/* ==========================================================
   GLOBAL STYLES
========================================================== */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Kumbh Sans', system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

a { text-decoration: none; }
ul { list-style: none; }
img { max-width: 100%; display: block; }

/* ==========================================================
   NAVBAR STYLES
========================================================== */

/* Logo */
.navbar-logo {
  display: flex;
  align-items: center;
  cursor: pointer;
}

.navbar-logo img {
  height: 103px;
  margin: 0 -32px -20px;
  width: auto;
  object-fit: contain;
}

/* Navbar container */
.navbar__container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 80px;
  width: 100%;
  padding: 0 50px;
  position: fixed;
  top: 0;
  z-index: 1000;
  background-color: rgba(0, 0, 0, 0.5);
}

/* Menu */
.navbar__menu {
  display: flex;
  justify-content: center;
  list-style: none;
  margin: 0 auto;
  padding: 0;
}

.navbar__item {
  height: 80px;
  position: relative;
}

.navbar__links {
  color: #fff;
  text-decoration: none;
  height: 100%;
  padding: 0 1rem;
  display: flex;
  align-items: center;
  transition: all 0.3s ease;
}

.navbar__links:hover {
  color: #e40c0c;
}

/* Buttons */
.navbar__btn.desktop {
  display: flex;
}

.navbar__btn.mobile {
  display: none;
}

.button {
  background: #e40c0c;
  padding: 10px 20px;
  border: none;
  border-radius: 4px;
  color: #fff;
  text-decoration: none;
  transition: all 0.3s ease;
}

.button:hover {
  background: #ae3737;
}

/* ==========================================================
   DESKTOP DROPDOWNS
========================================================== */

/* Main dropdown arrow */
.navbar__item.dropdown > .navbar__links::after {
  content: '▼';
  font-size: 0.6rem;
  margin-left: 5px;
  transition: transform 0.3s ease;
  color: #b60f0f;
}

.navbar__item.dropdown.active > .navbar__links::after {
  transform: rotate(-180deg);
}

/* Main dropdown menu */
.dropdown-menu {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  background: #111;
  min-width: 180px;
  border-radius: 2px;
  flex-direction: column;
  z-index: 1000;
  list-style: none;
  padding: 0;
  margin: 0;
}

.navbar__item.dropdown:hover > .dropdown-menu {
  display: flex;
}

.dropdown-menu li a {
  display: block;
  padding: 10px 20px;
  color: #fff;
  text-decoration: none;
  white-space: nowrap;
}

.dropdown-menu li a:hover {
  background: #e40c0c;
}

/* Sub-dropdown */
.dropdown-sub {
  position: relative;
}

.dropdown-sub-menu {
  display: none;
  position: absolute;
  top: 0;
  left: 100%;
  background: #222;
  min-width: 180px;
  border-radius: 2px;
  flex-direction: column;
  z-index: 1000;
  list-style: none;
  padding: 0;
  margin: 0;
}

.dropdown-sub:hover > .dropdown-sub-menu {
  display: flex;
}

.dropdown-sub > a::after {
  content: "▸";
  float: right;
  margin-left: 10px;
  transition: transform 0.3s ease;
}

.dropdown-sub:hover > a::after {
  transform: rotate(90deg);
}

.dropdown-sub-menu li a:hover {
  background: #e40c0c;
}

/* Hamburger toggle */
.navbar__toggle {
  display: none;
}

/* ==========================================================
   MOBILE MENU (≤968px)
========================================================== */
@media screen and (max-width: 968px) {

  /* Hamburger */
  .navbar__toggle {
    display: block;
    position: absolute;
    right: 20px;
    top: 50%;
    transform: translateY(-50%);
    color: #fff;
    font-size: 1.5rem;
    cursor: pointer;
    background: none;
    border: none;
    z-index: 2000;
  }

  /* Fullscreen menu */
  .navbar__menu {
    flex-direction: column;
    justify-content: flex-start;
    position: fixed;
    top: 80px;
    left: -100%;
    width: 100%;
    height: calc(100% - 80px);
    opacity: 0;
    transition: all 0.4s ease;
    background: #000;
    display: flex;
    overflow-y: auto;
    padding: 0;
  }

  .navbar__menu.active {
    left: 0;
    opacity: 1;
  }

  .navbar__item {
    width: 100%;
  }

  .navbar__links {
    width: 100%;
    text-align: center;
    padding: 12px 0;
    justify-content: center;
    display: block;
  }

  /* Buttons */
  .navbar__btn.desktop { display: none; }

  .navbar__btn.mobile {
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 20px auto;
    padding: 12px 20px;
    width: 60%;
  }

  .button {
    width: 80%;
    text-align: center;
    padding: 14px 20px;
    margin: 0 auto;
    display: block;
  }

  /* Mobile dropdown slide-down */
  .navbar__item.dropdown .dropdown-menu {
    position: relative;
    top: 0;
    left: 0;
    display: flex;
    flex-direction: column;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.4s ease;
    padding: 0;
  }

