:root {
  --brand: #34a853;
  --brand-pressed: #2c8e46;
  --brand-tint: #f2faf4;
  --on-brand: #ffffff;

  --neutral-900: #14181a;
  --neutral-700: #3a4248;
  --neutral-500: #616e78;
  --neutral-400: #8a949b;
  --neutral-300: #c5cdd2;
  --neutral-200: #e4e8eb;
  --neutral-100: #eef1f3;
  --fill-soft: #f7f8f9;
  --summary: #fafbfc;
  --border-muted: #e8ecef;
  --hairline: #f2f4f5;
  --surface: #ffffff;

  --grade-a: #2e9e5b;
  --grade-b: #55a46f;
  --grade-c: #e8a33d;
  --grade-c-fg: #4a3910;
  --grade-d: #dc4c3e;

  --font-sans: "Pretendard", -apple-system, BlinkMacSystemFont,
    "Apple SD Gothic Neo", "Malgun Gothic", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas,
    monospace;

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --shadow-card: 0 1px 2px rgba(20, 24, 26, 0.06);

  --header-h: 68px;
  --gutter: 20px;
  --max: 1160px;

  /* --fs-title (card/legal headings) is larger than --fs-lead (intro copy).
     Do not shrink --fs-lead or .hero-lead on small screens. */
  --fs-meta: 13px;
  --fs-caption: 14px;
  --fs-body: 16px;
  --fs-label: 17px;
  --fs-lead: 18px;
  --fs-title: 20px;
  --fs-brand: 21px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
  word-break: keep-all;
  overflow-wrap: break-word;
  line-break: strict;
}

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

body {
  margin: 0;
  color: var(--neutral-900);
  background: var(--surface);
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

body.is-nav-open {
  overflow: hidden;
}

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

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  padding: 0;
  cursor: pointer;
}

:focus-visible {
  outline: 2px solid var(--brand);
  outline-offset: 3px;
}

[hidden] {
  display: none !important;
}

.skip-link {
  position: absolute;
  left: 16px;
  top: -48px;
  z-index: 100;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  background: var(--neutral-900);
  color: #fff;
  font-size: 14px;
  font-weight: 600;
}

.skip-link:focus {
  top: 12px;
}

.wrap {
  width: min(var(--max), calc(100% - var(--gutter) * 2));
  margin-inline: auto;
}

.mono {
  font-family: var(--font-mono);
  font-feature-settings: "tnum" 1;
  letter-spacing: -0.02em;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 12px;
  color: var(--brand-pressed);
  font-size: var(--fs-caption);
  font-weight: 700;
  letter-spacing: 0.02em;
}

.eyebrow::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--brand);
}

h1,
h2,
h3,
p {
  margin: 0;
}

.section {
  padding: 96px 0;
}

.section-head {
  max-width: 680px;
  margin-bottom: 40px;
}

.section-head h2,
.install h2,
.cta-band h2 {
  font-size: clamp(30px, 4.5vw, 44px);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1.22;
}

.section-head p {
  margin-top: 14px;
  color: var(--neutral-700);
  font-size: var(--fs-lead);
  line-height: 1.65;
}

.header {
  position: sticky;
  top: 0;
  z-index: 40;
  height: calc(var(--header-h) + env(safe-area-inset-top, 0px));
  padding-top: env(safe-area-inset-top, 0px);
  padding-left: env(safe-area-inset-left, 0px);
  padding-right: env(safe-area-inset-right, 0px);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

.header.is-scrolled {
  box-shadow: 0 1px 0 var(--hairline);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  height: var(--header-h);
}

.header-end {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: none;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 48px;
}

.brand-mark {
  width: 32px;
  height: 32px;
  color: var(--brand);
}

.brand-name {
  font-size: var(--fs-brand);
  font-weight: 800;
  letter-spacing: -0.03em;
}

.nav-desktop {
  display: none;
  align-items: center;
  gap: 28px;
}

.nav-desktop a {
  color: var(--neutral-700);
  font-size: var(--fs-body);
  font-weight: 600;
}

.nav-desktop a:hover {
  color: var(--neutral-900);
}

.nav-toggle {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  color: var(--neutral-900);
}

.nav-toggle svg {
  width: 22px;
  height: 22px;
}

.nav-panel {
  position: fixed;
  top: calc(var(--header-h) + env(safe-area-inset-top, 0px));
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 35;
  box-sizing: border-box;
  padding: 16px max(20px, env(safe-area-inset-right, 0px))
    max(32px, env(safe-area-inset-bottom, 0px))
    max(20px, env(safe-area-inset-left, 0px));
  background: #fff;
  overflow: auto;
}

