/* 기본 리셋 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  margin: 0; 
  padding: 0;
  width: 100%; 
  height: 100%;
  background-color: #000;
  font-family: "Paperlogy", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
  overflow-x: hidden;
}

/* 배경 비디오 */
.bg-video {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 0;
  opacity: 0.8;
  pointer-events: none;
}

/* 비디오 컨트롤 완전히 숨기기 */
.bg-video::-webkit-media-controls {
  display: none !important;
}

.bg-video::-webkit-media-controls-enclosure {
  display: none !important;
}

.bg-video::-webkit-media-controls-panel {
  display: none !important;
}

.bg-video::-webkit-media-controls-play-button {
  display: none !important;
}

.bg-video::-webkit-media-controls-start-playback-button {
  display: none !important;
}

/* 컨테이너 */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 2rem;
}

/* Header - Floating Liquid Glass Design */
.header {
  position: fixed;
  top: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 100;
  width: calc(100% - 4rem);
  max-width: 1280px;
  background: transparent;
  border-radius: 20px;
  overflow: hidden;
  
  /* Liquid Glass Effect - SVG Displacement + Backdrop Filters */
  backdrop-filter: brightness(1.1) blur(3px) saturate(100%) url(#displacementFilter);
  -webkit-backdrop-filter: brightness(1.1) blur(3px) saturate(100%) url(#displacementFilter);
  
  /* Enhanced shadow for depth */
  box-shadow: 
    0 10px 40px rgba(0, 0, 0, 0.15),
    0 4px 15px rgba(0, 0, 0, 0.1),
    0 0 0 1px rgba(255, 255, 255, 0.2) inset;
  
  transition: all 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.5);
  
  /* Hardware acceleration */
  will-change: transform, box-shadow;
}

/* Specular Highlight (glass-like effect) */
.header::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 1;
  border-radius: 20px;
  
  /* Glass-like specular highlight */
  box-shadow: 
    inset 8px 8px 0px -6px rgba(255, 255, 255, 0.6), 
    inset 0 0 10px 1px rgba(255, 255, 255, 0.5);
  
  pointer-events: none;
}

.header:hover {
  /* Enhanced glass effect on hover */
  backdrop-filter: brightness(1.15) blur(4px) saturate(100%) url(#displacementFilter);
  -webkit-backdrop-filter: brightness(1.15) blur(4px) saturate(100%) url(#displacementFilter);
  
  box-shadow: 
    0 15px 50px rgba(0, 0, 0, 0.2),
    0 6px 20px rgba(0, 0, 0, 0.15),
    0 0 0 1px rgba(255, 255, 255, 0.25) inset;
}

.header-content {
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
  gap: 3rem;
}

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

.logo img {
  height: 32px;
  width: auto;
  display: block;
  filter: drop-shadow(0 2px 8px rgba(0, 0, 0, 0.3));
  transition: transform 0.3s ease;
}

.logo img:hover {
  transform: scale(1.05);
}

.nav {
  display: none;
  align-items: center;
  gap: 2.5rem;
  flex: 1;
  justify-content: flex-start;
  margin-left: 1rem;
}

.nav-link {
  color: #1a1a1a;
  text-decoration: none;
  transition: all 0.3s;
  font-size: 0.95rem;
  font-weight: 500;
  position: relative;
  padding: 0.5rem 0;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: #1a1a1a;
  transition: width 0.3s;
}

.nav-link:hover {
  color: #000;
}

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

.header-actions {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  margin-left: auto;
}

.search-box {
  display: none;
  align-items: center;
  background: rgba(0, 0, 0, 0.05);
  border-radius: 10px;
  padding: 0.6rem 1rem;
  gap: 0.5rem;
  transition: all 0.3s;
}

.search-box:hover {
  background: rgba(0, 0, 0, 0.08);
}

.search-input {
  background: transparent;
  border: none;
  color: #1a1a1a;
  outline: none;
  width: 180px;
  font-size: 0.9rem;
}

.search-input::placeholder {
  color: rgba(0, 0, 0, 0.4);
}

.icon-button {
  background: transparent;
  border: none;
  color: #1a1a1a;
  cursor: pointer;
  padding: 0.6rem;
  border-radius: 10px;
  transition: all 0.3s;
  display: flex;
  align-items: center;
  justify-content: center;
}

