.filter-tab .count {
  font-size: 12px;
  margin-left: 6px;
  opacity: 0.75;
}

/* Capability grid */
.capability-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  border-radius: var(--radius-card);
  overflow: hidden;
}
.capability-card {
  display: flex; flex-direction: column;
  gap: 16px;
  padding: 24px;
  background: var(--Background-L2);
  cursor: pointer;
  transition: background 0.2s;
  text-align: left;
  color: inherit;
  font: inherit;
  min-width: 0;
  text-decoration: none;
}
.capability-card:hover { background: var(--Background-L3); }
.capability-head {
  display: flex; align-items: flex-start; gap: 12px;
}
.capability-icon {
  width: 40px; height: 40px;
  background: #fff;
  border: 1px solid var(--Border-L2);
  border-radius: 10px;
  display: grid; place-items: center;
  font-size: 20px;
  flex-shrink: 0;
}
.capability-title-wrap { flex: 1; min-width: 0; }
.capability-title {
  margin: 0;
  font-size: 18px;
  line-height: 24px;
  font-weight: 500;
  color: var(--Text-L1);
}
.capability-desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.6;
  color: var(--Text-L3);
}

/* ===== Detail page ===== */
.detail-wrap {
  max-width: 1080px; margin: 0 auto;
  padding: 32px 24px 80px;
}
.breadcrumb {
  font-size: 13px; color: var(--Text-L3);
  margin-bottom: 20px;
}
.breadcrumb a { color: var(--Text-L3); }
.breadcrumb a:hover { color: var(--Functional-Blue); }

.d-hero {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 28px;
  padding: 32px;
  background: linear-gradient(135deg, #f6faff 0%, #f0f5fb 100%);
  border: 1px solid var(--Border-L2);
  border-radius: var(--radius-section);
  margin-bottom: 24px;
}
.d-hero-left { display: flex; gap: 18px; }
.d-hero-icon {
  width: 64px; height: 64px;
  background: #fff;
  border: 1px solid var(--Border-L2);
  border-radius: 16px;
  display: grid; place-items: center;
  font-size: 32px;
  flex-shrink: 0;
}
.d-hero-meta { flex: 1; min-width: 0; }
.d-hero-tag {
  display: inline-block;
  font-size: 12px;
  padding: 3px 10px;
  background: rgba(0, 127, 255, 0.1);
  color: var(--Functional-Blue);
  border-radius: 99px;
  font-weight: 500;
  margin-bottom: 10px;
}
.d-hero-title {
  margin: 0 0 10px;
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.5px;
  color: var(--Text-L1);
}
.d-hero-desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--Text-L2);
}

.d-install {
  background: #fff;
  border: 1px solid var(--Border-L2);
  border-radius: var(--radius-card);
  padding: 18px;
  display: flex; flex-direction: column;
  gap: 12px;
}
.d-install-label {
  font-size: 12px;
  color: var(--Text-L3);
  font-weight: 500;
  letter-spacing: 0.4px;
  text-transform: uppercase;
}
.d-install-cmd {
  background: var(--Background-L2);
  border-radius: 8px;
  padding: 10px 12px;
  display: flex; align-items: center; gap: 10px;
}
.d-install-cmd code {
  flex: 1;
  background: transparent;
  padding: 0;
  font-size: 12px;
  color: var(--Text-L1);
  white-space: nowrap;
  overflow-x: auto;
  font-family: 'SF Mono', 'Consolas', monospace;
}
.d-install-cmd code::-webkit-scrollbar { display: none; }
.d-install-cmd .copy-btn {
  flex-shrink: 0;
  padding: 5px 14px;
  background: var(--Functional-Blue);
  color: #fff;
  border: none;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 500;
  cursor: pointer;
  font-family: inherit;
}
.d-install-cmd .copy-btn:hover { background: var(--Functional-Blue-dark); }
.d-install-link {
  font-size: 13px;
  color: var(--Functional-Blue);
  font-weight: 500;
}

.d-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-bottom: 32px;
}
.d-stat {
  display: flex; align-items: center; gap: 12px;
  padding: 16px 18px;
  background: var(--Background-L2);
  border-radius: var(--radius-card);
}
.d-stat-icon {
  font-size: 22px;
  width: 40px; height: 40px;
  background: #fff;
  border-radius: 10px;
  display: grid; place-items: center;
  flex-shrink: 0;
}
.d-stat-label { font-size: 12px; color: var(--Text-L3); }
.d-stat-value {
  font-size: 14px; font-weight: 600; color: var(--Text-L1);
  margin-top: 2px;
}

.d-block { margin-bottom: 36px; }
.d-block-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--Text-L1);
  margin: 0 0 8px;
  display: flex; align-items: center; gap: 10px;
}
.d-block-title::before {
  content: '';
  width: 3px; height: 18px;
  background: var(--Functional-Blue);
  border-radius: 2px;
}
.d-block-sub {
  font-size: 13px; color: var(--Text-L3);
  margin: 0 0 16px;
}

.d-bubbles {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.bubble {
  display: flex; align-items: flex-start; gap: 10px;
  padding: 14px 16px;
  background: var(--Background-L2);
  border-radius: var(--radius-card);
  border-left: 3px solid var(--Functional-Blue);
}
.bubble-avatar {
  width: 28px; height: 28px;
  background: #fff;
  border-radius: 50%;
  display: grid; place-items: center;
  font-size: 14px;
  flex-shrink: 0;
}
.bubble-text { font-size: 14px; line-height: 1.5; color: var(--Text-L1); }

