:root {
  --brand: #6166f6;
  --brand-dark: #4a4fe0;
  --brand-light: #eceafd;
  --ink: #1c1d3e;
  --ink-soft: #5b5c7a;
  --bg: #ffffff;
  --bg-soft: #f6f6ff;
  --border: #e6e6fb;
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 10px;
  --shadow: 0 20px 40px -20px rgba(97, 102, 246, 0.35);
  --max-width: 1120px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Segoe UI", -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
  padding-bottom: 100px;
}

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

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

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

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.3rem;
  color: var(--ink);
}

.logo img {
  width: 34px;
  height: 34px;
  border-radius: 9px;
}

.nav {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav a {
  font-weight: 600;
  color: var(--ink-soft);
  font-size: 0.95rem;
  transition: color 0.2s ease;
}

.nav a:hover {
  color: var(--brand);
}

.nav-cta {
  background: var(--brand);
  color: #fff !important;
  padding: 10px 20px;
  border-radius: 999px;
}

.nav-cta:hover {
  background: var(--brand-dark);
  color: #fff !important;
}

.lang-picker {
  position: relative;
}

.lang-picker-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  background: none;
  border: 1px solid var(--border);
  color: var(--ink-soft);
  font-weight: 700;
  font-size: 0.85rem;
  font-family: inherit;
  padding: 7px 14px;
  border-radius: 999px;
  cursor: pointer;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.lang-picker-btn svg {
  flex-shrink: 0;
  transition: transform 0.2s ease;
}

.lang-picker-btn:hover {
  color: var(--brand);
  border-color: var(--brand);
}

.lang-picker.open .lang-picker-btn svg {
  transform: rotate(180deg);
}

.lang-menu {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow);
  padding: 8px;
  display: grid;
  grid-template-columns: repeat(2, minmax(140px, 1fr));
  gap: 2px;
  min-width: 300px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-6px);
  transition: opacity 0.18s ease, transform 0.18s ease, visibility 0.18s;
  z-index: 200;
}

.lang-picker.open .lang-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.lang-option {
  display: block;
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--ink);
  padding: 9px 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background 0.15s ease;
}

.lang-option:hover {
  background: var(--bg-soft);
}

.lang-option.active {
  color: var(--brand);
  background: var(--brand-light);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}

.nav-toggle span {
  width: 22px;
  height: 2px;
  background: var(--ink);
  border-radius: 2px;
}

/* Hero */
.hero {
  background: var(--brand);
  color: #fff;
  overflow: hidden;
  position: relative;
}

.hero-inner {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  align-items: center;
  gap: 40px;
  padding-top: 80px;
  padding-bottom: 80px;
}

.badge {
  display: inline-block;
  background: rgba(255, 255, 255, 0.16);
  border: 1px solid rgba(255, 255, 255, 0.3);
  padding: 6px 14px;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  margin-bottom: 22px;
}

.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 20px;
}

.hero-copy p {
  font-size: 1.1rem;
  color: rgba(255, 255, 255, 0.9);
  max-width: 480px;
  margin-bottom: 32px;
}

.store-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-bottom: 40px;
}

.store-btn {
  display: flex;
  align-items: center;
  gap: 12px;
  background: #101124;
  color: #fff;
  padding: 14px 26px;
  border-radius: var(--radius-sm);
  font-weight: 700;
  border: 1px solid rgba(255, 255, 255, 0.15);
  transition: transform 0.2s ease, background 0.2s ease;
}

.store-btn:hover {
  transform: translateY(-2px);
  background: #000;
}

.store-btn.light {
  background: #fff;
  color: var(--ink);
  border-color: var(--border);
}

.store-btn.light:hover {
  background: var(--bg-soft);
}

.store-icon {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  flex-shrink: 0;
}

.store-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
  font-size: 1.1rem;
}

