:root {
  color-scheme: light;
  --bg: #f5f3ee;
  --panel: #fffdf8;
  --ink: #1d1c18;
  --muted: #6b665c;
  --line: #d8d2c6;
  --accent: #23685a;
  --accent-dark: #16483e;
  --soft: #e8eee8;
  --shadow: 0 24px 70px rgba(60, 54, 42, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  background:
    linear-gradient(120deg, rgba(35, 104, 90, 0.1), transparent 32rem),
    var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.6;
}

a {
  color: inherit;
  text-decoration: none;
}

.site-header,
main,
footer {
  width: min(1120px, calc(100% - 36px));
  margin: 0 auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px 0 12px;
}

.brand {
  font-size: 18px;
  font-weight: 800;
  letter-spacing: 0.08em;
}

nav {
  display: flex;
  gap: 18px;
  color: var(--muted);
  font-size: 14px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(280px, 0.7fr);
  gap: 28px;
  align-items: stretch;
  padding: 56px 0 42px;
}

.hero-copy,
.hero-panel,
.workspace,
.seo-notes,
.keyword-section,
.faq-section {
  border: 1px solid var(--line);
  background: rgba(255, 253, 248, 0.82);
  box-shadow: var(--shadow);
}

.hero-copy {
  min-height: 420px;
  padding: clamp(28px, 5vw, 60px);
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

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

h1 {
  margin-bottom: 18px;
  font-size: clamp(48px, 9vw, 96px);
  line-height: 0.95;
  letter-spacing: 0;
}

.hero-text {
  max-width: 620px;
  margin-bottom: 28px;
  color: var(--muted);
  font-size: clamp(17px, 2vw, 22px);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.button,
.copy-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border: 1px solid var(--ink);
  border-radius: 999px;
  font: inherit;
  font-weight: 750;
  cursor: pointer;
}

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

.button.ghost,
.copy-button {
  background: transparent;
  color: var(--ink);
}

.button:active,
.copy-button:active,
.tool-tab:active {
  transform: translateY(1px);
}

.hero-panel {
  padding: 26px;
  display: grid;
  align-content: center;
  gap: 12px;
}

.hero-panel span {
  display: block;
  padding: 16px 18px;
  border: 1px solid var(--line);
  background: var(--soft);
  font-weight: 750;
}

.workspace,
.seo-notes,
.keyword-section,
.faq-section {
  margin: 22px 0;
  padding: clamp(22px, 4vw, 36px);
}

.section-heading {
  max-width: 760px;
  margin-bottom: 24px;
}

.section-heading h2,
.seo-notes h2,
.keyword-section h2,
.faq-section h2 {
  margin-bottom: 10px;
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1.08;
}

.section-heading p,
.seo-notes > p,
.keyword-section > p {
  color: var(--muted);
}

.tool-layout {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 18px;
}

.tool-tabs {
  display: grid;
  align-content: start;
  gap: 10px;
}

.tool-tab {
  width: 100%;
  min-height: 46px;
  padding: 0 14px;
  border: 1px solid var(--line);
  background: #faf7ef;
  color: var(--muted);
  text-align: left;
  font: inherit;
  font-weight: 750;
  cursor: pointer;
}

.tool-tab.active {
  border-color: var(--accent);
  background: var(--accent);
  color: #fff;
}

.tool-form,
.output-card {
  border: 1px solid var(--line);
  background: var(--panel);
  padding: 22px;
}

.form-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

label {
  display: grid;
  gap: 8px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 700;
}

label.wide {
  grid-column: 1 / -1;
}

input,
select,
textarea {
  width: 100%;
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
  font: inherit;
  font-weight: 500;
  padding: 12px 13px;
  outline: none;
}

textarea {
  resize: vertical;
}

input:focus,
select:focus,
textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(35, 104, 90, 0.16);
}

.generate-button {
  margin-top: 18px;
}

.output-card {
  grid-column: 2;
}

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

.output-head h2 {
  margin-bottom: 0;
}

pre {
  min-height: 260px;
  margin: 0;
  padding: 18px;
  overflow: auto;
  border: 1px solid var(--line);
  background: #f8f5ee;
  color: var(--ink);
  white-space: pre-wrap;
  font: 15px/1.75 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

.note-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 12px;
}

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

.note-grid article,
.keyword-grid article {
  min-height: 210px;
  padding: 18px;
  border: 1px solid var(--line);
  background: #faf7ef;
}

.note-grid h3,
.keyword-grid h3 {
  margin-bottom: 10px;
  font-size: 18px;
  line-height: 1.25;
}

.note-grid p,
.keyword-grid p,
.faq-section p {
  color: var(--muted);
  font-size: 14px;
}

.faq-section details {
  border-top: 1px solid var(--line);
  padding: 18px 0;
}

.faq-section details:last-child {
  border-bottom: 1px solid var(--line);
}

.faq-section summary {
  color: var(--ink);
  cursor: pointer;
  font-size: 18px;
  font-weight: 850;
}

.faq-section details p {
  max-width: 760px;
  margin: 12px 0 0;
}

footer {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 32px 0 44px;
  color: var(--muted);
  font-size: 14px;
}

footer a {
  color: var(--accent-dark);
  font-weight: 800;
}

@media (max-width: 900px) {
  .hero,
  .tool-layout {
    grid-template-columns: 1fr;
  }

  .hero-copy {
    min-height: auto;
  }

  .tool-tabs {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .output-card {
    grid-column: auto;
  }

  .note-grid,
  .keyword-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 620px) {
  .site-header,
  main,
  footer {
    width: min(100% - 24px, 1120px);
  }

  .site-header,
  footer {
    align-items: flex-start;
    flex-direction: column;
  }

  .hero {
    padding-top: 28px;
  }

  .form-grid,
  .tool-tabs,
  .note-grid,
  .keyword-grid {
    grid-template-columns: 1fr;
  }

  .button,
  .copy-button {
    width: 100%;
  }

  .output-head {
    flex-direction: column;
  }
}