/* ==========================================================================
   Footer Component Styles
   ========================================================================== */

.footer {
  background-color: var(--pearl-white);
  color: var(--velvet-black);
  font-family: 'Sora', sans-serif;
  font-weight: 300;
  padding: 60px 0 40px;
}

.footer__container {
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 80px;
}

/* Navigation Grid
   ========================================================================== */

.footer__nav-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 80px;
  margin-bottom: 120px;
}

.footer__nav-column {
  display: flex;
  flex-direction: column;
}

.footer__nav-column--no-heading .footer__nav-list {
  margin-top: 0;
}

.footer__nav-heading {
  font-family: 'Noto Serif TC', serif;
  font-weight: 600;
  font-size: 22px;
  line-height: 1.4;
  margin: 0 0 24px;
  color: var(--velvet-black);
}

.footer__nav-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.footer__nav-link {
  font-family: 'Sora', sans-serif;
  font-weight: 300;
  font-size: 14px;
  line-height: 1.5;
  color: var(--velvet-black);
  text-decoration: none;
  position: relative;
  display: inline-block;
  transition: color 0.3s ease;
}

.footer__nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1px;
  background-color: var(--velvet-black);
  transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.footer__nav-link:hover::after {
  width: 100%;
}

.footer__nav-link:hover {
  color: var(--velvet-black);
}

/* Logo and Social Section
   ========================================================================== */

.footer__bottom {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  position: relative;
}

.footer__logo {
  display: flex;
  align-items: center;
}

.footer__logo-image {
  height: 80px;
  width: auto;
  display: block;
  filter: brightness(0);
}

/* Social Icons
   ========================================================================== */

.footer__social {
  display: flex;
  gap: 24px;
  align-items: center;
}

.footer__social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  color: var(--velvet-black);
  transition: color 0.3s ease;
  text-decoration: none;
}

.footer__social-link:hover {
  opacity: 1;
}

/* Facebook hover */
.footer__social-link:nth-child(1):hover {
  color: #1877F2;
}

/* YouTube hover */
.footer__social-link:nth-child(2):hover {
  color: #FF0000;
}

/* Instagram hover */
.footer__social-link:nth-child(3):hover {
  color: #E4405F;
}

/* LinkedIn hover */
.footer__social-link:nth-child(4):hover {
  color: #0A66C2;
}

.footer__social-link svg {
  width: 24px;
  height: 24px;
}

/* Tablet Styles (768px - 1024px)
   ========================================================================== */

@media (max-width: 1024px) and (min-width: 768px) {
  .footer__container {
    padding: 0 40px;
  }

  .footer__nav-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 60px 40px;
    margin-bottom: 80px;
  }

  .footer__nav-heading {
    font-size: 20px;
  }

  .footer__nav-link {
    font-size: 13px;
  }

  .footer__logo-image {
    height: 50px;
  }

  .footer__social {
    gap: 20px;
  }

  .footer__social-link {
    width: 44px;
    height: 44px;
  }
}

/* Mobile Styles (<768px)
   ========================================================================== */

@media (max-width: 767px) {
  .footer {
    padding: 40px 0 32px;
  }

  .footer__container {
    padding: 0 24px;
  }

  .footer__nav-grid {
    grid-template-columns: 1fr;
    gap: 40px;
    margin-bottom: 60px;
  }

  .footer__nav-heading {
    font-size: 18px;
    margin-bottom: 20px;
  }

  .footer__nav-list {
    gap: 14px;
  }

  .footer__nav-link {
    font-size: 12px;
  }

  .footer__bottom {
    flex-direction: column;
    align-items: center;
    gap: 32px;
  }

  .footer__logo {
    justify-content: center;
  }

  .footer__logo-image {
    height: 36px;
  }

  .footer__social {
    gap: 16px;
    justify-content: center;
  }

  .footer__social-link {
    width: 40px;
    height: 40px;
  }

  .footer__social-link svg {
    width: 20px;
    height: 20px;
  }
}

/* Small Mobile Styles (<480px)
   ========================================================================== */

@media (max-width: 480px) {
  .footer__container {
    padding: 0 20px;
  }

  .footer__nav-grid {
    gap: 32px;
  }

  .footer__nav-heading {
    font-size: 16px;
  }

  .footer__nav-link {
    font-size: 11px;
  }

  .footer__logo-image {
    height: 30px;
  }
}