/* === Reset & Base === */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --color-bg: #fafafa;
  --color-surface: #ffffff;
  --color-text: #1d1d1f;
  --color-text-secondary: #6e6e73;
  --color-accent: #0071e3;
  --color-accent-hover: #0077ed;
  --color-border: #e5e5e7;
  --color-privacy-bg: #f5f5f7;
  --radius: 12px;
  --max-width: 1080px;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

a:hover {
  text-decoration: underline;
}

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

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

section {
  padding: 96px 0;
}

/* === Nav === */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250, 250, 250, 0.85);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--color-border);
}

nav .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 52px;
}

nav .logo {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: -0.01em;
}

nav .logo:hover {
  text-decoration: none;
}

nav ul {
  list-style: none;
  display: flex;
  gap: 28px;
}

nav ul a {
  color: var(--color-text-secondary);
  font-size: 14px;
  font-weight: 500;
  transition: color 0.15s;
}

nav ul a:hover {
  color: var(--color-text);
  text-decoration: none;
}

/* === Hero === */
.hero {
  text-align: center;
  padding: 80px 0 64px;
}

.hero h1 {
  font-size: 48px;
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.1;
  margin-bottom: 16px;
}

.hero .subtitle {
  font-size: 20px;
  color: var(--color-text-secondary);
  max-width: 560px;
  margin: 0 auto 40px;
  line-height: 1.5;
}

.hero .app-store-badge {
  display: inline-block;
  transition: opacity 0.15s;
}

.hero .app-store-badge:hover {
  opacity: 0.8;
}

.hero .app-store-badge img {
  height: 48px;
  width: auto;
}

.hero-screenshot {
  margin-top: 56px;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.12), 0 0 0 1px rgba(0, 0, 0, 0.04);
}

.hero-screenshot img {
  width: 100%;
}

/* === Features === */
.features {
  background: var(--color-surface);
}

.features h2,
.privacy h2,
.how-it-works h2,
.screenshots h2,
.providers h2,
.download h2 {
  font-size: 36px;
  font-weight: 700;
  letter-spacing: -0.02em;
  text-align: center;
  margin-bottom: 12px;
}

.section-subtitle {
  font-size: 18px;
  color: var(--color-text-secondary);
  text-align: center;
  margin-bottom: 56px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.feature-card {
  padding: 32px;
  border-radius: var(--radius);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
}

.feature-card .icon {
  font-size: 28px;
  margin-bottom: 16px;
  display: block;
  width: 48px;
  height: 48px;
  line-height: 48px;
  text-align: center;
  background: var(--color-surface);
  border-radius: 10px;
  border: 1px solid var(--color-border);
}

.feature-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
}

.feature-card p {
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.55;
}

/* === Privacy === */
.privacy {
  background: var(--color-privacy-bg);
}

.privacy-points {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  margin-top: 48px;
}

.privacy-point {
  text-align: center;
  padding: 24px;
}

.privacy-point .icon {
  font-size: 32px;
  margin-bottom: 16px;
}

.privacy-point h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 8px;
}

.privacy-point p {
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

/* === How It Works === */
.how-it-works {
  background: var(--color-surface);
}

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
  margin-top: 48px;
}

.step {
  text-align: center;
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--color-accent);
  color: #fff;
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 16px;
}

.step h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 8px;
}

.step p {
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

/* === Providers === */
.providers {
  background: var(--color-privacy-bg);
}

.provider-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 16px;
  margin-top: 48px;
}

.provider-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 100px;
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text);
}

.provider-pill .badge {
  font-size: 12px;
  font-weight: 600;
  color: var(--color-accent);
  background: rgba(0, 113, 227, 0.08);
  padding: 2px 8px;
  border-radius: 100px;
}

/* === Screenshots === */
.screenshots {
  background: var(--color-surface);
}

.screenshot-gallery {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
  margin-top: 48px;
}

.screenshot-gallery figure {
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.08), 0 0 0 1px rgba(0, 0, 0, 0.04);
}

.screenshot-gallery figcaption {
  text-align: center;
  font-size: 14px;
  color: var(--color-text-secondary);
  padding: 16px 0;
}

/* === Download === */
.download {
  text-align: center;
  background: var(--color-bg);
}

.download p {
  font-size: 18px;
  color: var(--color-text-secondary);
  margin-bottom: 32px;
}

.download .app-store-badge {
  display: inline-block;
  transition: opacity 0.15s;
}

.download .app-store-badge:hover {
  opacity: 0.8;
}

.download .app-store-badge img {
  height: 52px;
  width: auto;
}

.system-req {
  margin-top: 24px;
  font-size: 13px;
  color: var(--color-text-secondary);
}

/* === Footer === */
footer {
  padding: 40px 0;
  border-top: 1px solid var(--color-border);
  background: var(--color-bg);
}

footer .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

footer .copyright {
  font-size: 13px;
  color: var(--color-text-secondary);
}

footer ul {
  list-style: none;
  display: flex;
  gap: 24px;
}

footer ul a {
  font-size: 13px;
  color: var(--color-text-secondary);
}

footer ul a:hover {
  color: var(--color-text);
}

/* === Responsive === */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 32px;
  }

  .hero .subtitle {
    font-size: 17px;
  }

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

  .privacy-points {
    grid-template-columns: 1fr;
  }

  .steps {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  nav ul {
    gap: 16px;
  }

  nav ul a {
    font-size: 13px;
  }

  section {
    padding: 64px 0;
  }

  footer .container {
    flex-direction: column;
    gap: 16px;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .hero h1 {
    font-size: 28px;
  }

  nav ul {
    display: none;
  }
}