/* ==========================================================================
   GASDEP.RU — DESIGN SYSTEM & STYLESHEET (Mobile-First)
   ========================================================================== */
:root {
  --bg-primary: #0b0f17;
  --bg-secondary: #111827;
  --bg-card: #172033;
  --bg-card-hover: #1e2942;
  --border-color: #24324a;
  --border-focus: #00d2ff;
  --accent-cyan: #00d2ff;
  --accent-cyan-glow: rgba(0, 210, 255, 0.25);
  --accent-orange: #ff6b00;
  --accent-orange-hover: #e05e00;
  --accent-green: #10b981;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --font-main: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --shadow-card: 0 10px 25px -5px rgba(0, 0, 0, 0.5), 0 8px 10px -6px rgba(0, 0, 0, 0.5);
  --container-width: 1200px;
  --transition: all 0.25s ease-in-out;
}

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

body {
  font-family: var(--font-main);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  padding-bottom: 70px;
}

@media (min-width: 992px) {
  body { padding-bottom: 0; }
}

a {
  color: inherit;
  text-decoration: none;
  transition: var(--transition);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 16px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.95rem;
  padding: 12px 24px;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
  gap: 8px;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-orange) 0%, #ff8800 100%);
  color: #fff;
  box-shadow: 0 4px 15px rgba(255, 107, 0, 0.4);
}

.btn-primary:hover {
  background: var(--accent-orange-hover);
  box-shadow: 0 6px 20px rgba(255, 107, 0, 0.6);
  transform: translateY(-2px);
}

.btn-outline-cyan {
  background: transparent;
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
}

.btn-outline-cyan:hover {
  background: var(--accent-cyan);
  color: #000;
  box-shadow: 0 0 15px var(--accent-cyan-glow);
}

.btn-sm {
  padding: 8px 14px;
  font-size: 0.85rem;
}

.badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
}

.badge-sale { background: #ef4444; color: #fff; }
.badge-cyan { background: rgba(0, 210, 255, 0.15); color: var(--accent-cyan); border: 1px solid rgba(0, 210, 255, 0.3); }

.header-top {
  background-color: #06090e;
  border-bottom: 1px solid var(--border-color);
  font-size: 0.85rem;
  color: var(--text-secondary);
  padding: 8px 0;
}

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

.status-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--accent-green);
  font-weight: 600;
}

.status-badge::before {
  content: "";
  width: 8px;
  height: 8px;
  background-color: var(--accent-green);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--accent-green);
}

.header-main {
  background-color: rgba(17, 24, 39, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 0;
}

.logo {
  font-size: 1.6rem;
  font-weight: 900;
  letter-spacing: -0.03em;
  color: #fff;
}
.logo span { color: var(--accent-cyan); }

.nav-menu { display: none; }
@media (min-width: 992px) {
  .nav-menu {
    display: flex;
    gap: 20px;
    list-style: none;
  }
  .nav-menu a {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
  }
  .nav-menu a:hover, .nav-menu a.active { color: var(--accent-cyan); }
}

.header-contacts { display: flex; align-items: center; gap: 15px; }
.phone-link { font-weight: 700; font-size: 1.1rem; color: #fff; }
.phone-link:hover { color: var(--accent-cyan); }

.burger-btn {
  display: flex;
  flex-direction: column;
  gap: 5px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 5px;
}
@media (min-width: 992px) { .burger-btn { display: none; } }
.burger-btn span {
  display: block;
  width: 24px;
  height: 2px;
  background-color: #fff;
  transition: var(--transition);
}

.breadcrumbs {
  padding: 18px 0;
  font-size: 0.85rem;
  color: var(--text-muted);
}
.breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  list-style: none;
  gap: 8px;
}
.breadcrumbs li:not(:last-child)::after {
  content: "›";
  margin-left: 8px;
  color: var(--border-color);
}
.breadcrumbs a { color: var(--text-secondary); }
.breadcrumbs a:hover { color: var(--accent-cyan); }
.breadcrumbs span[aria-current="page"] { color: var(--accent-cyan); }

