/* ============================================
   Advanced Informatics — Main Stylesheet
   ============================================ */

/* --- Reset & Base --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --green-dark: #1B5E20;
  --green-mid: #2E7D32;
  --green-light: #4CAF50;
  --green-pale: #E8F5E9;
  --white: #FFFFFF;
  --grey-50: #FAFAFA;
  --grey-100: #F5F5F5;
  --grey-200: #EEEEEE;
  --grey-400: #BDBDBD;
  --grey-600: #757575;
  --grey-800: #424242;
  --grey-900: #212121;
  --text: #333333;
  --text-light: #666666;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --max-width: 1120px;
  --radius: 8px;
  --transition: 0.2s ease;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--white);
  line-height: 1.6;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a:hover {
  color: var(--green-dark);
}

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

h1, h2, h3, h4 {
  line-height: 1.2;
  color: var(--grey-900);
}

/* --- Utility --- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 96px 0;
}

.section--grey {
  background: var(--grey-50);
}

.section--dark {
  background: var(--green-dark);
  color: var(--white);
}

.section--dark h2,
.section--dark h3,
.section--dark h4 {
  color: var(--white);
}

.text-center {
  text-align: center;
}

/* --- Header / Nav --- */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--grey-200);
  transition: box-shadow var(--transition);
}

.header--scrolled {
  box-shadow: 0 1px 12px rgba(0, 0, 0, 0.08);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav__logo {
  font-size: 18px;
  font-weight: 700;
  color: var(--green-dark);
  letter-spacing: -0.02em;
}

.nav__logo span {
  color: var(--green-light);
}

.nav__links {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav__links a {
  color: var(--text);
  font-size: 14px;
  font-weight: 500;
  transition: color var(--transition);
}

.nav__links a:hover,
.nav__links a.active {
  color: var(--green-mid);
}

.nav__cta {
  display: inline-flex;
  align-items: center;
  padding: 8px 20px;
  background: var(--green-dark);
  color: var(--white) !important;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 500;
  transition: background var(--transition);
}

.nav__cta:hover {
  background: var(--green-mid);
  color: var(--white) !important;
}

.nav__toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav__toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--grey-900);
  margin: 5px 0;
  transition: transform var(--transition), opacity var(--transition);
  border-radius: 1px;
}

/* --- Hero --- */
.hero {
  padding: 160px 0 96px;
  background: linear-gradient(168deg, var(--green-dark) 0%, #14451a 100%);
  color: var(--white);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(76, 175, 80, 0.12) 0%, transparent 70%);
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 400px;
  height: 400px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(76, 175, 80, 0.08) 0%, transparent 70%);
  pointer-events: none;
}

.hero__content {
  position: relative;
  z-index: 1;
  max-width: 680px;
}

.hero__badge {
  display: inline-block;
  padding: 6px 14px;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 20px;
  font-size: 13px;
  font-weight: 500;
  color: var(--green-pale);
  margin-bottom: 24px;
  letter-spacing: 0.02em;
}

.hero h1 {
  font-size: 52px;
  font-weight: 800;
  color: var(--white);
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 20px;
}

.hero p {
  font-size: 19px;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: 36px;
}

.hero__actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all var(--transition);
  text-decoration: none;
}

.btn--primary {
  background: var(--white);
  color: var(--green-dark);
}

.btn--primary:hover {
  background: var(--green-pale);
  color: var(--green-dark);
}

.btn--outline {
  background: transparent;
  color: var(--white);
  border: 1px solid rgba(255, 255, 255, 0.3);
}

.btn--outline:hover {
  background: rgba(255, 255, 255, 0.1);
  color: var(--white);
}

.btn--green {
  background: var(--green-dark);
  color: var(--white);
}

.btn--green:hover {
  background: var(--green-mid);
  color: var(--white);
}

.btn--arrow::after {
  content: '\2192';
  transition: transform var(--transition);
}

.btn--arrow:hover::after {
  transform: translateX(3px);
}

/* --- Capability Cards --- */
.capabilities__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-top: 56px;
}

.cap-card {
  padding: 32px 28px;
  background: var(--white);
  border: 1px solid var(--grey-200);
  border-radius: 12px;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.cap-card:hover {
  border-color: var(--green-light);
  box-shadow: 0 4px 24px rgba(27, 94, 32, 0.08);
}

.cap-card__icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--green-pale);
  border-radius: 10px;
  margin-bottom: 20px;
  font-size: 20px;
  color: var(--green-dark);
}

