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

:root {
  --bg: #FFFFFF;
  --surface: #F5F5F5;
  --surface2: #ECECEC;
  --text: #111111;
  --text-sub: #555555;
  --radius: 12px;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Barlow', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

/* NAV */
nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 48px;
  border-bottom: 1px solid var(--surface2);
  position: sticky;
  top: 0;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(8px);
  z-index: 10;
}

.nav-logo {
  font-family: 'Barlow Condensed', sans-serif;
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: 0.02em;
  text-decoration: none;
  color: var(--text);
}

.nav-links {
  display: flex;
  gap: 32px;
  list-style: none;
  align-items: center;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-sub);
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.15s;
}

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

.nav-cta {
  background: var(--text);
  color: #fff !important;
  padding: 8px 20px;
  border-radius: 8px;
  transition: background 0.15s !important;
}

.nav-cta:hover { background: #333 !important; color: #fff !important; }

/* HERO */
.hero {
  text-align: center;
  padding: 96px 24px 80px;
  max-width: 800px;
  margin: 0 auto;
}

.hero-tag {
  display: inline-block;
  background: var(--surface);
  color: var(--text-sub);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 4px 12px;
  border-radius: 100px;
  margin-bottom: 24px;
}

.hero h1 {
  font-family: 'Barlow Condensed', sans-serif;
  font-size: clamp(2.8rem, 7vw, 5rem);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: -0.01em;
  margin-bottom: 20px;
}

.hero p {
  font-size: 1.15rem;
  color: var(--text-sub);
  max-width: 540px;
  margin: 0 auto 40px;
}

.btn-primary {
  display: inline-block;
  background: var(--text);
  color: #fff;
  font-family: 'Barlow', sans-serif;
  font-size: 1rem;
  font-weight: 600;
  padding: 14px 36px;
  border-radius: 10px;
  text-decoration: none;
  transition: background 0.15s, transform 0.1s;
}

.btn-primary:hover {
  background: #333;
  transform: translateY(-1px);
}

.btn-primary:active { transform: translateY(0); }

/* SCREENSHOT / VIDEO */
.hero-visual {
  max-width: 960px;
  margin: 64px auto 0;
  padding: 0 24px;
}

.hero-visual .screen {
  background: var(--surface);
  border-radius: 16px;
  border: 1px solid var(--surface2);
  aspect-ratio: 16/9;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-sub);
  font-size: 0.9rem;
  overflow: hidden;
}

.hero-visual .screen img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 16px;
}

/* FEATURES */
.section {
  padding: 96px 24px;
  max-width: 1040px;
  margin: 0 auto;
}

.section-label {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-sub);
  margin-bottom: 12px;
}

.section h2 {
  font-family: 'Barlow Condensed', sans-serif;
  font-size: clamp(2rem, 4vw, 2.8rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 48px;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.feature-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 28px;
}

.feature-icon {
  font-size: 1.6rem;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-family: 'Barlow Condensed', sans-serif;
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.feature-card p {
  font-size: 0.9rem;
  color: var(--text-sub);
  line-height: 1.6;
}

/* HOW IT WORKS */
.how-section {
  background: var(--surface);
  height: 100vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.how-header {
  text-align: center;
  padding: 48px 24px 20px;
  flex-shrink: 0;
}

.how-header h2 {
  font-family: 'Barlow Condensed', sans-serif;
  font-size: clamp(1.6rem, 4vw, 2.8rem);
  font-weight: 900;
  margin-top: 8px;
}

.steps-carousel {
  flex: 1;
  min-height: 0;
  position: relative;
  display: flex;
  align-items: center;
}

.steps-track {
  flex: 1;
  position: relative;
  height: 100%;
  overflow: hidden;
}

.step {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 12px 72px;
  gap: 16px;
  opacity: 0;
  transform: translateX(60px);
  transition: opacity 0.35s ease, transform 0.35s ease;
  pointer-events: none;
}

.step.active {
  opacity: 1;
  transform: translateX(0);
  pointer-events: auto;
}

.step.exit-left {
  opacity: 0;
  transform: translateX(-60px);
}

.step-visual {
  flex: 1;
  min-height: 0;
  width: 100%;
  max-width: 960px;
  border-radius: 12px;
  overflow: hidden;
  background: var(--surface2);
}

.step-visual img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.step-text {
  flex-shrink: 0;
  text-align: center;
}

.step-num {
  font-family: 'Barlow Condensed', sans-serif;
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-sub);
  letter-spacing: 0.1em;
}

.step h3 {
  font-family: 'Barlow Condensed', sans-serif;
  font-size: 1.5rem;
  font-weight: 800;
  margin: 2px 0 4px;
}

.step p {
  font-size: 0.9rem;
  color: var(--text-sub);
  max-width: 480px;
  margin: 0 auto;
}

.carousel-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 10;
  background: var(--bg);
  border: 1px solid var(--surface2);
  color: var(--text);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  font-size: 1.1rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s, border-color 0.15s;
  flex-shrink: 0;
}

.carousel-arrow:hover { background: var(--surface2); }
.carousel-arrow:disabled { opacity: 0.25; cursor: default; }
.prev-arrow { left: 16px; }
.next-arrow { right: 16px; }

.carousel-dots {
  display: flex;
  justify-content: center;
  gap: 10px;
  padding: 12px 0 24px;
  flex-shrink: 0;
}

.dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--surface2);
  border: 1px solid #ccc;
  cursor: pointer;
  transition: background 0.2s, transform 0.2s;
}

.dot.active {
  background: var(--text);
  border-color: var(--text);
  transform: scale(1.35);
}

/* CTA */
.cta-section {
  text-align: center;
  padding: 112px 24px;
}

.cta-section h2 {
  font-family: 'Barlow Condensed', sans-serif;
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 900;
  margin-bottom: 16px;
}

.cta-section p {
  color: var(--text-sub);
  font-size: 1.05rem;
  margin-bottom: 36px;
}

.install-hint {
  margin-top: 16px;
  font-size: 0.85rem;
  color: var(--text-sub);
}

/* FOOTER */
footer {
  border-top: 1px solid var(--surface2);
  padding: 24px 48px;
  font-size: 0.85rem;
  color: var(--text-sub);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

@media (max-width: 640px) {
  nav { padding: 14px 20px; }
  .nav-links { display: none; }
  footer { padding: 20px; flex-direction: column; text-align: center; }
}