.icon-button:hover {
  background: rgba(0, 0, 0, 0.08);
  transform: translateY(-2px);
}

.icon {
  display: block;
}

/* Hero Section */
.hero-section {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  z-index: 10;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: transparent;
  pointer-events: none;
}

.hero-container {
  padding: 10rem 0 4rem;
  position: relative;
  z-index: 10;
  width: 100%;
}

.hero-content {
  max-width: 56rem;
  min-height: calc(100vh - 14rem);
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: flex-end;
  padding-bottom: 4rem;
  animation: fadeInUp 1s ease-out;
  margin-left: 0;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero-title {
  color: #1a1a1a;
  font-size: 3.5rem;
  line-height: 1.1;
  margin-bottom: 2.5rem;
  font-weight: 700;
  text-shadow: 0 2px 4px rgba(255, 255, 255, 0.3);
  letter-spacing: -0.02em;
  display: inline-block;
}

.hero-text {
  color: #2a2a2a;
  font-size: 1.15rem;
  margin-bottom: 0.5rem;
  line-height: 1.8;
  text-shadow: 0 1px 2px rgba(255, 255, 255, 0.2);
}

.hero-text-muted {
  color: #3a3a3a;
  margin-bottom: 3rem;
  line-height: 1.8;
  font-size: 1.05rem;
  text-shadow: 0 1px 2px rgba(255, 255, 255, 0.2);
}

.hero-button {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  width: 650px;
  background: transparent;
  border: none;
  color: #1a1a1a;
  padding: 1rem 1.5rem;
  font-size: 1.125rem;
  font-weight: 600;
  cursor: pointer;
  border-radius: 12px;
  letter-spacing: 0.05em;
  text-decoration: none;
  font-family: "Paperlogy", sans-serif;
  overflow: hidden;
  
  /* Liquid Glass Effect */
  backdrop-filter: brightness(1.1) blur(3px) saturate(100%) url(#displacementFilter);
  -webkit-backdrop-filter: brightness(1.1) blur(3px) saturate(100%) url(#displacementFilter);
  
  /* Enhanced shadow for depth */
  box-shadow: 
    0 6px 20px rgba(0, 0, 0, 0.15),
    0 2px 8px rgba(0, 0, 0, 0.1),
    0 0 0 1px rgba(255, 255, 255, 0.2) inset;
  
  transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.5);
  
  /* Hardware acceleration */
  will-change: transform, box-shadow;
}

.hero-button span {
  flex: 0 0 auto;
}

.button-arrow {
  transition: transform 0.3s ease;
}

/* Specular Highlight (glass-like effect) */
.hero-button::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: -1;
  border-radius: 12px;
  
  /* Glass-like specular highlight */
  box-shadow: 
    inset 6px 6px 0px -6px rgba(255, 255, 255, 0.6), 
    inset 0 0 8px 1px rgba(255, 255, 255, 0.5);
  
  pointer-events: none;
}

.hero-button:hover {
  /* Enhanced glass effect on hover */
  backdrop-filter: brightness(1.15) blur(4px) saturate(100%) url(#displacementFilter);
  -webkit-backdrop-filter: brightness(1.15) blur(4px) saturate(100%) url(#displacementFilter);
  
  color: #000;
  transform: translateY(-3px);
  box-shadow: 
    0 10px 30px rgba(0, 0, 0, 0.2),
    0 4px 12px rgba(0, 0, 0, 0.15),
    0 0 0 1px rgba(255, 255, 255, 0.25) inset;
}

.hero-button:hover .button-arrow {
  transform: translateX(3px);
}

/* Info Cards */
.info-cards {
  position: fixed;
  right: 2rem;
  bottom: 7.5rem;
  z-index: 50;
  display: none;
  animation: slideInRight 0.8s ease-out;
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(100px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.cards-container {
  position: relative;
  background: transparent;
  border-radius: 20px;
  padding: 1.75rem;
  width: 350px;
  overflow: hidden;
  
  /* Liquid Glass Effect - SVG Displacement + Backdrop Filters */
  backdrop-filter: brightness(1.1) blur(3px) saturate(100%) url(#displacementFilter);
  -webkit-backdrop-filter: brightness(1.1) blur(3px) saturate(100%) url(#displacementFilter);
  
