/* ── ESP32-DIV — clean minimal theme ───────────────── */

:root {
  --bg: #0a0a0b;
  --bg-soft: #101012;
  --fg: #f4f4f5;
  --muted: #8e8e96;
  --accent: #ee3a17;
  --accent-soft: rgba(238, 58, 23, 0.12);
  --border: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.14);
  --sans: "Inter", system-ui, -apple-system, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, monospace;
  --pixel: "Doto", "JetBrains Mono", ui-monospace, monospace;
  --radius: 12px;
  --maxw: 1120px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: auto; }

body {
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; }

::selection { background: var(--accent); color: #fff; }

.accent { color: var(--accent); }

/* ── Buttons ───────────────────────────── */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 10px;
  border: 1px solid transparent;
  font-family: var(--sans);
  font-size: 0.92rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, color 0.15s, transform 0.1s;
}

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

.btn--primary {
  background: var(--accent);
  color: #fff;
}
.btn--primary:hover { background: #ff4d22; }

.btn--ghost {
  background: transparent;
  color: var(--fg);
  border-color: var(--border-strong);
}
.btn--ghost:hover { border-color: var(--fg); }

.btn--sm { padding: 8px 16px; font-size: 0.85rem; }

/* ── Navbar ────────────────────────────── */

.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 10, 11, 0.94);
  border-bottom: 1px solid var(--border);
}

.nav__inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.nav__brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.nav__logo {
  font-weight: 800;
  font-size: 1.05rem;
  letter-spacing: -0.02em;
}
.nav__logo em { color: var(--accent); font-style: normal; }

.nav__badge {
  font-family: var(--mono);
  font-size: 0.68rem;
  padding: 3px 8px;
  border-radius: 99px;
  background: var(--accent-soft);
  color: var(--accent);
  border: 1px solid rgba(238, 58, 23, 0.3);
}

.nav__links {
  display: flex;
  gap: 28px;
}
.nav__links a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--muted);
  text-decoration: none;
  transition: color 0.15s;
}
.nav__links a:hover { color: var(--fg); }

.nav__actions { display: flex; align-items: center; gap: 12px; }

.nav__burger {
  display: none;
  background: none;
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  color: var(--fg);
  font-size: 1.2rem;
  padding: 6px 9px;
  cursor: pointer;
}

/* ── Hero ──────────────────────────────── */

.hero { padding: 72px 24px 56px; }

.hero__inner {
  max-width: var(--maxw);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  gap: 48px;
  align-items: center;
}

.hero__kicker {
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 18px;
}

.hero__title {
  font-size: clamp(2.4rem, 5vw, 3.6rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.08;
  margin-bottom: 20px;
}

.hero__sub {
  font-size: 1.08rem;
  color: var(--muted);
  max-width: 480px;
  margin-bottom: 32px;
}

.hero__cta { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 40px; }

.hero__stats {
  display: grid;
  grid-template-columns: repeat(2, auto);
  column-gap: 28px;
  row-gap: 16px;
  align-items: center;
}

.stat {
  display: flex;
  align-items: center;
  gap: 10px;
}

.stat__body {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.stat__v {
  display: block;
  font-family: var(--pixel);
  font-size: 1.1rem;
  font-weight: 700;
  line-height: 1.2;
  color: var(--fg);
}

.stat__l {
  display: block;
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  line-height: 1.2;
}

.stat__icon {
  font-size: 1.05rem;
  color: var(--accent);
  line-height: 1;
  flex-shrink: 0;
  filter: drop-shadow(0 0 6px rgba(238, 58, 23, 0.45));
}

.stat:nth-child(3) .stat__v { color: var(--accent); }

@media (min-width: 720px) {
  .hero__stats {
    display: flex;
    flex-wrap: nowrap;
    gap: 0;
  }

  .stat {
    padding: 0 22px;
    border-left: 1px solid var(--border);
  }

  .stat:first-child {
    padding-left: 0;
    border-left: none;
  }
}

/* ── 3D viewer ─────────────────────────── */

.viewer {
  position: relative;
  z-index: 1;
  width: 100%;
  height: clamp(360px, 48vh, 520px);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background:
    radial-gradient(ellipse 75% 65% at 50% 40%, rgba(238, 58, 23, 0.07), transparent 65%),
    var(--bg-soft);
  overflow: hidden;
  touch-action: none;
  cursor: grab;
  contain: layout paint;
}
.viewer:active { cursor: grabbing; }

