/* ScrollCha marketing — white/green light · grey/green dark */
:root {
  --mint: #58cc02;
  --mint-bright: #89e219;
  --mint-deep: #3d9a00;
  --ink: #121412;
  --ink-soft: #3a403a;
  --mute: #5c665c;
  --bg: #f7faf5;
  --bg-elev: #ffffff;
  --bg-alt: #eef3ea;
  --line: #d0ddd0;
  --shadow: 0 24px 60px rgba(18, 20, 18, 0.08);
  --hero-glow: radial-gradient(ellipse 80% 70% at 50% 35%, rgba(88, 204, 2, 0.22), transparent 65%),
    linear-gradient(165deg, #f0f7eb 0%, #fafcfa 45%, #e8f2e2 100%);
  --font-display: "Fraunces", "Noto Sans HK", Georgia, serif;
  --font-body: "Nunito", "Noto Sans HK", system-ui, sans-serif;
  --radius: 1.25rem;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  color-scheme: light;
}

[data-theme="dark"] {
  --ink: #f2f6f0;
  --ink-soft: #c5d0c2;
  --mute: #8a9688;
  --bg: #121512;
  --bg-elev: #1a1f1a;
  --bg-alt: #171c17;
  --line: #2a332a;
  --shadow: 0 24px 60px rgba(0, 0, 0, 0.45);
  --hero-glow: radial-gradient(ellipse 75% 65% at 50% 30%, rgba(88, 204, 2, 0.18), transparent 60%),
    linear-gradient(165deg, #0e120e 0%, #151a15 50%, #101410 100%);
  color-scheme: dark;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  font-weight: 500;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; height: auto; display: block; }
a { color: inherit; }

.skip {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--mint);
  color: #0b1404;
  padding: 0.6rem 1rem;
  z-index: 100;
  font-weight: 800;
}
.skip:focus { left: 0.75rem; top: 0.75rem; }

/* —— Top bar —— */
.top {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.75rem clamp(1rem, 4vw, 2.5rem);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s var(--ease), background 0.3s;
}
.top.is-scrolled { border-bottom-color: var(--line); }

.top__brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  text-decoration: none;
  font-weight: 900;
  letter-spacing: -0.02em;
}
.top__brand img { width: 1.75rem; height: 1.75rem; }

.top__nav {
  margin-left: auto;
  display: flex;
  gap: clamp(0.75rem, 2vw, 1.5rem);
}
.top__nav a {
  text-decoration: none;
  font-weight: 700;
  font-size: 0.92rem;
  color: var(--mute);
  transition: color 0.2s;
}
.top__nav a:hover,
.top__nav a:focus-visible { color: var(--mint-deep); }
[data-theme="dark"] .top__nav a:hover { color: var(--mint-bright); }

@media (max-width: 720px) {
  .top__nav { display: none; }
}

.theme-toggle {
  appearance: none;
  width: 2.6rem;
  height: 2.6rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--bg-elev);
  cursor: pointer;
  position: relative;
  flex-shrink: 0;
  transition: border-color 0.2s, transform 0.35s var(--ease);
}
.theme-toggle:hover { border-color: var(--mint); }
.theme-toggle:active { transform: rotate(25deg) scale(0.96); }
.theme-toggle__sun,
.theme-toggle__moon {
  position: absolute;
  inset: 0;
  margin: auto;
  width: 1rem;
  height: 1rem;
  border-radius: 50%;
  transition: opacity 0.3s, transform 0.35s var(--ease);
}
.theme-toggle__sun {
  background: radial-gradient(circle at 35% 35%, #ffe566, #ffb020);
  box-shadow: 0 0 0 2px rgba(255, 176, 32, 0.25);
}
.theme-toggle__moon {
  background: #c8d4e0;
  box-shadow: inset -4px -2px 0 0 #7a8794;
  opacity: 0;
  transform: scale(0.4) rotate(-40deg);
}
[data-theme="dark"] .theme-toggle__sun {
  opacity: 0;
  transform: scale(0.4) rotate(40deg);
}
[data-theme="dark"] .theme-toggle__moon {
  opacity: 1;
  transform: scale(1) rotate(0);
}

