/* ═══════════════════════════════════════════════════════════
   Clean IP Scanner — Handbook (GitHub Pages)
   Dark emerald theme · bilingual FA/EN · animated
   ═══════════════════════════════════════════════════════════ */

:root {
  --bg: #070b09;
  --bg2: #0b110e;
  --panel: rgba(16, 25, 21, .72);
  --panel-solid: #101915;
  --ink: #e8f3ed;
  --muted: #93aca0;
  --brand: #10b981;
  --brand2: #34d399;
  --teal: #2dd4bf;
  --amber: #f59e0b;
  --line: rgba(52, 211, 153, .16);
  --line-soft: rgba(148, 172, 160, .12);
  --radius: 16px;
  --font-fa: "Vazirmatn", system-ui, sans-serif;
  --font-en: "Inter", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, monospace;
  --shadow: 0 20px 60px rgba(0, 0, 0, .45);
}

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

img { max-width: 100%; }

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-fa);
  line-height: 1.85;
  overflow-x: hidden;
  background-image:
    radial-gradient(1100px 500px at 85% -5%, rgba(16, 185, 129, .07), transparent 60%),
    radial-gradient(900px 500px at 10% 30%, rgba(45, 212, 191, .05), transparent 60%);
}

html[data-lang="en"] body { font-family: var(--font-en); line-height: 1.7; }

/* ── language switching ─────────────────────────────────── */
.t-en { display: none; }
html[data-lang="en"] .t-fa { display: none; }
html[data-lang="en"] .t-en { display: revert; }
html[data-lang="en"] { direction: ltr; }
html[data-lang="fa"] { direction: rtl; }

/* ── scrollbar ──────────────────────────────────────────── */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--bg2); }
::-webkit-scrollbar-thumb { background: #1d2f28; border-radius: 8px; border: 2px solid var(--bg2); }
::-webkit-scrollbar-thumb:hover { background: #274237; }

::selection { background: rgba(16, 185, 129, .35); }

/* ── progress bar ───────────────────────────────────────── */
.progress { position: fixed; inset-inline: 0; top: 0; height: 3px; z-index: 100; background: transparent; }
.progress__bar {
  height: 100%; width: 0%;
  background: linear-gradient(90deg, var(--brand), var(--teal), var(--brand2));
  box-shadow: 0 0 12px rgba(16, 185, 129, .7);
  transition: width .1s linear;
}

/* ── nav ────────────────────────────────────────────────── */
.nav {
  position: sticky; top: 0; z-index: 90;
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  background: rgba(7, 11, 9, .82);
  border-bottom: 1px solid var(--line-soft);
}
.nav__inner {
  max-width: 1180px; margin: 0 auto; padding: .7rem 1.25rem;
  display: flex; align-items: center; gap: 1rem; flex-wrap: wrap;
}
.nav__brand { display: flex; align-items: center; gap: .65rem; text-decoration: none; color: var(--ink); }
.nav__logo { position: relative; width: 42px; height: 42px; display: grid; place-items: center; }
.nav__logo img { width: 38px; height: 38px; border-radius: 10px; }
.nav__ping {
  position: absolute; inset: -3px; border-radius: 14px;
  border: 1px solid rgba(52, 211, 153, .55);
  animation: ping 2.6s ease-out infinite;
}
@keyframes ping {
  0% { transform: scale(.9); opacity: .9; }
  70%, 100% { transform: scale(1.25); opacity: 0; }
}
.nav__title { display: flex; flex-direction: column; line-height: 1.25; font-weight: 800; font-size: .95rem; }
.nav__title small { color: var(--brand2); font-weight: 600; font-size: .68rem; font-family: var(--font-mono); }
.nav__links { display: flex; gap: .15rem; flex-wrap: wrap; margin-inline: auto; }
.nav__links a {
  color: var(--muted); text-decoration: none; font-size: .85rem; font-weight: 600;
  padding: .35rem .7rem; border-radius: 999px; transition: all .25s;
}
.nav__links a:hover { color: var(--brand2); background: rgba(16, 185, 129, .1); }
.nav__actions { display: flex; gap: .5rem; align-items: center; }