.viewer canvas {
  position: absolute;
  inset: 0;
  width: 100% !important;
  height: 100% !important;
}

.viewer__status {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--muted);
  pointer-events: none;
  transition: opacity 0.3s;
}
.viewer.is-ready .viewer__status { opacity: 0; }

.viewer__hint {
  position: absolute;
  bottom: 12px;
  right: 14px;
  display: flex;
  align-items: center;
  gap: 6px;
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--muted);
  opacity: 0;
  transition: opacity 0.4s;
  pointer-events: none;
}
.viewer.is-ready .viewer__hint { opacity: 0.75; }

/* ── Notice strip ──────────────────────── */

.notice {
  border-block: 1px solid var(--border);
  background: var(--bg-soft);
}
.notice__inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.86rem;
  color: var(--muted);
}
.notice__inner i { color: var(--accent); font-size: 1.1rem; flex-shrink: 0; }
.notice__inner strong { color: var(--fg); }

/* ── Sections ──────────────────────────── */

.section {
  padding: 96px 24px;
  content-visibility: auto;
  contain-intrinsic-size: auto 600px;
}
.section--alt { background: var(--bg-soft); border-block: 1px solid var(--border); }

.section__inner { max-width: var(--maxw); margin: 0 auto; }

.section__title {
  font-size: clamp(1.9rem, 4vw, 2.8rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.12;
  margin-bottom: 16px;
}

.section__sub {
  font-size: 1.02rem;
  color: var(--muted);
  max-width: 520px;
  margin-bottom: 48px;
}

.section__more {
  margin-top: 40px;
  font-size: 0.95rem;
  color: var(--muted);
}
.section__more a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 600;
}
.section__more a:hover { text-decoration: underline; }

/* ── Feature cards ─────────────────────── */

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 16px;
}

.card {
  padding: 26px 24px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg);
  transition: border-color 0.2s, transform 0.2s;
}
.card:hover {
  border-color: rgba(238, 58, 23, 0.4);
  transform: translateY(-2px);
}

.card__icon {
  width: 42px;
  height: 42px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  background: var(--accent-soft);
  border: 1px solid rgba(238, 58, 23, 0.25);
  margin-bottom: 16px;
}
.card__icon i { color: var(--accent); font-size: 1.25rem; }

.card__title {
  font-size: 1.02rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.card__desc {
  font-size: 0.86rem;
  color: var(--muted);
  line-height: 1.65;
}

/* ── Hardware ──────────────────────────── */

.hw {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.hw__col {
  padding: 30px 28px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg);
}

.hw__head {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 20px;
}
.hw__head i { color: var(--accent); font-size: 1.3rem; }

.hw__list { list-style: none; display: flex; flex-direction: column; gap: 10px; }
.hw__list li {
  font-size: 0.9rem;
  color: var(--muted);
  padding-left: 18px;
  position: relative;
}
.hw__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
}
.hw__list strong { color: var(--fg); font-weight: 600; }

.hw__compat { margin-top: 28px; }
.hw__compat-title {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 12px;
}

.chip {
  display: inline-block;
  font-family: var(--mono);
  font-size: 0.74rem;
  padding: 5px 12px;
  border-radius: 99px;
  margin: 0 6px 8px 0;
  border: 1px solid var(--border-strong);
  color: var(--muted);
}
.chip--ok {
  border-color: rgba(29, 184, 112, 0.35);
  color: #1db870;
  background: rgba(29, 184, 112, 0.07);
}

/* ── Flasher ───────────────────────────── */

.flasher {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-soft);
  padding: 28px;
  max-width: 720px;
}

.flasher__head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 22px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--border);
}

.flasher__label {
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

.flasher__ver {
  font-family: var(--mono);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--fg);
}

.flasher__releases {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
}
.flasher__releases:hover { text-decoration: underline; }

.flasher__boards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 10px;
  margin-bottom: 24px;
}

