/* ==========================================================================
   TRAN BA HO - RESPONSIVE & MOBILE FIRST STYLES
   Breakpoints:
   - Mobile: 320px – 767px
   - Tablet: 768px – 1023px
   - Desktop: 1024px – 1439px
   - Large Desktop: 1440px+
   ========================================================================== */

/* ==========================================================================
   FLOATING BOTTOM ACTION BAR (MOBILE ONLY)
   ========================================================================== */
.floating-mobile-bar {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  background-color: #ffffff;
  border-top: 1px solid var(--border);
  box-shadow: 0 -4px 16px rgba(0, 0, 0, 0.08);
  z-index: 990;
  padding: 8px 12px calc(8px + env(safe-area-inset-bottom, 0px));
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.floating-mobile-bar.hidden {
  transform: translateY(100%);
  opacity: 0;
  pointer-events: none;
}

.floating-bar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  max-width: 480px;
  margin: 0 auto;
}

.floating-action-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  flex: 1;
  min-height: 48px;
  padding: 4px;
  border-radius: var(--radius-sm);
  font-size: 0.6875rem;
  font-weight: 700;
  color: var(--text-muted);
  text-decoration: none;
  background-color: var(--bg-soft);
  border: 1px solid var(--border);
  transition: var(--transition);
}

.floating-action-btn:active {
  transform: scale(0.96);
  background-color: var(--border);
}

.floating-action-btn.btn-call {
  color: #10b981;
}

.floating-action-btn.btn-zalo {
  color: #0068ff;
}

.floating-action-btn.btn-messenger {
  color: #0084ff;
}

.floating-action-btn.btn-primary-action {
  flex: 1.4;
  background-color: var(--primary);
  color: #ffffff;
  border-color: var(--primary);
}

.floating-action-btn.btn-primary-action:active {
  background-color: var(--primary-dark);
}

.floating-action-btn .btn-icon {
  width: 18px;
  height: 18px;
}

/* ==========================================================================
   MOBILE VIEWPORT RULES (max-width: 767px)
   ========================================================================== */
@media (max-width: 767px) {
  body {
    padding-bottom: 72px; /* Space for floating mobile bar */
  }

  .floating-mobile-bar {
    display: block;
  }

  .section {
    padding-top: 56px;
    padding-bottom: 56px;
  }

  .container {
    padding-left: 16px;
    padding-right: 16px;
  }

  .section-title {
    font-size: 1.75rem;
  }

  .section-subtitle {
    font-size: 0.9375rem;
  }

  .section-header {
    margin-bottom: 32px;
  }

  /* Header & Mobile Drawer Navigation */
  .menu-toggle {
    display: flex;
  }

  .header-actions .btn-contact-header {
    display: none;
  }

  .header-nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    width: 100%;
    height: calc(100vh - var(--header-height));
    background-color: #ffffff;
    flex-direction: column;
    align-items: flex-start;
    padding: 32px 24px;
    gap: 20px;
    border-top: 1px solid var(--border);
    transform: translateX(-100%);
    transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    z-index: 1005;
    overflow-y: auto;
  }

  .header-nav.open {
    transform: translateX(0);
  }

  .nav-link {
    font-size: 1.125rem;
    font-weight: 700;
    width: 100%;
    padding: 10px 0;
    border-bottom: 1px solid var(--border);
  }

  .nav-link.active::after {
    display: none;
  }

  /* Hero Section */
  .hero-section {
    padding-top: 24px;
    padding-bottom: 40px;
  }

  .hero-slide-item {
    padding: 10px 0 24px;
  }

  .hero-nav-arrow {
    width: 38px;
    height: 38px;
    background-color: rgba(255, 255, 255, 0.88);
  }

  .hero-prev-arrow {
    left: 8px;
  }

  .hero-next-arrow {
    right: 8px;
  }

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

  .hero-content {
    padding-left: 42px;
    padding-right: 42px;
  }

  .hero-headline {
    font-size: 2.125rem;
  }

  .hero-subheadline {
    font-size: 1rem;
    margin-bottom: 24px;
  }

  .hero-ctas {
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
  }

  .hero-ctas .btn {
    width: 100%;
  }

  /* Short Intro Section */
  .intro-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .intro-pillars {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .intro-content .quote-title {
    font-size: 1.375rem;
  }