/* mobile menu — burger, scrim and in-menu GitHub (desktop-inert) */
.nav__burger { display: none; }
.nav__gh-item { display: none; }
.nav__scrim {
  position: fixed; inset: 0; z-index: 85;
  background: rgba(4, 7, 5, .55);
  -webkit-backdrop-filter: blur(3px);
  backdrop-filter: blur(3px);
  opacity: 0; pointer-events: none;
  transition: opacity .3s ease;
}
.nav.menu-open + .nav__scrim { opacity: 1; pointer-events: auto; }

/* ── buttons ────────────────────────────────────────────── */
.btn {
  display: inline-flex; align-items: center; gap: .5rem;
  border-radius: 999px; text-decoration: none; cursor: pointer;
  font-family: inherit; font-weight: 700; border: 1px solid transparent;
  transition: transform .2s, box-shadow .3s, background .3s, border-color .3s;
}
.btn--sm { padding: .35rem .9rem; font-size: .8rem; }
.btn--lg { padding: .85rem 1.9rem; font-size: 1rem; }
.btn--primary {
  background: linear-gradient(135deg, var(--brand), #0d9488);
  color: #04150e; box-shadow: 0 8px 30px rgba(16, 185, 129, .35);
}
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 14px 40px rgba(16, 185, 129, .5); }
.btn--outline { border-color: var(--line); color: var(--brand2); background: rgba(16, 185, 129, .06); }
.btn--outline:hover { background: rgba(16, 185, 129, .14); transform: translateY(-2px); }
.btn--ghost { border-color: var(--line-soft); color: var(--muted); background: transparent; }
.btn--ghost:hover { color: var(--brand2); border-color: var(--line); }

/* ── hero ───────────────────────────────────────────────── */
.hero { position: relative; min-height: 92vh; min-height: 92svh; display: grid; place-items: center; overflow: hidden; }
.hero__bg { position: absolute; inset: 0; }
.hero__bg img {
  width: 100%; height: 100%; object-fit: cover; opacity: .38;
  animation: drift 26s ease-in-out infinite alternate;
  filter: saturate(1.15);
}
@keyframes drift {
  from { transform: scale(1.05) translateY(0); }
  to { transform: scale(1.14) translateY(-14px); }
}
.hero__glow {
  position: absolute; inset: 0;
  background:
    radial-gradient(720px 380px at 50% 8%, rgba(16, 185, 129, .22), transparent 65%),
    linear-gradient(180deg, rgba(7, 11, 9, .25) 0%, rgba(7, 11, 9, .72) 55%, var(--bg) 100%);
}
.particles i {
  position: absolute; width: 4px; height: 4px; border-radius: 50%;
  background: var(--brand2); opacity: 0;
  animation: float 9s ease-in infinite;
  box-shadow: 0 0 10px rgba(52, 211, 153, .8);
}
.particles i:nth-child(1) { left: 8%; animation-delay: 0s; }
.particles i:nth-child(2) { left: 16%; animation-delay: 1.2s; }
.particles i:nth-child(3) { left: 24%; animation-delay: 2.4s; }
.particles i:nth-child(4) { left: 33%; animation-delay: .6s; }
.particles i:nth-child(5) { left: 41%; animation-delay: 3.1s; }
.particles i:nth-child(6) { left: 50%; animation-delay: 1.8s; }
.particles i:nth-child(7) { left: 58%; animation-delay: 4.2s; }
.particles i:nth-child(8) { left: 66%; animation-delay: .9s; }
.particles i:nth-child(9) { left: 74%; animation-delay: 2.8s; }
.particles i:nth-child(10) { left: 82%; animation-delay: 1.4s; }
.particles i:nth-child(11) { left: 90%; animation-delay: 3.6s; }
.particles i:nth-child(12) { left: 96%; animation-delay: 2s; }
@keyframes float {
  0% { transform: translateY(105vh) scale(.6); opacity: 0; }
  12% { opacity: .85; }
  85% { opacity: .5; }
  100% { transform: translateY(-8vh) scale(1.1); opacity: 0; }
}

