:root {
  --bg: #111820;
  --surface: #1a2433;
  --surface-2: #243044;
  --border: #3a4d66;
  --text: #f3f7fb;
  --text-secondary: #c9d4e3;
  --text-muted: #93a3b8;
  --accent: #00c471;
  --accent-dim: #00a862;
  --accent-soft: rgba(0, 196, 113, 0.14);
  --accent-glow: rgba(0, 196, 113, 0.07);
  --warn: #f0b429;
  --radius: 10px;
  --max-w: 1280px;
  --page-x: clamp(20px, 4vw, 48px);
  --band-alt: rgba(22, 31, 44, 0.72);
  --band-line: rgba(255, 255, 255, 0.04);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Apple SD Gothic Neo", "Malgun Gothic", "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.65;
  background: var(--bg);
  color: var(--text);
}

.page {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  position: relative;
  isolation: isolate;
}

.page::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(ellipse 55% 40% at 12% 8%, rgba(0, 196, 113, 0.11), transparent 68%),
    radial-gradient(ellipse 45% 35% at 88% 18%, rgba(88, 130, 190, 0.1), transparent 62%),
    radial-gradient(ellipse 50% 40% at 50% 100%, rgba(0, 196, 113, 0.07), transparent 65%),
    linear-gradient(168deg, #172231 0%, #121a26 42%, #0d1219 100%);
  pointer-events: none;
}

.page::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  opacity: 0.28;
  background-image: radial-gradient(rgba(255, 255, 255, 0.05) 0.65px, transparent 0.65px);
  background-size: 24px 24px;
  mask-image: linear-gradient(to bottom, #000 0%, #000 75%, transparent 100%);
  pointer-events: none;
}

code {
  font-family: "JetBrains Mono", "Consolas", monospace;
  font-size: 0.88em;
  padding: 0.12em 0.4em;
  border-radius: 4px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text);
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  color: var(--accent-dim);
}

.skip-link {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link:focus {
  position: fixed;
  left: 16px;
  top: 16px;
  z-index: 100;
  width: auto;
  height: auto;
  margin: 0;
  padding: 8px 16px;
  overflow: visible;
  clip: auto;
  background: var(--accent);
  color: #041a10;
  font-weight: 600;
  border-radius: 6px;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  background: rgba(14, 20, 28, 0.78);
  backdrop-filter: blur(14px) saturate(1.2);
  padding: 0 var(--page-x);
}

.topbar-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px 16px;
  min-height: 56px;
  padding: 8px 0;
}

.brand {
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: -0.02em;
  white-space: nowrap;
}

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

.nav {
  display: none;
  gap: 2px;
  margin-left: auto;
}

.nav a {
  padding: 8px 12px;
  border-radius: 6px;
  color: var(--text-secondary);
  font-size: 0.88rem;
  font-weight: 500;
}

.nav a:hover {
  color: var(--text);
  background: var(--surface);
  text-decoration: none;
}

.badge {
  margin-left: auto;
  font-size: 0.75rem;
  padding: 4px 10px;
  border-radius: 999px;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  white-space: nowrap;
}

.badge-ok {
  color: var(--accent);
  border-color: rgba(0, 196, 113, 0.4);
  background: var(--accent-soft);
}

.badge-warn {
  color: var(--warn);
  border-color: rgba(240, 180, 41, 0.35);
}

main {
  flex: 1;
  width: 100%;
  max-width: none;
  margin: 0;
  padding: 0;
}

.hero-wrap {
  position: relative;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 48px var(--page-x) 56px;
}

.hero-wrap::before {
  content: "";
  position: absolute;
  inset: 0 -24px;
  z-index: -1;
  background:
    radial-gradient(ellipse 70% 85% at 78% 42%, rgba(0, 196, 113, 0.14), transparent 62%),
    radial-gradient(ellipse 50% 60% at 10% 80%, rgba(70, 110, 170, 0.08), transparent 55%);
  pointer-events: none;
}

.section-band {
  position: relative;
  isolation: isolate;
  border-top: 1px solid rgba(255, 255, 255, 0.07);
  padding: 64px var(--page-x);
  scroll-margin-top: 72px;
}

.section-band::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
}

#features::before {
  background:
    radial-gradient(ellipse 75% 90% at 0% 40%, rgba(0, 196, 113, 0.13), transparent 58%),
    linear-gradient(180deg, rgba(28, 40, 56, 0.72) 0%, rgba(20, 30, 44, 0.45) 100%);
}