.d-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}
.d-step {
  display: flex; gap: 14px;
  padding: 20px;
  background: var(--Background-L2);
  border-radius: var(--radius-card);
}
.d-step-num {
  width: 32px; height: 32px;
  background: var(--Functional-Blue);
  color: #fff;
  border-radius: 50%;
  display: grid; place-items: center;
  font-weight: 700;
  font-size: 14px;
  flex-shrink: 0;
}
.d-step-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--Text-L1);
  margin-bottom: 4px;
}
.d-step-desc {
  font-size: 13px;
  color: var(--Text-L3);
  line-height: 1.6;
}

.d-cta { padding: 24px 28px; background: var(--Background-L2); border-radius: var(--radius-section); }
.d-cta-row {
  display: flex; gap: 10px;
  margin-top: 14px;
  flex-wrap: wrap;
}

.btn {
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  font-size: 14px; font-weight: 500;
  cursor: pointer; border: none;
  display: inline-flex; align-items: center; gap: 8px;
  transition: all 0.15s;
  font-family: inherit;
  text-decoration: none;
}
.btn-primary { background: var(--Functional-Blue); color: #fff; }
.btn-primary:hover { background: var(--Functional-Blue-dark); color: #fff; }
.btn-secondary {
  background: var(--Background-L2);
  border: 1px solid var(--Border-L2);
  color: var(--Text-L1);
}
.btn-secondary:hover {
  background: var(--Background-L3);
  border-color: var(--Border-L1);
}

.tag-cloud { display: flex; gap: 6px; flex-wrap: wrap; }
.tag {
  font-size: 12px; padding: 4px 10px;
  background: var(--Background-L2);
  border: 1px solid var(--Border-L2);
  border-radius: 99px;
  color: var(--Text-L2);
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 12px;
}
.related-card {
  padding: 14px 16px;
  background: var(--Background-L2);
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  font-size: 13px;
  color: var(--Text-L2);
  display: flex; align-items: center; gap: 12px;
  text-decoration: none;
  transition: background 0.15s;
}
.related-card:hover { background: var(--Background-L3); color: var(--Text-L1); }
.related-card .icon { font-size: 22px; flex-shrink: 0; }
.related-card b { color: var(--Text-L1); font-weight: 600; display: block; font-size: 14px; margin-bottom: 2px; }
.related-card small { color: var(--Text-L3); font-size: 12px; }

/* ===== FAQ ===== */
.faq-section {
  max-width: 1200px;
  margin: 80px auto 80px;
  padding: 0 40px;
}
.faq-title {
  font-size: 28px;
  font-weight: 700;
  margin: 0 0 28px;
  color: var(--Text-L1);
  text-align: center;
}
.faq-list {
  display: flex; flex-direction: column;
  gap: 12px;
}
.faq-item {
  background: var(--Background-L2);
  border-radius: var(--radius-card);
  overflow: hidden;
  transition: background 0.15s;
}
.faq-item[open] { background: var(--Background-L3); }
.faq-q {
  display: flex; align-items: center; justify-content: space-between;
  padding: 20px 24px;
  font-size: 16px;
  font-weight: 500;
  color: var(--Text-L1);
  cursor: pointer;
  list-style: none;
  user-select: none;
}
.faq-q::-webkit-details-marker { display: none; }
.faq-icon {
  width: 16px; height: 16px;
  position: relative;
  flex-shrink: 0;
}
.faq-icon::before, .faq-icon::after {
  content: '';
  position: absolute;
  left: 50%; top: 50%;
  width: 12px; height: 2px;
  background: var(--Text-L2);
  transform-origin: center;
}
.faq-icon::before { transform: translate(-50%, -50%); }
.faq-icon::after  { transform: translate(-50%, -50%) rotate(90deg); transition: transform 0.2s; }
.faq-item[open] .faq-icon::after { transform: translate(-50%, -50%) rotate(0deg); }
.faq-a {
  padding: 0 24px 22px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--Text-L2);
}

/* ===== Footer ===== */
.footer {
  border-top: 1px solid var(--Border-L2);
  padding: 32px 24px;
  text-align: center;
  color: var(--Text-L3);
  font-size: 13px;
  margin-top: 60px;
  background: var(--Background-L1-dim);
}
.footer a { color: var(--Text-L2); margin: 0 12px; }
.footer a:hover { color: var(--Functional-Blue); }

/* ===== Mobile ===== */
@media (max-width: 1000px) {
  .hero { padding: 48px 16px 80px; }
  .hero h1 { font-size: 32px; line-height: 1.213em; }
  .hero .subtitle { font-size: 14px; line-height: 1.429em; }
  .skill-capability-area {
    margin: 0 16px 48px;
    padding: 24px 16px;
    border-radius: var(--radius-card);
  }
  .capability-grid { grid-template-columns: 1fr; gap: 12px; }
  .capability-card { padding: 20px 16px; border-radius: var(--radius-card); }
  .capability-title { font-size: 16px; line-height: 22px; }
  .htx-nav-menu, .htx-nav-search, .htx-nav-icon { display: none; }
  .htx-nav-actions { gap: 10px; }
  .d-hero { grid-template-columns: 1fr; padding: 20px; gap: 18px; }
  .d-hero-left { flex-direction: column; gap: 14px; }
  .d-hero-icon { width: 48px; height: 48px; font-size: 24px; }
  .d-hero-title { font-size: 22px; }
  .d-stats { grid-template-columns: 1fr; }
  .d-bubbles, .d-steps { grid-template-columns: 1fr; }
  .related-grid { grid-template-columns: 1fr; }
  .faq-section { padding: 0 16px; margin: 48px auto 60px; }
  .faq-title { font-size: 22px; }
  .faq-q { font-size: 15px; padding: 16px 18px; }
  .faq-a { padding: 0 18px 18px; }
}