.hero__inner { position: relative; z-index: 2; max-width: 900px; padding: 7rem 1.5rem 6rem; text-align: center; }
.hero__badge {
  display: inline-flex; align-items: center; gap: .55rem;
  border: 1px solid var(--line); background: rgba(16, 185, 129, .08);
  color: var(--brand2); border-radius: 999px; padding: .4rem 1.1rem;
  font-size: .82rem; font-weight: 700;
}
.hero__badge .dot {
  width: 8px; height: 8px; border-radius: 50%; background: var(--brand2);
  box-shadow: 0 0 0 0 rgba(52, 211, 153, .6); animation: pulse 2s infinite;
}
@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(52, 211, 153, .55); }
  70% { box-shadow: 0 0 0 9px rgba(52, 211, 153, 0); }
  100% { box-shadow: 0 0 0 0 rgba(52, 211, 153, 0); }
}
.hero__title {
  font-size: clamp(2.3rem, 6vw, 4.3rem); font-weight: 900; line-height: 1.25;
  margin: 1.4rem 0 1rem; letter-spacing: -.01em;
}
html[data-lang="en"] .hero__title { line-height: 1.12; }
.hero__title em { font-style: normal; color: var(--brand2); }
.shimmer {
  background: linear-gradient(110deg, var(--brand) 20%, #a7f3d0 40%, var(--teal) 60%, var(--brand) 80%);
  background-size: 220% 100%;
  -webkit-background-clip: text; background-clip: text; color: transparent;
  animation: shimmer 4.5s linear infinite;
}
@keyframes shimmer { to { background-position: -220% 0; } }
.hero__sub { color: var(--muted); font-size: clamp(1rem, 2.2vw, 1.2rem); max-width: 640px; margin: 0 auto 2.2rem; }
.hero__cta { display: flex; gap: .9rem; justify-content: center; flex-wrap: wrap; margin-bottom: 3.4rem; }

/* ── terminal ───────────────────────────────────────────── */
.terminal {
  max-width: 640px; margin: 0 auto; text-align: start;
  background: rgba(5, 9, 7, .88); border: 1px solid var(--line);
  border-radius: 14px; overflow: hidden; box-shadow: var(--shadow);
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
}
.terminal__bar {
  display: flex; align-items: center; gap: .45rem; padding: .55rem .9rem;
  background: rgba(16, 25, 21, .9); border-bottom: 1px solid var(--line-soft);
}
.terminal__bar i { width: 11px; height: 11px; border-radius: 50%; background: #1f2f28; }
.terminal__bar i:nth-child(1) { background: #ef4444aa; }
.terminal__bar i:nth-child(2) { background: #f59e0baa; }
.terminal__bar i:nth-child(3) { background: #10b981aa; }
.terminal__bar span { margin-inline-start: auto; color: var(--muted); font-size: .72rem; font-family: var(--font-mono); }
.terminal__body {
  padding: 1rem 1.1rem; min-height: 158px; text-align: left;
  font-family: var(--font-mono); font-size: .82rem; line-height: 1.9;
  color: #9fe8c6; white-space: pre-wrap; word-break: break-word;
}
.terminal__body::after {
  content: "▋"; color: var(--brand2); animation: blink 1s steps(1) infinite;
}
@keyframes blink { 50% { opacity: 0; } }

.hero__wave {
  position: absolute; bottom: -2px; inset-inline: 0; height: 90px; z-index: 3;
  background: var(--bg);
  clip-path: ellipse(65% 100% at 50% 100%);
}

/* ── reveal on scroll ───────────────────────────────────── */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .8s ease, transform .8s cubic-bezier(.22, .61, .36, 1); }
.reveal.in { opacity: 1; transform: none; }
.d1 { transition-delay: .08s; } .d2 { transition-delay: .16s; } .d3 { transition-delay: .24s; }
.d4 { transition-delay: .32s; } .d5 { transition-delay: .4s; } .d6 { transition-delay: .48s; } .d7 { transition-delay: .56s; }