#download::before {
  background:
    radial-gradient(ellipse 50% 60% at 90% 20%, rgba(100, 145, 210, 0.09), transparent 55%),
    linear-gradient(180deg, rgba(16, 24, 36, 0.35) 0%, rgba(22, 32, 46, 0.55) 100%);
}

#start::before {
  background:
    radial-gradient(ellipse 65% 75% at 100% 35%, rgba(0, 196, 113, 0.12), transparent 58%),
    radial-gradient(ellipse 40% 50% at 0% 90%, rgba(80, 120, 180, 0.07), transparent 50%),
    linear-gradient(180deg, rgba(26, 38, 54, 0.78) 0%, rgba(18, 28, 40, 0.5) 100%);
}

#commands::before {
  background:
    radial-gradient(ellipse 55% 65% at 85% 75%, rgba(110, 150, 210, 0.1), transparent 58%),
    linear-gradient(180deg, rgba(18, 27, 40, 0.42) 0%, rgba(14, 21, 32, 0.62) 100%);
}

#help::before {
  background:
    radial-gradient(ellipse 60% 55% at 15% 100%, rgba(0, 196, 113, 0.1), transparent 55%),
    linear-gradient(180deg, rgba(24, 36, 50, 0.7) 0%, rgba(11, 16, 24, 0.88) 100%);
}

.section-band-alt {
  box-shadow: inset 0 1px 0 var(--band-line);
}

.section-inner {
  max-width: var(--max-w);
  margin: 0 auto;
}

.section-header {
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
}

.section-eyebrow {
  display: block;
  margin: 0 0 8px;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
}

.section-header h2 {
  margin: 0 0 10px;
  font-size: 1.45rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--text);
}

.section-header .section-lead {
  margin: 0;
  max-width: 52em;
}

section {
  scroll-margin-top: 72px;
}

section h2 {
  margin: 0 0 10px;
  font-size: 1.45rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--text);
}

.section-lead {
  margin: 0 0 24px;
  color: var(--text-secondary);
  font-size: 1rem;
  max-width: 52em;
}

.hero {
  display: grid;
  gap: 36px;
  margin-bottom: 0;
}

.hero-eyebrow {
  margin: 0 0 12px;
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
}

.hero h1 {
  margin: 0 0 18px;
  font-size: clamp(2.1rem, 4.5vw, 3rem);
  line-height: 1.16;
  letter-spacing: -0.04em;
  font-weight: 800;
  max-width: 14em;
}

.hero-lead {
  margin: 0 0 28px;
  color: var(--text-secondary);
  font-size: 1.1rem;
  max-width: 38em;
  line-height: 1.7;
}

.hero-highlights {
  list-style: none;
  margin: 0 0 28px;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.hero-highlights li {
  position: relative;
  padding-left: 1.35em;
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.55;
}

.hero-highlights li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 8px var(--accent-glow);
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 22px;
  border-radius: var(--radius);
  font-size: 0.92rem;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}

.btn-lg {
  min-height: 48px;
  padding: 0 24px;
  font-size: 0.95rem;
  width: 100%;
}

.btn-primary {
  background: var(--accent);
  color: #041a10;
}

.btn-primary:hover {
  background: var(--accent-dim);
  color: #041a10;
  text-decoration: none;
}

.btn-secondary {
  background: var(--surface-2);
  border-color: var(--border);
  color: var(--text);
}

.btn-secondary:hover {
  border-color: rgba(0, 196, 113, 0.45);
  color: var(--accent);
  text-decoration: none;
}

.btn-disabled {
  background: var(--surface-2);
  border-color: var(--border);
  color: var(--text-muted);
  cursor: not-allowed;
  pointer-events: none;
}

.hero-showcase {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: calc(var(--radius) + 2px);
  overflow: hidden;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.22);
}

.showcase-tabs {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--border);
  background: var(--surface-2);
  padding: 0;
}

.showcase-tab {
  position: relative;
  flex: 1;
  min-height: 44px;
  padding: 0 12px;
  margin: 0;
  border: 0;
  border-radius: 0;
  appearance: none;
  -webkit-appearance: none;
  background-color: var(--surface-2);
  color: var(--text-secondary);
  font: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  overflow: hidden;
  transition: color 0.2s ease, background-color 0.2s ease;
}

