/**
* Air Quality Index App - Custom Styles
* Clean, modern design focused on environmental data visualization
*/

:root {
  --color-primary: #2563eb;
  --color-secondary: #10b981;
  --color-accent: #06b6d4;
  --color-dark: #1e293b;
  --color-light: #f8fafc;
  --color-text: #334155;
  --color-text-light: #64748b;
  --color-border: #e2e8f0;
  --color-bg: #ffffff;
  --color-bg-alt: #f8fafc;
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

/* Dark mode */
@media (prefers-color-scheme: dark) {
  :root {
    --color-primary: #60a5fa;
    --color-secondary: #34d399;
    --color-accent: #22d3ee;
    --color-dark: #f1f5f9;
    --color-light: #1e293b;
    --color-text: #e2e8f0;
    --color-text-light: #94a3b8;
    --color-border: #334155;
    --color-bg: #0f172a;
    --color-bg-alt: #1e293b;
  }
}

/*--------------------------------------------------------------
# General
--------------------------------------------------------------*/
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: var(--font-primary);
  color: var(--color-text);
  line-height: 1.6;
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: all 0.3s ease;
}

a:hover {
  color: var(--color-accent);
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-primary);
  font-weight: 600;
  line-height: 1.2;
  color: var(--color-dark);
}

/*--------------------------------------------------------------
# Back to top button
--------------------------------------------------------------*/
.back-to-top {
  position: fixed;
  visibility: hidden;
  opacity: 0;
  right: 20px;
  bottom: 20px;
  z-index: 996;
  background: var(--color-primary);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  transition: all 0.4s;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2);
}

.back-to-top i {
  font-size: 24px;
  color: #fff;
  line-height: 0;
}

.back-to-top:hover {
  background: var(--color-accent);
  transform: translateY(-3px);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.3);
}

.back-to-top.active {
  visibility: visible;
  opacity: 1;
}

/*--------------------------------------------------------------
# Hero Section
--------------------------------------------------------------*/
#hero {
  width: 100%;
  min-height: 100vh;
  padding: 80px 0 60px 0;
  background: var(--color-bg-alt);
  position: relative;
  overflow: hidden;
}

/* Light mode gradient */
@media (prefers-color-scheme: light) {
  #hero {
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 50%, #f8fafc 100%);
  }
}

/* Dark mode gradient */
@media (prefers-color-scheme: dark) {
  #hero {
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #0f172a 100%);
  }
}

#hero::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -20%;
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(37, 99, 235, 0.08) 0%, transparent 70%);
  border-radius: 50%;
  z-index: 0;
}

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

#hero .hero-content {
  padding: 40px 0;
}

#hero h1 {
  font-size: 56px;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--color-dark);
  letter-spacing: -0.02em;
}

#hero .hero-subtitle {
  font-size: 24px;
  font-weight: 500;
  color: var(--color-primary);
  margin-bottom: 20px;
}

#hero .hero-description {
  font-size: 18px;
  line-height: 1.7;
  color: var(--color-text-light);
  margin-bottom: 30px;
  max-width: 540px;
}

#hero .hero-badges {
  display: flex;
  gap: 12px;
  margin-bottom: 32px;
  flex-wrap: wrap;
}

#hero .hero-badges .badge {
  background: white;
  color: var(--color-primary);
  padding: 8px 16px;
  border-radius: 20px;
  font-size: 14px;
  font-weight: 500;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
  border: 1px solid var(--color-border);
}

#hero .download-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 32px;
  background: var(--color-dark);
  color: white;
  border-radius: 12px;
  font-size: 16px;
  font-weight: 500;
  transition: all 0.3s ease;
  box-shadow: 0 4px 14px rgba(30, 41, 59, 0.25);
}

#hero .download-btn i {
  font-size: 24px;
}

#hero .download-btn:hover {
  background: var(--color-primary);
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(37, 99, 235, 0.3);
  color: white;
}

#hero .hero-note {
  margin-top: 20px;
  font-size: 14px;
  color: var(--color-secondary);
  font-weight: 500;
}

#hero .hero-img img {
  max-width: 100%;
  height: auto;
  border-radius: 24px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.12);
}

