/* Observability Mesh — site styles */

:root {
  --ink: #0c1a22;
  --ink-soft: #163040;
  --fog: #e8eef1;
  --fog-deep: #d5e0e6;
  --paper: #f4f7f8;
  --sea: #2f8f84;
  --sea-bright: #3d9b8f;
  --mist: #7eb8c9;
  --brass: #b8954a;
  --muted: #5a6f7a;
  --line: rgba(12, 26, 34, 0.12);
  --line-strong: rgba(12, 26, 34, 0.22);
  --header-h: 4.25rem;
  --font-display: "Syne", system-ui, sans-serif;
  --font-body: "Source Sans 3", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, monospace;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --max: 72rem;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 1.125rem;
  line-height: 1.65;
  color: var(--ink);
  background:
    radial-gradient(1200px 600px at 10% -10%, rgba(126, 184, 201, 0.18), transparent 55%),
    radial-gradient(900px 500px at 100% 20%, rgba(47, 143, 132, 0.1), transparent 50%),
    linear-gradient(180deg, var(--paper) 0%, var(--fog) 45%, #dde7ec 100%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
}

img,
svg {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
}

.section a:not(.btn):not(.repo):not(.path-switch__btn):not(.topic) {
  color: var(--ink-soft);
  font-weight: 600;
  text-decoration: none;
  border-bottom: 1.5px solid var(--sea);
}

.section a:not(.btn):not(.repo):not(.path-switch__btn):not(.topic):hover {
  color: var(--ink);
}

code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: rgba(12, 26, 34, 0.06);
  padding: 0.1em 0.35em;
  border-radius: 3px;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -4rem;
  z-index: 100;
  padding: 0.6rem 1rem;
  background: var(--ink);
  color: var(--paper);
  text-decoration: none;
  font-weight: 600;
}

.skip-link:focus {
  top: 1rem;
}

/* Header */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(14px);
  background: rgba(244, 247, 248, 0.82);
  border-bottom: 1px solid var(--line);
}

.site-header__inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0.9rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  min-height: var(--header-h);
}

.wordmark {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: -0.02em;
  text-decoration: none;
  flex-shrink: 0;
}

.wordmark__mark {
  width: 0.85rem;
  height: 0.85rem;
  border: 2px solid var(--sea);
  border-radius: 2px;
  box-shadow: 4px 4px 0 -1px var(--mist);
  transform: rotate(12deg);
}

.nav {
  display: none;
  gap: 1.35rem;
  margin-left: auto;
  font-size: 0.95rem;
  font-weight: 500;
}

.nav a {
  text-decoration: none;
  color: var(--muted);
  transition: color 0.2s var(--ease);
}

.nav a:hover,
.nav a:focus-visible {
  color: var(--ink);
}

.nav-cta {
  margin-left: auto;
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  color: var(--ink);
  border-bottom: 1.5px solid var(--sea);
  padding-bottom: 0.1rem;
}

@media (min-width: 820px) {
  .nav {
    display: flex;
  }

  .nav-cta {
    margin-left: 0;
  }
}

/* Hero */

.hero {
  position: relative;
  min-height: calc(100vh - var(--header-h));
  display: grid;
  align-items: end;
  overflow: hidden;
  color: var(--fog);
  background: var(--ink);
}

.hero__atmosphere {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.hero__mesh {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero__nodes path {
  stroke-dasharray: 12 10;
  animation: mesh-drift 28s linear infinite;
}

.hero__nodes path:nth-child(2) {
  animation-duration: 36s;
  animation-direction: reverse;
}

.hero__nodes path:nth-child(3) {
  animation-duration: 42s;
}

.hero__dots circle {
  animation: node-pulse 4.5s ease-in-out infinite;
}

.hero__dots circle:nth-child(2) {
  animation-delay: 0.6s;
}

.hero__dots circle:nth-child(3) {
  animation-delay: 1.2s;
}

.hero__dots circle:nth-child(4) {
  animation-delay: 1.8s;
}

.hero__dots circle:nth-child(5) {
  animation-delay: 0.9s;
}

@keyframes mesh-drift {
  to {
    stroke-dashoffset: -220;
  }
}

@keyframes node-pulse {
  0%,
  100% {
    opacity: 0.45;
    transform: scale(1);
  }
  50% {
    opacity: 1;
    transform: scale(1.35);
  }
}

.hero__content {
  position: relative;
  z-index: 1;
  max-width: var(--max);
  width: 100%;
  margin: 0 auto;
  padding: 4.5rem 1.5rem 4rem;
}

.hero__brand {
  margin: 0 0 1.25rem;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2.6rem, 7vw, 4.75rem);
  line-height: 0.95;
  letter-spacing: -0.04em;
  color: #f4f7f8;
  animation: rise 0.9s var(--ease) both;
}