.nav-panel a {
  display: block;
  padding: 16px 4px;
  border-bottom: 1px solid var(--hairline);
  font-size: var(--fs-label);
  font-weight: 700;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 18px;
  border-radius: var(--radius-md);
  font-size: var(--fs-body);
  font-weight: 700;
  text-align: center;
}

.btn-lg {
  min-height: 52px;
  padding: 0 22px;
  font-size: var(--fs-body);
}

.btn-primary {
  background: var(--brand);
  color: var(--on-brand);
}

.btn-primary:hover {
  background: var(--brand-pressed);
}

.btn-secondary {
  background: #fff;
  color: var(--neutral-900);
  border: 1.5px solid var(--border-muted);
}

.btn-secondary:hover {
  border-color: var(--neutral-300);
  background: var(--fill-soft);
}

.store-btn.is-disabled {
  cursor: default;
  opacity: 0.72;
}

.header-cta {
  display: inline-flex;
  min-height: 40px;
  padding: 0 12px;
  font-size: var(--fs-caption);
  white-space: nowrap;
}

.hero {
  padding: 40px 0 48px;
  background: var(--surface);
}

.band-soft {
  background: var(--fill-soft);
}

.hero-grid {
  display: grid;
  gap: 40px;
  align-items: center;
}

.hero h1 {
  max-width: 16ch;
  font-size: clamp(40px, 6.5vw, 64px);
  font-weight: 800;
  letter-spacing: -0.045em;
  line-height: 1.15;
}

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

.hero-lead {
  max-width: 36em;
  margin-top: 18px;
  color: var(--neutral-700);
  font-size: var(--fs-lead);
  line-height: 1.65;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 28px;
}

.hero-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px 16px;
  max-width: 560px;
  margin: 40px 0 0;
}

.hero-stats dt {
  color: var(--neutral-900);
  font-size: var(--fs-label);
  font-weight: 700;
}

.hero-stats dd {
  margin: 4px 0 0;
  color: var(--neutral-500);
  font-size: var(--fs-body);
}

.phone-stage {
  position: relative;
  display: flex;
  justify-content: center;
  padding-bottom: 28px;
}

.phone-stage::before {
  content: "";
  position: absolute;
  width: 260px;
  height: 220px;
  left: 50%;
  bottom: 48px;
  border-radius: 50%;
  background: rgba(52, 168, 83, 0.18);
  filter: blur(48px);
  transform: translateX(-50%);
  pointer-events: none;
}

.phone-stage::after {
  content: "";
  position: absolute;
  z-index: 0;
  left: 50%;
  bottom: 8px;
  width: 210px;
  height: 28px;
  border-radius: 50%;
  background: rgba(20, 24, 26, 0.38);
  filter: blur(18px);
  transform: translateX(-50%);
  pointer-events: none;
}

.phone {
  position: relative;
  z-index: 1;
  width: 280px;
  height: 580px;
  border-radius: 44px;
  padding: 10px;
  background: linear-gradient(160deg, #4a4a4a 0%, #2a2a2a 38%, #161616 100%);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.28),
    inset 0 -1px 0 rgba(0, 0, 0, 0.5),
    0 4px 8px rgba(20, 24, 26, 0.2),
    0 16px 28px rgba(20, 24, 26, 0.16),
    0 36px 60px rgba(20, 24, 26, 0.22);
}

.phone-screen {
  position: relative;
  height: 100%;
  overflow: hidden;
  border-radius: 36px;
  background: var(--surface);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.06);
}

.island {
  position: absolute;
  top: 8px;
  left: 50%;
  z-index: 3;
  width: 86px;
  height: 22px;
  background: #14181a;
  border-radius: 12px;
  transform: translateX(-50%);
}

.phone-status {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 16px 4px;
  font-size: 11px;
  font-weight: 700;
}

.os-ic {
  display: flex;
  align-items: center;
  gap: 4px;
}

.phone-appbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 6px 16px 8px;
}

.phone-appbar strong {
  font-size: 18px;
  font-weight: 800;
  letter-spacing: -0.04em;
}

.phone-icons {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--neutral-900);
}

.phone-icons svg {
  width: 18px;
  height: 18px;
}

.bell {
  position: relative;
}

.bell i {
  position: absolute;
  top: 0;
  right: 0;
  width: 7px;
  height: 7px;
  background: var(--grade-d);
  border: 1.5px solid #fff;
  border-radius: 50%;
}

