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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background-color: #e8e8e8;
  color: #1a1a1a;
  min-height: 100vh;
  overflow-x: hidden;
}

/* Animated background particles */
.particles {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.particle {
  position: absolute;
  border-radius: 50%;
  background: rgba(150, 150, 160, 0.25);
  animation: float linear infinite;
}

@keyframes float {
  0% { transform: translateY(110vh) scale(0.8); opacity: 0; }
  10% { opacity: 1; }
  90% { opacity: 0.6; }
  100% { transform: translateY(-10vh) scale(1.1); opacity: 0; }
}

/* Nav */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 48px;
  background: rgba(210, 212, 216, 0.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(0,0,0,0.06);
}

.logo {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  color: #3d5068;
  text-decoration: none;
  text-transform: uppercase;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 36px;
  list-style: none;
}

.nav-links a {
  text-decoration: none;
  color: #2a2a2a;
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
  color: #000;
  text-decoration: underline;
  text-underline-offset: 4px;
}

.cta-btn {
  background: #111;
  color: #fff !important;
  padding: 12px 24px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.9rem;
  text-decoration: none !important;
  transition: background 0.2s, transform 0.15s;
  white-space: nowrap;
}

.cta-btn:hover {
  background: #333;
  transform: translateY(-1px);
}

/* Page wrapper */
.page {
  position: relative;
  z-index: 1;
}

/* Hero section */
.hero {
  text-align: center;
  padding: 90px 48px 60px;
  max-width: 1000px;
  margin: 0 auto;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.4rem);
  font-weight: 700;
  line-height: 1.15;
  color: #111;
  margin-bottom: 36px;
  letter-spacing: -0.02em;
}

.hero p {
  font-size: 1.05rem;
  line-height: 1.8;
  color: #444;
  max-width: 780px;
  margin: 0 auto;
}

/* Divider */
.divider {
  border: none;
  border-top: 1px solid rgba(0,0,0,0.1);
  margin: 20px 48px;
}

/* BoltStudy section */
.boltstudy-section {
  text-align: center;
  padding: 60px 48px;
}

.boltstudy-logo {
  font-size: clamp(3rem, 10vw, 6rem);
  font-weight: 900;
  letter-spacing: 0.12em;
  color: #e8952a;
  text-transform: uppercase;
  margin-bottom: 32px;
  line-height: 1;
}

.boltstudy-section p {
  font-size: 1.05rem;
  line-height: 1.8;
  color: #444;
  max-width: 700px;
  margin: 0 auto 32px;
}

/* Features grid */
.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
  max-width: 900px;
  margin: 48px auto 0;
  padding: 0 48px 80px;
}

.feature-card {
  background: rgba(255,255,255,0.55);
  border: 1px solid rgba(0,0,0,0.08);
  border-radius: 16px;
  padding: 28px 24px;
  backdrop-filter: blur(6px);
  transition: transform 0.2s, box-shadow 0.2s;
}

.feature-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.1);
}

.feature-card .icon {
  font-size: 2rem;
  margin-bottom: 12px;
}

.feature-card h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: #111;
}

.feature-card p {
  font-size: 0.9rem;
  color: #555;
  line-height: 1.6;
}

/* Products page */
.products-hero {
  text-align: center;
  padding: 80px 48px 40px;
}

.products-hero h1 {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  color: #111;
  margin-bottom: 16px;
}

.products-hero p {
  color: #555;
  font-size: 1.05rem;
  max-width: 600px;
  margin: 0 auto;
}

.product-card {
  max-width: 800px;
  margin: 40px auto;
  padding: 0 48px;
}

.product-card-inner {
  background: rgba(255,255,255,0.6);
  border: 1px solid rgba(0,0,0,0.08);
  border-radius: 20px;
  padding: 40px;
  backdrop-filter: blur(6px);
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 16px;
}

.product-card-inner .boltstudy-logo {
  font-size: 3rem;
  margin-bottom: 0;
}

.product-card-inner p {
  color: #444;
  line-height: 1.7;
  max-width: 560px;
}

.product-card-inner .cta-btn {
  margin-top: 8px;
}

/* Blog page */
.blog-hero {
  text-align: center;
  padding: 80px 48px 40px;
}

.blog-hero h1 {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  color: #111;
  margin-bottom: 16px;
}

.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  max-width: 960px;
  margin: 40px auto 80px;
  padding: 0 48px;
}

.blog-card {
  background: rgba(255,255,255,0.6);
  border: 1px solid rgba(0,0,0,0.08);
  border-radius: 16px;
  padding: 28px 24px;
  backdrop-filter: blur(6px);
  transition: transform 0.2s, box-shadow 0.2s;
  cursor: pointer;
}

.blog-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.1);
}

.blog-card .tag {
  display: inline-block;
  background: #e8952a22;
  color: #c47a1a;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: 999px;
  margin-bottom: 12px;
}

.blog-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: #111;
  margin-bottom: 10px;
  line-height: 1.4;
}

.blog-card p {
  font-size: 0.9rem;
  color: #555;
  line-height: 1.6;
}

.blog-card .date {
  font-size: 0.8rem;
  color: #888;
  margin-top: 14px;
}

/* Contact page */
.contact-section {
  max-width: 560px;
  margin: 80px auto;
  padding: 0 48px 80px;
  text-align: center;
}

.contact-section h1 {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  color: #111;
  margin-bottom: 12px;
}

.contact-section .subtitle {
  color: #555;
  margin-bottom: 40px;
  line-height: 1.6;
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
  text-align: left;
}

.contact-form label {
  font-size: 0.85rem;
  font-weight: 600;
  color: #333;
  margin-bottom: 4px;
  display: block;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid rgba(0,0,0,0.15);
  border-radius: 10px;
  font-size: 0.95rem;
  font-family: inherit;
  background: rgba(255,255,255,0.7);
  color: #111;
  transition: border-color 0.2s, box-shadow 0.2s;
  outline: none;
}

.contact-form input:focus,
.contact-form textarea:focus {
  border-color: #3d5068;
  box-shadow: 0 0 0 3px rgba(61,80,104,0.12);
}

.contact-form textarea {
  min-height: 130px;
  resize: vertical;
}

.contact-form button {
  background: #111;
  color: #fff;
  border: none;
  padding: 14px 28px;
  border-radius: 999px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s, transform 0.15s;
  align-self: center;
  margin-top: 4px;
}

.contact-form button:hover {
  background: #333;
  transform: translateY(-1px);
}

/* Footer */
footer {
  text-align: center;
  padding: 24px 48px;
  font-size: 0.82rem;
  color: #888;
  border-top: 1px solid rgba(0,0,0,0.08);
  position: relative;
  z-index: 1;
}

/* Responsive */
@media (max-width: 640px) {
  nav {
    padding: 14px 20px;
    flex-wrap: wrap;
    gap: 12px;
  }

  .nav-links {
    gap: 18px;
  }

  .hero, .boltstudy-section, .products-hero, .blog-hero {
    padding-left: 20px;
    padding-right: 20px;
  }

  .features, .blog-grid, .product-card {
    padding-left: 20px;
    padding-right: 20px;
  }

  .contact-section {
    padding-left: 20px;
    padding-right: 20px;
  }
}