.showcase-tab-label {
  position: relative;
  z-index: 1;
}

.showcase-tab-progress {
  position: absolute;
  left: 0;
  bottom: 0;
  height: 2px;
  width: 100%;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left center;
  opacity: 0;
}

.showcase-tab.is-active .showcase-tab-progress {
  opacity: 1;
  animation: showcase-progress 4.5s linear forwards;
}

.hero-showcase.is-paused .showcase-tab.is-active .showcase-tab-progress {
  animation-play-state: paused;
}

@keyframes showcase-progress {
  from {
    transform: scaleX(0);
  }

  to {
    transform: scaleX(1);
  }
}

.showcase-tab:hover {
  color: var(--text);
}

.showcase-tab.is-active {
  color: var(--accent);
  background-color: var(--surface);
}

.showcase-panels {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  padding: 18px;
}

.showcase-panel {
  grid-area: 1 / 1;
  margin: 0;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.45s ease;
}

.showcase-panel.is-active {
  opacity: 1;
  pointer-events: auto;
  z-index: 1;
}

.showcase-panel figcaption {
  margin-top: 12px;
  font-size: 0.88rem;
  color: var(--text-secondary);
  text-align: center;
}

.mock {
  border-radius: calc(var(--radius) - 2px);
  background: #151d28;
  border: 1px solid var(--border);
  overflow: hidden;
  min-height: 240px;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.mock-bar {
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-muted);
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

.mock-line {
  font-size: 0.84rem;
  font-family: "JetBrains Mono", "Consolas", monospace;
  color: var(--text);
}

.mock-line.muted {
  color: var(--text-secondary);
}

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

.mock-pill {
  margin-top: auto;
  align-self: flex-start;
  font-size: 0.75rem;
  padding: 6px 10px;
  border-radius: 999px;
  background: var(--accent-soft);
  border: 1px solid rgba(0, 196, 113, 0.4);
  color: var(--accent);
}

.mock-ui-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  border-radius: 6px;
  background: var(--surface);
  border: 1px solid var(--border);
  font-size: 0.86rem;
  color: var(--text);
}

.mock-tag {
  font-size: 0.72rem;
  padding: 2px 8px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
}

.mock-code {
  font-family: "JetBrains Mono", "Consolas", monospace;
  font-size: 0.78rem;
  padding: 10px 12px;
  border-radius: 6px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text-secondary);
}

.mock-ui-foot {
  margin-top: auto;
  font-size: 0.78rem;
  color: var(--text-muted);
}

.mock-donation {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 12px;
  border-radius: 8px;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-secondary);
}

.mock-amount {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--accent);
  letter-spacing: -0.03em;
}

.mock-blocks {
  display: flex;
  gap: 6px;
  margin-top: auto;
}

.mock-blocks span {
  width: 28px;
  height: 28px;
  border-radius: 4px;
  background: var(--surface-2);
  border: 1px solid var(--border);
}

.mock-blocks span.active {
  background: var(--accent-soft);
  border-color: rgba(0, 196, 113, 0.5);
  box-shadow: inset 0 0 0 1px rgba(0, 196, 113, 0.25);
}

.download-card {
  display: grid;
  gap: 24px;
  padding: 28px 32px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: calc(var(--radius) + 2px);
}

.download-icon {
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  background: var(--accent-soft);
  border: 1px solid rgba(0, 196, 113, 0.4);
  color: var(--accent);
  font-size: 1.25rem;
}


.download-body {
  min-width: 0;
}

.req-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.req-list li {
  font-size: 0.95rem;
  color: var(--text-secondary);
}

.req-list strong {
  color: var(--text);
}

.download-action {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.download-note {
  margin: 0;
  font-size: 0.84rem;
  color: var(--text-muted);
  text-align: center;
}

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

.feature-card {
  background: linear-gradient(145deg, rgba(30, 42, 58, 0.95) 0%, rgba(22, 32, 46, 0.88) 100%);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius);
  padding: 22px 24px;
  box-shadow:
    0 1px 0 rgba(255, 255, 255, 0.04) inset,
    0 12px 32px rgba(0, 0, 0, 0.18);
}

.feature-icon {
  display: inline-block;
  margin-bottom: 12px;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--accent);
}

.feature-card h3 {
  margin: 0 0 8px;
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
}

.feature-card p {
  margin: 0;
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

.stepper {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0;
}

.stepper > li {
  list-style: none;
}

.step {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 16px;
  padding: 0 0 28px;
  position: relative;
}