.page-header {
  padding: 30px 0 40px;
  border-bottom: 1px solid var(--border-color);
  background: radial-gradient(circle at 90% 10%, rgba(0, 210, 255, 0.05) 0%, transparent 50%), var(--bg-primary);
}
.page-title {
  font-size: 2.2rem;
  font-weight: 900;
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}
.page-subtitle {
  color: var(--text-secondary);
  font-size: 1.05rem;
  max-width: 800px;
}

.hero {
  padding: 40px 0 60px;
  background: radial-gradient(circle at 80% 20%, rgba(0, 210, 255, 0.08) 0%, transparent 60%),
              radial-gradient(circle at 10% 80%, rgba(255, 107, 0, 0.06) 0%, transparent 50%),
              var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
}
.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
  align-items: center;
}
@media (min-width: 992px) { .hero-grid { grid-template-columns: 1.2fr 0.8fr; } }
.hero-badge { margin-bottom: 16px; }
.hero-title {
  font-size: 2.2rem;
  line-height: 1.15;
  font-weight: 900;
  margin-bottom: 16px;
}
@media (min-width: 768px) { .hero-title { font-size: 3.2rem; } }
.hero-title span {
  color: var(--accent-cyan);
  display: inline-block;
  text-shadow: 0 0 20px var(--accent-cyan-glow);
}
.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-secondary);
  margin-bottom: 24px;
}
.hero-usp-badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: rgba(255, 107, 0, 0.12);
  border: 1px solid rgba(255, 107, 0, 0.3);
  padding: 10px 16px;
  border-radius: var(--radius-md);
  margin-bottom: 30px;
  color: #ff9d42;
  font-weight: 600;
  font-size: 0.95rem;
}
.hero-actions { display: flex; flex-direction: column; gap: 14px; }
@media (min-width: 576px) { .hero-actions { flex-direction: row; } }

.section {
  padding: 60px 0;
  border-bottom: 1px solid var(--border-color);
}
.section-header { text-align: center; margin-bottom: 40px; }
.section-title { font-size: 1.8rem; font-weight: 800; letter-spacing: -0.02em; margin-bottom: 10px; }
@media (min-width: 768px) { .section-title { font-size: 2.3rem; } }
.section-subtitle { color: var(--text-secondary); font-size: 1rem; }

.advantages-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}
@media (min-width: 576px) { .advantages-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 992px) { .advantages-grid { grid-template-columns: repeat(4, 1fr); } }

.advantage-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 24px;
  border-radius: var(--radius-md);
  transition: var(--transition);
}
.advantage-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-cyan);
  box-shadow: 0 10px 30px rgba(0, 210, 255, 0.1);
}
.advantage-icon {
  width: 48px;
  height: 48px;
  background: rgba(0, 210, 255, 0.1);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-cyan);
  font-size: 1.4rem;
  margin-bottom: 16px;
}
.advantage-card h3 { font-size: 1.1rem; margin-bottom: 8px; }
.advantage-card p { color: var(--text-secondary); font-size: 0.9rem; }

.catalog-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}
@media (min-width: 768px) { .catalog-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1200px) { .catalog-grid { grid-template-columns: repeat(4, 1fr); } }

.product-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 20px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: var(--transition);
}
.product-card:hover {
  border-color: rgba(0, 210, 255, 0.5);
  box-shadow: var(--shadow-card);
  transform: translateY(-4px);
}
.product-badge-wrap { position: absolute; top: 16px; left: 16px; z-index: 2; }
.product-img-wrap {
  height: 220px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.04) 0%, transparent 70%);
  border-radius: var(--radius-md);
  overflow: hidden;
}
.product-img-wrap img {
  max-height: 190px;
  object-fit: contain;
  transition: transform 0.3s ease;
}
.product-card:hover .product-img-wrap img { transform: scale(1.05); }
.product-title { font-size: 1.25rem; font-weight: 700; margin-bottom: 12px; }
.product-prices {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 12px;
  margin-bottom: 16px;
}
.price-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 4px 0;
}
.price-row:not(:last-child) {
  border-bottom: 1px dashed var(--border-color);
  margin-bottom: 4px;
}
.price-label { font-size: 0.85rem; color: var(--text-secondary); }
.price-val { font-size: 1.15rem; font-weight: 800; color: #fff; }
.price-val.accent { color: var(--accent-cyan); }
.product-card .btn { margin-top: auto; width: 100%; }

