:root {
  --bg: #f7f9fc;
  --surface: #ffffff;
  --surface-soft: #eef4f8;
  --text: #152238;
  --muted: #60708a;
  --line: #d9e2ec;
  --green: #10a37f;
  --blue: #2166f3;
  --amber: #f2a51a;
  --ink: #101828;
  --shadow: 0 18px 48px rgba(22, 34, 51, 0.11);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "Microsoft YaHei", sans-serif;
  line-height: 1.6;
}

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

code,
pre {
  font-family: "JetBrains Mono", "SFMono-Regular", Consolas, monospace;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 68px;
  padding: 0 32px;
  border-bottom: 1px solid rgba(217, 226, 236, 0.8);
  background: rgba(247, 249, 252, 0.88);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 750;
  color: var(--ink);
}

.brand-mark {
  display: inline-grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: 8px;
  background: var(--ink);
  color: #fff;
  font-size: 13px;
  letter-spacing: 0;
}

.top-nav {
  display: flex;
  gap: 22px;
  color: var(--muted);
  font-size: 14px;
}

.top-nav a:hover {
  color: var(--blue);
}

.hero {
  position: relative;
  display: flex;
  align-items: center;
  min-height: 720px;
  overflow: hidden;
  padding: 96px 32px 72px;
  background: #0b1220;
  color: #fff;
}

.hero::after {
  position: absolute;
  inset: 0;
  content: "";
  background: linear-gradient(
    90deg,
    rgba(8, 14, 25, 0.94) 0%,
    rgba(8, 14, 25, 0.82) 44%,
    rgba(8, 14, 25, 0.44) 100%
  );
}

.hero-backdrop {
  position: absolute;
  inset: 0;
  background-image: url("./assets/agent-dashboard.png");
  background-position: center right;
  background-size: cover;
  opacity: 0.82;
  transform: scale(1.02);
}

.hero-content,
.section,
.cta-section,
.site-footer {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
}

.hero-content {
  position: relative;
  z-index: 1;
  padding: 32px 0;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--green);
  font-size: 13px;
  font-weight: 760;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

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

h1 {
  max-width: 760px;
  margin-bottom: 18px;
  color: var(--ink);
  font-size: clamp(40px, 6vw, 72px);
  line-height: 1.04;
  letter-spacing: 0;
}

.hero h1,
.hero .subtitle {
  color: #fff;
}

.hero .eyebrow {
  color: #7ee0c3;
}

h2 {
  margin-bottom: 14px;
  color: var(--ink);
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1.14;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 10px;
  color: var(--ink);
  font-size: 20px;
  line-height: 1.25;
}

.subtitle {
  margin-bottom: 12px;
  color: var(--ink);
  font-size: 22px;
  font-weight: 700;
}

.hero-text {
  max-width: 720px;
  color: #d8e6f7;
  font-size: 18px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 8px;
  font-weight: 720;
  border: 1px solid transparent;
}

.button.primary {
  background: var(--blue);
  color: #fff;
  box-shadow: 0 10px 22px rgba(33, 102, 243, 0.22);
}

.button.secondary {
  border-color: var(--line);
  background: #fff;
  color: var(--ink);
}

.hero .button.secondary {
  border-color: rgba(255, 255, 255, 0.26);
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
  backdrop-filter: blur(12px);
}

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 28px;
}

.tag-row span,
.guardrail-grid span {
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.82);
  padding: 7px 11px;
  color: #3b4b63;
  font-size: 13px;
  font-weight: 650;
}

.hero .tag-row span {
  border-color: rgba(255, 255, 255, 0.22);
  background: rgba(255, 255, 255, 0.12);
  color: #f8fbff;
  backdrop-filter: blur(10px);
}

.hero-proof {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  max-width: 760px;
  margin-top: 30px;
}

.hero-proof span {
  display: inline-flex;
  align-items: center;
  min-height: 38px;
  padding: 0 14px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.09);
  color: #e9f3ff;
  font-weight: 720;
  backdrop-filter: blur(12px);
}

