:root {
  --panel: rgba(255, 249, 242, 0.75);
  --ink: #221b18;
  --muted: #63554e;
  --accent-3: #1773b0;
  --allow: #38c786;
  --reject: #e06257;
  --incoming: #f3c060;
  --shadow: 0 20px 60px rgba(109, 60, 23, 0.14);
  --radius: 24px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "Manrope", sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at top left, rgba(168, 214, 255, 0.4), transparent 28%),
    radial-gradient(circle at 85% 15%, rgba(63, 173, 122, 0.14), transparent 25%),
    linear-gradient(180deg, #fff9f2 0%, #f4efe8 36%, #eef4f8 100%);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.35;
  background-image:
    linear-gradient(rgba(34, 27, 24, 0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(34, 27, 24, 0.02) 1px, transparent 1px);
  background-size: 28px 28px;
}

.page-shell {
  width: min(1500px, calc(100% - 48px));
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.hero { min-height: 100vh; padding: 24px 0 60px; }

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 18px;
  margin-bottom: 42px;
  padding: 10px 12px 10px 18px;
  border: 1px solid rgba(34, 27, 24, 0.08);
  border-radius: 999px;
  background: rgba(255, 252, 247, 0.68);
  backdrop-filter: blur(18px);
  box-shadow: 0 18px 48px rgba(109, 60, 23, 0.1);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-weight: 800;
  margin-right: auto;
}

.brand-mark {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent-3), #6dbdff);
  box-shadow: inset 0 0 0 8px rgba(255, 255, 255, 0.46), 0 10px 20px rgba(23, 115, 176, 0.18);
}

.nav-group {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  justify-content: flex-end;
  padding: 5px;
  border: 1px solid rgba(34, 27, 24, 0.07);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.48);
}
.nav-pill, .cta { text-decoration: none; color: inherit; }

.nav-pill {
  border: 1px solid transparent;
  padding: 10px 16px;
  border-radius: 999px;
  background: transparent;
  font-weight: 700;
  transition: transform 180ms ease, background 180ms ease, border-color 180ms ease, box-shadow 180ms ease;
}

.nav-pill:hover,
.nav-pill:focus-visible {
  transform: translateY(-1px);
  border-color: rgba(23, 115, 176, 0.18);
  background: rgba(255, 255, 255, 0.86);
  box-shadow: 0 10px 22px rgba(109, 60, 23, 0.1);
  outline: none;
}

.button-pill { font: inherit; cursor: pointer; }

.back-button {
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  width: 50px;
  height: 50px;
  border: 2px solid rgba(23, 115, 176, 0.28);
  border-radius: 999px;
  background: linear-gradient(135deg, var(--accent-3), #6dbdff);
  color: #fffaf3;
  font: inherit;
  cursor: pointer;
  box-shadow: 0 16px 28px rgba(23, 115, 176, 0.24), inset 0 0 0 1px rgba(255, 255, 255, 0.28);
  transition: transform 180ms ease, background 180ms ease, box-shadow 180ms ease;
}

.back-icon {
  position: relative;
  display: block;
  width: 20px;
  height: 14px;
}

.back-icon::before,
.back-icon::after {
  content: "";
  position: absolute;
  left: 1px;
}

.back-icon::before {
  top: 5px;
  width: 18px;
  height: 3px;
  border-radius: 999px;
  background: currentColor;
}

.back-icon::after {
  top: 2px;
  width: 9px;
  height: 9px;
  border-left: 3px solid currentColor;
  border-bottom: 3px solid currentColor;
  transform: rotate(45deg);
}

.back-button:hover,
.back-button:focus-visible {
  transform: translateX(-2px) scale(1.04);
  background: linear-gradient(135deg, #0f659d, var(--accent-3));
  color: #fffaf3;
  box-shadow: 0 18px 34px rgba(23, 115, 176, 0.3), inset 0 0 0 1px rgba(255, 255, 255, 0.34);
  outline: none;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.08fr 0.92fr;
  gap: 36px;
  align-items: center;
}