/* —— Hero —— */
.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 5rem 1.25rem 4rem;
  overflow: hidden;
}
.hero__plane {
  position: absolute;
  inset: 0;
  background: var(--hero-glow);
  z-index: 0;
}
.hero__plane::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle at 1px 1px, color-mix(in srgb, var(--mint) 18%, transparent) 1px, transparent 0);
  background-size: 28px 28px;
  opacity: 0.35;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, #000 20%, transparent 75%);
}
.hero__inner {
  position: relative;
  z-index: 1;
  width: min(720px, 100%);
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.15rem;
}
.hero__logo {
  width: min(78vw, 420px);
  height: auto;
  border-radius: 22%;
  box-shadow: var(--shadow), 0 0 0 1px color-mix(in srgb, var(--mint) 15%, transparent);
  animation: breathe 5.5s var(--ease) infinite;
}
@keyframes breathe {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}
@media (prefers-reduced-motion: reduce) {
  .hero__logo { animation: none; }
}

.status-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.4rem 0.9rem;
  border-radius: 999px;
  font-weight: 800;
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--mint-deep);
  background: color-mix(in srgb, var(--mint) 16%, transparent);
  border: 1px solid color-mix(in srgb, var(--mint) 35%, transparent);
}
[data-theme="dark"] .status-badge { color: var(--mint-bright); }

.hero__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2.4rem, 6.5vw, 3.75rem);
  letter-spacing: -0.03em;
  line-height: 1.08;
  max-width: 14ch;
}
.hero__sub {
  font-size: clamp(1.05rem, 2.2vw, 1.28rem);
  font-weight: 600;
  color: var(--ink-soft);
  max-width: 34rem;
  line-height: 1.45;
}
.hero__cta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  justify-content: center;
  margin-top: 0.5rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.85rem 1.35rem;
  border-radius: 999px;
  font-weight: 800;
  font-size: 0.98rem;
  text-decoration: none;
  transition: transform 0.2s var(--ease), background 0.2s, color 0.2s, box-shadow 0.2s;
}
.btn:active { transform: scale(0.98); }
.btn--primary {
  background: linear-gradient(135deg, var(--mint), var(--mint-bright));
  color: #0b1404;
  box-shadow: 0 10px 28px rgba(88, 204, 2, 0.35);
}
.btn--primary:hover {
  box-shadow: 0 14px 36px rgba(88, 204, 2, 0.45);
  transform: translateY(-1px);
}
.btn--ghost {
  background: transparent;
  border: 1.5px solid var(--line);
  color: var(--ink);
}
.btn--ghost:hover {
  border-color: var(--mint);
  color: var(--mint-deep);
}
[data-theme="dark"] .btn--ghost:hover { color: var(--mint-bright); }

/* —— Sections —— */
.section {
  padding: clamp(4rem, 10vw, 7rem) clamp(1.25rem, 5vw, 3rem);
  max-width: 1100px;
  margin: 0 auto;
}
.section--alt {
  max-width: none;
  background: var(--bg-alt);
  border-block: 1px solid var(--line);
}
.section--alt > * {
  max-width: 1100px;
  margin-inline: auto;
}
.section--alt .research { max-width: 1100px; margin-inline: auto; }

.eyebrow {
  font-weight: 800;
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--mint-deep);
  margin-bottom: 0.75rem;
}
[data-theme="dark"] .eyebrow { color: var(--mint-bright); }

.section__title {
  font-family: var(--font-display);
  font-size: clamp(1.85rem, 4vw, 2.75rem);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.12;
  max-width: 18ch;
  margin-bottom: 0.85rem;
}
.section__lead {
  font-size: clamp(1.05rem, 2vw, 1.2rem);
  font-weight: 600;
  color: var(--ink-soft);
  max-width: 38rem;
  margin-bottom: 2.5rem;
  line-height: 1.5;
}

/* Steps */
.steps {
  list-style: none;
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-bottom: 2.75rem;
}
@media (max-width: 700px) {
  .steps { grid-template-columns: 1fr; }
}
.step {
  padding: 1.35rem 1.4rem 1.45rem;
  border-left: 3px solid var(--mint);
  background: transparent;
}
.step__num {
  display: inline-block;
  font-weight: 900;
  font-size: 0.85rem;
  color: var(--mint-deep);
  letter-spacing: 0.06em;
  margin-bottom: 0.45rem;
}
[data-theme="dark"] .step__num { color: var(--mint-bright); }
.step h3 {
  font-size: 1.15rem;
  font-weight: 800;
  margin-bottom: 0.35rem;
  letter-spacing: -0.015em;
}
.step p {
  color: var(--mute);
  font-weight: 600;
  font-size: 0.98rem;
  line-height: 1.45;
}