  .navbar__item.dropdown.active .dropdown-menu {
    max-height: 1000px;
    padding: 10px 0;
  }

  .dropdown-menu li a {
    text-align: center;
  }

  /* Nested sub-dropdown slide-down */
  .dropdown-sub-menu {
    position: relative;
    top: 0;
    left: 0;
    display: flex;
    flex-direction: column;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.4s ease;
    padding: 0;
  }

  .dropdown-sub.active .dropdown-sub-menu {
    max-height: 500px;
    padding: 10px 0;
  }

  /* Remove list bullets globally in mobile dropdowns */
  .dropdown-menu,
  .dropdown-sub-menu {
    list-style: none;
    margin: 0;
    padding: 0;
  }

  /* Arrow rotation for mobile */
  .navbar__item.dropdown > .navbar__links::after {
    transition: transform 0.4s ease;
  }

  .dropdown-sub > a::after {
    transition: transform 0.4s ease;
  }
}


/* ==========================================================
   TECHNICAL ADVISORY SECTION
========================================================== */
.fuel-about {
    background: linear-gradient(to bottom, #f7f7f7, #ffffff);
    color: #333;
    padding: 180px 20px 60px;
}

.fuel-about-container {
    max-width: 900px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.fuel-about-text h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
}
.fuel-about-text h3 { font-size: 1.5rem; color: #e40c0c; margin: 30px 0 15px; }
.fuel-about-text h4 { font-size: 1.2rem; color: #e40c0c; margin: 20px 0 8px; font-weight: 600; }
.fuel-about-text p { font-size: 1rem; line-height: 1.7; margin-bottom: 15px; color: #0f0f0f; }

.advantages-list li {
    display: flex;
    gap: 10px;
    align-items: flex-start;
    margin-bottom: 12px;
}
.advantages-list li i { color: #e40c0c; font-size: 1.2rem; margin-top: 3px; }

.fuel-analyzers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-top: 15px;
}
.analyzer-item {
    background: #fff;
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
    transition: transform 0.2s, box-shadow 0.2s;
}
.analyzer-item:hover { transform: translateY(-3px); box-shadow: 0 6px 15px rgba(0,0,0,0.12); }
.analyzer-item h4 { color: #e40c0c; margin-bottom: 10px; }

.fuel-cta { text-align: center; margin-top: 40px; }
.fuel-cta a.button-cta {
    background-color: #e40c0c;
    color: #fff;
    padding: 12px 28px;
    border-radius: 50px;
    font-weight: 600;
    transition: 0.3s;
}
.fuel-cta a.button-cta:hover { background-color: #ae3737; transform: translateY(-2px); }

/* Responsive adjustments */
@media screen and (max-width: 768px) {
    .fuel-about-container { padding: 0 15px; gap: 20px; }
    .fuel-about-text h2 { font-size: 1.7rem; }
    .fuel-about-text h3 { font-size: 1.3rem; }
    .fuel-about-text h4 { font-size: 1.1rem; }
    .fuel-analyzers-grid { grid-template-columns: 1fr; gap: 15px; }
}

/* ==========================================================
   FOOTER
========================================================== */
.site-footer {
    background: #0c0c0c;
    color: #eee;
    padding: 70px 20px 25px;
}

.footer-container {
    display: grid;
    grid-template-columns: 1.3fr 1fr 1fr 1fr;
    gap: 40px;
    max-width: 1400px;
    margin: 0 auto;
}

.footer-col h3 {
    color: #e40c0c;
    font-size: 1.25rem;
    margin-bottom: 15px;
    position: relative;
}
.footer-col h3::after {
    content: "";
    position: absolute;
    width: 45px;
    height: 3px;
    background: linear-gradient(90deg,#e40c0c,#ff544e);
    bottom: -6px;
    left: 0;
    border-radius: 6px;
}

.footer-about p,
.footer-contact p { color: #bfbfbf; line-height: 1.7; }
.footer-logo { width: 160px; margin-bottom: 20px; filter: brightness(1.1); transition: transform 0.25s; }
.footer-logo:hover { transform: scale(1.07); }

.footer-links ul li { margin-bottom: 12px; }
.footer-links ul li a { color: #ccc; transition: 0.25s; }
.footer-links ul li a:hover { color: #e40c0c; padding-left: 6px; }

.footer-bottom {
    margin-top: 45px;
    padding-top: 15px;
    border-top: 1px solid rgba(255,255,255,0.12);
    text-align: center;
    font-size: 0.9rem;
    color: #aaa;
}

@media (max-width: 1000px) { .footer-container { grid-template-columns: 1fr 1fr; } }
@media (max-width: 650px) {
    .footer-container { grid-template-columns: 1fr; text-align: center; }
    .footer-col h3::after { left: 50%; transform: translateX(-50%); }
    .footer-about p,
    .footer-contact p { margin: 0 auto 10px; max-width: 350px; }
}