.eyebrow {
  margin: 0 0 12px;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: 0.8rem;
  color: var(--accent-3);
  font-weight: 800;
}

.hero-copy h1, .section-heading h2 {
  margin: 0;
  font-family: "DM Serif Display", serif;
  letter-spacing: 0;
  line-height: 0.98;
}

.hero-copy h1 { font-size: clamp(2.8rem, 5.6vw, 4.8rem); max-width: 9ch; }

.hero-text {
  margin: 24px 0 0;
  font-size: 1.08rem;
  line-height: 1.75;
  max-width: 60ch;
  color: var(--muted);
}

.hero-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  margin-top: 28px;
}

.cta {
  padding: 14px 20px;
  border-radius: 999px;
  font-weight: 800;
}

.cta.primary {
  background: linear-gradient(135deg, var(--accent-3), #6dbdff);
  color: #fffdf9;
  box-shadow: 0 18px 28px rgba(23, 115, 176, 0.22);
}

.cta.secondary {
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid rgba(34, 27, 24, 0.08);
}

.hero-metrics {
  margin-top: 36px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.hero-metrics article,
.panel,
.info-card,
.timeline-step,
.algorithm-card {
  background: var(--panel);
  backdrop-filter: blur(16px);
  border: 1px solid rgba(255, 255, 255, 0.42);
  box-shadow: var(--shadow);
}

.hero-metrics article { padding: 18px; border-radius: 18px; }
.hero-metrics strong { display: block; font-size: 1.55rem; }
.hero-metrics span,
.info-card p,
.algorithm-copy p,
.timeline-step p,
.compiler-note,
.visual-note { color: var(--muted); line-height: 1.7; }

.visual-card {
  background: rgba(34, 27, 24, 0.96);
  color: #fffaf3;
  border-radius: 30px;
  padding: 18px;
  box-shadow: 0 28px 80px rgba(34, 27, 24, 0.26);
  position: relative;
  overflow: hidden;
}

.visual-card::after {
  content: "";
  position: absolute;
  inset: auto -20% -25% auto;
  width: 260px;
  height: 260px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(109, 189, 255, 0.22), transparent 70%);
}

.visual-header {
  display: flex;
  align-items: center;
  gap: 10px;
  color: rgba(255, 250, 243, 0.8);
  font-size: 0.93rem;
}

.status-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #6dbdff;
  box-shadow: 0 0 18px rgba(109, 189, 255, 0.8);
}

.request-flow,
.algorithm-flow {
  display: grid;
  grid-template-columns: 1fr 40px 1fr 40px 1fr;
  gap: 8px;
  align-items: center;
}

.request-flow { margin: 18px 0; }

.flow-column,
.algorithm-stage {
  display: grid;
  gap: 10px;
}

.flow-label {
  color: rgba(255, 250, 243, 0.75);
  font-size: 0.84rem;
}

.flow-stage {
  min-height: 76px;
  display: grid;
  place-items: center;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.flow-arrow {
  text-align: center;
  color: rgba(255, 250, 243, 0.72);
  font-weight: 800;
}

.flow-arrow.small {
  font-size: 0.9rem;
}

.request-block,
.server-block {
  min-width: 90px;
  padding: 12px 14px;
  border-radius: 14px;
  text-align: center;
  font-weight: 800;
  transition: transform 320ms ease, background 320ms ease, color 320ms ease;
}

.request-block.incoming {
  background: linear-gradient(135deg, #f3c060, #df6d2d);
  color: #2a211d;
}

.request-block.allowed {
  background: linear-gradient(135deg, #5bdd9d, #229a66);
  color: #f7fffb;
}

.request-block.rejected {
  background: linear-gradient(135deg, #f08b84, #d45449);
  color: #fff8f7;
}