/* ── stats ──────────────────────────────────────────────── */
.stats { border-block: 1px solid var(--line-soft); background: rgba(11, 17, 14, .6); }
.stats__inner {
  max-width: 1080px; margin: 0 auto; padding: 2.2rem 1.5rem;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem; text-align: center;
}
.stat b {
  display: block; font-size: clamp(1.7rem, 4vw, 2.6rem); font-weight: 900;
  font-family: var(--font-mono); color: var(--brand2);
  text-shadow: 0 0 24px rgba(52, 211, 153, .4);
}
.stat span { color: var(--muted); font-size: .88rem; font-weight: 600; }

/* ── section titles ─────────────────────────────────────── */
.sec-title { text-align: center; font-size: clamp(1.7rem, 4vw, 2.5rem); font-weight: 900; margin-top: 4.5rem; }
.sec-sub { text-align: center; color: var(--muted); margin: .6rem auto 3rem; max-width: 560px; }

/* ── features ───────────────────────────────────────────── */
.features { max-width: 1180px; margin: 0 auto; padding: 0 1.5rem 4rem; }
.features__grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem; }
.card {
  background: var(--panel); border: 1px solid var(--line-soft);
  border-radius: var(--radius); padding: 1.5rem 1.3rem;
  transition: transform .35s, border-color .35s, box-shadow .35s, background .35s;
  position: relative; overflow: hidden;
}
.card::before {
  content: ""; position: absolute; inset-inline-start: 0; top: 0; height: 100%; width: 3px;
  background: linear-gradient(180deg, var(--brand), var(--teal));
  opacity: 0; transition: opacity .35s;
}
.card:hover { transform: translateY(-7px); border-color: var(--line); box-shadow: 0 18px 50px rgba(0, 0, 0, .4), 0 0 0 1px rgba(16, 185, 129, .12); background: rgba(16, 25, 21, .9); }
.card:hover::before { opacity: 1; }
.card__icon {
  font-size: 1.6rem; width: 52px; height: 52px; display: grid; place-items: center;
  background: rgba(16, 185, 129, .1); border: 1px solid var(--line);
  border-radius: 14px; margin-bottom: 1rem;
  transition: transform .35s;
}
.card:hover .card__icon { transform: scale(1.12) rotate(-5deg); }
.card h3 { font-size: 1.02rem; font-weight: 800; margin-bottom: .45rem; }
.card p { color: var(--muted); font-size: .87rem; line-height: 1.8; }

/* ── book / chapters ────────────────────────────────────── */
.book { max-width: 1180px; margin: 0 auto; padding: 2rem 1.5rem 1rem; }
.chapter {
  position: relative; padding: 4.2rem 0; border-bottom: 1px dashed var(--line-soft);
}
.chapter:last-child { border-bottom: 0; }
.chapter__num {
  position: absolute; top: 1.6rem; inset-inline-end: 0;
  font-size: clamp(4rem, 10vw, 7.5rem); font-weight: 900; line-height: 1;
  font-family: var(--font-mono);
  color: transparent; -webkit-text-stroke: 1.5px rgba(52, 211, 153, .16);
  user-select: none; pointer-events: none;
}
.chapter__grid { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr); gap: 3rem; align-items: center; }
.chapter__grid > div { position: relative; z-index: 2; min-width: 0; }
.chapter__grid--wide { grid-template-columns: minmax(0, 1fr); gap: 0; max-width: 860px; }
.chip {
  display: inline-block; color: var(--brand2); background: rgba(16, 185, 129, .1);
  border: 1px solid var(--line); border-radius: 999px;
  padding: .22rem .85rem; font-size: .78rem; font-weight: 700; margin-bottom: 1rem;
}
.chapter h2 { font-size: clamp(1.5rem, 3.4vw, 2.15rem); font-weight: 900; margin-bottom: 1.1rem; }
.chapter h3 { font-size: 1.15rem; font-weight: 800; margin: 1.8rem 0 .8rem; color: var(--brand2); }
.chapter p { color: #c4d6cc; margin-bottom: 1rem; font-size: .97rem; }
.chapter p b { color: var(--ink); }
.chapter a { color: var(--brand2); }

/* anchor jumps land below the sticky nav */
section[id], header[id] { scroll-margin-top: 92px; }
code {
  font-family: var(--font-mono); font-size: .84em;
  background: rgba(16, 185, 129, .1); border: 1px solid var(--line);
  border-radius: 6px; padding: .08em .45em; color: #a7f3d0;
}