  /* Enhanced shadow for depth */
  box-shadow: 
    0 10px 40px rgba(0, 0, 0, 0.4),
    0 4px 15px rgba(0, 0, 0, 0.3),
    0 0 0 1px rgba(255, 255, 255, 0.15) inset;
  
  transition: all 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.5);
  
  /* Hardware acceleration */
  will-change: transform, box-shadow;
  transform: translateZ(0);
}

/* Specular Highlight (glass-like effect) */
.cards-container::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 1;
  border-radius: 20px;
  
  /* Glass-like specular highlight */
  box-shadow: 
    inset 8px 8px 0px -6px rgba(255, 255, 255, 0.6), 
    inset 0 0 10px 1px rgba(255, 255, 255, 0.5);
  
  pointer-events: none;
}

.cards-container:hover {
  /* Enhanced glass effect on hover */
  backdrop-filter: brightness(1.15) blur(4px) saturate(100%) url(#displacementFilter);
  -webkit-backdrop-filter: brightness(1.15) blur(4px) saturate(100%) url(#displacementFilter);
  
  box-shadow: 
    0 15px 50px rgba(0, 0, 0, 0.5),
    0 6px 20px rgba(0, 0, 0, 0.4),
    0 0 0 1px rgba(255, 255, 255, 0.2) inset;
}

.card {
  position: relative;
  z-index: 2;
  border-bottom: 1px solid rgba(255, 255, 255, 0.15);
  padding-bottom: 1.5rem;
  margin-bottom: 1.5rem;
  transition: transform 0.3s;
}

.card:hover {
  transform: translateX(-5px);
}

.card:last-child {
  border-bottom: none;
  padding-bottom: 0;
  margin-bottom: 0;
}

.card-content {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}

.card-number {
  color: rgba(255, 255, 255, 1);
  font-size: 2rem;
  line-height: 1;
  font-weight: 300;
  min-width: 3rem;
}

.card-text {
  flex: 1;
}

.card-label {
  color: #ffffff;
  font-size: 0.875rem;
  margin-bottom: 0.5rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.card-title {
  color: white;
  margin-bottom: 0.75rem;
  font-size: 1.1rem;
  font-weight: 600;
  line-height: 1.4;
}

.card-description {
  color: rgba(255, 255, 255, 0.75);
  font-size: 0.9rem;
  line-height: 1.7;
}


/* 반응형 스타일 */
@media (min-width: 768px) {
  .nav {
    display: flex;
  }
  
  .hero-title {
    font-size: 4rem;
  }
  
  .hero-text {
    font-size: 1.2rem;
  }
}

@media (min-width: 1024px) {
  .search-box {
    display: flex;
  }
  
  .menu-button {
    display: none;
  }
  
  .hero-title {
    font-size: 4.5rem;
  }
}

@media (min-width: 1440px) {
  .info-cards {
    display: block;
  }
}

/* 모바일 스타일 */
@media (max-width: 767px) {
  .container {
    padding: 0 1.25rem;
  }
  
  .header {
    top: 1rem;
    width: calc(100% - 2.5rem);
    max-width: none;
    border-radius: 16px;
  }
  
  .header::before {
    border-radius: 16px;
  }
  
  .header-content {
    padding: 0.875rem 1.25rem;
  }
  
  .logo img {
    height: 27px;
  }
  
  .hero-container {
    padding: 7rem 0 3rem;
  }
  
  .hero-content {
    min-height: auto;
    max-width: 100%;
    width: 100%;
  }
  
  .hero-title {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
  }
  
  .hero-button {
    width: 100%;
    max-width: 100%;
  }
  
  .hero-text {
    font-size: 1rem;
    margin-bottom: 0.5rem;
  }
  
  .hero-text-muted {
    font-size: 0.95rem;
    margin-bottom: 2rem;
  }
  
  .hero-button {
    padding: 0.875rem 2rem;
    font-size: 1rem;
  }
}

/* 태블릿 최적화 */
@media (min-width: 768px) and (max-width: 1023px) {
  .cards-container {
    width: 340px;
    padding: 1.5rem;
  }
  
  .card-description {
    font-size: 0.85rem;
  }
}

/* ============================================
   PROJECTS SECTION
   ============================================ */

.projects-section {
  position: relative;
  min-height: 100vh;
  padding: 10rem 0 4rem;
  z-index: 10;
}

.projects-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 2rem;
}

/* Projects Navigation */
.projects-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 3rem;
  animation: fadeInUp 0.6s ease-out;
}