.table-responsive {
  width: 100%;
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  margin: 24px 0;
}
.custom-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.95rem;
}
.custom-table th {
  background: var(--bg-secondary);
  padding: 16px 20px;
  font-weight: 700;
  color: var(--accent-cyan);
  border-bottom: 1px solid var(--border-color);
  white-space: nowrap;
}
.custom-table td {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-secondary);
}
.custom-table tbody tr:hover { background: rgba(255, 255, 255, 0.02); }
.custom-table tbody tr:last-child td { border-bottom: none; }
.custom-table .highlight { color: #fff; font-weight: 700; }
.custom-table .price-cell { color: var(--accent-cyan); font-weight: 800; font-size: 1.1rem; }

.product-detail-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  align-items: start;
}
@media (min-width: 992px) { .product-detail-grid { grid-template-columns: 1fr 1fr; } }
.product-gallery {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 40px;
  text-align: center;
}
.product-gallery img {
  max-height: 420px;
  margin: 0 auto;
  filter: drop-shadow(0 15px 30px rgba(0, 210, 255, 0.15));
}
.product-info-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px;
}
.spec-list { list-style: none; margin: 20px 0; }
.spec-item {
  display: flex;
  justify-content: space-between;
  padding: 10px 0;
  border-bottom: 1px dashed var(--border-color);
  font-size: 0.95rem;
}
.spec-name { color: var(--text-secondary); }
.spec-val { font-weight: 600; color: #fff; }

.cert-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}
@media (min-width: 576px) { .cert-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 992px) { .cert-grid { grid-template-columns: repeat(4, 1fr); } }
.cert-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 16px;
  text-align: center;
  transition: var(--transition);
}
.cert-card:hover {
  border-color: var(--accent-cyan);
  transform: translateY(-4px);
  box-shadow: 0 10px 25px rgba(0, 210, 255, 0.15);
}
.cert-thumb {
  height: 200px;
  background: #0f1624;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 14px;
  font-size: 3rem;
}

.articles-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}
@media (min-width: 768px) { .articles-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1200px) { .articles-grid { grid-template-columns: repeat(3, 1fr); } }
.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}
.article-card:hover { border-color: var(--accent-cyan); transform: translateY(-4px); }
.article-body { padding: 24px; display: flex; flex-direction: column; flex: 1; }
.article-date { font-size: 0.8rem; color: var(--accent-cyan); margin-bottom: 8px; }
.article-title { font-size: 1.2rem; font-weight: 700; margin-bottom: 12px; }
.article-excerpt { color: var(--text-secondary); font-size: 0.9rem; margin-bottom: 20px; flex: 1; }

.notice-box {
  background: rgba(255, 107, 0, 0.08);
  border-left: 4px solid var(--accent-orange);
  padding: 20px 24px;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 24px 0;
}
.notice-box.cyan {
  background: rgba(0, 210, 255, 0.08);
  border-left-color: var(--accent-cyan);
}
.notice-box p { color: var(--text-secondary); font-size: 0.95rem; margin: 0; }
.notice-box strong { color: #fff; }

.contacts-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
}
@media (min-width: 992px) { .contacts-grid { grid-template-columns: 1.2fr 0.8fr; } }
.contact-item { display: flex; gap: 16px; align-items: flex-start; margin-bottom: 24px; }
.contact-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: rgba(0, 210, 255, 0.1);
  color: var(--accent-cyan);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  flex-shrink: 0;
}

.seo-block {
  background: #090d14;
  border-top: 1px solid var(--border-color);
  padding: 60px 0;
}
.seo-content {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.85;
}
.seo-content h2, .seo-content h3 {
  color: #fff;
  margin: 28px 0 14px;
}
.seo-content h2 { font-size: 1.6rem; letter-spacing: -0.01em; }
.seo-content h3 { font-size: 1.25rem; color: var(--accent-cyan); }
.seo-content p { margin-bottom: 16px; }
.seo-content ul { margin-bottom: 20px; padding-left: 20px; }
.seo-content li { margin-bottom: 8px; }