.board {
  text-align: left;
  padding: 14px 16px;
  border-radius: 10px;
  border: 1px solid var(--border-strong);
  background: var(--bg);
  cursor: pointer;
  font-family: var(--sans);
  transition: border-color 0.15s, background 0.15s;
}
.board:hover { border-color: rgba(238, 58, 23, 0.45); }
.board.is-active {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.board__name {
  display: block;
  font-weight: 700;
  font-size: 0.92rem;
  color: var(--fg);
}
.board__chip {
  display: block;
  font-family: var(--mono);
  font-size: 0.7rem;
  color: var(--muted);
  margin-top: 3px;
}

.flasher__file {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 13px 16px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--bg);
  margin-bottom: 22px;
}
.flasher__file > i { color: var(--accent); font-size: 1.3rem; flex-shrink: 0; }

.flasher__file-info { display: flex; flex-direction: column; min-width: 0; }

.flasher__file-name {
  font-family: var(--mono);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--fg);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.flasher__file-meta {
  font-family: var(--mono);
  font-size: 0.7rem;
  color: var(--muted);
  margin-top: 2px;
}

.flasher__file-tag {
  margin-left: auto;
  font-family: var(--mono);
  font-size: 0.68rem;
  padding: 3px 9px;
  border-radius: 99px;
  border: 1px solid rgba(29, 184, 112, 0.35);
  color: #1db870;
  background: rgba(29, 184, 112, 0.07);
  flex-shrink: 0;
}

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

.flasher__warn {
  display: none;
  margin-top: 18px;
  font-size: 0.84rem;
  color: var(--muted);
  align-items: center;
  gap: 8px;
}
.flasher__warn i { color: var(--accent); }
.flasher__warn.is-visible { display: flex; }

.flasher__desktop {
  margin-top: 18px;
  font-size: 0.86rem;
  color: var(--muted);
}
.flasher__desktop a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 600;
}
.flasher__desktop a:hover { text-decoration: underline; }
.flasher__desktop .hn { font-size: 0.95rem; margin-right: 4px; }

.flasher__alt { margin-top: 22px; }

.flasher__alt summary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--muted);
  cursor: pointer;
  list-style: none;
  transition: color 0.15s;
}
.flasher__alt summary::-webkit-details-marker { display: none; }
.flasher__alt summary:hover { color: var(--fg); }
.flasher__alt summary i { color: var(--accent); }

.flasher__cmd-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 14px;
}

.flasher__cmd {
  flex: 1;
  padding: 11px 14px;
  border-radius: 8px;
  background: var(--bg);
  border: 1px solid var(--border);
  font-family: var(--mono);
  font-size: 0.76rem;
  color: #22d3ee;
  overflow-x: auto;
  white-space: nowrap;
}

.flasher__tips {
  list-style: none;
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.flasher__tips li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.84rem;
  color: var(--muted);
}
.flasher__tips li i { color: var(--accent); font-size: 1rem; margin-top: 2px; flex-shrink: 0; }
.flasher__tips strong { color: var(--fg); }
.flasher__tips a { color: var(--accent); text-decoration: none; font-weight: 600; }
.flasher__tips a:hover { text-decoration: underline; }

/* ── Steps ─────────────────────────────── */

.steps {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0;
  max-width: 720px;
}

.step {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 20px;
  padding: 26px 0;
  border-bottom: 1px solid var(--border);
}
.step:last-child { border-bottom: none; }

.step__num {
  font-family: var(--mono);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--accent);
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(238, 58, 23, 0.3);
  border-radius: 10px;
  background: var(--accent-soft);
}

.step__title { font-size: 1rem; font-weight: 700; margin-bottom: 5px; }
.step__desc { font-size: 0.9rem; color: var(--muted); }
.step__desc a { color: var(--accent); text-decoration: none; font-weight: 600; }
.step__desc a:hover { text-decoration: underline; }

.step__code {
  display: block;
  margin-top: 10px;
  padding: 10px 14px;
  border-radius: 8px;
  background: var(--bg);
  border: 1px solid var(--border);
  font-family: var(--mono);
  font-size: 0.78rem;
  color: #22d3ee;
  overflow-x: auto;
  white-space: nowrap;
}
.step__code--inline {
  display: inline;
  margin-top: 0;
  padding: 2px 7px;
  white-space: nowrap;
  font-size: 0.76rem;
}

.step__cmd-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 10px;
}
.step__cmd-row .step__code {
  flex: 1;
  margin-top: 0;
}

/* ── Get started tabs ──────────────────── */

.start-tabs {
  max-width: none;
  width: 100%;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.02), rgba(255, 255, 255, 0)), var(--bg);
  overflow: hidden;
}

