:root {
  --bg: #060a11;
  --card: #0f1723;
  --text: #f2f5f9;
  --muted: #94a1b6;
  --line: rgba(255, 255, 255, 0.1);
  --accent: #5eead4;
  --ink: #05201b;
}
* { box-sizing: border-box; }
html, body {
  margin: 0;
  min-height: 100%;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.5 "Plus Jakarta Sans", Inter, system-ui, -apple-system, sans-serif;
  -webkit-font-smoothing: antialiased;
}
body {
  max-width: 480px;
  margin: 0 auto;
  padding: 14px 16px 40px;
  background:
    radial-gradient(680px 380px at 50% -8%, rgba(94, 234, 212, 0.16), transparent 70%),
    var(--bg);
}
[hidden] { display: none !important; }

.in-top {
  display: flex;
  align-items: center;
  gap: 10px;
  height: 44px;
  margin-bottom: 10px;
}
.in-back {
  color: var(--muted);
  text-decoration: none;
  font-weight: 700;
  font-size: 0.9rem;
}
.in-top strong {
  margin-left: auto;
  font-size: 0.9rem;
  color: var(--muted);
  font-weight: 700;
}

/* Hero */
.in-hero {
  text-align: center;
  padding: 26px 20px 22px;
  border-radius: 24px;
  background: linear-gradient(180deg, rgba(94, 234, 212, 0.1), rgba(15, 23, 35, 0.9) 55%);
  border: 1px solid rgba(94, 234, 212, 0.24);
  box-shadow: 0 24px 60px -30px rgba(94, 234, 212, 0.4);
}
.in-mark {
  width: 76px;
  height: 76px;
  border-radius: 20px;
  display: block;
  margin: 0 auto 14px;
  box-shadow: 0 14px 32px -14px rgba(0, 0, 0, 0.9);
}
.in-hero h1 {
  margin: 0 0 4px;
  font-size: 1.6rem;
  letter-spacing: -0.035em;
}
.in-hero .in-sub {
  margin: 0 0 18px;
  color: var(--muted);
  font-size: 0.94rem;
}
.in-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 10px;
  padding: 4px 12px;
  border-radius: 999px;
  background: rgba(94, 234, 212, 0.14);
  color: var(--accent);
  font-size: 0.74rem;
  font-weight: 800;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.in-cta {
  appearance: none;
  width: 100%;
  border: 0;
  border-radius: 16px;
  min-height: 56px;
  display: grid;
  place-items: center;
  font: inherit;
  font-size: 1.02rem;
  font-weight: 800;
  cursor: pointer;
  text-decoration: none;
  background: var(--accent);
  color: var(--ink);
  transition: transform 0.12s ease, filter 0.12s ease;
}
.in-cta:hover { filter: brightness(1.06); }
.in-cta:active { transform: scale(0.985); }
.in-cta[disabled] {
  opacity: 0.55;
  cursor: default;
}
.in-cta.is-ghost {
  background: transparent;
  color: var(--accent);
  border: 1px solid rgba(94, 234, 212, 0.4);
}

/* Always-visible 1-2-3 comic */
.in-strip {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  align-items: stretch;
  gap: 6px;
  margin: 16px 0 4px;
  text-align: center;
}
.in-strip-arr {
  align-self: center;
  color: var(--accent);
  font-size: 1.1rem;
  font-weight: 800;
  opacity: 0.7;
}
.in-strip-item {
  padding: 10px 6px 8px;
  border-radius: 14px;
  background: rgba(0, 0, 0, 0.28);
  border: 1px solid var(--line);
}
.in-strip-n {
  display: inline-grid;
  place-items: center;
  width: 20px;
  height: 20px;
  margin-bottom: 6px;
  border-radius: 6px;
  background: rgba(94, 234, 212, 0.18);
  color: var(--accent);
  font-size: 0.7rem;
  font-weight: 800;
}
.in-strip-item b {
  display: block;
  font-size: 0.72rem;
  line-height: 1.3;
  font-weight: 800;
}

/* Fake Windows save dialog */
.win-dlg {
  margin: 0 0 16px;
  border-radius: 10px;
  overflow: hidden;
  background: #202020;
  border: 1px solid #3a3a3a;
  text-align: left;
  font-size: 0.78rem;
  box-shadow: 0 18px 40px -20px #000;
}
.win-dlg-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 7px 10px;
  background: #2b2b2b;
  color: #e8e8e8;
  font-weight: 700;
}
.win-dlg-bar span { margin-left: auto; opacity: 0.45; letter-spacing: 6px; }
.win-dlg-body {
  display: grid;
  grid-template-columns: 118px 1fr;
  min-height: 132px;
}
.win-dlg-side {
  padding: 8px 6px;
  background: #191919;
  color: #cfcfcf;
}
.win-dlg-side div {
  padding: 6px 8px;
  border-radius: 6px;
  margin-bottom: 2px;
}
.win-dlg-side .on {
  background: rgba(94, 234, 212, 0.2);
  color: var(--accent);
  font-weight: 800;
}
.win-dlg-main {
  padding: 16px 12px 10px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.win-file {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 800;
  color: #f2f5f9;
}
.win-file img { width: 32px; height: 32px; border-radius: 8px; }
.win-dlg-foot {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  padding: 8px 10px 10px;
  background: #2b2b2b;
}
.win-btn {
  min-width: 88px;
  height: 28px;
  border-radius: 4px;
  display: grid;
  place-items: center;
  font-weight: 800;
  font-size: 0.75rem;
}
.win-btn-ok {
  background: var(--accent);
  color: var(--ink);
  animation: pulse 1.3s ease-in-out infinite;
}
.win-btn-no {
  background: #3a3a3a;
  color: #ddd;
}