.cap-card h3 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 10px;
  letter-spacing: -0.01em;
}

.cap-card p {
  font-size: 14px;
  color: var(--text-light);
  line-height: 1.6;
}

/* --- Section Headers --- */
.section__header {
  max-width: 560px;
  margin: 0 auto 0 0;
}

.section__header--center {
  margin: 0 auto;
  text-align: center;
}

.section__label {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--green-mid);
  margin-bottom: 12px;
}

.section--dark .section__label {
  color: var(--green-light);
}

.section__header h2 {
  font-size: 36px;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.section__header p {
  font-size: 17px;
  color: var(--text-light);
  line-height: 1.7;
}

.section--dark .section__header p {
  color: rgba(255, 255, 255, 0.7);
}

/* --- Why Us --- */
.why__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
  margin-top: 56px;
}

.why-item__number {
  font-size: 13px;
  font-weight: 700;
  color: var(--green-light);
  margin-bottom: 16px;
  letter-spacing: 0.04em;
}

.section--dark .why-item__number {
  color: var(--green-light);
}

.why-item h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
  letter-spacing: -0.01em;
}

.why-item p {
  font-size: 15px;
  color: rgba(255, 255, 255, 0.7);
  line-height: 1.7;
}

/* --- CTA Banner --- */
.cta-banner {
  padding: 80px 0;
  text-align: center;
}

.cta-banner h2 {
  font-size: 36px;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.cta-banner p {
  font-size: 17px;
  color: var(--text-light);
  margin-bottom: 32px;
  max-width: 480px;
  margin-left: auto;
  margin-right: auto;
}

/* --- About Page --- */
.about-intro {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.about-intro__text h2 {
  font-size: 36px;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
}

.about-intro__text p {
  font-size: 16px;
  color: var(--text-light);
  line-height: 1.7;
  margin-bottom: 16px;
}

.about-visual {
  background: linear-gradient(135deg, var(--green-dark), #14451a);
  border-radius: 16px;
  height: 360px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.about-visual::before {
  content: '';
  position: absolute;
  width: 200px;
  height: 200px;
  border: 2px solid rgba(255, 255, 255, 0.1);
  border-radius: 50%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.about-visual::after {
  content: '';
  position: absolute;
  width: 300px;
  height: 300px;
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: 50%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.about-visual__inner {
  position: relative;
  z-index: 1;
  text-align: center;
  color: var(--white);
}

.about-visual__inner .stat {
  font-size: 48px;
  font-weight: 800;
  letter-spacing: -0.03em;
}

.about-visual__inner .stat-label {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.6);
  margin-top: 4px;
}

/* --- How We Work --- */
.how__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  margin-top: 56px;
}

.how-card {
  padding: 36px 28px;
  background: var(--white);
  border: 1px solid var(--grey-200);
  border-radius: 12px;
}

.how-card__step {
  font-size: 12px;
  font-weight: 700;
  color: var(--green-mid);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 16px;
}

.how-card h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 12px;
}

.how-card p {
  font-size: 14px;
  color: var(--text-light);
  line-height: 1.7;
}

/* --- Tech Stack --- */
.tech__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-top: 56px;
}

.tech-item {
  padding: 24px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 10px;
  text-align: center;
  transition: background var(--transition);
}

.tech-item:hover {
  background: rgba(255, 255, 255, 0.1);
}

.tech-item__icon {
  font-size: 28px;
  margin-bottom: 12px;
}

.tech-item h4 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 6px;
}

.tech-item p {
  font-size: 13px;
  color: rgba(255, 255, 255, 0.5);
}

/* --- Team section --- */
.team-quote {
  max-width: 640px;
  margin: 48px auto 0;
  text-align: center;
}

.team-quote blockquote {
  font-size: 20px;
  font-style: italic;
  color: var(--grey-800);
  line-height: 1.7;
  position: relative;
  padding: 0 24px;
}

.team-quote blockquote::before {
  content: '\201C';
  font-size: 64px;
  color: var(--green-light);
  position: absolute;
  top: -20px;
  left: -8px;
  line-height: 1;
  font-style: normal;
}

/* --- Contact Page --- */
.contact__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
}

.contact__info h2 {
  font-size: 36px;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.contact__info > p {
  font-size: 16px;
  color: var(--text-light);
  line-height: 1.7;
  margin-bottom: 40px;
}