.server-block {
  background: linear-gradient(135deg, #78bfff, #1773b0);
  color: #f5fbff;
}

.small-block {
  min-width: 110px;
}

.turn-console { display: grid; gap: 10px; }

.console-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 13px 14px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.console-row span { color: rgba(255, 250, 243, 0.7); }

.section { padding: 72px 0; }
.section-heading { margin-bottom: 28px; }
.section-heading h2 { font-size: clamp(2.2rem, 5vw, 4rem); max-width: 15ch; }

.logic-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.info-card, .panel { border-radius: var(--radius); padding: 24px; }

.accent-orange { background: linear-gradient(180deg, rgba(255, 239, 224, 0.96), rgba(255, 249, 242, 0.88)); }
.accent-green { background: linear-gradient(180deg, rgba(227, 252, 238, 0.96), rgba(255, 249, 242, 0.88)); }
.accent-blue { background: linear-gradient(180deg, rgba(228, 245, 255, 0.96), rgba(255, 249, 242, 0.88)); }

.algorithm-stack { display: grid; gap: 20px; }

.algorithm-card {
  border-radius: 28px;
  padding: 24px;
  display: grid;
  grid-template-columns: 1.12fr 0.88fr;
  gap: 22px;
}

.algorithm-tag {
  margin: 0 0 10px;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent-3);
}

.algorithm-copy h3 { margin: 0 0 12px; font-size: 1.3rem; }

pre {
  margin: 18px 0 0;
  padding: 18px;
  border-radius: 18px;
  background: rgba(34, 27, 24, 0.96);
  color: #fff7ee;
  overflow-x: auto;
}

code { font-family: "Courier New", monospace; font-size: 0.94em; }

.algorithm-visual {
  border-radius: 22px;
  padding: 18px;
  background: rgba(34, 27, 24, 0.95);
  color: #fffaf3;
  min-height: 320px;
}

.visual-title { font-weight: 800; margin-bottom: 18px; }

.reason-card {
  margin: 14px 0;
  padding: 12px 14px;
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.08);
  color: rgba(255, 250, 243, 0.86);
}

.fixed-window-track {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 10px;
  margin-bottom: 16px;
}

.fixed-slot {
  min-height: 90px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.08);
  transition: transform 300ms ease, background 300ms ease;
}

.fixed-slot.active {
  background: linear-gradient(180deg, rgba(243, 192, 96, 0.95), rgba(223, 109, 45, 0.92));
  transform: translateY(-4px);
}

.sliding-lane {
  min-height: 120px;
  border-radius: 22px;
  position: relative;
  background: rgba(255, 255, 255, 0.08);
  overflow: hidden;
  margin-bottom: 16px;
}

.sliding-chip {
  position: absolute;
  top: 38px;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: linear-gradient(135deg, #57d4a2, #1f7a5c);
  box-shadow: 0 12px 18px rgba(31, 122, 92, 0.24);
  transition: left 550ms ease, opacity 350ms ease;
}

.token-bucket-box {
  position: relative;
  height: 180px;
  border-radius: 22px;
  background: rgba(255, 255, 255, 0.08);
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.08);
  margin-bottom: 16px;
}

.token-liquid {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 65%;
  background: linear-gradient(180deg, rgba(109, 189, 255, 0.9), rgba(23, 115, 176, 0.95));
  transition: height 550ms ease;
}

.token-count {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-weight: 800;
  z-index: 1;
}

.timeline { display: grid; gap: 14px; }

.timeline-step {
  border-radius: 24px;
  padding: 20px;
  display: grid;
  grid-template-columns: 90px 1fr;
  gap: 18px;
}

.step-number {
  font-family: "DM Serif Display", serif;
  font-size: 2.2rem;
  color: var(--accent-3);
  line-height: 1;
}

.compiler-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}

.code-panel, .compiler-panel {
  min-height: 820px;
  border-radius: var(--radius);
  padding: 24px;
}

