/* ============================================================
   ARGON S.L. — Modern static site
   Mobile-first · Dark anthracite + red accent
   ============================================================ */

/* ---------- Custom Properties ---------- */
:root {
  --bg-body:      #1B1F23;
  --bg-card:      #252A2E;
  --bg-card-alt:  #2C3136;
  --bg-header:    #14171A;
  --bg-footer:    #111416;

  --accent:       #C0392B;
  --accent-hover: #E74C3C;
  --accent-dark:  #962D22;

  --text:         #D5D5D5;
  --text-light:   #9CA3AF;
  --text-heading: #F0F0F0;
  --text-white:   #FFFFFF;

  --border:       #333840;
  --border-light: #444B54;

  --success:      #27AE60;
  --error:        #C0392B;

  --radius:       6px;
  --radius-lg:    10px;
  --shadow:       0 2px 8px rgba(0,0,0,.35);

  --container:    1200px;
  --header-h:     70px;

  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg-body);
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent-hover); text-decoration: none; transition: color .2s; }
a:hover { color: var(--text-white); }
ul { list-style: none; }

/* ---------- Utilities ---------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 1rem;
}
.section { padding: 3rem 0; }
.section--alt { background: var(--bg-card); }
.text-center { text-align: center; }
.sr-only {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0,0,0,0); border: 0;
}

/* ---------- Typography ---------- */
h1, h2, h3, h4 {
  color: var(--text-heading);
  font-weight: 700;
  line-height: 1.25;
}
h1 { font-size: 1.75rem; margin-bottom: 1rem; }
h2 { font-size: 1.4rem;  margin-bottom: .75rem; }
h3 { font-size: 1.15rem; margin-bottom: .5rem; }
p  { margin-bottom: 1rem; }
strong { color: var(--text-heading); }

.section-title {
  font-size: 1.5rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  border-left: 4px solid var(--accent);
  padding-left: .75rem;
  margin-bottom: 2rem;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-block;
  padding: .65rem 1.5rem;
  font-size: .95rem;
  font-weight: 600;
  border-radius: var(--radius);
  border: 2px solid transparent;
  cursor: pointer;
  transition: all .2s;
  text-align: center;
  line-height: 1.4;
}
.btn--primary {
  background: var(--accent);
  color: var(--text-white);
  border-color: var(--accent);
}
.btn--primary:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
  color: var(--text-white);
}
.btn--outline {
  background: transparent;
  color: var(--accent-hover);
  border-color: var(--accent);
}
.btn--outline:hover {
  background: var(--accent);
  color: var(--text-white);
}
.btn:disabled, .btn[disabled] {
  opacity: .5;
  cursor: not-allowed;
}

/* ============================================================
   HEADER
   ============================================================ */
.site-header {
  background: var(--bg-header);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}
.site-header .container {
  display: flex;
  align-items: center;
  height: var(--header-h);
  gap: .75rem;
}
.logo img {
  height: 42px;
  width: auto;
}
.logo-text {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--text-white);
  letter-spacing: .04em;
}
.logo-text span {
  color: var(--accent);
}

/* --- Language Switcher --- */
.lang-switch {
  display: flex;
  gap: .2rem;
  align-items: center;
  margin-left: auto;
  margin-right: 1rem;
}
.lang-switch a {
  padding: .2rem .45rem;
  font-size: .7rem;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--text-light);
  border-radius: 3px;
  transition: color .2s, background .2s;
}
.lang-switch a:hover {
  color: var(--text-white);
  background: rgba(255,255,255,.1);
}
.lang-switch a.lang-active {
  color: var(--text-white);
  background: var(--accent);
}

/* --- Desktop Navigation --- */
.main-nav ul {
  display: flex;
  gap: .25rem;
}
.main-nav a {
  display: block;
  padding: .5rem .9rem;
  font-size: .85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--text-light);
  border-radius: var(--radius);
  transition: background .2s, color .2s;
}
.main-nav a:hover,
.main-nav a.active {
  color: var(--text-white);
  background: rgba(255,255,255,.07);
}
.main-nav a.active {
  color: var(--accent-hover);
}