/* art figures */
.chapter__art { position: relative; }
.chapter__art img, .shot img {
  width: 100%; height: auto; border-radius: var(--radius); border: 1px solid var(--line);
  box-shadow: var(--shadow); display: block;
}
.chapter__art img { transition: transform .5s; }
.tilt { perspective: 900px; }
.tilt img { transform: rotate3d(0, 0, 0, 0); }
.tilt:hover img { transform: rotate3d(1, -1, 0, 3.5deg) scale(1.02); }
.shot { margin: 1.8rem 0; cursor: zoom-in; }
.shot img { transition: transform .45s, box-shadow .45s; }
.shot:hover img { transform: translateY(-4px); box-shadow: 0 26px 70px rgba(0, 0, 0, .55), 0 0 0 1px rgba(16, 185, 129, .25); }
.shot figcaption, .chapter__art figcaption { text-align: center; color: var(--muted); font-size: .8rem; margin-top: .7rem; }

/* callouts */
.callout {
  border-radius: 14px; padding: 1rem 1.2rem; margin: 1.4rem 0;
  border: 1px solid; font-size: .92rem;
}
.callout b { display: inline-block; margin-inline-end: .5rem; }
.callout--tip { background: rgba(16, 185, 129, .07); border-color: var(--line); color: #bfe9d6; }
.callout--warn { background: rgba(245, 158, 11, .07); border-color: rgba(245, 158, 11, .3); color: #fcd9a2; }

/* code cards */
.codecard {
  background: rgba(5, 9, 7, .9); border: 1px solid var(--line-soft);
  border-radius: 12px; margin: .9rem 0; overflow: hidden;
  min-width: 0; max-width: 100%;
  transition: border-color .3s, box-shadow .3s;
}
.codecard:hover { border-color: var(--line); box-shadow: 0 8px 30px rgba(0, 0, 0, .35); }
.codecard__head {
  display: flex; align-items: center; justify-content: space-between;
  padding: .45rem .9rem; background: rgba(16, 25, 21, .85);
  border-bottom: 1px solid var(--line-soft);
  color: var(--muted); font-size: .74rem; font-family: var(--font-mono);
}
.codecard pre {
  padding: .9rem 1.1rem; overflow-x: auto; text-align: left;
  font-family: var(--font-mono); font-size: .84rem; line-height: 1.8; color: #9fe8c6;
  min-width: 0; max-width: 100%;
}
.codecard code { overflow-wrap: anywhere; word-break: break-word; }
.copy {
  background: transparent; border: 1px solid var(--line-soft); color: var(--muted);
  border-radius: 8px; padding: .15rem .55rem; cursor: pointer; font-size: .8rem;
  transition: all .25s; font-family: var(--font-mono);
}
.copy:hover { color: var(--brand2); border-color: var(--line); background: rgba(16, 185, 129, .1); }
.copy.done { color: #04150e; background: var(--brand2); border-color: var(--brand2); }

/* steps / checklist / kbd */
.steps { list-style: none; counter-reset: step; margin: 1.4rem 0; }
.steps li {
  counter-increment: step; position: relative; padding: .9rem 0 .9rem 0;
  padding-inline-start: 3.2rem; border-bottom: 1px dashed var(--line-soft);
}
.steps li:last-child { border-bottom: 0; }
.steps li::before {
  content: counter(step, decimal-leading-zero);
  position: absolute; inset-inline-start: 0; top: 1rem;
  width: 2.2rem; height: 2.2rem; display: grid; place-items: center;
  background: rgba(16, 185, 129, .12); border: 1px solid var(--line);
  border-radius: 10px; color: var(--brand2); font-weight: 800; font-family: var(--font-mono); font-size: .8rem;
}
.steps b { display: block; margin-bottom: .2rem; }
.steps span:not(b) { color: var(--muted); font-size: .92rem; }
.checklist { list-style: none; margin: 1.2rem 0; }
.checklist li {
  padding: .55rem 0 .55rem 0; padding-inline-start: 2rem; position: relative; color: #c4d6cc;
}
.checklist li::before {
  content: "✓"; position: absolute; inset-inline-start: 0; top: .55rem;
  color: var(--brand2); font-weight: 900;
}
.kbd-grid {
  display: flex; flex-wrap: wrap; gap: .6rem 1.4rem; align-items: center;
  margin-top: 1.4rem; color: var(--muted); font-size: .88rem;
}
kbd {
  font-family: var(--font-mono); font-size: .78rem;
  background: var(--panel-solid); border: 1px solid var(--line-soft); border-bottom-width: 2.5px;
  border-radius: 7px; padding: .12rem .5rem; color: var(--brand2);
}

