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

:root {
  --bg: #0D0D0F;
  --bg-card: #16161A;
  --bg-card-hover: #1E1E24;
  --border: #2A2A32;
  --text: #F9F4D1;
  --text-secondary: #8A8A9A;
  --accent: #5B9E72;
  --accent-hover: #4A8A60;
}

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

/* Nav */
nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 3rem;
  border-bottom: 1px solid var(--border);
}

.nav-logo img {
  height: 32px;
  width: auto;
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.lang-toggle {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.lang-toggle button {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 0.85rem;
  color: var(--text-secondary);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  transition: color 0.2s;
}

.lang-toggle button.active {
  color: var(--accent);
  font-weight: 600;
}

.nav-github {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.2s;
}

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

/* Hero */
.hero {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 4rem;
  max-width: 1100px;
  margin: 0 auto;
  padding: 6rem 3rem;
}

.hero-text {
  flex: 1;
  max-width: 480px;
}

.hero-title {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
}

.hero-logo {
  width: 72px;
  height: 72px;
  border-radius: 16px;
}

.hero-text h1 {
  font-size: 4rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 0;
  color: var(--text);
}

.tagline {
  font-size: 1.15rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  line-height: 1.7;
}

.hero-buttons {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 1rem;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background-color: var(--accent);
  color: #fff;
  padding: 0.75rem 1.5rem;
  border-radius: 10px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  transition: background-color 0.2s;
}

.btn-primary:hover {
  background-color: var(--accent-hover);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.75rem 1.5rem;
  border-radius: 10px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  transition: background-color 0.2s;
}

.btn-secondary:hover {
  background-color: var(--bg-card-hover);
}

.version-note {
  font-size: 0.82rem;
  color: var(--text-secondary);
}

.hero-media {
  flex: 1;
  display: flex;
  justify-content: center;
}

.hero-media video {
  width: 100%;
  max-width: 340px;
  border-radius: 16px;
  box-shadow: 0 30px 80px rgba(0,0,0,0.5);
}

/* Features */
.features {
  max-width: 1100px;
  margin: 0 auto;
  padding: 5rem 3rem;
  text-align: center;
}

.features h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 3rem;
  letter-spacing: -0.02em;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  text-align: left;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1.5rem;
  transition: background-color 0.2s;
}

.feature-card:hover {
  background-color: var(--bg-card-hover);
}

.feature-card .icon {
  font-size: 1.75rem;
  display: block;
  margin-bottom: 1rem;
}

.feature-card h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--text);
}

.feature-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Security */
.security-section {
  max-width: 680px;
  margin: 0 auto;
  padding: 0 3rem 5rem;
  text-align: center;
}

.security-section h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.security-section p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.security-section ol {
  list-style: none;
  counter-reset: steps;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: 1rem;
  text-align: left;
  display: inline-block;
}

.security-section ol li {
  counter-increment: steps;
  font-size: 0.9rem;
  color: var(--text);
}

.security-section ol li::before {
  content: counter(steps) ". ";
  color: var(--accent);
  font-weight: 600;
}

.security-sub {
  font-size: 0.82rem !important;
  color: var(--text-secondary);
}

/* Footer */
footer {
  border-top: 1px solid var(--border);
  padding: 3rem;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
}

.footer-text {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

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

.footer-text a:hover {
  text-decoration: underline;
}

.btn-coffee {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background-color: #FFDD00;
  color: #1A1A1A;
  padding: 0.85rem 2rem;
  border-radius: 12px;
  font-size: 1rem;
  font-weight: 700;
  text-decoration: none;
  transition: opacity 0.2s;
}

.btn-coffee:hover {
  opacity: 0.9;
}

/* Responsive */
@media (max-width: 768px) {
  .hero {
    flex-direction: column;
    padding: 3rem 1.5rem;
    gap: 2rem;
  }

  .hero-text h1 {
    font-size: 2.8rem;
  }

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

  nav {
    padding: 1rem 1.5rem;
  }

  .features, .security-section {
    padding-left: 1.5rem;
    padding-right: 1.5rem;
  }
}