:root {
  --ink: #172026;
  --muted: #64717c;
  --paper: #ffffff;
  --soft: #f5f7f7;
  --line: #dbe4e5;
  --blue: #0f3b8f;
  --teal: #0f766e;
  --gold: #d97706;
  --red: #b42318;
  --green: #15803d;
  --shadow: 0 18px 48px rgba(22, 34, 42, 0.1);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: linear-gradient(180deg, #f7faf9 0%, #eef4f2 48%, #f8fafc 100%);
  font-family: Inter, "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
}

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

button,
a {
  -webkit-tap-highlight-color: transparent;
}

.dh-topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  padding: 14px 28px;
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(16px);
}

.dh-brand {
  display: flex;
  gap: 10px;
  align-items: center;
  color: var(--ink);
  text-decoration: none;
}

.brand-mark {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  color: #fff;
  background: var(--blue);
  border-radius: 8px;
  font-weight: 800;
}

.dh-brand strong,
.dh-brand small {
  display: block;
}

.dh-brand small {
  margin-top: 2px;
  color: var(--muted);
  font-size: 12px;
}

.dh-nav {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.dh-nav a {
  color: var(--muted);
  text-decoration: none;
  font-weight: 700;
}

main {
  max-width: 1220px;
  margin: 0 auto;
  padding: 28px 22px 56px;
}

.hero-shell {
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(360px, 0.82fr);
  gap: 22px;
  align-items: stretch;
}

.hero-copy,
.hero-visual,
.workspace,
.strip,
.case-strip,
.order-panel,
.pricing article,
.input-panel,
.result-panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  box-shadow: var(--shadow);
}

.hero-copy {
  padding: 38px;
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.96), rgba(242, 248, 247, 0.94)),
    linear-gradient(120deg, rgba(15, 59, 143, 0.12), rgba(15, 118, 110, 0.1));
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--teal);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 780px;
  margin-bottom: 18px;
  font-size: 42px;
  line-height: 1.16;
  letter-spacing: 0;
}

.lead {
  max-width: 760px;
  color: #34434c;
  font-size: 17px;
  line-height: 1.8;
}

.lead-note {
  max-width: 760px;
  margin-top: -4px;
  padding: 10px 12px;
  color: #394952;
  border: 1px solid #dbe4e5;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.76);
  line-height: 1.65;
}

.hero-actions,
.form-actions,
.toolbar-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  align-items: center;
}

.button {
  display: inline-flex;
  min-height: 42px;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 10px 14px;
  color: var(--ink);
  background: #fff;
  text-decoration: none;
  cursor: pointer;
}

.button.primary {
  color: #fff;
  background: var(--blue);
  border-color: var(--blue);
}

.button.ghost {
  background: transparent;
}

.button.subtle {
  background: #eef6f4;
  color: #0b4d46;
  border-color: #cbe5df;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin: 28px 0 0;
}

.hero-stats div {
  padding: 12px;
  border: 1px solid #dce7e5;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.72);
}

.hero-stats dt {
  color: var(--blue);
  font-size: 24px;
  font-weight: 850;
}

.hero-stats dd {
  margin: 2px 0 0;
  color: var(--muted);
}

.hero-visual {
  margin: 0;
  overflow: hidden;
}

.hero-visual img {
  display: block;
  width: 100%;
  height: 360px;
  object-fit: cover;
  object-position: left top;
}

.hero-visual figcaption {
  padding: 14px 16px;
  color: var(--muted);
  font-size: 13px;
}

.strip {
  display: flex;
  justify-content: space-between;
  gap: 22px;
  align-items: center;
  margin: 22px 0;
  padding: 18px 20px;
}

.case-strip,
.order-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 0.72fr);
  gap: 18px;
  margin: 22px 0;
  padding: 22px;
}

.seo-guides,
.seo-page {
  margin: 22px 0;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  box-shadow: var(--shadow);
}

.section-heading {
  max-width: 760px;
  margin-bottom: 16px;
}

.section-heading h2 {
  margin-bottom: 8px;
  font-size: 28px;
}

.section-heading p {
  color: var(--muted);
  line-height: 1.7;
}

.guide-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 10px;
}

.guide-grid a {
  display: block;
  min-height: 142px;
  padding: 14px;
  color: var(--ink);
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfdfd;
}

.guide-grid strong,
.guide-grid span {
  display: block;
}

.guide-grid span {
  margin-top: 8px;
  color: var(--muted);
  line-height: 1.55;
}

.seo-hero {
  padding: 34px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: linear-gradient(135deg, #fff, #f3f8f7);
}

.seo-hero h1 {
  max-width: 900px;
  font-size: 38px;
}

.seo-hero .lead {
  max-width: 900px;
}

.seo-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 310px;
  gap: 18px;
  margin-top: 18px;
  align-items: start;
}

.seo-card,
.seo-toc {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.seo-card {
  margin-bottom: 14px;
}

.seo-card h2 {
  margin-bottom: 10px;
  font-size: 24px;
}

.seo-card p,
.seo-card li,
.seo-toc li {
  color: #34434c;
  line-height: 1.75;
}

.seo-card table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}

.seo-card th,
.seo-card td {
  padding: 10px;
  text-align: left;
  border: 1px solid var(--line);
  vertical-align: top;
}

.seo-card th {
  background: #f5f7f7;
}

.seo-toc {
  position: sticky;
  top: 84px;
}

.seo-toc strong {
  display: block;
  margin-bottom: 10px;
}

.seo-toc ul {
  display: grid;
  gap: 8px;
  margin: 0 0 14px;
  padding-left: 18px;
}

.seo-toc a {
  color: var(--blue);
  text-decoration: none;
}

.faq-item {
  border-top: 1px solid var(--line);
  padding-top: 12px;
  margin-top: 12px;
}