/* table */
.tablewrap { overflow-x: auto; -webkit-overflow-scrolling: touch; border: 1px solid var(--line-soft); border-radius: 14px; margin: .8rem 0 1.6rem; }
table { width: 100%; border-collapse: collapse; font-size: .88rem; min-width: 560px; }
th {
  text-align: start; padding: .8rem 1.1rem; background: rgba(16, 25, 21, .9);
  color: var(--brand2); font-weight: 800; border-bottom: 1px solid var(--line);
}
td { padding: .75rem 1.1rem; border-bottom: 1px solid var(--line-soft); color: #c4d6cc; }
tr:last-child td { border-bottom: 0; }
tbody tr { transition: background .25s; }
tbody tr:hover { background: rgba(16, 185, 129, .05); }

/* faq */
.faq {
  border: 1px solid var(--line-soft); border-radius: 13px;
  margin: .7rem 0; overflow: hidden; background: rgba(11, 17, 14, .55);
  transition: border-color .3s;
}
.faq:hover { border-color: var(--line); }
.faq summary {
  cursor: pointer; padding: .95rem 1.2rem; font-weight: 700; list-style: none;
  position: relative; user-select: none;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+"; position: absolute; inset-inline-end: 1.1rem; top: 50%;
  transform: translateY(-50%); color: var(--brand2); font-weight: 900; font-size: 1.15rem;
  transition: transform .3s;
}
.faq[open] summary::after { transform: translateY(-50%) rotate(45deg); }
.faq p { padding: 0 1.2rem 1.1rem; color: var(--muted); font-size: .93rem; margin: 0; }

/* timeline */
.timeline { position: relative; margin: 1.6rem 0; padding-inline-start: 1.6rem; border-inline-start: 2px solid var(--line); }
.tl { position: relative; padding: .4rem 0 1.6rem; }
.tl:last-child { padding-bottom: .4rem; }
.tl::before {
  content: ""; position: absolute; inset-inline-start: calc(-1.6rem - 7px); top: .75rem;
  width: 12px; height: 12px; border-radius: 50%;
  background: var(--bg); border: 2.5px solid var(--brand2);
  box-shadow: 0 0 12px rgba(52, 211, 153, .6);
}
.tl b { color: var(--brand2); font-family: var(--font-mono); margin-inline-end: .7rem; }
.tl span { color: #c4d6cc; font-size: .93rem; }

.cta-final { display: flex; gap: 1rem; flex-wrap: wrap; margin-top: 2.4rem; }

/* ── footer ─────────────────────────────────────────────── */
.foot {
  border-top: 1px solid var(--line-soft);
  background: linear-gradient(180deg, transparent, rgba(16, 185, 129, .05));
  text-align: center; padding: 3.4rem 1.5rem 2.6rem;
}
.foot__logo { width: 54px; height: 54px; border-radius: 14px; margin-bottom: 1rem; }
.foot__made { font-size: .95rem; color: #c4d6cc; }
.foot__made b { color: var(--brand2); }
.foot__links { margin: .7rem 0 .4rem; }
.foot__links a { color: var(--muted); text-decoration: none; transition: color .25s; }
.foot__links a:hover { color: var(--brand2); }
.foot__copy { color: #5f7a6e; font-size: .8rem; font-family: var(--font-mono); }

