/* 부드러운 스크롤 */
html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

/* 타이포그래피 강화 */
h1 {
  letter-spacing: -0.02em;
  font-weight: 800;
}

h2 {
  letter-spacing: -0.02em;
  font-weight: 700;
}

/* 그라데이션 애니메이션 */
@keyframes gradient-shift {
  0%, 100% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
}

@keyframes pulse-slow {
  0%, 100% {
    opacity: 0.2;
    transform: scale(1);
  }
  50% {
    opacity: 0.3;
    transform: scale(1.05);
  }
}

.animate-pulse-slow {
  animation: pulse-slow 8s ease-in-out infinite;
}

.animate-pulse-slow-delay {
  animation: pulse-slow 8s ease-in-out infinite;
  animation-delay: 4s;
}

/* 다크모드 전환 애니메이션 */
body,
nav,
section,
footer,
.project-card,
.bg-white,
.bg-gray-50 {
  transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

/* fade-in 애니메이션 */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* 프로젝트 카드 호버 */
.project-card {
  transition: transform 0.3s ease, box-shadow 0.3s ease, background-color 0.3s ease, border-color 0.3s ease;
}

.project-card:hover {
  transform: translateY(-8px) scale(1.01);
  box-shadow:
    0 20px 25px -5px rgba(0, 0, 0, 0.1),
    0 10px 10px -5px rgba(0, 0, 0, 0.04),
    0 0 0 1px rgba(59, 130, 246, 0.1),
    0 0 40px rgba(59, 130, 246, 0.2);
}

.dark .project-card:hover {
  box-shadow:
    0 20px 25px -5px rgba(0, 0, 0, 0.4),
    0 10px 10px -5px rgba(0, 0, 0, 0.3),
    0 0 0 1px rgba(96, 165, 250, 0.3),
    0 0 50px rgba(96, 165, 250, 0.4);
}

/* 기술 스택 태그 호버 */
.skill-tag {
  transition: all 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
  cursor: pointer;
}

.skill-tag:hover {
  transform: translateY(-6px) scale(1.1);
}

/* 네비게이션 활성 링크 */
.nav-link.active {
  color: #2563eb;
  font-weight: 600;
}

.dark .nav-link.active {
  color: #60a5fa;
}

/* 네비게이션 스크롤 효과 */
#navbar {
  transition: all 0.3s ease;
}

#navbar.scrolled {
  background-color: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(20px);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08), 0 0 0 1px rgba(59, 130, 246, 0.1);
}

.dark #navbar.scrolled {
  background-color: rgba(31, 41, 55, 0.85);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3), 0 0 0 1px rgba(96, 165, 250, 0.2);
}

/* 모바일 메뉴 토글 애니메이션 */
#menu-toggle.open span:nth-child(1) {
  transform: rotate(45deg) translate(4px, 4px);
}

#menu-toggle.open span:nth-child(2) {
  opacity: 0;
}

#menu-toggle.open span:nth-child(3) {
  transform: rotate(-45deg) translate(4px, -4px);
}

/* 맨 위로 가기 버튼 활성화 */
#scroll-top.visible {
  opacity: 1;
  pointer-events: auto;
}

/* 스크롤바 - 라이트 모드 */
::-webkit-scrollbar {
  width: 10px;
}

::-webkit-scrollbar-track {
  background: #f1f5f9;
}

::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, #3b82f6, #6366f1);
  border-radius: 5px;
  border: 2px solid #f1f5f9;
}

::-webkit-scrollbar-thumb:hover {
  background: linear-gradient(180deg, #2563eb, #4f46e5);
}

/* 스크롤바 - 다크 모드 */
.dark ::-webkit-scrollbar-track {
  background: #1f2937;
}

.dark ::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, #60a5fa, #818cf8);
  border: 2px solid #1f2937;
}

.dark ::-webkit-scrollbar-thumb:hover {
  background: linear-gradient(180deg, #3b82f6, #6366f1);
}