:root {
  --bg: #f7f8fb;
  --bg-alt: #eef2f7;
  --surface: #ffffff;
  --surface-hover: #f3f7ff;
  --border: #dce3ed;
  --text: #172033;
  --text-muted: #667085;
  --accent: #2563eb;
  --accent-2: #0f9cc6;
  --success: #168a5b;
  --danger: #d04343;
  --radius: 14px;
  --font-heading: 'Sora', sans-serif;
  --font-body: 'Inter', sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  scroll-behavior: smooth;
}

h1, h2, h3, h4 {
  font-family: var(--font-heading);
  margin: 0 0 0.5em;
  line-height: 1.2;
}

p { color: var(--text-muted); line-height: 1.6; margin: 0 0 1em; }

a { color: inherit; text-decoration: none; }

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.3rem;
  letter-spacing: -0.02em;
}

.logo span { color: var(--accent); }

.main-nav { display: flex; gap: 28px; }

.main-nav a {
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.95rem;
  transition: color 0.2s;
}

.main-nav a:hover, .main-nav a.active { color: var(--text); }

.nav-cta { display: inline-flex; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.2s ease, border-color 0.2s ease;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
}

.btn-primary:hover { transform: translateY(-1px); }

.btn-ghost {
  background: transparent;
  border-color: var(--border);
  color: var(--text);
}

.btn-ghost:hover { border-color: var(--accent); }

.btn-selected {
  background: var(--success);
  color: #fff;
}

.btn-sm { padding: 8px 16px; font-size: 0.85rem; }
.btn-block { width: 100%; margin: 16px 0; }
.btn[disabled] { opacity: 0.4; cursor: not-allowed; }

/* ---------- Hero ---------- */
.hero { padding: 80px 0 60px; overflow: hidden; }

.hero-inner {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
}

.eyebrow {
  display: inline-block;
  color: var(--accent);
  font-weight: 600;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 14px;
}

.hero h1 { font-size: 3rem; font-weight: 800; letter-spacing: -0.02em; }
.accent { background: linear-gradient(135deg, var(--accent), var(--accent-2)); -webkit-background-clip: text; background-clip: text; color: transparent; }

.hero-actions { display: flex; gap: 14px; margin: 28px 0; }

.hero-stats { list-style: none; display: flex; gap: 28px; padding: 0; margin: 0; }
.hero-stats li { color: var(--text-muted); font-size: 0.9rem; }
.hero-stats strong { display: block; color: var(--text); font-size: 1.4rem; font-family: var(--font-heading); }

.hero-visual { position: relative; }
.glow {
  position: absolute; inset: -40px;
  background: radial-gradient(circle at 30% 30%, rgba(37,99,235,0.18), transparent 60%);
  filter: blur(30px);
}

.mock-card {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: 0 20px 60px rgba(23,32,51,0.12);
}

.mock-row {
  display: flex;
  justify-content: space-between;
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
  font-size: 0.9rem;
  color: var(--text-muted);
}

.mock-row span:last-child { color: var(--text); font-weight: 600; }
.mock-row.total { border-bottom: none; font-size: 1.1rem; }
.mock-row.total span { color: var(--accent); font-family: var(--font-heading); }

/* ---------- Sections ---------- */
.section { padding: 64px 0; }
.section-alt { background: var(--bg-alt); }

.section-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 32px;
}

.link-more { color: var(--accent); font-weight: 600; font-size: 0.9rem; }

.page-hero { padding: 56px 0 32px; border-bottom: 1px solid var(--border); }
.page-hero-compact { padding: 48px 0 24px; }
.page-hero h1 { font-size: 2.2rem; }
.sequence-hint { color: var(--accent); font-size: 0.9rem; }
.sequence-hint strong { color: var(--text); }

/* ---------- Build cards ---------- */
.build-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.build-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  display: flex;
  flex-direction: column;
  transition: border-color 0.2s, transform 0.2s;
}

.build-card:hover { border-color: var(--accent); transform: translateY(-3px); }

.build-card-image {
  width: calc(100% + 48px);
  height: 150px;
  object-fit: contain;
  background: var(--bg-alt);
  margin: -24px -24px 20px;
  border-radius: var(--radius) var(--radius) 0 0;
  border-bottom: 1px solid var(--border);
}

.lock-badge {
  align-self: flex-start;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  background: var(--bg-alt);
  border: 1px solid var(--border);
  padding: 4px 10px;
  border-radius: 999px;
  margin-bottom: 12px;
}

.build-card-tag {
  align-self: flex-start;
  background: rgba(37,99,235,0.10);
  color: var(--accent);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 4px 10px;
  border-radius: 999px;
  margin-bottom: 12px;
}

.build-card h3 { font-size: 1.2rem; }

.build-card-specs {
  list-style: none;
  padding: 0;
  margin: 12px 0;
  flex: 1;
}