.start-tabs__nav {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 10px;
  border-bottom: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.015);
}

.start-tab {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  border: 1px solid transparent;
  border-radius: 10px;
  background: transparent;
  color: var(--muted);
  font-family: var(--sans);
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  transition: color 0.15s, background 0.15s, border-color 0.15s;
}
.start-tab .hn { font-size: 0.95rem; color: var(--accent); }
.start-tab:hover { color: var(--fg); background: rgba(255, 255, 255, 0.03); }
.start-tab.is-active {
  color: var(--fg);
  border-color: var(--accent);
  background: var(--accent-soft);
  box-shadow: 0 8px 24px -14px rgba(238, 58, 23, 0.7);
}

.start-tabs__panels { padding: 8px 24px 16px; }
.start-panel { display: none; }
.start-panel.is-active { display: block; }

.start-panel .steps { max-width: none; }

.start-panel__note,
.start-panel__foot {
  font-size: 0.88rem;
  color: var(--muted);
  line-height: 1.55;
  margin-bottom: 18px;
}
.start-panel__note a,
.start-panel__foot a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 600;
}
.start-panel__note a:hover,
.start-panel__foot a:hover { text-decoration: underline; }
.start-panel__foot { margin-top: 8px; margin-bottom: 0; }

.start-subhead {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--fg);
  margin: 28px 0 4px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}
.start-subhead:first-of-type {
  margin-top: 0;
  padding-top: 0;
  border-top: none;
}
.start-subhead .hn { color: var(--accent); font-size: 1rem; }

@media (max-width: 600px) {
  .start-tab { flex: 1 1 calc(50% - 6px); justify-content: center; }
  .start-tabs__panels { padding: 4px 16px 12px; }
}

/* ── Video playlist ────────────────────── */

.video {
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  background: var(--bg-soft);
  padding: 16px;
  overflow: hidden;
}

.video__layout {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.video__player {
  flex: 1.75;
  min-width: 0;
}

.video__side {
  flex: 1;
  min-width: 0;
  display: flex;
  min-height: 0;
}

.video__frame {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: calc(var(--radius) - 4px);
  overflow: hidden;
  background: #000;
  border: 1px solid var(--border);
}

.video__frame iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

.video__grid {
  --video-rows: 3;
  width: 100%;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  grid-auto-rows: calc((100% - (var(--video-rows) - 1) * 10px) / var(--video-rows));
  gap: 10px;
  align-content: start;
  overflow-y: auto;
  padding-right: 4px;
  scrollbar-width: thin;
  scrollbar-color: var(--border-strong) transparent;
}

.video-card {
  display: flex;
  flex-direction: column;
  height: 100%;
  min-height: 0;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg);
  cursor: pointer;
  text-align: left;
  overflow: hidden;
  transition: border-color 0.15s, background 0.15s;
}

.video-card:hover {
  border-color: rgba(238, 58, 23, 0.45);
}

.video-card.is-active {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.video-card__thumb {
  position: relative;
  flex: 1;
  min-height: 0;
  background: #000;
  overflow: hidden;
}

.video-card__thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.video-card__play {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.28);
  color: #fff;
  font-size: 1.4rem;
  opacity: 0;
  transition: opacity 0.15s;
}

.video-card:hover .video-card__play,
.video-card.is-active .video-card__play { opacity: 1; }

.video-card__title {
  flex-shrink: 0;
  padding: 8px 10px 10px;
  font-size: 0.72rem;
  line-height: 1.35;
  color: var(--muted);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.video-card.is-active .video-card__title { color: var(--fg); }

.video__meta {
  margin-top: 14px;
  font-size: 0.88rem;
  text-align: left;
}

.video__meta a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--accent);
  text-decoration: none;
  font-weight: 600;
}

.video__meta a:hover { text-decoration: underline; }

@media (max-width: 900px) {
  .video__layout {
    flex-direction: column;
    align-items: stretch;
  }

  .video__player { display: block; }

  .video__frame {
    flex: none;
    aspect-ratio: 16 / 9;
  }

  .video__side { display: block; }

  .video__grid {
    height: auto !important;
    max-height: none !important;
    grid-auto-rows: auto;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    overflow: visible;
  }