.phone-section {
  padding: 4px 16px 10px;
  font-size: 15px;
  font-weight: 700;
}

.phone-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px 8px;
  padding: 0 12px 58px;
}

.feed-card {
  min-width: 0;
}

.feed-thumb {
  position: relative;
  aspect-ratio: 1;
  border-radius: 12px;
  overflow: hidden;
  background: #1c2225;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.06);
}

.feed-thumb svg {
  width: 100%;
  height: 100%;
}

.grade {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 22px;
  height: 22px;
  padding: 0 6px;
  border-radius: 999px;
  color: #fff;
  font-size: 11px;
  font-weight: 800;
}

.grade-a {
  background: var(--grade-a);
}

.grade-b {
  background: var(--grade-b);
}

.grade-c {
  background: var(--grade-c);
  color: var(--grade-c-fg);
}

.grade-d {
  background: var(--grade-d);
}

.feed-badge {
  position: absolute;
  left: 6px;
  top: 6px;
}

.feed-thumb em {
  position: absolute;
  top: 6px;
  right: 6px;
  height: 18px;
  padding: 0 6px;
  border-radius: 999px;
  background: rgba(20, 24, 26, 0.72);
  color: #fff;
  font-size: 10px;
  font-style: normal;
  font-weight: 700;
  line-height: 18px;
}

.feed-spec {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-top: 8px;
  font-size: 12px;
  font-weight: 700;
}

.feed-spec small {
  color: var(--neutral-500);
  font-size: 11px;
  font-weight: 600;
}

.feed-brand {
  margin-top: 2px;
  overflow: hidden;
  color: var(--neutral-700);
  font-size: 11px;
  white-space: nowrap;
  text-overflow: ellipsis;
}

.feed-price {
  margin-top: 4px;
  font-size: 14px;
  font-weight: 800;
}

.phone .mono {
  font-family: var(--font-sans);
}

.feed-meta {
  margin-top: 2px;
  color: var(--neutral-500);
  font-size: 11px;
}

.phone-tabs {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--hairline);
  padding: 8px 0 14px;
  background: #fff;
  color: var(--neutral-400);
  font-size: 10px;
  font-weight: 600;
  text-align: center;
}

.phone-tabs span {
  display: grid;
  gap: 3px;
  justify-items: center;
}

.phone-tabs svg {
  width: 18px;
  height: 18px;
}

.phone-tabs .is-on {
  color: var(--brand);
}

.feature-grid,
.receive-grid,
.grade-grid {
  display: grid;
  gap: 12px;
}

.card {
  padding: 28px 24px;
  border: 1px solid var(--border-muted);
  border-radius: var(--radius-lg);
  background: var(--surface);
  box-shadow: var(--shadow-card);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 28px rgba(20, 24, 26, 0.08);
}

@media (prefers-reduced-motion: reduce) {
  .card {
    transition: none;
  }

  .card:hover {
    transform: none;
    box-shadow: var(--shadow-card);
  }
}

.card h3 {
  margin: 10px 0 8px;
  font-size: var(--fs-title);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.card p {
  color: var(--neutral-700);
  font-size: var(--fs-body);
  line-height: 1.6;
}

.card-index {
  color: var(--neutral-400);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
}

.steps {
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.step {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 16px;
  align-items: start;
  list-style: none;
}

.step-num {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--brand);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
}

#howto .step {
  padding: 22px 22px 22px 20px;
  border: 1px solid var(--border-muted);
  border-radius: var(--radius-lg);
  background: #fff;
  box-shadow: var(--shadow-card);
}

.step h3 {
  font-size: var(--fs-label);
  font-weight: 700;
}

.step p {
  margin-top: 6px;
  color: var(--neutral-700);
  font-size: var(--fs-body);
  line-height: 1.6;
}

.tabs {
  display: flex;
  width: fit-content;
  margin-bottom: 28px;
  padding: 4px;
  border-radius: 999px;
  background: #e8ecef;
}

.tabs [role="tab"] {
  min-height: 44px;
  padding: 0 20px;
  border-radius: 999px;
  color: var(--neutral-500);
  font-size: var(--fs-body);
  font-weight: 700;
}

.tabs [role="tab"]:hover {
  color: var(--neutral-900);
}

.tabs [aria-selected="true"] {
  background: var(--brand);
  color: var(--on-brand);
}

.tabs [aria-selected="true"]:hover {
  background: var(--brand-pressed);
  color: var(--on-brand);
}