.store-text small {
  font-size: 0.7rem;
  font-weight: 500;
  opacity: 0.8;
}

.hero-stats {
  display: flex;
  gap: 36px;
}

.hero-stats div {
  display: flex;
  flex-direction: column;
}

.hero-stats strong {
  font-size: 1.4rem;
  font-weight: 800;
}

.hero-stats span {
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.75);
}

.hero-art {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 420px;
}

.hero-screens {
  position: relative;
  z-index: 1;
  width: 140%;
  max-width: none;
  filter: drop-shadow(0 30px 50px rgba(16, 17, 36, 0.35));
}

.phone-mock {
  position: absolute;
  bottom: -20px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  width: 200px;
  height: 200px;
  background: rgba(255, 255, 255, 0.16);
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow);
  backdrop-filter: blur(4px);
}

.hero-icon {
  width: 110px;
  height: 110px;
  border-radius: 26px;
  box-shadow: 0 14px 28px rgba(0, 0, 0, 0.25);
}

/* Logos strip */
.logos {
  background: var(--bg-soft);
  padding: 20px 0;
  text-align: center;
  border-bottom: 1px solid var(--border);
}

.logos p {
  color: var(--ink-soft);
  font-size: 0.9rem;
  font-weight: 600;
}

/* Features */
.features {
  padding: 100px 0;
  text-align: center;
}

.features h2, .how h2, .cta h2, .faq h2 {
  font-size: 2.1rem;
  font-weight: 800;
}

.section-sub {
  color: var(--ink-soft);
  margin: 12px 0 50px;
  font-size: 1.05rem;
}

.section-head {
  margin-bottom: 20px;
}

/* Deep-dive feature rows */
.deep-row {
  padding: 64px 0;
  border-top: 1px solid var(--border);
}

.deep-row.reverse {
  background: var(--bg-soft);
}

.deep-row-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
  align-items: center;
  text-align: left;
}

.deep-media {
  order: 1;
}

.deep-text {
  order: 2;
}

.deep-row.reverse .deep-media {
  order: 2;
}

.deep-row.reverse .deep-text {
  order: 1;
}

.deep-media-img,
.deep-media-video {
  width: 100%;
  height: auto;
  max-height: 770px;
  border-radius: var(--radius-md);
  display: block;
  object-fit: contain;
}

.deep-num {
  display: block;
  color: var(--brand);
  font-weight: 800;
  font-size: 0.9rem;
  letter-spacing: 0.06em;
  margin-bottom: 12px;
}

.deep-text h3 {
  font-size: 1.7rem;
  font-weight: 800;
  margin-bottom: 16px;
}

.deep-text p {
  color: var(--ink-soft);
  font-size: 1.05rem;
}

.deep-link {
  display: inline-block;
  margin-top: 18px;
  color: var(--brand);
  font-weight: 700;
  font-size: 0.95rem;
}

.deep-link:hover {
  color: var(--brand-dark);
}

/* Mini feature strip */
.mini-feature-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 36px;
  padding: 60px 0 10px;
}

.mini-feature {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  max-width: 280px;
  text-align: left;
}

.mini-feature span {
  font-size: 1.6rem;
  line-height: 1;
}

.mini-feature strong {
  display: block;
  margin-bottom: 4px;
  font-size: 1rem;
}

.mini-feature p {
  color: var(--ink-soft);
  font-size: 0.88rem;
  margin: 0;
}

/* How it works */
.how {
  background: #101124;
  padding: 100px 0;
  text-align: center;
}

.how h2 {
  color: #fff;
}

.how-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-top: 50px;
  text-align: left;
}

.how-step {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-md);
  padding: 26px;
}

.how-num {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--brand);
  color: #fff;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
}

.how-step h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: #fff;
}

.how-step p {
  color: rgba(255, 255, 255, 0.65);
  font-size: 0.92rem;
}

/* Science section */
.science {
  padding: 100px 0;
  background: var(--bg-soft);
  text-align: center;
}

.eyebrow {
  display: inline-block;
  color: var(--brand);
  font-weight: 800;
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 10px;
}

.eyebrow-dark {
  color: #b7b9f9;
}

.section-sub-dark {
  color: rgba(255, 255, 255, 0.65);
}

.science-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 24px;
  text-align: left;
  margin-top: 50px;
}