  .video-card { height: auto; }

  .video-card__thumb {
    flex: none;
    aspect-ratio: 16 / 9;
  }
}

@media (max-width: 600px) {
  .video__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

/* ── Footer ────────────────────────────── */

.footer {
  border-top: 1px solid var(--border);
  padding: 56px 24px 32px;
}

.footer__inner {
  max-width: var(--maxw);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  gap: 40px;
  flex-wrap: wrap;
}

.footer__tag {
  font-size: 0.85rem;
  color: var(--muted);
  margin-top: 8px;
  max-width: 280px;
}

.footer__links {
  display: flex;
  gap: 22px;
  flex-wrap: wrap;
  align-items: flex-start;
}
.footer__links a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.88rem;
  color: var(--muted);
  text-decoration: none;
  transition: color 0.15s;
}
.footer__links a:hover { color: var(--fg); }

.footer__copy {
  max-width: var(--maxw);
  margin: 40px auto 0;
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--muted);
}

/* ── Scroll reveal ─────────────────────── */

[data-reveal] {
  opacity: 0;
  transform: translate3d(0, 12px, 0);
  transition: opacity 0.35s ease, transform 0.35s ease;
}
[data-reveal].is-in {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  [data-reveal] { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

/* ── Responsive ────────────────────────── */

@media (max-width: 900px) {
  .hero__inner { grid-template-columns: 1fr; gap: 36px; }
  .hw { grid-template-columns: 1fr; }
}

@media (max-width: 720px) {
  .nav__links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 8px 0;
  }
  .nav__links.is-open { display: flex; }
  .nav__links a { padding: 12px 24px; }
  .nav__burger { display: block; }

  .hero { padding: 48px 20px 40px; }
  .section { padding: 64px 20px; }
}

/* ════════════════════════════════════════════
   VISUAL ENHANCEMENTS
   ════════════════════════════════════════════ */

/* ── Ambient background (fixed grid + glows) ── */

body { position: relative; }

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    linear-gradient(rgba(255, 255, 255, 0.022) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.022) 1px, transparent 1px);
  background-size: 56px 56px;
  -webkit-mask-image: radial-gradient(ellipse 110% 80% at 50% 0%, #000 30%, transparent 78%);
  mask-image: radial-gradient(ellipse 110% 80% at 50% 0%, #000 30%, transparent 78%);
  pointer-events: none;
}

body::after {
  content: "";
  position: fixed;
  top: -10%;
  left: 50%;
  width: 70vw;
  height: 60vh;
  transform: translateX(-50%);
  z-index: -2;
  background: radial-gradient(ellipse at center, rgba(238, 58, 23, 0.08), transparent 68%);
  pointer-events: none;
}

/* Let the grid breathe through alt sections */
.section--alt { background: rgba(255, 255, 255, 0.018); }
.notice { background: rgba(255, 255, 255, 0.018); }

/* ── Eyebrow label ── */

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--mono);
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
  padding: 5px 12px 5px 10px;
  margin-bottom: 20px;
  border: 1px solid var(--border);
  border-radius: 99px;
  background: rgba(255, 255, 255, 0.02);
}
.eyebrow__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 8px var(--accent);
}

/* ── Nav polish ── */

.nav__logo em { text-shadow: 0 0 18px rgba(238, 58, 23, 0.5); }

/* ── Hero polish ── */

.hero { position: relative; overflow: hidden; }

.hero__kicker {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 6px 14px 6px 11px;
  border: 1px solid var(--border);
  border-radius: 99px;
  background: rgba(255, 255, 255, 0.02);
  text-transform: none;
  letter-spacing: 0.04em;
  color: var(--muted);
}
.hero__kicker-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 10px var(--accent);
  animation: pulse-dot 2.4s ease-in-out infinite;
}
@keyframes pulse-dot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.55; transform: scale(0.82); }
}

.hero__title { text-wrap: balance; }
.hero__title .accent { text-shadow: 0 0 24px rgba(238, 58, 23, 0.55); }

