/* ================================================
   VoltStack Product Page — matches dark theme system
   ================================================ */

/* --- Layout helpers --- */
.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

/* --- Header (matches landing page) --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  padding: 20px 0;
  border-bottom: 1px solid var(--border, #30363d);
  background: rgba(13, 17, 23, 0.9);
  backdrop-filter: blur(12px);
}
.header-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.wordmark {
  font-family: 'Syne', sans-serif;
  font-size: 20px;
  font-weight: 800;
  color: #f0a500;
  letter-spacing: -0.02em;
  text-decoration: none;
}
.header-nav {
  display: flex;
  gap: 24px;
}
.nav-link {
  font-size: 14px;
  color: #8b949e;
  text-decoration: none;
  transition: color 0.15s;
}
.nav-link:hover,
.nav-link-active {
  color: #e6edf3;
}
.nav-link-active {
  color: #f0a500;
}

/* --- Breadcrumb --- */
.breadcrumb-bar {
  padding: 16px 0;
  border-bottom: 1px solid #21262d;
}
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: #8b949e;
}
.breadcrumb a {
  color: #8b949e;
  text-decoration: none;
}
.breadcrumb a:hover { color: #e6edf3; }
.breadcrumb-sep { color: #30363d; }
.breadcrumb-current { color: #e6edf3; }

/* --- Product Hero --- */
.product-hero {
  padding: 56px 0 64px;
  border-bottom: 1px solid #30363d;
}
.product-hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
}

/* Image */
.product-image-frame {
  position: relative;
  background: #161b22;
  border: 1px solid #30363d;
  border-radius: 12px;
  aspect-ratio: 4/3;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}
.product-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.product-badge {
  position: absolute;
  top: 16px;
  left: 16px;
  background: #f0a500;
  color: #0d1117;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: 4px;
}

/* Info side */
.product-info-wrap {
  display: flex;
  flex-direction: column;
  gap: 0;
}
.section-label {
  font-family: 'DM Sans', sans-serif;
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #f0a500;
  margin-bottom: 12px;
}
.product-name {
  font-family: 'Syne', sans-serif;
  font-size: clamp(32px, 4vw, 48px);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: #e6edf3;
  margin: 0 0 6px;
}
.product-tagline {
  font-size: 14px;
  color: #8b949e;
  margin: 0 0 28px;
  font-family: 'DM Sans', monospace;
  letter-spacing: 0.04em;
}

/* Price */
.product-price-row {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 24px;
}
.product-price {
  font-family: 'Syne', sans-serif;
  font-size: 38px;
  font-weight: 800;
  color: #e6edf3;
}
.product-price-sub {
  font-size: 13px;
  color: #8b949e;
}

/* CTA Button */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: #f0a500;
  color: #0d1117;
  font-family: 'DM Sans', sans-serif;
  font-size: 15px;
  font-weight: 700;
  border: none;
  border-radius: 8px;
  padding: 14px 28px;
  cursor: pointer;
  transition: background 0.15s, transform 0.1s, opacity 0.15s;
  margin-bottom: 12px;
}
.btn-primary:hover { background: #f5b832; transform: translateY(-1px); }
.btn-primary:active { transform: translateY(0); }
.btn-primary:disabled { opacity: 0.6; cursor: not-allowed; transform: none; }
.btn-primary.btn-success {
  background: #238636;
  color: #fff;
  cursor: default;
}
.btn-loading {
  position: relative;
  opacity: 0.7;
}
.cart-feedback {
  font-size: 13px;
  color: #8b949e;
  margin: 0 0 24px;
  min-height: 20px;
}

/* Quick Specs */
.product-quick-specs {
  border: 1px solid #30363d;
  border-radius: 10px;
  overflow: hidden;
  margin-top: 8px;
}
.spec-row {
  display: flex;
  align-items: center;
  padding: 12px 16px;
  border-bottom: 1px solid #21262d;
}
.spec-row:last-child { border-bottom: none; }
.spec-label {
  font-size: 13px;
  color: #8b949e;
  width: 100px;
  flex-shrink: 0;
}
.spec-value {
  font-size: 13px;
  color: #e6edf3;
  font-weight: 500;
}