.science-chart-card,
.science-stat-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 30px;
}

.science-chart-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 4px;
}

.chart-caption {
  color: var(--ink-soft);
  font-size: 0.85rem;
  margin-bottom: 26px;
}

.bar-chart {
  display: flex;
  flex-direction: column;
  gap: 22px;
  margin-bottom: 20px;
}

.bar-row {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.bar-label {
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--ink);
}

.bar-track {
  background: var(--bg-soft);
  border-radius: 999px;
  height: 34px;
  overflow: hidden;
  border: 1px solid var(--border);
}

.bar-fill {
  height: 100%;
  border-radius: 999px;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  padding: 0 14px;
  color: #fff;
  font-weight: 800;
  font-size: 0.85rem;
  animation: grow-bar 1s ease;
}

.bar-fill.words {
  background: #b7b9f9;
}

.bar-fill.pictures {
  background: var(--brand);
}

@keyframes grow-bar {
  from { width: 0 !important; }
}

.chart-source {
  color: var(--ink-soft);
  font-size: 0.78rem;
  display: block;
}

.science-stats {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.science-stat-card strong {
  display: block;
  font-size: 2rem;
  font-weight: 800;
  color: var(--brand);
  margin-bottom: 10px;
}

.science-stat-card p {
  color: var(--ink-soft);
  font-size: 0.92rem;
  margin-bottom: 12px;
}

.science-footnote {
  max-width: 560px;
  margin: 40px auto 0;
  color: var(--ink-soft);
  font-size: 0.95rem;
}

/* CTA */
.cta {
  background: var(--brand);
  color: #fff;
  text-align: center;
  padding: 90px 0;
}

.cta p {
  color: rgba(255, 255, 255, 0.9);
  max-width: 480px;
  margin: 16px auto 36px;
  font-size: 1.05rem;
}

.cta .store-buttons {
  justify-content: center;
  margin-bottom: 0;
}

/* FAQ */
.faq {
  padding: 100px 0;
  max-width: 760px;
  margin: 0 auto;
}

.faq h2 {
  text-align: center;
  margin-bottom: 40px;
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.faq-list details {
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 16px 20px;
}

.faq-list summary {
  font-weight: 700;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-list summary::-webkit-details-marker {
  display: none;
}

.faq-list summary::after {
  content: "+";
  font-size: 1.3rem;
  color: var(--brand);
  font-weight: 400;
  transition: transform 0.2s ease;
}

.faq-list details[open] summary::after {
  transform: rotate(45deg);
}

.faq-list p {
  color: var(--ink-soft);
  margin-top: 12px;
  font-size: 0.95rem;
}

/* Footer */
.site-footer {
  background: #101124;
  color: rgba(255, 255, 255, 0.85);
  padding-top: 70px;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 40px;
  padding-bottom: 50px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.2rem;
  color: #fff;
}

.footer-brand img {
  width: 32px;
  height: 32px;
  border-radius: 8px;
}

.footer-contact {
  max-width: 380px;
}

.footer-contact h3 {
  color: #fff;
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.footer-contact p {
  color: rgba(255, 255, 255, 0.65);
  margin-bottom: 18px;
  font-size: 0.95rem;
}

.contact-btn {
  display: inline-block;
  background: var(--brand);
  color: #fff;
  font-weight: 700;
  padding: 12px 26px;
  border-radius: 999px;
  transition: background 0.2s ease, transform 0.2s ease;
}

.contact-btn:hover {
  background: var(--brand-dark);
  transform: translateY(-2px);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  padding: 24px;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.5);
}

.footer-links a {
  color: rgba(255, 255, 255, 0.5);
}

.footer-links a:hover {
  color: #fff;
}

/* Toast */
.toast {
  position: fixed;
  left: 50%;
  bottom: 96px;
  transform: translate(-50%, 12px);
  background: var(--ink);
  color: #fff;
  padding: 14px 24px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.9rem;
  box-shadow: 0 16px 34px -12px rgba(0, 0, 0, 0.45);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease;
  z-index: 1001;
  white-space: nowrap;
}