.build-card-specs li {
  font-size: 0.85rem;
  color: var(--text-muted);
  padding: 6px 0;
  border-top: 1px solid var(--border);
}

.build-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 12px;
}

.price { font-family: var(--font-heading); font-weight: 700; font-size: 1.3rem; color: var(--text); }

/* ---------- How it works ---------- */
.how-it-works h2 { text-align: center; margin-bottom: 40px; }
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.step { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 28px; }
.step-number {
  display: inline-flex; align-items: center; justify-content: center;
  width: 36px; height: 36px; border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff; font-weight: 700; margin-bottom: 16px;
}

/* ---------- Build detail ---------- */
.build-detail-layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 32px;
  align-items: start;
}

.build-items { display: flex; flex-direction: column; gap: 16px; }

.component-row {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

.component-category {
  display: block;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
}

.component-info h3 { font-size: 1.05rem; margin: 2px 0; }
.qty { font-size: 0.8rem; color: var(--accent); font-weight: 600; }

.component-offer { text-align: right; }
.best-offer { display: flex; flex-direction: column; align-items: flex-end; gap: 6px; }
.offer-price { font-family: var(--font-heading); font-weight: 700; font-size: 1.15rem; }
.offer-source { font-size: 0.8rem; color: var(--success); }
.offer-unavailable { color: var(--danger); font-size: 0.9rem; }

.alt-offers { margin-top: 10px; text-align: left; }
.alt-offers summary { cursor: pointer; color: var(--accent); font-size: 0.85rem; }
.alt-offers ul { list-style: none; padding: 0; margin: 10px 0 0; }
.alt-offers li {
  display: flex; justify-content: space-between; gap: 12px;
  font-size: 0.85rem; color: var(--text-muted);
  padding: 6px 0; border-top: 1px solid var(--border);
}
.alt-offers li a { color: var(--accent); }

.build-summary {
  position: sticky;
  top: 96px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
}

.summary-note { font-size: 0.7rem; margin-top: 10px; }

/* ---------- Configurator ---------- */
.configurator-section { padding-top: 40px; }

.configurator {
  display: grid;
  grid-template-columns: 220px 1fr 320px;
  gap: 24px;
  align-items: start;
}

.cat-nav {
  display: flex;
  flex-direction: column;
  gap: 6px;
  position: sticky;
  top: 96px;
}

.cat-btn {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-muted);
  padding: 12px 16px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  text-align: left;
  transition: border-color 0.2s, color 0.2s;
}

.cat-btn:hover { color: var(--text); }
.cat-btn.active { color: var(--text); border-color: var(--accent); background: var(--surface-hover); }
.cat-btn.locked { opacity: 0.45; cursor: not-allowed; }
.cat-btn.locked:hover { color: var(--text-muted); }
.cat-check { color: var(--success); font-weight: 800; }
.cat-lock { font-size: 0.8rem; }

.components-panel-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  flex-wrap: wrap;
  gap: 12px;
}

.toggle-incompatible {
  display: flex; align-items: center; gap: 8px;
  font-size: 0.85rem; color: var(--text-muted); cursor: pointer;
}

.components-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-bottom: 20px;
}

.filter-field {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 0.78rem;
  color: var(--text-muted);
  font-weight: 600;
}

.filter-field[hidden],
.case-fan-capacity[hidden] { display: none; }

.filter-field select,
.filter-field input {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 8px 12px;
  border-radius: 8px;
  font-size: 0.85rem;
  min-width: 180px;
}

.filter-search { flex: 1; min-width: 220px; }
.filter-search input { width: 100%; min-width: 0; }

.case-fan-capacity {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 10px 20px;
  align-items: end;
  margin: 0 0 20px;
  padding: 14px 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent-2);
  box-shadow: inset 0 1px 0 rgba(37, 99, 235, 0.08);
  color: var(--text-muted);
  font-size: 0.8rem;
  line-height: 1.4;
}

.case-fan-capacity strong {
  grid-column: 1 / -1;
  color: var(--text);
  font-family: var(--font-heading);
  font-size: 0.95rem;
  line-height: 1.3;
}

.case-fan-capacity span {
  min-width: 0;
}

.case-fan-capacity span + span {
  border-left: 1px solid var(--border);
  padding-left: 20px;
  text-align: right;
}

.components-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 18px;
}

.component-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  display: flex;
  flex-direction: column;
  transition: border-color 0.2s;
}

.component-card.selected { border-color: var(--success); }
.component-card.incompatible { opacity: 0.55; }

.component-image {
  width: 100%;
  height: 150px;
  object-fit: contain;
  margin-bottom: 14px;
}

.component-card h3 { font-size: 1rem; margin-bottom: 10px; }

.component-row-image {
  width: 88px;
  height: 88px;
  object-fit: contain;
  flex: 0 0 88px;
}

.badges { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 10px; }
.badge {
  font-size: 0.72rem;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  color: var(--text-muted);
  padding: 3px 8px;
  border-radius: 999px;
}