/* --- Tabs Section --- */
.product-tabs-section {
  padding: 48px 0 80px;
}
.tabs {
  display: flex;
  gap: 0;
  border-bottom: 1px solid #30363d;
  margin-bottom: 40px;
}
.tab-btn {
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  padding: 12px 20px;
  font-family: 'DM Sans', sans-serif;
  font-size: 15px;
  font-weight: 500;
  color: #8b949e;
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s;
  margin-bottom: -1px;
}
.tab-btn:hover { color: #e6edf3; }
.tab-btn-active {
  color: #f0a500;
  border-bottom-color: #f0a500;
}
.tab-panel { display: none; }
.tab-panel-active { display: block; }

/* Description */
.product-description h2 {
  font-family: 'Syne', sans-serif;
  font-size: 26px;
  font-weight: 700;
  color: #e6edf3;
  margin-bottom: 20px;
}
.product-description p {
  font-size: 15px;
  line-height: 1.7;
  color: #c9d1d9;
  max-width: 720px;
  margin-bottom: 16px;
}
.description-features {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-top: 36px;
}
.desc-feature {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}
.desc-feature-icon {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  background: rgba(240, 165, 0, 0.12);
  border: 1px solid rgba(240, 165, 0, 0.2);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #f0a500;
}
.desc-feature strong {
  display: block;
  font-size: 14px;
  font-weight: 600;
  color: #e6edf3;
  margin-bottom: 4px;
}
.desc-feature p {
  font-size: 13px;
  color: #8b949e;
  line-height: 1.5;
  margin: 0;
}

/* Specs table */
.specs-table-wrap { overflow-x: auto; }
.specs-table {
  width: 100%;
  border-collapse: collapse;
  border: 1px solid #30363d;
  border-radius: 10px;
  overflow: hidden;
}
.specs-table thead tr {
  background: #161b22;
}
.specs-table thead th {
  font-family: 'Syne', sans-serif;
  font-size: 16px;
  font-weight: 700;
  color: #e6edf3;
  text-align: left;
  padding: 14px 20px;
  border-bottom: 1px solid #30363d;
}
.specs-table tbody tr:nth-child(even) { background: #161b22; }
.specs-table tbody tr:nth-child(odd) { background: #0d1117; }
.specs-table td {
  padding: 12px 20px;
  font-size: 14px;
  color: #c9d1d9;
  border-bottom: 1px solid #21262d;
}
.specs-table td:first-child {
  color: #8b949e;
  width: 40%;
  font-weight: 500;
}
.specs-table tbody tr:last-child td { border-bottom: none; }

/* Included list */
.included-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  max-width: 680px;
}
.included-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  background: #161b22;
  border: 1px solid #30363d;
  border-radius: 8px;
  font-size: 14px;
  color: #e6edf3;
  font-weight: 500;
}
.included-check {
  width: 24px;
  height: 24px;
  background: rgba(35, 134, 54, 0.2);
  border: 1px solid #238636;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #3fb950;
  flex-shrink: 0;
}

/* --- Footer --- */
.site-footer {
  border-top: 1px solid #21262d;
  padding: 24px 0;
}
.footer-copy {
  font-size: 13px;
  color: #484f58;
  text-align: center;
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .product-hero-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .product-image-frame {
    aspect-ratio: 16/10;
  }
  .description-features {
    grid-template-columns: 1fr;
  }
  .included-list {
    grid-template-columns: 1fr;
  }
  .tabs {
    overflow-x: auto;
  }
  .tab-btn {
    padding: 10px 14px;
    font-size: 14px;
    white-space: nowrap;
  }
}