.grade-card {
  padding: 24px 22px;
  border: 1px solid var(--border-muted);
  border-radius: var(--radius-md);
  background: var(--summary);
}

.grade-card .grade {
  min-width: 48px;
  height: 48px;
  padding: 0 14px;
  font-size: 22px;
}

.grade-card p {
  margin-top: 16px;
  color: var(--neutral-700);
  font-size: var(--fs-body);
  line-height: 1.6;
}

.install {
  background: var(--brand-tint);
}

.install-box {
  display: grid;
  gap: 28px;
}

.install-box > div > p {
  margin-top: 14px;
  color: var(--neutral-700);
  font-size: var(--fs-lead);
  line-height: 1.65;
}

.chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 20px;
}

.chip {
  padding: 8px 12px;
  border-radius: 999px;
  background: var(--surface);
  border: 1px solid var(--border-muted);
  font-size: var(--fs-caption);
  font-weight: 600;
}

.faq-item + .faq-item {
  border-top: 1px solid var(--hairline);
}

.faq-item h3 {
  margin: 0;
  width: 100%;
  font-size: inherit;
  font-weight: inherit;
}

.faq-item button {
  display: flex;
  width: 100%;
  min-height: 64px;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  text-align: left;
  font-size: var(--fs-label);
  font-weight: 700;
}

.faq-item button::after {
  content: "";
  width: 10px;
  height: 10px;
  flex: none;
  border-right: 2px solid var(--neutral-500);
  border-bottom: 2px solid var(--neutral-500);
  transform: rotate(45deg);
  translate: 0 -3px;
}

.faq-item button[aria-expanded="true"]::after {
  transform: rotate(225deg);
  translate: 0 3px;
}

.faq-item [data-accordion-panel] {
  padding: 0 0 20px;
  color: var(--neutral-700);
  font-size: var(--fs-body);
  line-height: 1.65;
}

.faq-item [data-accordion-panel] p + p {
  margin-top: 10px;
}

.cta-band {
  padding: 72px 0;
  background: var(--brand-tint);
  color: var(--neutral-900);
  text-align: center;
}

.cta-band h2 {
  letter-spacing: -0.04em;
}

.cta-band p {
  max-width: 520px;
  margin: 12px auto 28px;
  color: var(--neutral-700);
  font-size: var(--fs-lead);
  line-height: 1.65;
}

.store-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
}

.store-btn {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  min-width: 200px;
  min-height: 56px;
  padding: 0 18px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-muted);
  background: #fff;
  color: var(--neutral-900);
  font-weight: 700;
}

.store-btn small {
  color: var(--neutral-500);
  font-size: 12px;
  font-weight: 600;
}

.footer {
  padding: 40px env(safe-area-inset-right, 0px)
    calc(48px + env(safe-area-inset-bottom, 0px))
    env(safe-area-inset-left, 0px);
  border-top: 1px solid var(--hairline);
  color: var(--neutral-500);
  font-size: var(--fs-caption);
}

.footer-top {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 16px;
}

.footer-top strong {
  color: var(--neutral-900);
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-nav a:hover {
  color: var(--neutral-900);
}

.footer p + p {
  margin-top: 8px;
}

@media (min-width: 840px) {
  :root {
    --gutter: 32px;
    --header-h: 76px;
  }

  .nav-desktop {
    display: flex;
  }

  .header-end {
    gap: 32px;
  }

  .header-cta {
    min-height: 48px;
    padding: 0 18px;
    font-size: var(--fs-body);
  }

  .nav-toggle,
  .nav-panel {
    display: none;
  }

  .hero {
    padding: 56px 0 64px;
  }

  .hero-grid {
    grid-template-columns: 1fr 320px;
    gap: 48px;
  }

  .hero-stats {
    max-width: none;
  }

  .grade-grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .feature-grid {
    grid-template-columns: 1fr 1fr;
  }

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

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

}

@media (max-width: 839px) {
  .section {
    padding: 64px 0;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .hero {
    padding-bottom: 40px;
  }

  .phone-stage {
    padding-bottom: 4px;
  }

  .phone-stage::before,
  .phone-stage::after {
    display: none;
  }

  .phone {
    width: min(252px, calc(100vw - 56px));
    height: auto;
    aspect-ratio: 280 / 580;
    box-shadow:
      inset 0 1px 0 rgba(255, 255, 255, 0.22),
      inset 0 -1px 0 rgba(0, 0, 0, 0.45),
      0 6px 16px rgba(20, 24, 26, 0.1),
      0 14px 28px rgba(20, 24, 26, 0.08);
  }
}