.contact__details {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.contact__details li {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.contact__details .detail-icon {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--green-pale);
  border-radius: 10px;
  font-size: 18px;
  flex-shrink: 0;
}

.contact__details .detail-text {
  display: flex;
  flex-direction: column;
}

.contact__details .detail-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--grey-600);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 2px;
}

.contact__details .detail-value {
  font-size: 15px;
  color: var(--grey-900);
}

.contact__details .detail-value a {
  color: var(--green-mid);
  font-weight: 500;
}

.contact__form {
  background: var(--grey-50);
  border: 1px solid var(--grey-200);
  border-radius: 16px;
  padding: 40px;
}

.contact__form h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 24px;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  color: var(--grey-800);
  margin-bottom: 6px;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--grey-200);
  border-radius: var(--radius);
  font-family: var(--font);
  font-size: 15px;
  color: var(--text);
  background: var(--white);
  transition: border-color var(--transition);
  outline: none;
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--green-mid);
}

.form-group textarea {
  resize: vertical;
  min-height: 120px;
}

.form-submit {
  width: 100%;
  padding: 14px 28px;
  background: var(--green-dark);
  color: var(--white);
  border: none;
  border-radius: var(--radius);
  font-family: var(--font);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition);
}

.form-submit:hover {
  background: var(--green-mid);
}

.form-success {
  font-size: 1.125rem;
  color: var(--green-dark);
  padding: 32px 0;
}

/* --- Footer --- */
.footer {
  background: var(--grey-900);
  color: rgba(255, 255, 255, 0.6);
  padding: 56px 0 32px;
}

.footer__inner {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  padding-bottom: 32px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  margin-bottom: 24px;
}

.footer__brand .nav__logo {
  color: var(--white);
  margin-bottom: 12px;
  display: inline-block;
}

.footer__brand .nav__logo span {
  color: var(--green-light);
}

.footer__brand p {
  font-size: 14px;
  max-width: 280px;
  line-height: 1.6;
}

.footer__nav {
  display: flex;
  gap: 48px;
}

.footer__nav-group h4 {
  color: var(--white);
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 16px;
}

.footer__nav-group ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer__nav-group a {
  color: rgba(255, 255, 255, 0.5);
  font-size: 14px;
  transition: color var(--transition);
}

.footer__nav-group a:hover {
  color: var(--white);
}

.footer__bottom {
  display: flex;
  justify-content: space-between;
  font-size: 13px;
}

.footer__bottom a {
  color: rgba(255, 255, 255, 0.4);
}

.footer__bottom a:hover {
  color: var(--white);
}

/* --- Page Header (interior pages) --- */
.page-header {
  padding: 140px 0 64px;
  background: linear-gradient(168deg, var(--green-dark) 0%, #14451a 100%);
  color: var(--white);
}

.page-header h1 {
  font-size: 42px;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--white);
  margin-bottom: 12px;
}

.page-header p {
  font-size: 18px;
  color: rgba(255, 255, 255, 0.7);
  max-width: 520px;
}

/* --- Responsive --- */
@media (max-width: 1024px) {
  .capabilities__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .tech__grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .section {
    padding: 64px 0;
  }

  .hero {
    padding: 120px 0 64px;
  }

  .hero h1 {
    font-size: 36px;
  }

  .hero p {
    font-size: 17px;
  }

  .section__header h2 {
    font-size: 28px;
  }

  .capabilities__grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .why__grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .how__grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .tech__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .about-intro {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .about-visual {
    height: 240px;
  }

  .contact__grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .footer__inner {
    flex-direction: column;
    gap: 32px;
  }

  .footer__bottom {
    flex-direction: column;
    gap: 8px;
  }

  .page-header {
    padding: 120px 0 48px;
  }

  .page-header h1 {
    font-size: 32px;
  }

  .cta-banner h2 {
    font-size: 28px;
  }

  /* Mobile nav */
  .nav__links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    padding: 24px;
    gap: 20px;
    border-bottom: 1px solid var(--grey-200);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
  }

  .nav__links.active {
    display: flex;
  }

  .nav__toggle {
    display: block;
  }

  .nav__toggle.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

  .nav__toggle.active span:nth-child(2) {
    opacity: 0;
  }

  .nav__toggle.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }
}

@media (max-width: 480px) {
  .hero h1 {
    font-size: 30px;
  }

  .hero__actions {
    flex-direction: column;
  }

  .hero__actions .btn {
    width: 100%;
    justify-content: center;
  }

  .contact__form {
    padding: 24px;
  }
}