.code-panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}

.copy-button {
  border: 0;
  border-radius: 999px;
  padding: 11px 16px;
  background: linear-gradient(135deg, var(--accent-3), #6dbdff);
  color: #fffaf3;
  font-weight: 800;
  cursor: pointer;
  box-shadow: 0 14px 24px rgba(23, 115, 176, 0.2);
}

.code-textarea {
  width: 100%;
  min-height: 680px;
  resize: vertical;
  border-radius: 20px;
  border: 1px solid rgba(34, 27, 24, 0.12);
  background: rgba(34, 27, 24, 0.96);
  color: #fff7ee;
  padding: 18px;
  line-height: 1.55;
  font-size: 0.92rem;
  font-family: "Courier New", monospace;
}

.compiler-actions { margin-top: 14px; }

.compiler-frame {
  width: 100%;
  min-height: 750px;
  border: 1px solid rgba(34, 27, 24, 0.1);
  border-radius: 20px;
  background: #fff;
}

.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 700ms ease, transform 700ms ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 980px) {
  .hero-grid,
  .logic-grid,
  .algorithm-card,
  .compiler-layout,
  .request-flow,
  .algorithm-flow {
    grid-template-columns: 1fr;
  }

  .hero { min-height: auto; }
}

@media (max-width: 720px) {
  .page-shell { width: min(100% - 18px, 1500px); }

  .topbar {
    gap: 14px;
    flex-direction: column;
    align-items: flex-start;
    margin-bottom: 34px;
    border-radius: 24px;
    padding: 14px;
  }

  .nav-group {
    width: 100%;
    justify-content: flex-start;
    border-radius: 20px;
  }

  .hero-copy h1 { font-size: 2.4rem; }
  .hero-metrics { grid-template-columns: 1fr; }
  .timeline-step { grid-template-columns: 1fr; }
  .code-panel, .compiler-panel { min-height: auto; }
}

pre {
  position: relative;
}

.snippet-expand-button {
  position: absolute;
  top: 10px;
  right: 10px;
  width: 38px;
  height: 38px;
  border: 0;
  border-radius: 999px;
  display: grid;
  place-items: center;
  background: rgba(255, 255, 255, 0.15);
  color: #fffaf3;
  cursor: pointer;
  backdrop-filter: blur(10px);
}

.expand-icon {
  position: relative;
  width: 16px;
  height: 16px;
  display: inline-block;
}

.expand-icon::before,
.expand-icon::after {
  content: "";
  position: absolute;
  width: 7px;
  height: 7px;
  border-color: currentColor;
}

.expand-icon::before {
  top: 0;
  right: 0;
  border-top: 2px solid;
  border-right: 2px solid;
}

.expand-icon::after {
  left: 0;
  bottom: 0;
  border-left: 2px solid;
  border-bottom: 2px solid;
}

.code-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.icon-button {
  width: 42px;
  height: 42px;
  padding: 0;
  display: grid;
  place-items: center;
}

.secondary-button {
  background: rgba(255, 255, 255, 0.72);
  color: var(--ink);
  border: 1px solid rgba(34, 27, 24, 0.1);
  box-shadow: none;
}

.code-modal {
  position: fixed;
  inset: 0;
  z-index: 20;
  display: none;
  grid-template-rows: auto 1fr;
  background: rgba(18, 15, 13, 0.98);
  padding: 18px;
}

.code-modal.open {
  display: grid;
}

.modal-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 14px;
  color: #fffaf3;
  padding-bottom: 14px;
}

.modal-code {
  width: 100%;
  min-height: 0;
  resize: none;
  border-radius: 18px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  background: #0f1512;
  color: #f5fff9;
  padding: 22px;
  line-height: 1.58;
  font-size: 1rem;
  font-family: "Courier New", monospace;
}

body.modal-open {
  overflow: hidden;
}