.step:not(:last-child)::before {
  content: "";
  position: absolute;
  left: 19px;
  top: 40px;
  bottom: 0;
  width: 2px;
  background: var(--border);
}

.step-marker {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  background: var(--accent-soft);
  border: 1px solid rgba(0, 196, 113, 0.4);
  color: var(--accent);
  font-size: 0.9rem;
  font-weight: 700;
  flex-shrink: 0;
}

.step-body h3 {
  margin: 8px 0 6px;
  font-size: 1.02rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
}

.step-body p {
  margin: 0 0 6px;
  color: var(--text-secondary);
  font-size: 0.96rem;
  line-height: 1.65;
}

.table-wrap {
  overflow-x: auto;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}

th,
td {
  text-align: left;
  padding: 14px 18px;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}

th {
  position: sticky;
  top: 0;
  background: var(--surface-2);
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

td {
  color: var(--text-secondary);
}

tr:last-child td {
  border-bottom: none;
}

td code {
  white-space: nowrap;
  color: var(--text);
}

.alert {
  border-radius: var(--radius);
  padding: 18px 20px;
  margin-bottom: 16px;
}

.alert-info {
  background: var(--accent-soft);
  border: 1px solid rgba(0, 196, 113, 0.32);
}

.alert strong {
  display: block;
  margin-bottom: 6px;
  font-size: 0.98rem;
  color: var(--text);
}

.alert p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.65;
}

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

.help-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 22px;
}

.help-card h3 {
  margin: 0 0 10px;
  font-size: 0.98rem;
  font-weight: 700;
  color: var(--text);
}

.help-card ul {
  margin: 0 0 8px;
  padding-left: 1.2rem;
  color: var(--text-secondary);
}

.help-card li {
  margin-bottom: 4px;
}

.help-muted {
  margin: 0;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 10px;
}

.tag-list code {
  font-size: 0.8rem;
}

.site-footer {
  position: relative;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  padding: 28px var(--page-x) 32px;
  background: rgba(8, 12, 18, 0.6);
}

.footer-inner {
  max-width: var(--max-w);
  margin: 0 auto;
}

.footer-row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px 16px;
  margin-bottom: 10px;
}

.footer-brand {
  margin: 0;
  font-size: 0.92rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
}

.footer-brand span {
  color: var(--accent);
}

.footer-contact {
  font-size: 0.88rem;
  color: var(--text-secondary);
  text-decoration: none;
}

.footer-contact:hover {
  color: var(--accent);
  text-decoration: underline;
}

.footer-terms {
  margin: 0 0 12px;
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.55;
  max-width: 36em;
}

.footer-copy {
  margin: 0;
  font-size: 0.78rem;
  color: var(--text-muted);
  opacity: 0.75;
}

@media (min-width: 640px) {
  .topbar-inner {
    flex-wrap: nowrap;
    padding: 0;
  }

  .nav {
    display: flex;
    margin-left: auto;
  }

  .badge {
    margin-left: 0;
    flex-shrink: 0;
  }

  .download-card {
    grid-template-columns: auto 1fr auto;
    align-items: start;
  }

  .download-action {
    min-width: 240px;
  }

  .btn-lg {
    width: auto;
    min-width: 240px;
  }

  .download-note {
    text-align: left;
  }

  .feature-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .help-grid {
    grid-template-columns: 1fr 1.4fr;
  }
}

@media (min-width: 900px) {
  .hero {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 48px;
    align-items: stretch;
    margin-bottom: 72px;
    padding-top: 12px;
  }

  .hero-showcase {
    display: flex;
    flex-direction: column;
  }

  .showcase-panels {
    flex: 1;
    display: grid;
    grid-template-columns: 1fr;
    padding: 20px;
  }

  .showcase-panel.is-active {
    display: flex;
    flex-direction: column;
  }

  .showcase-panel.is-active .mock {
    flex: 1;
    min-height: 280px;
  }

  .step {
    grid-template-columns: 48px 1fr;
    gap: 20px;
  }

  .step-marker {
    width: 48px;
    height: 48px;
  }

  .step:not(:last-child)::before {
    left: 23px;
    top: 48px;
  }
}

@media (min-width: 1440px) {
  :root {
    --max-w: 1360px;
  }
}

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

  .btn,
  .showcase-tab,
  .showcase-panel {
    transition: none;
  }

  .showcase-tab.is-active .showcase-tab-progress {
    animation: none;
    transform: scaleX(1);
    opacity: 0.5;
  }
}