/* ── lightbox ───────────────────────────────────────────── */
.lightbox[hidden] { display: none; }
.lightbox {
  position: fixed; inset: 0; z-index: 200; background: rgba(4, 7, 5, .92);
  display: grid; place-items: center; padding: 2rem;
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  animation: fadeIn .25s ease;
}
@keyframes fadeIn { from { opacity: 0; } }
.lightbox img { max-width: min(1200px, 94vw); max-height: 88vh; max-height: 88svh; border-radius: 14px; border: 1px solid var(--line); box-shadow: var(--shadow); }
.lightbox button {
  position: absolute; top: 1.2rem; inset-inline-end: 1.2rem;
  width: 42px; height: 42px; border-radius: 50%;
  background: rgba(16, 25, 21, .9); border: 1px solid var(--line);
  color: var(--ink); font-size: 1rem; cursor: pointer; transition: all .25s;
}
.lightbox button:hover { color: var(--brand2); transform: rotate(90deg); }

/* ── responsive ─────────────────────────────────────────── */
@media (max-width: 1020px) {
  .features__grid { grid-template-columns: repeat(2, 1fr); }
  .chapter__grid { grid-template-columns: minmax(0, 1fr); gap: 2rem; }
  .chapter__art { order: -1; max-width: 480px; }
  /* ── compact single-row header + hamburger drawer ── */
  .nav__inner { flex-wrap: nowrap; gap: .6rem; min-height: 62px; }
  .nav__actions { margin-inline-start: auto; }
  .nav__gh { display: none; }
  .nav__burger {
    display: inline-flex; flex-direction: column; justify-content: center; gap: 5px;
    width: 42px; height: 42px; padding: 0 11px; flex: 0 0 auto;
    background: transparent; border: 1px solid var(--line-soft); border-radius: 12px;
    cursor: pointer; transition: border-color .25s, background .25s;
  }
  .nav__burger:hover { border-color: var(--line); background: rgba(16, 185, 129, .08); }
  .nav__burger span {
    display: block; width: 100%; height: 2px; border-radius: 2px; background: var(--ink);
    transition: transform .3s ease, opacity .25s ease;
  }
  .nav.menu-open .nav__burger span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .nav.menu-open .nav__burger span:nth-child(2) { opacity: 0; transform: scaleX(.3); }
  .nav.menu-open .nav__burger span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
  /* chapter links become a dropdown card under the bar */
  .nav__links {
    display: flex; flex-direction: column; gap: .2rem;
    position: fixed; top: 70px; inset-inline: .75rem;
    margin: 0; padding: .55rem; width: auto;
    background: rgba(9, 14, 11, .97);
    border: 1px solid var(--line); border-radius: 18px;
    box-shadow: var(--shadow);
    max-height: calc(100dvh - 90px); overflow-y: auto;
    opacity: 0; visibility: hidden;
    transform: translateY(-10px) scale(.985); transform-origin: top center;
    transition: opacity .28s ease, transform .28s ease, visibility .28s;
    z-index: 95; scrollbar-width: none;
  }
  .nav__links::-webkit-scrollbar { display: none; }
  .nav.menu-open .nav__links { opacity: 1; visibility: visible; transform: none; }
  .nav__links a { flex: 0 0 auto; font-size: .98rem; padding: .85rem 1rem; border-radius: 12px; }
  .nav__links a:hover { background: rgba(16, 185, 129, .1); }
  .nav__gh-item {
    display: flex; margin-top: .4rem; padding-top: .8rem;
    border-top: 1px dashed var(--line-soft); color: var(--brand2);
  }
}
@media (max-width: 640px) {
  .features__grid { grid-template-columns: 1fr; }
  .stats__inner { grid-template-columns: repeat(2, 1fr); gap: 1.6rem; padding: 1.8rem 1.2rem; }
  .nav__inner { padding: .5rem .75rem; gap: .5rem; min-height: 58px; }
  .nav__logo { width: 36px; height: 36px; }
  .nav__logo img { width: 32px; height: 32px; border-radius: 9px; }
  .nav__title { font-size: .8rem; }
  .nav__title small { font-size: .6rem; }
  .nav__actions { gap: .4rem; }
  .nav__actions .btn { padding: .45rem .8rem; font-size: .75rem; min-height: 42px; }
  .nav__burger { width: 42px; height: 42px; }
  .nav__links { top: 64px; inset-inline: .6rem; }
  .hero { min-height: 86svh; }
  .hero__inner { padding: 4.6rem 1.1rem 4rem; }
  .hero__cta .btn--lg { width: 100%; justify-content: center; }
  .terminal__body { font-size: .72rem; padding: .85rem .9rem; min-height: 140px; }
  .codecard pre { font-size: .76rem; padding: .8rem .9rem; }
  .chapter { padding: 2.8rem 0; }
  .chapter__num { top: .7rem; font-size: 3rem; -webkit-text-stroke-width: 1px; }
  .chapter p { font-size: .95rem; }
  .sec-title { margin-top: 3rem; }
  .kbd-grid { gap: .5rem 1rem; font-size: .82rem; }
  .shot { margin: 1.4rem 0; }
  .cta-final .btn--lg { width: 100%; justify-content: center; }
  .foot { padding: 2.6rem 1.2rem 2.2rem; }
  .lightbox { padding: 1rem; }
  .lightbox img { max-height: 80svh; }
}