.incompatible-reasons {
  list-style: none;
  padding: 0;
  margin: 0 0 10px;
  font-size: 0.78rem;
  color: var(--danger);
}

.card-footer {
  margin-top: auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--border);
}

.offers-count { display: block; font-size: 0.72rem; color: var(--text-muted); }

.fan-qty-control { display: flex; align-items: center; gap: 8px; }
.fan-qty-input {
  width: 56px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  padding: 6px 8px;
  font-size: 0.85rem;
  text-align: center;
}

.summary-qty { color: var(--text-muted); font-weight: 400; font-size: 0.8rem; }

.loading, .empty, .error { color: var(--text-muted); padding: 40px 0; text-align: center; grid-column: 1 / -1; }
.error { color: var(--danger); }

.configurator-summary {
  position: sticky;
  top: 96px;
  display: flex;
  flex-direction: column;
  height: calc(100vh - 96px);
  max-height: calc(100vh - 96px);
  overflow: hidden;
}

.configurator-summary-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}

.configurator-summary-header h3 { margin: 0; font-size: 1rem; }
.configurator-summary-actions { display: flex; align-items: center; gap: 8px; }
.summary-total { color: var(--accent); font-family: var(--font-heading); font-size: 1rem; white-space: nowrap; }

.summary-clear-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  padding: 0;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 1rem;
  line-height: 1;
  transition: background 0.2s, border-color 0.2s, color 0.2s;
}

.summary-clear-btn:hover {
  background: rgba(255,107,107,0.1);
  border-color: var(--danger);
  color: var(--danger);
}

.summary-list {
  list-style: none;
  min-height: 0;
  flex: 1 1 auto;
  overflow-y: auto;
  padding: 0 6px 0 0;
  margin: 0 0 12px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}

.summary-list::-webkit-scrollbar { width: 6px; }
.summary-list::-webkit-scrollbar-thumb { background: var(--border); border-radius: 999px; }
.summary-list::-webkit-scrollbar-track { background: transparent; }

.summary-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
}

.summary-item.empty .summary-name { color: var(--text-muted); font-style: italic; }

.summary-item-info { display: flex; flex-direction: column; }
.summary-cat { font-size: 0.64rem; text-transform: uppercase; letter-spacing: 0.05em; color: var(--text-muted); }
.summary-name { font-size: 0.78rem; font-weight: 600; }

.summary-item-actions { display: flex; align-items: center; gap: 10px; }
.summary-price { font-weight: 700; font-size: 0.78rem; }

.summary-cart-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 5px;
  min-width: 30px;
  height: 30px;
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--accent);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0 8px;
  white-space: nowrap;
  transition: background 0.2s, border-color 0.2s;
}

.summary-cart-link:hover {
  background: var(--surface-hover);
  border-color: var(--accent);
}

.summary-cart-link.unavailable {
  color: var(--text-muted);
  cursor: not-allowed;
  opacity: 0.65;
}

.purchase-all-btn { margin: 0 0 12px; }

.remove-btn {
  background: none; border: none; color: var(--danger);
  font-size: 1.1rem; cursor: pointer; line-height: 1;
}

.summary-warnings {
  background: rgba(255,107,107,0.1);
  border: 1px solid rgba(255,107,107,0.3);
  border-radius: 10px;
  padding: 14px;
  margin-top: 12px;
}

.summary-warnings h4 { font-size: 0.75rem; color: var(--danger); margin-bottom: 6px; }
.summary-warnings ul { margin: 0; padding-left: 16px; font-size: 0.7rem; color: var(--text-muted); }

/* ---------- Footer ---------- */
.site-footer { background: var(--bg-alt); border-top: 1px solid var(--border); margin-top: 80px; }
.footer-inner {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
  padding: 56px 24px;
}
.footer-links h4 { font-size: 0.9rem; margin-bottom: 14px; }
.footer-links a { display: block; color: var(--text-muted); font-size: 0.9rem; margin-bottom: 10px; }
.footer-links a:hover { color: var(--text); }
.footer-bottom {
  border-top: 1px solid var(--border);
  padding: 20px 24px;
  font-size: 0.8rem;
  color: var(--text-muted);
  text-align: center;
}

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .hero-inner { grid-template-columns: 1fr; }
  .build-detail-layout { grid-template-columns: 1fr; }
  .configurator { grid-template-columns: 1fr; }
  .cat-nav { position: static; flex-direction: row; overflow-x: auto; }
  .configurator-summary {
    position: static;
    display: block;
    height: auto;
    max-height: none;
    overflow: visible;
  }
  .summary-list {
    flex: none;
    overflow: visible;
    padding-right: 0;
  }
  .steps { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  .main-nav { display: none; }
  .hero h1 { font-size: 2.2rem; }
  .case-fan-capacity { grid-template-columns: 1fr; gap: 8px; }
  .case-fan-capacity span + span { border-left: 0; padding-left: 0; text-align: left; }
}