.gallery {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: clamp(1rem, 2.5vw, 1.75rem);
  align-items: end;
}
@media (max-width: 900px) {
  .gallery { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
.phone {
  margin: 0;
}
.phone img {
  width: 100%;
  border-radius: 1.6rem;
  box-shadow: var(--shadow);
  border: 1px solid var(--line);
  background: var(--bg-elev);
}
.phone figcaption {
  margin-top: 0.7rem;
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--mute);
  text-align: center;
}

/* Research grid — not cards-as-decoration: interaction/reading containers with clear separation via spacing */
.research {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.75rem 2rem;
  margin-top: 0.5rem;
}
@media (max-width: 900px) {
  .research { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 560px) {
  .research { grid-template-columns: 1fr; }
}
.research__card h3 {
  font-size: 1.15rem;
  font-weight: 800;
  margin-bottom: 0.45rem;
  color: var(--ink);
  letter-spacing: -0.015em;
}
.research__card h3::before {
  content: "";
  display: inline-block;
  width: 0.55rem;
  height: 0.55rem;
  border-radius: 50%;
  background: var(--mint);
  margin-right: 0.55rem;
  vertical-align: 0.15em;
  box-shadow: 0 0 12px rgba(88, 204, 2, 0.45);
}
.research__card p {
  color: var(--mute);
  font-weight: 600;
  font-size: 0.98rem;
  line-height: 1.5;
}

.bullets {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  max-width: 36rem;
}
.bullets li {
  position: relative;
  padding-left: 1.5rem;
  font-weight: 700;
  font-size: 1.05rem;
}
.bullets li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 0.55rem;
  height: 0.55rem;
  border-radius: 50%;
  background: var(--mint);
}

/* CTA */
.cta {
  padding: clamp(4rem, 10vw, 6.5rem) clamp(1.25rem, 5vw, 3rem);
  background: var(--hero-glow);
  border-top: 1px solid var(--line);
}
.cta__inner {
  max-width: 640px;
  margin: 0 auto;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}
.cta__mark { margin-bottom: 0.25rem; }
.cta h2 {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 4vw, 2.4rem);
  letter-spacing: -0.025em;
  line-height: 1.15;
}
.cta p {
  color: var(--ink-soft);
  font-weight: 600;
  font-size: 1.08rem;
  max-width: 32rem;
}

.foot {
  padding: 2rem clamp(1.25rem, 5vw, 3rem) 2.5rem;
  text-align: center;
  border-top: 1px solid var(--line);
  color: var(--mute);
  font-weight: 600;
  font-size: 0.92rem;
}
.foot strong { color: var(--ink); font-weight: 800; }
.foot a { color: var(--mint-deep); font-weight: 800; text-decoration: none; }
[data-theme="dark"] .foot a { color: var(--mint-bright); }
.foot__meta { margin-top: 0.35rem; }

/* —— Privacy / legal prose —— */
.legal {
  max-width: 720px;
  margin: 0 auto;
  padding: 4.5rem clamp(1.25rem, 5vw, 2.5rem) 3rem;
}
.legal__hero { margin-bottom: 2.5rem; }
.legal__title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 2.75rem);
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin: 0.35rem 0 1rem;
}
.legal__meta {
  color: var(--mute);
  font-weight: 600;
  font-size: 0.95rem;
  line-height: 1.55;
  margin-bottom: 1rem;
}
.legal__meta a { color: var(--mint-deep); font-weight: 800; }
[data-theme="dark"] .legal__meta a { color: var(--mint-bright); }
.legal__body section { margin-bottom: 2rem; }
.legal__body h2 {
  font-size: 1.2rem;
  font-weight: 800;
  letter-spacing: -0.015em;
  margin-bottom: 0.65rem;
  color: var(--ink);
}
.legal__body p,
.legal__body li {
  color: var(--ink-soft);
  font-weight: 600;
  font-size: 1rem;
  line-height: 1.6;
  margin-bottom: 0.75rem;
}
.legal__body ul {
  margin: 0 0 0.85rem 1.15rem;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}
.legal__body li { margin-bottom: 0; }
.legal__body a { color: var(--mint-deep); font-weight: 800; }
[data-theme="dark"] .legal__body a { color: var(--mint-bright); }
.legal__body code {
  font-size: 0.9em;
  padding: 0.1em 0.35em;
  border-radius: 0.35rem;
  background: color-mix(in srgb, var(--mint) 12%, var(--bg-alt));
  border: 1px solid var(--line);
}
.legal__note {
  margin-top: 1.25rem;
  font-size: 0.9rem !important;
  color: var(--mute) !important;
}

/* Reveal motion */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}
.reveal.is-in {
  opacity: 1;
  transform: none;
}
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
}