.case-strip h2,
.order-panel h2 {
  margin-bottom: 10px;
  font-size: 27px;
}

.case-strip p,
.order-panel p {
  color: #34434c;
  line-height: 1.75;
}

.case-strip ul {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.case-strip li,
.order-card {
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfdfd;
}

.case-strip li strong,
.case-strip li span {
  display: block;
}

.case-strip li span {
  margin-top: 4px;
  color: var(--muted);
  line-height: 1.55;
}

.order-card {
  align-self: start;
  background: #f8fbff;
}

.order-card strong {
  display: block;
  margin-bottom: 8px;
  color: var(--blue);
}

.strip strong,
.strip span {
  display: block;
}

.strip span {
  margin-top: 4px;
  color: var(--muted);
}

.strip ul {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: flex-end;
  margin: 0;
  padding: 0;
  list-style: none;
}

.strip li,
.status-pill,
.tag {
  border-radius: 999px;
  padding: 7px 10px;
  background: #edf7f4;
  color: #0b5d54;
  font-size: 13px;
  font-weight: 800;
}

.pricing {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
  margin: 22px 0;
}

.pricing article {
  padding: 18px;
}

.pricing .featured {
  border-color: rgba(15, 59, 143, 0.45);
  background: linear-gradient(180deg, #ffffff, #eef4ff);
}

.pricing p {
  margin-bottom: 8px;
  color: var(--muted);
  font-weight: 700;
}

.pricing strong {
  display: block;
  margin-bottom: 8px;
  color: var(--blue);
  font-size: 30px;
}

.pricing span {
  color: #41515a;
  line-height: 1.55;
}

.workspace {
  margin-top: 22px;
  padding: 22px;
}

.workspace-head {
  display: flex;
  justify-content: space-between;
  align-items: end;
  gap: 16px;
  margin-bottom: 16px;
}

.workspace-head h2 {
  margin-bottom: 0;
  font-size: 28px;
}

.tool-grid {
  display: grid;
  grid-template-columns: minmax(320px, 0.82fr) minmax(0, 1.18fr);
  gap: 16px;
  align-items: start;
}

.input-panel,
.result-panel {
  padding: 18px;
  box-shadow: none;
}

label {
  display: grid;
  gap: 7px;
  margin-bottom: 14px;
  color: #26343d;
  font-weight: 800;
}

input,
select,
textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 11px 12px;
  background: #fff;
  color: var(--ink);
}

textarea {
  resize: vertical;
  line-height: 1.65;
}

.result-panel {
  min-height: 740px;
}

.result-empty {
  display: grid;
  min-height: 520px;
  place-items: center;
  align-content: center;
  text-align: center;
  color: var(--muted);
}

.empty-icon {
  display: grid;
  width: 56px;
  height: 56px;
  margin-bottom: 14px;
  place-items: center;
  color: #fff;
  background: var(--teal);
  border-radius: 8px;
  font-size: 32px;
}

.hidden {
  display: none;
}

.result-toolbar {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: start;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.result-toolbar h3 {
  margin-bottom: 0;
}

.tabs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin: 16px 0;
}

.tabs button {
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 9px 12px;
  color: var(--muted);
  background: #fff;
  cursor: pointer;
}

.tabs button.active {
  color: #fff;
  background: var(--blue);
  border-color: var(--blue);
}

.tab-panel {
  display: none;
}

.tab-panel.active {
  display: block;
}

.section-block {
  margin-bottom: 14px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfdfd;
}

.section-block h4 {
  margin: 0 0 8px;
}

.section-block p,
.section-block li {
  color: #34434c;
  line-height: 1.7;
}

.plan-list,
.check-list {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.plan-list li,
.check-list li {
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.plan-level {
  display: inline-block;
  min-width: 36px;
  margin-right: 8px;
  color: #fff;
  text-align: center;
  border-radius: 999px;
  background: var(--gold);
  font-size: 12px;
  font-weight: 900;
}

.reply-box {
  border-left: 4px solid var(--blue);
  padding: 14px;
  background: #f3f7ff;
  border-radius: 0 8px 8px 0;
  white-space: pre-wrap;
  line-height: 1.75;
}

.site-preview {
  overflow: hidden;
  border: 1px solid #cfd8dc;
  border-radius: 8px;
  background: #fff;
}

.site-preview header {
  padding: 26px;
  color: #fff;
  background: linear-gradient(120deg, #0f3b8f, #0f766e);
}

.site-preview header h4 {
  margin: 0 0 8px;
  font-size: 26px;
}

.site-preview .preview-sections {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
  padding: 14px;
}

.site-preview article {
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f8fafc;
}

.dh-footer {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 22px 28px;
  color: var(--muted);
  border-top: 1px solid var(--line);
  background: #fff;
}

@media (max-width: 980px) {
  .hero-shell,
  .tool-grid,
  .pricing,
  .case-strip,
  .order-panel,
  .guide-grid,
  .seo-layout {
    grid-template-columns: 1fr;
  }

  .hero-visual img {
    height: 300px;
  }

  .strip,
  .workspace-head,
  .result-toolbar,
  .dh-footer {
    align-items: flex-start;
    flex-direction: column;
  }

  .site-preview .preview-sections,
  .hero-stats {
    grid-template-columns: 1fr;
  }

  .seo-toc {
    position: static;
  }
}

@media (max-width: 640px) {
  .dh-topbar {
    align-items: flex-start;
    flex-direction: column;
    padding: 14px 18px;
  }

  main {
    padding: 18px 12px 42px;
  }

  h1 {
    font-size: 31px;
  }

  .hero-copy,
  .workspace {
    padding: 20px;
  }
}