.section {
  padding: 72px 0;
}

.section-heading {
  max-width: 820px;
  margin-bottom: 30px;
}

.problem-grid,
.output-grid,
.case-grid,
.boundary-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.problem-grid article,
.input-card,
.output-card,
.case-card,
.usage-steps article,
.boundary-grid article,
.prompt-box {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: 0 10px 26px rgba(22, 34, 51, 0.06);
}

.problem-grid article,
.input-card,
.output-card,
.case-card,
.usage-steps article,
.boundary-grid article {
  padding: 24px;
}

.check-list,
.output-card ul,
.case-card ul {
  padding-left: 18px;
  margin: 14px 0 0;
  color: #43546c;
}

.check-list li,
.output-card li,
.case-card li {
  margin: 8px 0;
}

.timeline {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
}

.step-card {
  display: grid;
  place-items: center;
  min-height: 76px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  text-align: center;
  color: #314158;
  font-weight: 700;
}

.step-card.highlight {
  border-color: rgba(33, 102, 243, 0.35);
  background: #edf4ff;
  color: #174ea6;
}

.step-card.wide {
  grid-column: span 2;
  background: #eff8f4;
  color: #0b6b55;
}

.input-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 42px;
  height: 30px;
  border-radius: 999px;
  background: var(--surface-soft);
  color: var(--blue);
  font-weight: 760;
  margin-bottom: 18px;
}

.callout {
  margin-top: 18px;
  padding: 18px 20px;
  border-left: 4px solid var(--green);
  border-radius: 8px;
  background: #eff8f4;
  color: #124b3d;
  font-weight: 690;
}

.output-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.icon-box {
  display: inline-grid;
  place-items: center;
  min-width: 50px;
  height: 40px;
  padding: 0 10px;
  border-radius: 8px;
  background: var(--ink);
  color: #fff;
  font-weight: 800;
  margin-bottom: 18px;
}

.case-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.case-card.featured {
  border-color: rgba(33, 102, 243, 0.4);
  background: #f4f8ff;
}

.case-label {
  color: var(--blue);
  font-size: 12px;
  font-weight: 800;
  text-transform: uppercase;
}

.case-type {
  color: var(--muted);
  font-weight: 650;
}

.guardrail-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

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

.usage-steps span {
  color: var(--green);
  font-weight: 820;
}

.prompt-box {
  margin-top: 18px;
  overflow: hidden;
}

.prompt-title {
  padding: 14px 18px;
  border-bottom: 1px solid var(--line);
  background: #fbfdff;
  color: var(--ink);
  font-weight: 780;
}

.prompt-box pre {
  margin: 0;
  padding: 18px;
  overflow-x: auto;
  color: #2c3d55;
  background: #fff;
  font-size: 13px;
  line-height: 1.6;
}

.boundary-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.cta-section {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  align-items: center;
  margin-bottom: 72px;
  padding: 36px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--ink);
  color: #dce8f5;
  box-shadow: var(--shadow);
}

.cta-section h2 {
  color: #fff;
}

.cta-section .button.secondary {
  background: transparent;
  color: #fff;
  border-color: rgba(255, 255, 255, 0.24);
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 28px 0 44px;
  color: var(--muted);
  border-top: 1px solid var(--line);
  font-size: 14px;
}

@media (max-width: 960px) {
  .problem-grid,
  .input-grid,
  .output-grid,
  .case-grid,
  .boundary-grid,
  .usage-steps {
    grid-template-columns: 1fr;
  }

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

  .hero {
    padding-top: 46px;
  }

  .cta-section {
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (max-width: 680px) {
  .site-header {
    position: static;
    padding: 14px 18px;
    align-items: flex-start;
    gap: 12px;
    flex-direction: column;
  }

  .top-nav {
    flex-wrap: wrap;
    gap: 12px;
  }

  .hero-content,
  .section,
  .cta-section,
  .site-footer {
    width: min(100% - 28px, 1180px);
  }

  .timeline {
    grid-template-columns: 1fr;
  }

  .step-card.wide {
    grid-column: span 1;
  }

  .site-footer {
    flex-direction: column;
  }
}