.back-button {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: transparent;
  border: none;
  color: #1a1a1a;
  padding: 0.75rem 1.25rem;
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  border-radius: 10px;
  font-family: "Paperlogy", sans-serif;
  transition: all 0.3s ease;
  
  /* Liquid Glass Effect */
  backdrop-filter: brightness(1.1) blur(3px) saturate(100%) url(#displacementFilter);
  -webkit-backdrop-filter: brightness(1.1) blur(3px) saturate(100%) url(#displacementFilter);
  box-shadow: 
    0 4px 15px rgba(0, 0, 0, 0.1),
    0 2px 6px rgba(0, 0, 0, 0.05),
    0 0 0 1px rgba(255, 255, 255, 0.15) inset;
}

.back-button:hover {
  transform: translateX(-3px);
  backdrop-filter: brightness(1.15) blur(4px) saturate(100%) url(#displacementFilter);
  -webkit-backdrop-filter: brightness(1.15) blur(4px) saturate(100%) url(#displacementFilter);
}

/* Category Filter */
.category-filter {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 0.75rem 1.5rem;
  background: transparent;
  border: none;
  color: #1a1a1a;
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  border-radius: 10px;
  font-family: "Paperlogy", sans-serif;
  transition: all 0.3s ease;
  
  backdrop-filter: brightness(1.05) blur(2px);
  -webkit-backdrop-filter: brightness(1.05) blur(2px);
  box-shadow: 
    0 2px 8px rgba(0, 0, 0, 0.08),
    0 0 0 1px rgba(255, 255, 255, 0.1) inset;
}

.filter-btn:hover {
  backdrop-filter: brightness(1.1) blur(3px);
  -webkit-backdrop-filter: brightness(1.1) blur(3px);
  transform: translateY(-2px);
}

.filter-btn.active {
  backdrop-filter: brightness(1.15) blur(3px) saturate(100%) url(#displacementFilter);
  -webkit-backdrop-filter: brightness(1.15) blur(3px) saturate(100%) url(#displacementFilter);
  box-shadow: 
    0 4px 12px rgba(0, 0, 0, 0.12),
    0 0 0 1px rgba(255, 255, 255, 0.2) inset;
}

/* Projects Grid */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 2rem;
  animation: fadeInUp 0.6s ease-out 0.2s backwards;
}

.project-item {
  position: relative;
  aspect-ratio: 4 / 3;
  border-radius: 16px;
  overflow: hidden;
  cursor: pointer;
  transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.5);
  
  box-shadow: 
    0 6px 20px rgba(0, 0, 0, 0.12),
    0 2px 8px rgba(0, 0, 0, 0.08);
}

.project-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.project-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(0, 0, 0, 0.8), transparent 60%);
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: 1.5rem;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.project-item:hover {
  transform: translateY(-8px);
  box-shadow: 
    0 12px 30px rgba(0, 0, 0, 0.18),
    0 6px 15px rgba(0, 0, 0, 0.12);
}

.project-item:hover img {
  transform: scale(1.05);
}

.project-item:hover .project-overlay {
  opacity: 1;
}

.project-overlay h3 {
  color: white;
  font-size: 1.25rem;
  font-weight: 600;
  margin: 0 0 0.5rem 0;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.5);
}

.project-overlay p {
  color: rgba(255, 255, 255, 0.9);
  font-size: 0.95rem;
  margin: 0;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.5);
}

/* Card Clickable */
.card-clickable {
  cursor: pointer;
  transition: all 0.3s ease;
}

.card-clickable:hover {
  transform: translateX(-8px) scale(1.02);
}

/* Hidden state for filtering */
.project-item.hidden {
  display: none;
}

/* Responsive */
@media (max-width: 767px) {
  .projects-section {
    padding: 7rem 0 3rem;
  }
  
  .projects-nav {
    flex-direction: column;
    align-items: flex-start;
    gap: 1.5rem;
  }
  
  .back-button {
    width: 100%;
    justify-content: center;
  }
  
  .projects-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  
  .category-filter {
    width: 100%;
    overflow-x: auto;
    flex-wrap: nowrap;
    padding-bottom: 0.5rem;
  }
  
  .filter-btn {
    white-space: nowrap;
    font-size: 0.875rem;
    padding: 0.625rem 1.25rem;
  }
}