/* --- Burger (mobile) --- */
.burger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  z-index: 110;
}
.burger span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--text-light);
  border-radius: 2px;
  transition: transform .3s, opacity .3s;
}
.burger[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.burger[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}
.burger[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  position: relative;
  background: linear-gradient(135deg, var(--bg-header) 0%, var(--bg-card) 100%);
  padding: 3rem 0;
  overflow: hidden;
  border-bottom: 3px solid var(--accent);
}
.hero::before {
  content: '';
  position: absolute;
  top: 0; right: 0; bottom: 0; left: 0;
  background: url('/assets/img/slider/headerpic.jpg') center/cover no-repeat;
  opacity: .15;
}
.hero .container {
  position: relative;
  z-index: 1;
}
.hero h1 {
  font-size: 2rem;
  margin-bottom: .5rem;
}
.hero h1 span {
  color: var(--accent);
}
.hero p {
  font-size: 1.05rem;
  color: var(--text-light);
  max-width: 600px;
  margin-bottom: 1.5rem;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
}

/* ============================================================
   PRODUCT CATEGORIES (home page)
   ============================================================ */
.categories-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

.cat-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  transition: border-color .2s, transform .2s;
  display: flex;
  align-items: center;
  gap: 1rem;
}
.cat-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}
.cat-card-icon {
  flex-shrink: 0;
  width: 56px;
  height: 56px;
  background: var(--accent-dark);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  color: var(--text-white);
}
.cat-card h3 {
  margin-bottom: .2rem;
}
.cat-card p {
  font-size: .85rem;
  color: var(--text-light);
  margin: 0;
}

/* ============================================================
   COMPANY INFO BLOCK (home page)
   ============================================================ */
.company-intro {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  align-items: center;
}
.company-intro img {
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
}

/* ============================================================
   EMPRESA — Feature grid
   ============================================================ */
.features-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
}
.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  transition: border-color .2s;
}
.feature-card:hover {
  border-color: var(--accent);
}
.feature-card h3 {
  color: var(--accent-hover);
  text-transform: uppercase;
  font-size: .95rem;
  letter-spacing: .06em;
  margin-bottom: .5rem;
}

/* ============================================================
   PRODUCTOS — product cards
   ============================================================ */
.product-index {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  margin-bottom: 2rem;
}
.product-index h3 {
  margin-bottom: .75rem;
  color: var(--accent-hover);
}
.product-index ul {
  column-count: 1;
  column-gap: 1.5rem;
}
.product-index li {
  margin-bottom: .35rem;
}
.product-index a {
  font-size: .9rem;
  color: var(--text);
  padding: .15rem 0;
  display: inline-block;
  border-bottom: 1px solid transparent;
}
.product-index a:hover {
  color: var(--accent-hover);
  border-bottom-color: var(--accent);
}

.product-section-title {
  font-size: 1.3rem;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--accent-hover);
  border-bottom: 2px solid var(--accent);
  padding-bottom: .5rem;
  margin: 2.5rem 0 1.5rem;
}

.product-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  scroll-margin-top: calc(var(--header-h) + 1rem);
}
.product-card h3 {
  font-size: 1.15rem;
  margin-bottom: .25rem;
}
.product-card .subtitle {
  color: var(--text-light);
  font-size: .9rem;
  margin-bottom: 1rem;
}
.product-card .product-img {
  text-align: center;
  margin-bottom: 1rem;
}
.product-card .product-img img {
  display: inline-block;
  max-height: 320px;
  border-radius: var(--radius);
}

/* Gas consumption table */
.specs-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: .75rem;
  margin-bottom: 1rem;
}
.spec-box {
  background: var(--bg-card-alt);
  border-radius: var(--radius);
  padding: .75rem 1rem;
}
.spec-box h4 {
  font-size: .8rem;
  text-transform: uppercase;
  letter-spacing: .05em;
  color: var(--accent-hover);
  margin-bottom: .35rem;
}
.spec-box p {
  font-size: .85rem;
  margin: 0;
  line-height: 1.5;
}

.product-weight {
  font-size: .95rem;
  font-weight: 600;
  color: var(--text-heading);
  margin-bottom: 1rem;
}
.product-dimensions {
  text-align: center;
  margin-bottom: 1rem;
}
.product-dimensions img {
  display: inline-block;
  max-width: 100%;
  border-radius: var(--radius);
}
.product-actions {
  display: flex;
  gap: .75rem;
  flex-wrap: wrap;
  align-items: center;
}

/* ============================================================
   CONTACT FORM
   ============================================================ */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