.toast.show {
  opacity: 1;
  transform: translate(-50%, 0);
}

/* Sticky download bar */
.sticky-download {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(270deg, var(--brand), #7b7ff9, var(--brand-dark), var(--brand));
  background-size: 300% 300%;
  animation: sticky-gradient-shift 6s ease infinite;
  box-shadow: 0 -12px 30px -18px rgba(16, 17, 36, 0.45);
  z-index: 1000;
}

@keyframes sticky-gradient-shift {
  0% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
  100% {
    background-position: 0% 50%;
  }
}

.sticky-download-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 24px;
}

.sticky-download-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 0.9rem;
  color: #fff;
  min-width: 0;
}

.sticky-download-brand img {
  width: 32px;
  height: 32px;
  border-radius: 9px;
  flex-shrink: 0;
}

.sticky-download-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.sticky-download-tagline {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.sticky-download-disclaimer {
  font-size: 0.68rem;
  font-weight: 400;
  line-height: 1.3;
  color: rgba(255, 255, 255, 0.6);
}

.sticky-download-btn {
  background: #fff;
  color: var(--brand);
  border: none;
  font-family: inherit;
  font-weight: 700;
  font-size: 0.95rem;
  padding: 12px 30px;
  border-radius: 999px;
  cursor: pointer;
  flex-shrink: 0;
  transition: background 0.2s ease;
  animation: sticky-btn-pulse 2.2s ease-in-out infinite;
}

.sticky-download-btn:hover {
  background: var(--bg-soft);
  animation-play-state: paused;
}

@keyframes sticky-btn-pulse {
  0%,
  100% {
    transform: scale(1);
    box-shadow: 0 0 0 0 rgba(255, 255, 255, 0.55);
  }
  50% {
    transform: scale(1.06);
    box-shadow: 0 0 0 10px rgba(255, 255, 255, 0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .sticky-download {
    animation: none;
  }

  .sticky-download-btn {
    animation: none;
  }
}

/* Responsive */
@media (max-width: 860px) {
  .hero-inner {
    grid-template-columns: 1fr;
    text-align: center;
    padding-top: 24px;
    padding-bottom: 56px;
  }

  .hero-copy p {
    margin-left: auto;
    margin-right: auto;
  }

  .store-buttons {
    flex-direction: column;
    align-items: center;
  }

  .store-btn {
    width: 240px;
    justify-content: center;
  }

  .hero-stats {
    justify-content: center;
  }

  .hero-art {
    order: -1;
    min-height: 0;
    margin-bottom: 8px;
  }

  .hero-screens {
    width: 130%;
  }

  .phone-mock {
    width: 150px;
    height: 150px;
  }

  .hero-icon {
    width: 100px;
    height: 100px;
  }

  .deep-row-inner {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .deep-media-img,
  .deep-media-video {
    max-height: 970px;
  }

  .deep-media,
  .deep-row.reverse .deep-media {
    order: 1;
  }

  .deep-text,
  .deep-row.reverse .deep-text {
    order: 2;
  }

  .how-steps {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (max-width: 640px) {
  .nav {
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: #fff;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    border-bottom: 1px solid var(--border);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.25s ease;
  }

  .nav.open {
    max-height: 300px;
  }

  .nav a {
    width: 100%;
    padding: 14px 24px;
    border-top: 1px solid var(--border);
  }

  .nav-cta {
    border-radius: 0;
    text-align: center;
  }

  .nav-toggle {
    display: flex;
  }

  .lang-picker {
    margin-left: auto;
    margin-right: 12px;
  }

  .lang-picker-btn span {
    display: none;
  }

  .lang-menu {
    grid-template-columns: 1fr;
    min-width: 220px;
    right: -8px;
  }

  .hero h1 {
    font-size: 2.2rem;
  }

  .how-steps {
    grid-template-columns: 1fr;
  }

  .mini-feature-row {
    flex-direction: column;
    align-items: center;
  }

  .footer-inner {
    flex-direction: column;
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
}