/* ================= VARIABLES ================= */
:root {
  --clr-primary: #0066ff;
  --clr-primary-dark: #0044b3;
  --clr-grey-100: #f8f9fa;
  --clr-grey-200: #e9ecef;
  --clr-grey-400: #ced4da;
  --clr-grey-700: #495057;
  --clr-grey-900: #212529;
  --radius: 0.5rem;
  --max-width: 1200px;
  --transition: 0.3s ease-in-out;
}

/* ================= RESET ================= */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Poppins', sans-serif;
  line-height: 1.6;
  color: var(--clr-grey-900);
  background-color: #fff;
}

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

ul {
  list-style: none;
}

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

.container {
  width: 90%;
  max-width: var(--max-width);
  margin: 0 auto;
}

.section {
  padding: 5rem 0;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  text-align: center;
  color: var(--clr-grey-900);
}

.section-subtitle {
  text-align: center;
  max-width: 700px;
  margin: 0 auto 3rem auto;
  color: var(--clr-grey-700);
}

/* ================= BUTTONS ================= */
.btn {
  display: inline-block;
  padding: 0.75rem 2rem;
  border-radius: var(--radius);
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.btn-primary {
  background: var(--clr-primary);
  color: #fff;
}

.btn-primary:hover {
  background: var(--clr-primary-dark);
}

.btn-block {
  width: 100%;
  text-align: center;
}

/* ================= NAVBAR ================= */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: rgba(255, 255, 255, 0.95);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
  z-index: 1000;
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 0;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--clr-primary);
}

.nav-menu {
  display: flex;
}

.nav-list {
  display: flex;
  gap: 2rem;
}

.nav-link {
  font-weight: 500;
  position: relative;
  padding-bottom: 0.25rem;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background: var(--clr-primary);
  transition: var(--transition);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  font-size: 1.5rem;
  cursor: pointer;
}

/* ================= HERO ================= */
.hero {
  position: relative;
  height: 100vh;
  background: url('../overtile-lab.png') center/cover no-repeat;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: #fff;
}

.hero-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
}

.hero-content {
  position: relative;
  z-index: 1;
}

.hero-title {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
  line-height: 1.2;
}

.hero-subtitle {
  font-size: 1.125rem;
  margin-bottom: 2rem;
  color: #f1f1f1;
}

/* ================= SERVICES ================= */
.services-grid {
  display: grid;
  gap: 2rem;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.service-card {
  background: var(--clr-grey-100);
  border-radius: var(--radius);
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.04);
  transition: var(--transition);
  overflow: hidden;
}

.service-card:hover {
  transform: translateY(-4px);
}

.service-img {
  width: 100%;
  height: 180px;
  object-fit: cover;
}

.service-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin: 1rem;
}

.service-desc {
  font-size: 0.95rem;
  color: var(--clr-grey-700);
  margin: 0 1rem 1.5rem 1rem;
}

/* ================= ABOUT ================= */
.about-grid {
  display: grid;
  gap: 2rem;
  align-items: center;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.about-content ul {
  margin-top: 1.5rem;
}

.about-list li {
  margin-bottom: 0.75rem;
  color: var(--clr-grey-700);
}

.about-list i {
  margin-right: 0.5rem;
  color: var(--clr-primary);
}

.about-image-wrapper {
  overflow: hidden;
  border-radius: var(--radius);
}

.about-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ================= CONTACT ================= */
.contact-grid {
  display: grid;
  gap: 2.5rem;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.contact-desc {
  margin: 1rem 0 2rem 0;
  color: var(--clr-grey-700);
}

.contact-list li {
  margin-bottom: 0.75rem;
  color: var(--clr-grey-700);
}

.contact-list i {
  color: var(--clr-primary);
  margin-right: 0.5rem;
}

.contact-form {
  background: var(--clr-grey-100);
  padding: 2rem;
  border-radius: var(--radius);
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.03);
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  font-weight: 500;
  margin-bottom: 0.5rem;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--clr-grey-400);
  border-radius: var(--radius);
  font-family: inherit;
  font-size: 0.95rem;
  resize: vertical;
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--clr-primary);
}

/* ================= FOOTER ================= */
.footer {
  background: var(--clr-grey-900);
  color: #fff;
  padding: 1.5rem 0;
  text-align: center;
}

/* ================= RESPONSIVE ================= */
@media (max-width: 768px) {
  .nav-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 250px;
    height: 100vh;
    background: #fff;
    box-shadow: -2px 0 8px rgba(0, 0, 0, 0.05);
    flex-direction: column;
    align-items: flex-start;
    padding: 4rem 2rem;
    gap: 1.5rem;
    transition: var(--transition);
  }

  .nav-menu.show {
    right: 0;
  }

  .nav-toggle {
    display: block;
  }

  .nav-list {
    flex-direction: column;
    gap: 1.5rem;
  }

  .hero-title {
    font-size: 2rem;
  }
}