/* ── open-app CTA ───────────────────────────────────────── */
.nav__open { white-space: nowrap; }
.nav__open-item { display: none; }
.open-app { position: relative; padding: .6rem 1.5rem 5.5rem; max-width: 1060px; margin: 0 auto; }
.open-app__card {
  position: relative; overflow: hidden;
  display: flex; align-items: center; gap: 2rem;
  padding: 2.6rem 2.8rem;
  background: linear-gradient(140deg, rgba(16, 185, 129, .13), rgba(45, 212, 191, .05) 55%, rgba(16, 185, 129, .03));
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) + 8px);
  box-shadow: var(--shadow);
}
.open-app__card::before {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background: radial-gradient(620px 240px at 80% 0%, rgba(16, 185, 129, .12), transparent 65%);
}
.open-app__glow {
  position: absolute; top: -140px; inset-inline-end: -80px;
  width: 340px; height: 340px; border-radius: 50%; pointer-events: none;
  background: radial-gradient(circle, rgba(16, 185, 129, .22), transparent 70%);
  filter: blur(10px);
  animation: openAppPulse 5s ease-in-out infinite alternate;
}
@keyframes openAppPulse {
  from { opacity: .55; transform: scale(.94); }
  to { opacity: 1; transform: scale(1.08); }
}
.open-app__brand {
  position: relative; flex: 0 0 auto;
  width: 88px; height: 88px; display: grid; place-items: center;
  background: var(--panel-solid);
  border: 1px solid var(--line); border-radius: 22px;
  box-shadow: 0 12px 34px rgba(0, 0, 0, .4);
}
.open-app__brand img { width: 64px; height: 64px; border-radius: 16px; }
.open-app__ping {
  position: absolute; top: 8px; inset-inline-end: 8px;
  width: 10px; height: 10px; border-radius: 50%; background: var(--brand);
  box-shadow: 0 0 0 0 rgba(16, 185, 129, .55); animation: ping 1.9s ease-out infinite;
}
.open-app__text { position: relative; display: flex; flex-direction: column; gap: .8rem; }
.open-app__text h2 { font-size: clamp(1.4rem, 3vw, 1.9rem); line-height: 1.3; }
.open-app__text p { color: var(--muted); max-width: 62ch; font-size: 1.02rem; }
.open-app__actions { display: flex; gap: .9rem; flex-wrap: wrap; margin-top: .3rem; }
.open-app__hint { color: var(--muted); opacity: .85; font-size: .8rem; }

@media (max-width: 1020px) {
  .nav__open { display: none; }
  .nav__open-item {
    display: flex; margin-top: .4rem; padding-top: .8rem;
    border-top: 1px dashed var(--line-soft); color: var(--brand2); font-weight: 700;
  }
  .open-app { padding: .4rem 1.2rem 4rem; }
  .open-app__card { flex-direction: column; text-align: center; gap: 1.4rem; padding: 2.2rem 1.6rem; }
  .open-app__text p { margin-inline: auto; }
  .open-app__actions { justify-content: center; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
  html { scroll-behavior: auto; }
}