.hero__headline {
  margin: 0 0 1.1rem;
  max-width: 18ch;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(1.45rem, 3.2vw, 2.15rem);
  line-height: 1.2;
  letter-spacing: -0.025em;
  color: rgba(244, 247, 248, 0.92);
  animation: rise 0.9s var(--ease) 0.12s both;
}

.hero__lede {
  margin: 0 0 2rem;
  max-width: 38rem;
  font-size: clamp(1.05rem, 2vw, 1.2rem);
  color: rgba(232, 238, 241, 0.78);
  animation: rise 0.9s var(--ease) 0.22s both;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem 1rem;
  animation: rise 0.9s var(--ease) 0.32s both;
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(1.1rem);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.85rem;
  padding: 0.65rem 1.25rem;
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  border-radius: 4px;
  border: 1.5px solid transparent;
  transition: transform 0.2s var(--ease), background 0.2s var(--ease), color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.btn:hover {
  transform: translateY(-1px);
}

.btn--primary {
  background: var(--sea-bright);
  color: var(--ink);
}

.btn--primary:hover {
  background: #4aada0;
}

.btn--ghost {
  background: transparent;
  color: var(--fog);
  border-color: rgba(232, 238, 241, 0.35);
}

.btn--ghost:hover {
  border-color: rgba(232, 238, 241, 0.7);
}

/* Sections */

.section {
  padding: 5.5rem 0;
}

.section__inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.eyebrow {
  margin: 0 0 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--sea);
}

.section h2 {
  margin: 0 0 1.25rem;
  max-width: 18ch;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.85rem, 4vw, 2.75rem);
  line-height: 1.1;
  letter-spacing: -0.03em;
}

.section__lede {
  margin: 0;
  max-width: 42rem;
  color: var(--muted);
  font-size: 1.15rem;
}

.section__lede--tight {
  margin-top: 1rem;
}

.section__lede em {
  font-style: italic;
  color: var(--ink-soft);
}

.section--practice {
  background:
    linear-gradient(180deg, transparent, rgba(255, 255, 255, 0.35)),
    repeating-linear-gradient(
      -12deg,
      transparent,
      transparent 22px,
      rgba(12, 26, 34, 0.015) 22px,
      rgba(12, 26, 34, 0.015) 23px
    );
}

/* Topics / categories */

.section--topics {
  padding-top: 2.5rem;
  padding-bottom: 3.5rem;
}

.topic-list {
  list-style: none;
  margin: 2.25rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.85rem;
}

@media (min-width: 700px) {
  .topic-list {
    grid-template-columns: 1fr 1fr;
  }
}

@media (min-width: 980px) {
  .topic-list {
    grid-template-columns: 1fr 1fr 1fr;
  }
}

.topic {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  height: 100%;
  padding: 1.1rem 1.15rem;
  text-decoration: none;
  border: 1.5px solid var(--line-strong);
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.45);
  transition: border-color 0.2s var(--ease), transform 0.2s var(--ease), background 0.2s var(--ease);
}

.topic:hover {
  border-color: var(--sea);
  background: rgba(255, 255, 255, 0.85);
  transform: translateY(-1px);
}

.topic__kind {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--sea);
  font-weight: 500;
}

.topic__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.topic__desc {
  font-size: 0.95rem;
  color: var(--muted);
  line-height: 1.45;
}

#logs,
#metrics,
#traces,
#slo-catalog,
#topics,
#practice,
#paths,
#model,
#start {
  scroll-margin-top: calc(var(--header-h) + 0.75rem);
}

/* Path switch */

.path-switch {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.75rem;
  margin: 2.5rem 0 2rem;
}

@media (min-width: 700px) {
  .path-switch {
    grid-template-columns: 1fr 1fr;
  }
}

.path-switch__btn {
  appearance: none;
  text-align: left;
  cursor: pointer;
  font: inherit;
  color: inherit;
  background: rgba(255, 255, 255, 0.45);
  border: 1.5px solid var(--line-strong);
  border-radius: 6px;
  padding: 1.15rem 1.25rem;
  transition: border-color 0.2s var(--ease), background 0.2s var(--ease), transform 0.2s var(--ease);
}

.path-switch__btn:hover {
  border-color: var(--sea);
  transform: translateY(-1px);
}

.path-switch__btn.is-active {
  background: var(--ink);
  color: var(--fog);
  border-color: var(--ink);
}

.path-switch__btn.is-active .path-switch__hint {
  color: rgba(232, 238, 241, 0.65);
}

.path-switch__label {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
  margin-bottom: 0.25rem;
}

