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

:root {
  --bg: #ffffff;
  --bg-alt: #f9fafb;
  --text: #111827;
  --text-secondary: #6b7280;
  --border: #e5e7eb;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --radius: 16px;
  --radius-sm: 12px;
  --max-width: 960px;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

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

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

/* Nav */
nav {
  padding: 20px 0;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 100;
}

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

.nav-brand {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text);
}

.nav-links { display: flex; gap: 28px; list-style: none; }
.nav-links a { color: var(--text-secondary); font-size: 0.9375rem; font-weight: 500; }
.nav-links a:hover { color: var(--text); }

.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 4px; }
.nav-toggle svg { width: 24px; height: 24px; color: var(--text); }

/* Hero */
.hero {
  padding: 100px 0 80px;
  text-align: center;
}

.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 16px;
}

.hero .subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 520px;
  margin: 0 auto 12px;
}

.hero .intro {
  font-size: 1.0625rem;
  color: var(--text-secondary);
  max-width: 480px;
  margin: 0 auto;
}

/* App Grid */
.app-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
  padding-bottom: 100px;
}

.app-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  transition: box-shadow 0.2s, transform 0.2s;
}

.app-card:hover {
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.06);
  transform: translateY(-2px);
}

.app-card-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 16px;
}

.app-icon {
  width: 64px;
  height: 64px;
  border-radius: 14px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  flex-shrink: 0;
}

.app-card h3 { font-size: 1.25rem; font-weight: 700; }

.app-card p {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  margin-bottom: 20px;
  line-height: 1.5;
}

.app-card-buttons { display: flex; gap: 10px; flex-wrap: wrap; }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  border-radius: 10px;
  font-size: 0.875rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: background 0.15s, transform 0.1s;
}

.btn:active { transform: scale(0.98); }

.btn-primary {
  background: var(--text);
  color: #fff;
}
.btn-primary:hover { background: #374151; color: #fff; }

.btn-secondary {
  background: var(--bg-alt);
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-secondary:hover { background: #f3f4f6; color: var(--text); }

/* App Page */
.app-hero {
  padding: 80px 0 60px;
  text-align: center;
}

.app-hero .app-icon-large {
  width: 120px;
  height: 120px;
  border-radius: 28px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  margin: 0 auto 24px;
}

.app-hero h1 {
  font-size: 2.5rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.app-hero .description {
  font-size: 1.125rem;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0 auto 32px;
  line-height: 1.6;
}

/* Screenshots */
.screenshots {
  padding: 40px 0;
}

.screenshots h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 24px;
  text-align: center;
}

.screenshot-gallery {
  display: flex;
  gap: 16px;
  overflow-x: auto;
  padding: 8px 0 24px;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}

.screenshot-placeholder {
  flex: 0 0 220px;
  height: 390px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  font-size: 0.875rem;
  scroll-snap-align: start;
}

/* Features */
.features {
  padding: 60px 0;
}

.features h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 32px;
  text-align: center;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
}

.feature-item {
  padding: 24px;
  background: var(--bg-alt);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
}

.feature-item h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 6px;
}

.feature-item p {
  font-size: 0.9375rem;
  color: var(--text-secondary);
}

/* Download Section */
.download-section {
  padding: 60px 0 100px;
  text-align: center;
}

.download-section h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.download-section p {
  color: var(--text-secondary);
  margin-bottom: 24px;
}

/* Content Pages */
.content-page {
  padding: 80px 0 100px;
}

.content-page h1 {
  font-size: 2.5rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 32px;
}

.content-page h2 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-top: 40px;
  margin-bottom: 12px;
}

.content-page p {
  color: var(--text-secondary);
  margin-bottom: 16px;
  line-height: 1.7;
  max-width: 640px;
}

.content-page a { font-weight: 500; }

.content-page ul {
  list-style: disc;
  padding-left: 24px;
  margin-bottom: 16px;
}

.content-page ul li {
  color: var(--text-secondary);
  margin-bottom: 8px;
  line-height: 1.6;
}

/* Contact Form */
.contact-form {
  max-width: 480px;
  margin-top: 32px;
}

.form-group { margin-bottom: 20px; }

.form-group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 6px;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 0.9375rem;
  font-family: inherit;
  background: var(--bg);
  color: var(--text);
  transition: border-color 0.15s;
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
}

.form-group textarea { resize: vertical; min-height: 120px; }

/* Footer */
footer {
  padding: 40px 0;
  border-top: 1px solid var(--border);
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.875rem;
}

footer .footer-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-bottom: 16px;
  list-style: none;
}

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

/* Responsive */
@media (max-width: 640px) {
  .hero { padding: 60px 0 48px; }
  .hero h1 { font-size: 2rem; }
  .hero .subtitle { font-size: 1.0625rem; }
  .app-grid { grid-template-columns: 1fr; }
  .app-hero { padding: 60px 0 40px; }
  .app-hero h1 { font-size: 2rem; }
  .content-page h1 { font-size: 1.75rem; }
  .features-grid { grid-template-columns: 1fr; }

  .nav-links-desktop { display: none; }
  .nav-toggle { display: block; }

  .nav-mobile {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 16px 24px;
  }

  .nav-mobile.open { display: block; }

  .nav-mobile ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 16px;
  }

  .nav-mobile a { color: var(--text-secondary); font-weight: 500; }
}

@media (min-width: 641px) {
  .nav-mobile { display: none !important; }
}