  /* Courses Section (Horizontal Scroll Mobile) */
  .courses-nav-controls {
    display: none;
  }

  .courses-scroll-container {
    margin-left: -16px;
    margin-right: -16px;
    padding-left: 16px;
    padding-right: 16px;
    width: calc(100% + 32px);
  }

  .course-card {
    flex: 0 0 clamp(275px, 80vw, 320px);
    width: clamp(275px, 80vw, 320px);
  }

  /* Services Grid */
  .service-cards-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

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

  /* Portfolio & Web Showcase */
  .portfolio-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

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

  .filter-tabs {
    justify-content: flex-start;
    overflow-x: auto;
    flex-wrap: nowrap;
    padding-bottom: 8px;
    -webkit-overflow-scrolling: touch;
  }

  .filter-btn {
    flex-shrink: 0;
  }

  /* Spotlight: Shop Có Web */
  .shop-co-web-card {
    padding: 32px 20px;
  }

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

  .shop-tagline {
    font-size: 1.25rem;
  }

  /* Process Steps */
  .process-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  /* Business / Droppii */
  .business-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .business-title {
    font-size: 1.5rem;
  }

  /* Library Gallery & Videos Slider */
  .gallery-slide-grid {
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: auto;
    gap: 10px;
  }

  .gallery-box-item {
    aspect-ratio: 1 / 1;
  }

  .gallery-box-overlay {
    padding: 10px 8px;
  }

  .gallery-box-cat {
    font-size: 0.625rem;
    margin-bottom: 2px;
  }

  .gallery-box-title {
    font-size: 0.75rem;
  }

  .videos-slide-grid {
    grid-template-columns: 1fr;
    grid-template-rows: auto;
    gap: 16px;
  }

  .slider-controls {
    margin-top: 24px;
    gap: 12px;
  }

  .slider-nav-btn {
    width: 36px;
    height: 36px;
  }

  /* Articles Slider */
  .articles-slide-grid {
    grid-template-columns: 1fr;
    grid-template-rows: auto;
    gap: 16px;
  }

  /* Mid CTA */
  .mid-cta-title {
    font-size: 1.75rem;
  }

  /* Contact Form */
  .contact-layout {
    grid-template-columns: 1fr;
    gap: 36px;
  }

  .form-wrapper {
    padding: 24px 16px;
  }

  /* Footer */
  .footer-top-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }
}

/* ==========================================================================
   TABLET VIEWPORT RULES (768px – 1023px)
   ========================================================================== */
@media (min-width: 768px) and (max-width: 1023px) {
  .section {
    padding-top: 72px;
    padding-bottom: 72px;
  }

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

  .hero-headline {
    font-size: 2.75rem;
  }

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

  .course-card {
    flex: 0 0 320px;
    width: 320px;
  }

  .service-cards-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }

  .web-services-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }

  .portfolio-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }

  .web-projects-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }

  .process-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }

  .shop-grid {
    grid-template-columns: 1fr;
    gap: 36px;
  }

  .business-grid {
    grid-template-columns: 1fr;
    gap: 36px;
  }

  .gallery-slide-grid {
    grid-template-columns: repeat(4, 1fr);
    gap: 14px;
  }

  .videos-slide-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }

  .articles-slide-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }

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

  .footer-top-grid {
    grid-template-columns: 1fr 1fr;
    gap: 36px;
  }
}

/* ==========================================================================
   DESKTOP & LARGE DESKTOP RULES (1024px+)
   ========================================================================== */
@media (min-width: 1024px) {
  .floating-mobile-bar {
    display: none !important;
  }
}

@media (min-width: 1440px) {
  :root {
    --container-max: 1280px;
  }
  
  .hero-headline {
    font-size: 3.5rem;
  }
}