.path-switch__hint {
  display: block;
  font-size: 0.95rem;
  color: var(--muted);
}

.path-panel[hidden] {
  display: none;
}

.path-panel.is-active {
  animation: panel-in 0.45s var(--ease) both;
}

@keyframes panel-in {
  from {
    opacity: 0;
    transform: translateY(0.6rem);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.path-intro {
  margin-bottom: 2.5rem;
  max-width: 40rem;
}

.path-intro h3 {
  margin: 0 0 0.75rem;
  font-family: var(--font-display);
  font-size: 1.45rem;
  letter-spacing: -0.02em;
}

.path-intro p {
  margin: 0;
  color: var(--muted);
}

/* Pillars */

.pillars {
  display: grid;
  gap: 2.25rem 2.5rem;
}

@media (min-width: 880px) {
  .pillars {
    grid-template-columns: repeat(3, 1fr);
  }
}

.pillar {
  padding-top: 1.25rem;
  border-top: 2px solid var(--ink);
}

.pillar__signal {
  margin: 0 0 0.85rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--sea);
}

.pillar h3 {
  margin: 0 0 0.75rem;
  font-family: var(--font-display);
  font-size: 1.2rem;
  letter-spacing: -0.02em;
  line-height: 1.25;
}

.pillar p {
  margin: 0;
  color: var(--muted);
  font-size: 1.02rem;
}

.pillar__stack {
  margin-top: 1rem !important;
  font-family: var(--font-mono);
  font-size: 0.78rem !important;
  letter-spacing: 0.01em;
  color: var(--ink-soft) !important;
}

/* SLO block (full path) */

.slo-block {
  margin-top: 3.5rem;
  display: grid;
  gap: 2rem;
  padding: 2rem 0 0;
  border-top: 1px solid var(--line-strong);
}

@media (min-width: 860px) {
  .slo-block {
    grid-template-columns: 1.4fr 0.8fr;
    gap: 3rem;
    align-items: start;
  }
}

.slo-block__copy h3 {
  margin: 0 0 0.85rem;
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 2.5vw, 1.7rem);
  letter-spacing: -0.02em;
}

.slo-block__copy > p {
  margin: 0 0 1.25rem;
  color: var(--muted);
}

.flow-list {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: flow;
}

.flow-list li {
  position: relative;
  padding: 0.65rem 0 0.65rem 2.4rem;
  border-top: 1px solid var(--line);
  color: var(--ink-soft);
  font-weight: 500;
}

.flow-list li::before {
  counter-increment: flow;
  content: counter(flow);
  position: absolute;
  left: 0;
  top: 0.7rem;
  width: 1.5rem;
  height: 1.5rem;
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  background: var(--ink);
  color: var(--fog);
  border-radius: 3px;
}

.slo-block__aside {
  background: var(--ink);
  color: var(--fog);
  padding: 1.5rem 1.35rem;
  border-radius: 6px;
}

.mono-label {
  margin: 0 0 1rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--mist);
}

.stack-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.stack-list li {
  display: grid;
  grid-template-columns: 5.5rem 1fr;
  gap: 0.75rem;
  padding: 0.7rem 0;
  border-top: 1px solid rgba(232, 238, 241, 0.12);
  font-size: 0.98rem;
}

.stack-list li span {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--sea-bright);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding-top: 0.15rem;
}

/* SLO-first path */

.trust-grid {
  display: grid;
  gap: 2rem;
  margin-bottom: 2.5rem;
}

@media (min-width: 800px) {
  .trust-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 2.25rem;
  }
}

.trust {
  padding-top: 1.15rem;
  border-top: 2px solid var(--sea);
}

.trust h3 {
  margin: 0 0 0.7rem;
  font-family: var(--font-display);
  font-size: 1.2rem;
  letter-spacing: -0.02em;
}

.trust p {
  margin: 0;
  color: var(--muted);
  font-size: 1.02rem;
}

.slo-strip {
  padding: 2rem 0 0;
  border-top: 1px solid var(--line-strong);
  max-width: 42rem;
}

.slo-strip h3 {
  margin: 0 0 0.85rem;
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 2.5vw, 1.7rem);
  letter-spacing: -0.02em;
}

.slo-strip > p {
  margin: 0 0 1rem;
  color: var(--muted);
}

.slo-strip__note {
  font-weight: 500;
  color: var(--ink-soft) !important;
}

/* Model */

.section--model {
  background: var(--ink);
  color: var(--fog);
}

.section--model .eyebrow {
  color: var(--mist);
}

.section--model .section__lede {
  color: rgba(232, 238, 241, 0.72);
}

.section--model .section__lede em {
  color: rgba(244, 247, 248, 0.95);
}

.model-split {
  display: grid;
  gap: 2.5rem;
  margin-top: 2.75rem;
}

@media (min-width: 800px) {
  .model-split {
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
  }
}