.footer {
  background: #06090e;
  border-top: 1px solid var(--border-color);
  padding: 40px 0 20px;
  font-size: 0.9rem;
  color: var(--text-secondary);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
  margin-bottom: 30px;
}
@media (min-width: 768px) { .footer-grid { grid-template-columns: 2fr 1fr 1fr; } }
.footer-title { color: #fff; font-size: 1rem; font-weight: 700; margin-bottom: 16px; }
.footer-links { list-style: none; display: flex; flex-direction: column; gap: 8px; }
.footer-links a:hover { color: var(--accent-cyan); }
.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-muted);
}
@media (min-width: 768px) {
  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
    text-align: left;
  }
}

.modal-overlay {
  display: none;
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0, 0, 0, 0.8);
  z-index: 2000;
  align-items: center;
  justify-content: center;
  padding: 16px;
}
.modal-overlay.active { display: flex; }
.modal-content {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  max-width: 450px;
  width: 100%;
  padding: 30px;
  position: relative;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.8);
}
.modal-close {
  position: absolute;
  top: 16px; right: 16px;
  background: transparent;
  border: none;
  font-size: 1.5rem;
  color: var(--text-muted);
  cursor: pointer;
}
.modal-title { font-size: 1.4rem; margin-bottom: 8px; }
.form-group { margin-bottom: 16px; }
.form-label { display: block; font-size: 0.85rem; margin-bottom: 6px; color: var(--text-secondary); }
.form-input {
  width: 100%;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  color: #fff;
  font-size: 0.95rem;
}
.form-input:focus { border-color: var(--accent-cyan); outline: none; }

/* ==========================================================================
   ИНФОРМАЦИЯ О ДОСТАВКЕ
   ========================================================================== */
.delivery-box {
  background: linear-gradient(145deg, #131b29, #0d131f);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 30px;
}

.delivery-list {
  list-style: none;
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  padding: 0;
  margin: 0;
}

@media (min-width: 768px) {
  .delivery-list {
    grid-template-columns: repeat(2, 1fr);
  }
}

.delivery-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.delivery-check {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: rgba(0, 210, 255, 0.15);
  color: var(--accent-cyan);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1.05rem;
  flex-shrink: 0;
  border: 1px solid rgba(0, 210, 255, 0.3);
}

.delivery-item strong {
  display: block;
  font-size: 1.05rem;
  color: #fff;
  margin-bottom: 6px;
}

.delivery-item p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin: 0;
  line-height: 1.6;
}

/* ==========================================================================
   КАК ЗАКАЗАТЬ: 4 ПРОСТЫХ ШАГА
   ========================================================================== */
.steps-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

@media (min-width: 576px) {
  .steps-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 992px) {
  .steps-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.step-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 26px 22px;
  position: relative;
  transition: var(--transition);
}

.step-card:hover {
  border-color: var(--accent-cyan);
  transform: translateY(-4px);
  box-shadow: 0 10px 25px rgba(0, 210, 255, 0.12);
}

.step-number {
  font-size: 2.6rem;
  font-weight: 900;
  color: rgba(0, 210, 255, 0.25);
  line-height: 1;
  margin-bottom: 14px;
  font-family: inherit;
}

.step-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: #fff;
}

.step-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.6;
}

/* ==========================================================================
   ЧАСТО ЗАДАВАЕМЫЕ ВОПРОСЫ (FAQ АККОРДЕОН)
   ========================================================================== */
.faq-list {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition);
}

.faq-item.active {
  border-color: var(--accent-cyan);
  box-shadow: 0 6px 20px rgba(0, 210, 255, 0.12);
}

.faq-question {
  width: 100%;
  padding: 18px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: transparent;
  border: none;
  color: #fff;
  font-size: 1.05rem;
  font-weight: 600;
  cursor: pointer;
  text-align: left;
  gap: 16px;
  font-family: inherit;
}

.faq-question:hover {
  color: var(--accent-cyan);
}

.faq-icon {
  font-size: 1.6rem;
  font-weight: 400;
  line-height: 1;
  color: var(--accent-cyan);
  transition: transform 0.25s ease;
  flex-shrink: 0;
}

.faq-item.active .faq-icon {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s cubic-bezier(0.4, 0, 0.2, 1), padding 0.3s ease;
  padding: 0 24px;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.75;
}

.faq-item.active .faq-answer {
  padding-bottom: 20px;
}

.faq-answer p {
  margin: 0;
}