.form-group {
  margin-bottom: 1.25rem;
}
.form-group label {
  display: block;
  font-size: .85rem;
  font-weight: 600;
  color: var(--text-heading);
  margin-bottom: .35rem;
}
.form-group input,
.form-group textarea {
  width: 100%;
  padding: .65rem .85rem;
  font-size: .95rem;
  font-family: var(--font);
  color: var(--text-heading);
  background: var(--bg-body);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: border-color .2s;
}
.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
}
.form-group textarea {
  min-height: 140px;
  resize: vertical;
}
.form-group .field-hint {
  font-size: .78rem;
  color: var(--text-light);
  margin-top: .25rem;
}

/* Honeypot: hidden from humans */
.ohnohoney {
  opacity: 0;
  position: absolute;
  top: 0;
  left: 0;
  height: 0;
  width: 0;
  z-index: -1;
  overflow: hidden;
}

/* Form messages */
.form-message {
  padding: .85rem 1rem;
  border-radius: var(--radius);
  margin-bottom: 1.25rem;
  font-size: .9rem;
  display: none;
}
.form-message--success {
  display: block;
  background: rgba(39,174,96,.12);
  border: 1px solid var(--success);
  color: var(--success);
}
.form-message--error {
  display: block;
  background: rgba(192,57,43,.12);
  border: 1px solid var(--error);
  color: var(--accent-hover);
}

/* Contact info sidebar */
.contact-info-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
}
.contact-info-card h3 {
  margin-bottom: 1rem;
}
.contact-info-card .info-item {
  margin-bottom: 1rem;
  padding-left: 0;
}
.contact-info-card .info-label {
  font-size: .78rem;
  text-transform: uppercase;
  letter-spacing: .05em;
  color: var(--accent-hover);
  font-weight: 600;
  margin-bottom: .15rem;
}
.contact-info-card .info-value {
  font-size: .95rem;
  color: var(--text-heading);
  margin: 0;
}

/* ============================================================
   ENLACES
   ============================================================ */
.links-list li {
  padding: .75rem 0;
  border-bottom: 1px solid var(--border);
}
.links-list li:last-child {
  border-bottom: none;
}
.links-list a {
  font-weight: 600;
}

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  background: var(--bg-footer);
  border-top: 1px solid var(--border);
  padding: 2rem 0;
  text-align: center;
  font-size: .85rem;
  color: var(--text-light);
}
.site-footer p {
  margin-bottom: .35rem;
}
.site-footer a {
  color: var(--text-light);
}
.site-footer a:hover {
  color: var(--accent-hover);
}
.footer-copy {
  color: var(--text-heading);
  font-weight: 600;
}

/* ============================================================
   RESPONSIVE
   ============================================================ */

/* Tablet (≥ 640px) */
@media (min-width: 640px) {
  h1 { font-size: 2rem; }
  .hero h1 { font-size: 2.5rem; }
  .section { padding: 4rem 0; }

  .categories-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .specs-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .contact-grid {
    grid-template-columns: 1fr;
  }
  .product-index ul {
    column-count: 2;
  }
}

/* Desktop (≥ 1024px) */
@media (min-width: 1024px) {
  .container { padding: 0 2rem; }
  h1 { font-size: 2.25rem; }
  .hero h1 { font-size: 2.75rem; }

  .categories-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .company-intro {
    grid-template-columns: 1fr 1fr;
  }
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .contact-grid {
    grid-template-columns: 1.5fr 1fr;
  }
  .product-index ul {
    column-count: 3;
  }
}

/* ============================================================
   MOBILE NAV
   ============================================================ */
@media (max-width: 767px) {
  .burger {
    display: flex;
  }
  .main-nav {
    position: fixed;
    top: 0;
    right: 0;
    width: 280px;
    height: 100vh;
    background: var(--bg-header);
    border-left: 1px solid var(--border);
    transform: translateX(100%);
    transition: transform .3s ease;
    z-index: 105;
    padding: calc(var(--header-h) + 1rem) 1.5rem 2rem;
    overflow-y: auto;
  }
  .main-nav.open {
    transform: translateX(0);
  }
  .main-nav ul {
    flex-direction: column;
    gap: 0;
  }
  .main-nav a {
    padding: .75rem 0;
    font-size: 1rem;
    border-bottom: 1px solid var(--border);
    border-radius: 0;
  }
  .nav-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,.5);
    z-index: 100;
  }
  .nav-overlay.active {
    display: block;
  }
}

@media (min-width: 768px) {
  .nav-overlay { display: none !important; }
}