.model-col {
  padding-top: 1.25rem;
  border-top: 2px solid rgba(126, 184, 201, 0.45);
}

.model-col h3 {
  margin: 0 0 0.55rem;
  font-family: var(--font-display);
  font-size: 1.25rem;
  letter-spacing: -0.02em;
}

.model-col > p {
  margin: 0 0 1.1rem;
  color: rgba(232, 238, 241, 0.68);
}

.model-col ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.model-col li {
  position: relative;
  padding: 0.55rem 0 0.55rem 1.1rem;
  border-top: 1px solid rgba(232, 238, 241, 0.1);
  color: rgba(244, 247, 248, 0.88);
  font-size: 1.02rem;
}

.model-col li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1.05rem;
  width: 0.4rem;
  height: 0.4rem;
  background: var(--sea-bright);
  border-radius: 1px;
}

.audiences {
  margin-top: 3.25rem;
  padding-top: 2.25rem;
  border-top: 1px solid rgba(232, 238, 241, 0.14);
  max-width: 46rem;
}

.audiences h3 {
  margin: 0 0 0.85rem;
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 2.5vw, 1.7rem);
  letter-spacing: -0.02em;
}

.audiences > p {
  margin: 0 0 1.5rem;
  color: rgba(232, 238, 241, 0.72);
}

.audience-split {
  display: grid;
  gap: 1.75rem;
  margin-bottom: 1.5rem;
}

@media (min-width: 720px) {
  .audience-split {
    grid-template-columns: 1fr 1fr;
    gap: 2.25rem;
  }
}

.audience-split h4 {
  margin: 0 0 0.55rem;
  font-family: var(--font-display);
  font-size: 1.05rem;
  letter-spacing: -0.015em;
  color: var(--sea-bright);
}

.audience-split p {
  margin: 0;
  color: rgba(244, 247, 248, 0.88);
  font-size: 1.02rem;
}

.audiences__close {
  margin: 0 !important;
  font-weight: 500;
  color: rgba(244, 247, 248, 0.9) !important;
}

/* Start / repos */

.repos {
  display: grid;
  gap: 1rem;
  margin-top: 2.5rem;
}

@media (min-width: 800px) {
  .repos {
    grid-template-columns: 1fr 1fr;
  }
}

.repo {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  padding: 1.5rem 1.35rem;
  text-decoration: none;
  background: rgba(255, 255, 255, 0.55);
  border: 1.5px solid var(--line-strong);
  border-radius: 6px;
  transition: border-color 0.2s var(--ease), transform 0.2s var(--ease), background 0.2s var(--ease);
}

.repo:hover,
.repo:focus-visible {
  border-color: var(--sea);
  background: rgba(255, 255, 255, 0.85);
  transform: translateY(-2px);
}

.repo__kind {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--sea);
}

.repo__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.3rem;
  letter-spacing: -0.02em;
}

.repo__desc {
  color: var(--muted);
  font-size: 1.02rem;
  flex: 1;
}

.repo__cta {
  margin-top: 0.5rem;
  font-weight: 600;
  font-size: 0.95rem;
  border-bottom: 1.5px solid var(--sea);
  align-self: flex-start;
}

/* Footer */

.site-footer {
  padding: 3rem 0 2.5rem;
  border-top: 1px solid var(--line);
  background: rgba(244, 247, 248, 0.7);
}

.site-footer__inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.site-footer__brand {
  margin: 0 0 0.4rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
}

.site-footer__tag,
.site-footer__meta {
  margin: 0;
  color: var(--muted);
  font-size: 0.98rem;
}

.site-footer__links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
  margin: 1.15rem 0 0;
  font-size: 0.95rem;
  font-weight: 600;
}

.site-footer__links a {
  text-decoration: none;
  border-bottom: 1.5px solid var(--sea);
  padding-bottom: 0.05rem;
}

.site-footer__links a:hover {
  color: var(--ink);
}

.site-footer__meta {
  margin-top: 0.85rem;
  font-size: 0.9rem;
}

.site-footer a {
  text-decoration: none;
  border-bottom: 1px solid var(--line-strong);
}

.site-footer a:hover {
  border-color: var(--sea);
}

/* Reveal on scroll */

.reveal {
  opacity: 0;
  transform: translateY(1rem);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}

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

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .hero__nodes path,
  .hero__dots circle,
  .hero__brand,
  .hero__headline,
  .hero__lede,
  .hero__actions,
  .path-panel.is-active,
  .reveal {
    animation: none !important;
    transition: none !important;
    opacity: 1 !important;
    transform: none !important;
  }
}