@media (max-width: 991px) {
  #hero {
    min-height: auto;
    padding: 60px 0 40px 0;
  }

  #hero h1 {
    font-size: 40px;
  }

  #hero .hero-subtitle {
    font-size: 20px;
  }

  #hero .hero-description {
    font-size: 16px;
  }

  #hero .hero-img {
    margin-bottom: 40px;
    text-align: center;
  }

  #hero .hero-img img {
    max-width: 80%;
  }
}

@media (max-width: 768px) {
  #hero h1 {
    font-size: 32px;
  }

  #hero .hero-img img {
    max-width: 100%;
  }
}

/*--------------------------------------------------------------
# Sections General
--------------------------------------------------------------*/
section {
  padding: 80px 0;
  overflow: hidden;
}

.section-title {
  text-align: center;
  padding-bottom: 40px;
}

.section-title h2 {
  font-size: 36px;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--color-dark);
}

.section-title p {
  color: var(--color-text-light);
  font-size: 18px;
}

/*--------------------------------------------------------------
# Features Section
--------------------------------------------------------------*/
.features {
  background: var(--color-bg);
}

.features .feature-row {
  margin-top: 20px;
}

.features .feature-box {
  padding: 40px 30px;
  text-align: center;
  transition: all 0.3s ease;
  border-radius: 16px;
  height: 100%;
}

.features .feature-box:hover {
  transform: translateY(-8px);
}

.features .feature-icon {
  width: 80px;
  height: 80px;
  margin: 0 auto 24px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
}

.features .feature-box:hover .feature-icon {
  transform: scale(1.1);
  box-shadow: 0 8px 24px rgba(37, 99, 235, 0.25);
}

.features .feature-icon i {
  font-size: 36px;
  color: white;
}

.features .feature-box h3 {
  font-size: 22px;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--color-dark);
}

.features .feature-box p {
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text-light);
  margin: 0;
}

/*--------------------------------------------------------------
# Gallery Section
--------------------------------------------------------------*/
.gallery {
  background: var(--color-bg-alt);
  padding: 80px 0;
}

.gallery .swiper-slide {
  transition: all 0.3s ease;
  opacity: 0.6;
}

.gallery .swiper-slide-active {
  opacity: 1;
}

.gallery .swiper-slide img {
  border-radius: 16px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
  transition: all 0.3s ease;
}

.gallery .swiper-slide:hover img {
  transform: scale(1.02);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.15);
}

.gallery .swiper-pagination {
  margin-top: 30px;
  position: relative;
}

.gallery .swiper-pagination-bullet {
  width: 12px;
  height: 12px;
  background-color: var(--color-text-light);
  opacity: 0.4;
  border: none;
  transition: all 0.3s ease;
}

.gallery .swiper-pagination-bullet-active {
  background: var(--color-primary);
  opacity: 1;
  width: 32px;
  border-radius: 6px;
}

@media (min-width: 992px) {
  .gallery .swiper-wrapper {
    padding: 40px 0;
  }

  .gallery .swiper-slide-active {
    transform: scale(1.15);
    z-index: 1;
  }
}

/*--------------------------------------------------------------
# Footer
--------------------------------------------------------------*/
#footer {
  background: var(--color-bg);
  padding: 40px 0;
  border-top: 1px solid var(--color-border);
}

#footer .footer-content {
  text-align: center;
}

#footer .copyright {
  font-size: 15px;
  color: var(--color-text-light);
  margin-bottom: 12px;
}

#footer .copyright strong {
  color: var(--color-dark);
  font-weight: 600;
}

#footer .footer-links {
  font-size: 15px;
  color: var(--color-text-light);
  margin: 0;
}

#footer .footer-links a {
  color: var(--color-primary);
  font-weight: 500;
  transition: all 0.3s ease;
}

#footer .footer-links a:hover {
  color: var(--color-accent);
}

#footer .separator {
  margin: 0 12px;
  color: var(--color-border);
}

@media (max-width: 768px) {
  #footer .footer-links {
    margin-top: 8px;
  }
}

/*--------------------------------------------------------------
# Disable aos animation delay on mobile
--------------------------------------------------------------*/
@media screen and (max-width: 768px) {
  [data-aos-delay] {
    transition-delay: 0 !important;
  }
}