/* glow behind the 3D viewer */
.hero__visual { position: relative; }

/* model selector (v1 / v2) */
.model-switch {
  position: absolute;
  top: 14px;
  left: 14px;
  z-index: 3;
  display: inline-flex;
  gap: 3px;
  padding: 4px;
  border: 1px solid var(--border-strong);
  border-radius: 99px;
  background: rgba(10, 10, 11, 0.88);
}
.model-switch button {
  min-width: 42px;
  padding: 6px 14px;
  border: none;
  border-radius: 99px;
  background: transparent;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: color 0.15s, background 0.15s, box-shadow 0.15s;
}
.model-switch button:hover { color: var(--fg); }
.model-switch button.is-active {
  color: #fff;
  background: var(--accent);
  box-shadow: 0 0 16px -4px var(--accent);
}
.hero__visual::before {
  content: "";
  position: absolute;
  inset: -12% -8%;
  z-index: 0;
  background: radial-gradient(ellipse at center, rgba(238, 58, 23, 0.12), transparent 70%);
  pointer-events: none;
}

/* ── Primary button glow ── */

.btn--primary {
  box-shadow: 0 6px 22px -8px rgba(238, 58, 23, 0.7);
}
.btn--primary:hover {
  box-shadow: 0 8px 28px -6px rgba(238, 58, 23, 0.85);
  transform: translateY(-1px);
}

/* ── Feature cards: accent line + icon glow + sheen ── */

.card {
  position: relative;
  overflow: hidden;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.025), rgba(255, 255, 255, 0)) , var(--bg);
}
.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), transparent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.35s ease;
}
.card:hover::before { transform: scaleX(1); }
.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 18px 40px -22px rgba(0, 0, 0, 0.9);
}
.card__icon { transition: box-shadow 0.25s, transform 0.25s; }
.card:hover .card__icon {
  box-shadow: 0 0 0 1px rgba(238, 58, 23, 0.4), 0 0 22px -4px rgba(238, 58, 23, 0.5);
  transform: scale(1.05);
}

/* ── Hardware / flasher card depth ── */

.hw__col, .flasher {
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.02), rgba(255, 255, 255, 0)), var(--bg);
}

/* ── Viewer ring glow when ready ── */

.viewer.is-ready {
  border-color: rgba(238, 58, 23, 0.22);
  box-shadow: inset 0 0 60px -30px rgba(238, 58, 23, 0.45);
}

/* ── Staggered reveal ── */

.grid [data-reveal]:nth-child(1) { transition-delay: 0.02s; }
.grid [data-reveal]:nth-child(2) { transition-delay: 0.06s; }
.grid [data-reveal]:nth-child(3) { transition-delay: 0.10s; }
.grid [data-reveal]:nth-child(4) { transition-delay: 0.14s; }
.grid [data-reveal]:nth-child(5) { transition-delay: 0.18s; }
.grid [data-reveal]:nth-child(6) { transition-delay: 0.22s; }
.grid [data-reveal]:nth-child(7) { transition-delay: 0.26s; }
.grid [data-reveal]:nth-child(8) { transition-delay: 0.30s; }

/* ── Footer accent ── */

.footer { position: relative; }
.footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(238, 58, 23, 0.5), transparent);
}
.footer__links a { transition: color 0.15s, transform 0.15s; }
.footer__links a:hover { color: var(--accent); }

@media (prefers-reduced-motion: reduce) {
  .hero__kicker-dot { animation: none; }
}

/* ════════════════════════════════════════════
   PIXEL THEME — retro headers + pixel icons
   ════════════════════════════════════════════ */

.nav__logo,
.hero__title,
.section__title,
.flasher__ver,
.step__num,
.stat__v,
.footer__brand .nav__logo {
  font-family: var(--pixel);
  letter-spacing: 0.01em;
}

.nav__logo { font-size: 1.15rem; font-weight: 800; }
.nav__logo em { text-shadow: 0 0 14px rgba(238, 58, 23, 0.55); }

.hero__title {
  font-size: clamp(2.4rem, 5.4vw, 3.9rem);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: 0.01em;
}
.hero__title .accent { text-shadow: 0 0 18px rgba(238, 58, 23, 0.6); }

.section__title {
  font-size: clamp(1.9rem, 4.2vw, 3rem);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: 0.01em;
}

.flasher__ver { font-size: 1.6rem; font-weight: 700; }

.stat__v { font-size: 1.05rem; font-weight: 700; letter-spacing: 0.01em; }

.step__num { font-size: 1rem; font-weight: 700; }

.footer__brand .nav__logo { font-size: 1.05rem; }

/* Eyebrow → pixel font + pixel icon */
.eyebrow {
  font-family: var(--pixel);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  gap: 9px;
  padding: 6px 13px 6px 11px;
}
.eyebrow .hn {
  color: var(--accent);
  font-size: 0.92rem;
  line-height: 1;
  filter: drop-shadow(0 0 6px rgba(238, 58, 23, 0.5));
}

