:root {
  --bg-dark: #0a192f;
  --bg-hero: #0d2137;
  --accent: #00b4d8;
  --text-light: #e6f1ff;
  --text-muted: #8892b0;
  --header-height: 64px;
}

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

html, body {
  height: 100%;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg-dark);
  color: var(--text-light);
  overflow: hidden; /* Container handles scrolling */
}

.top-bar {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--header-height);
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 2rem;
  background: rgba(10, 25, 47, 0.85);
  backdrop-filter: blur(12px);
  z-index: 100;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

.logo img { height: 32px; display: block; }

.lang-selector { position: relative; }
#lang-btn {
  background: transparent;
  border: 1px solid var(--accent);
  color: var(--text-light);
  padding: 0.45rem 0.9rem;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.9rem;
  transition: background 0.2s;
}
#lang-btn:hover { background: rgba(0,180,216,0.1); }

#lang-dropdown {
  position: absolute;
  top: 110%;
  right: 0;
  background: var(--bg-dark);
  border: 1px solid rgba(255,255,255,0.12);
  border-radius: 6px;
  list-style: none;
  min-width: 130px;
  box-shadow: 0 6px 16px rgba(0,0,0,0.4);
  overflow: hidden;
}
#lang-dropdown.hidden { display: none; }
#lang-dropdown li {
  padding: 0.6rem 1rem;
  cursor: pointer;
  transition: background 0.15s;
  font-size: 0.9rem;
}
#lang-dropdown li:hover { background: rgba(0,180,216,0.15); }

.snap-container {
  height: 100vh;
  overflow-y: auto;
  scroll-snap-type: y mandatory;
  scroll-behavior: smooth;
}

.page {
  height: 100vh;
  scroll-snap-align: start;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 2rem;
  text-align: center;
}

.hero { background: linear-gradient(160deg, #0a192f 0%, #0f2a4a 100%); }
.tech { background: #0b1a2e; }

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.5rem);
  margin-bottom: 2rem;
  letter-spacing: 2px;
  font-weight: 700;
}

.download-btn {
  background: var(--accent);
  color: #0a192f;
  padding: 1rem 2.8rem;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
  font-size: 1.1rem;
  transition: transform 0.2s, box-shadow 0.2s;
}
.download-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,180,216,0.35);
}

.tech h2 {
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  margin-bottom: 1rem;
}
.tech p {
  max-width: 620px;
  line-height: 1.65;
  color: var(--text-muted);
  font-size: 1.05rem;
}
.tech a {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 3px;
}

@media (max-width: 600px) {
  .top-bar { padding: 0 1rem; }
  .page { padding: 1.5rem; }
}