/* Fake desktop */
.win-desk {
  position: relative;
  margin: 0 0 16px;
  height: 148px;
  border-radius: 12px;
  overflow: hidden;
  background:
    linear-gradient(160deg, #1a4a6e 0%, #0c2740 50%, #071018 100%);
  border: 1px solid var(--line);
}
.win-desk-icon {
  position: absolute;
  left: 18px;
  top: 18px;
  width: 74px;
  text-align: center;
  animation: popin 0.45s ease both;
}
.win-desk-icon img {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: block;
  margin: 0 auto 6px;
  box-shadow: 0 8px 18px -8px #000;
}
.win-desk-icon b {
  font-size: 0.7rem;
  font-weight: 800;
  text-shadow: 0 1px 2px #000;
}
.win-task {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 22px;
  background: rgba(10, 16, 28, 0.78);
  border-top: 1px solid rgba(255,255,255,0.08);
}
@keyframes popin {
  from { opacity: 0; transform: scale(0.6); }
}

/* Chrome download shelf hint */
.in-shelf {
  margin: 14px 0 0;
  padding: 10px 12px;
  border-radius: 12px;
  background: #2b2b2b;
  border: 1px solid #444;
  display: flex;
  align-items: center;
  gap: 10px;
  text-align: left;
}
.in-shelf img { width: 32px; height: 32px; border-radius: 8px; }
.in-shelf b { display: block; font-size: 0.82rem; }
.in-shelf span { font-size: 0.75rem; color: #b8b8b8; }
.in-shelf-arrow {
  margin-left: auto;
  color: var(--accent);
  font-size: 1.4rem;
  animation: pulse 1.15s ease-in-out infinite;
}

.in-note {
  margin: 12px 0 0;
  font-size: 0.82rem;
  color: var(--muted);
  line-height: 1.45;
}
.in-ok {
  margin: 14px 0 0;
  padding: 11px 13px;
  border-radius: 12px;
  background: rgba(94, 234, 212, 0.13);
  border: 1px solid rgba(94, 234, 212, 0.32);
  color: var(--accent);
  font-size: 0.86rem;
  font-weight: 700;
  text-align: left;
}

/* Section head */
.in-h2 {
  margin: 26px 0 12px;
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--muted);
}

/* OS tabs */
.in-tabs {
  display: flex;
  gap: 6px;
  padding: 4px;
  margin-bottom: 14px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.05);
}
.in-tab {
  flex: 1;
  height: 38px;
  appearance: none;
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-weight: 700;
  font-size: 0.84rem;
  cursor: pointer;
  transition: background 0.15s ease, color 0.15s ease;
}
.in-tab.is-on {
  background: var(--accent);
  color: var(--ink);
}

/* Progress */
.in-bar {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 14px;
}
.in-dot {
  flex: 1;
  height: 5px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.1);
  transition: background 0.25s ease;
}
.in-dot.is-on { background: var(--accent); }

/* Step card */
.in-card {
  padding: 20px;
  border-radius: 20px;
  background: var(--card);
  border: 1px solid var(--line);
  animation: rise 0.24s ease both;
}
@keyframes rise {
  from { opacity: 0; transform: translateY(8px); }
}
.in-num {
  display: inline-grid;
  place-items: center;
  width: 30px;
  height: 30px;
  margin-bottom: 12px;
  border-radius: 10px;
  background: rgba(94, 234, 212, 0.16);
  color: var(--accent);
  font-weight: 800;
  font-size: 0.9rem;
}
.in-card h2 {
  margin: 0 0 8px;
  font-size: 1.2rem;
  letter-spacing: -0.03em;
}
.in-card p {
  margin: 0 0 16px;
  color: #c3cddb;
  font-size: 0.95rem;
}
.in-art {
  min-height: 92px;
  margin-bottom: 18px;
  padding: 12px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  text-align: center;
  background: rgba(255, 255, 255, 0.035);
  border: 1px solid var(--line);
  color: #c3cddb;
  font-weight: 700;
  font-size: 0.92rem;
}
.in-art img { width: 44px; height: 44px; border-radius: 11px; }
.in-art .on { color: var(--accent); }
.in-chip {
  display: inline-grid;
  place-items: center;
  min-width: 34px;
  height: 34px;
  padding: 0 9px;
  border-radius: 10px;
  background: rgba(94, 234, 212, 0.18);
  color: var(--accent);
  font-size: 1.05rem;
  animation: pulse 1.3s ease-in-out infinite;
}
@keyframes pulse {
  50% { transform: scale(1.1); }
}

.in-nav {
  display: flex;
  align-items: center;
  gap: 10px;
}
.in-next,
.in-prev {
  appearance: none;
  border: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 22px;
  border-radius: 14px;
  font: inherit;
  font-weight: 800;
  text-decoration: none;
  cursor: pointer;
}
.in-next {
  margin-left: auto;
  background: var(--accent);
  color: var(--ink);
}
.in-prev {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--line);
}