/* Pixel icons sit nicely inside buttons / links */
.btn .hn { font-size: 0.95rem; }
.nav__actions .hn,
.footer__links .hn { font-size: 0.95rem; }

/* ════════════════════════════════════════════
   FLASHER — visual refinement
   ════════════════════════════════════════════ */

.flasher {
  position: relative;
  overflow: hidden;
  max-width: none;
  width: 100%;
  padding: 32px 34px;
  border-color: var(--border-strong);
  background:
    radial-gradient(120% 80% at 50% -20%, rgba(238, 58, 23, 0.10), transparent 60%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.025), rgba(255, 255, 255, 0)),
    var(--bg-soft);
  box-shadow: 0 30px 70px -40px rgba(0, 0, 0, 0.9);
}
.flasher::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
  opacity: 0.8;
}

/* Header */
.flasher__head { align-items: center; }
.flasher__ver {
  display: flex;
  align-items: baseline;
  gap: 8px;
  letter-spacing: -0.01em;
}
.flasher__ver::after {
  content: "stable";
  font-size: 0.62rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #1db870;
  border: 1px solid rgba(29, 184, 112, 0.35);
  background: rgba(29, 184, 112, 0.08);
  padding: 2px 8px;
  border-radius: 99px;
  align-self: center;
}
.flasher__releases {
  padding: 7px 13px;
  border: 1px solid var(--border-strong);
  border-radius: 99px;
  transition: border-color 0.15s, background 0.15s;
}
.flasher__releases:hover {
  text-decoration: none;
  border-color: var(--accent);
  background: var(--accent-soft);
}

/* Board picker */
.board {
  position: relative;
  padding: 16px 18px;
  overflow: hidden;
  transition: border-color 0.18s, background 0.18s, transform 0.18s, box-shadow 0.18s;
}
.board::after {
  content: "";
  position: absolute;
  top: 13px;
  right: 13px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  border: 1.5px solid var(--border-strong);
  transition: all 0.18s;
}
.board:hover {
  transform: translateY(-2px);
  border-color: rgba(238, 58, 23, 0.5);
}
.board.is-active {
  border-color: var(--accent);
  background:
    linear-gradient(180deg, rgba(238, 58, 23, 0.10), rgba(238, 58, 23, 0.02));
  box-shadow: 0 10px 30px -16px rgba(238, 58, 23, 0.6);
}
.board.is-active::after {
  content: "✓";
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  font-weight: 700;
  color: #fff;
  background: var(--accent);
  border-color: var(--accent);
  box-shadow: 0 0 12px -2px var(--accent);
}
.board__name { font-size: 0.96rem; padding-right: 24px; }
.board__chip { font-size: 0.68rem; }

/* File row */
.flasher__file {
  padding: 15px 16px;
  border-color: var(--border-strong);
  background: rgba(255, 255, 255, 0.015);
}
.flasher__file > i {
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 9px;
  font-size: 1.15rem;
  background: var(--accent-soft);
  border: 1px solid rgba(238, 58, 23, 0.25);
}

/* Action buttons */
.flasher__action esp-web-install-button .btn--primary,
.flasher__action .btn { padding: 13px 24px; }

/* esptool command block */
.flasher__cmd {
  background: #08080a;
  border-color: var(--border-strong);
}

/* Tips: tidy two-column cells on wide screens */
.flasher__tips {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  border-top: 1px solid var(--border);
  padding-top: 22px;
  margin-top: 26px;
}
.flasher__tips li {
  align-items: flex-start;
  gap: 12px;
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.015);
  line-height: 1.55;
}
.flasher__tips li i {
  width: 30px;
  height: 30px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  font-size: 0.95rem;
  background: var(--accent-soft);
  border: 1px solid rgba(238, 58, 23, 0.2);
  margin-top: 1px;
  flex-shrink: 0;
}
.flasher__tips strong {
  font-weight: 600;
  color: var(--fg);
}

@media (max-width: 720px) {
  .flasher { padding: 22px; }
  .flasher__tips { grid-template-columns: 1fr; }
}