:root {
  --bg: #f8fafc;
  --text: #0f172a;
  --primary: #16a34a;
  --primary-dark: #15803d;
  --card-bg: #ffffff;
  --border: #e2e8f0;
  --shadow: 0 4px 6px -1px rgba(0,0,0,0.1);
  --radius: 12px;
  --transition: 0.3s ease;
}

[data-theme="dark"] {
  --bg: #0f172a;
  --text: #f1f5f9;
  --card-bg: #1e293b;
  --border: #334155;
  --shadow: 0 4px 6px -1px rgba(0,0,0,0.5);
}

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

body {
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  transition: background var(--transition), color var(--transition);
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.navbar {
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
  padding: 0.8rem 0;
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(8px);
}

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

.logo {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
  letter-spacing: -0.5px;
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
  padding: 0.25rem 0.5rem;
  border-radius: 6px;
  transition: background 0.2s;
}

.nav-links a:hover {
  background: var(--border);
}
.nav-links a.active {
  color: var(--primary);
  font-weight: 600;
}

#theme-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: 30px;
  padding: 0.3rem 0.8rem;
  cursor: pointer;
  font-size: 1.2rem;
  color: var(--text);
}

.hero {
  text-align: center;
  padding: 4rem 0 2rem;
}
.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: 0.5rem;
}
.hero p {
  font-size: 1.2rem;
  opacity: 0.8;
  max-width: 600px;
  margin: 0 auto 1.5rem;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  padding: 0.8rem 2rem;
  border-radius: 30px;
  text-decoration: none;
  font-weight: 600;
  display: inline-block;
  transition: background 0.2s;
}
.btn-primary:hover {
  background: var(--primary-dark);
}

.btn-outline {
  display: inline-block;
  margin-top: 1rem;
  color: var(--primary);
  border: 2px solid var(--primary);
  padding: 0.5rem 1.5rem;
  border-radius: 30px;
  text-decoration: none;
  font-weight: 500;
  transition: all 0.2s;
}
.btn-outline:hover {
  background: var(--primary);
  color: #fff;
}

.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.tool-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  text-decoration: none;
  color: var(--text);
  box-shadow: var(--shadow);
  transition: transform 0.2s, box-shadow 0.2s;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}
.tool-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 15px -3px rgba(0,0,0,0.15);
}
.tool-icon {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
}
.tool-card h3 {
  font-size: 1.2rem;
  margin-bottom: 0.3rem;
}
.tool-card p {
  font-size: 0.95rem;
  opacity: 0.75;
}

.changelog-item {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.2rem 1.8rem;
  margin-bottom: 1.2rem;
  box-shadow: var(--shadow);
}
.changelog-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
  flex-wrap: wrap;
}
.version {
  font-weight: 700;
  font-size: 1.2rem;
  color: var(--primary);
}
.date {
  opacity: 0.6;
  font-size: 0.9rem;
}
.changelog-item ul {
  padding-left: 1.5rem;
  list-style-type: disc;
}
.changelog-item li {
  margin: 0.2rem 0;
}

footer {
  margin-top: 4rem;
  padding: 2rem 0;
  border-top: 1px solid var(--border);
  text-align: center;
  opacity: 0.7;
}

@media (max-width: 700px) {
  .navbar .container {
    flex-direction: column;
    gap: 0.5rem;
  }
  .nav-links {
    gap: 1rem;
  }
  .hero h1 {
    font-size: 2.2rem;
  }
}