:root {
  --color-bg: #f5f7fa;
  --color-surface: #ffffff;
  --color-text: #191f28;
  --color-muted: #8b95a1;
  --color-primary: #3182f6;
  --color-primary-700: #1b64da;
  --color-accent: #00d084;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0f1115;
    --color-surface: #161a22;
    --color-text: #e6edf3;
    --color-muted: #9aa7b1;
    --color-primary: #4aa3ff;
    --color-primary-700: #2d7bd6;
    --color-accent: #51d88a;
    --shadow-md: 0 10px 30px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 20px 40px rgba(0, 0, 0, 0.45);
  }
}
/* Reset and Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Pretendard Variable", Pretendard, -apple-system,
    BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans KR", sans-serif;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  overflow-x: hidden;
}

/* Utility */
.text-primary {
  color: var(--color-primary) !important;
}

/* Page load fade-in */
body {
  opacity: 0;
  transition: opacity 0.5s ease;
}

body.loaded {
  opacity: 1;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Navigation */
.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
  z-index: 1000;
  transition: all 0.2s ease;
}

@media (prefers-color-scheme: dark) {
  .navbar {
    background: rgba(22, 26, 34, 0.9);
    border-bottom-color: rgba(255, 255, 255, 0.06);
  }
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 70px;
}

.nav-logo a {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
  transition: color 0.2s ease;
  letter-spacing: -0.02em;
}

.nav-logo a:hover {
  color: var(--color-primary);
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 40px;
}

.nav-link {
  color: var(--color-text);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  transition: color 0.2s ease;
  position: relative;
  letter-spacing: -0.01em;
}

.nav-link:hover {
  color: var(--color-primary);
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: width 0.3s ease;
}

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

/* Active nav link */
.nav-link.active {
  color: var(--color-primary);
}

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

.hamburger {
  display: none;
  flex-direction: column;
  cursor: pointer;
  padding: 8px;
  z-index: 1001;
}

.bar {
  width: 25px;
  height: 3px;
  background: var(--color-text);
  margin: 3px 0;
  transition: 0.3s;
  border-radius: 2px;
  display: block;
}

@media (prefers-color-scheme: dark) {
  .bar {
    background: var(--color-text);
  }
}

/* Hamburger to X animation */
.hamburger.active .bar:nth-child(2) {
  opacity: 0;
}

.hamburger.active .bar:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.hamburger.active .bar:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

/* Hero Section */
.hero {
  min-height: 90vh;
  display: flex;
  align-items: center;
  background: linear-gradient(135deg, #e3f2fd 0%, #ffffff 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: repeating-linear-gradient(
      45deg,
      transparent,
      transparent 10px,
      rgba(255, 255, 255, 0.1) 10px,
      rgba(255, 255, 255, 0.1) 20px
    ),
    repeating-linear-gradient(
      -45deg,
      transparent,
      transparent 10px,
      rgba(255, 255, 255, 0.05) 10px,
      rgba(255, 255, 255, 0.05) 20px
    );
  opacity: 0.3;
  pointer-events: none;
}

/* decorative overlay removed for simpler look */

.hero-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 60px;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-content {
  animation: fadeInUp 1s ease-out;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 20px;
  line-height: 1.2;
  letter-spacing: -0.02em;
  text-align: left;
}

.hero-title br {
  display: block;
  margin: 0;
  line-height: 0.3;
  height: 0.3em;
}

.word-wrapper {
  display: inline-block;
}

.char-animate {
  display: inline;
  animation: charFadeIn 0.6s cubic-bezier(0.16, 1, 0.3, 1) forwards;
  opacity: 0;
  transform: translateY(20px);
}

@keyframes charFadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* 쉼표 스타일 */
.hero-title .comma-char {
  color: var(--color-primary);
  font-weight: 700;
}

.highlight {
  color: #3498db;
  position: relative;
}

.highlight::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, #3498db, #2980b9);
  border-radius: 2px;
}

.hero-keywords {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 24px;
}

.keyword-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  background: var(--color-surface);
  border: 1px solid rgba(0, 0, 0, 0.08);
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text);
  letter-spacing: -0.01em;
  box-shadow: var(--shadow-sm);
  transition: all 0.2s ease;
}

.keyword-tag:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.keyword-tag i {
  font-size: 0.85rem;
  color: var(--color-primary);
}

.keyword-tag span {
  display: inline-block;
}

.hero-buttons {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
}

.btn {
  padding: 14px 28px;
  border: none;
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  display: inline-block;
  transition: all 0.2s ease;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  letter-spacing: -0.01em;
}

.btn-primary {
  background: var(--color-primary);
  color: white;
  box-shadow: var(--shadow-sm);
}
.btn:focus-visible,
.nav-link:focus-visible,
.project-link:focus-visible,
.social-link:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
  border-radius: 8px;
}

.btn-primary:hover {
  background: var(--color-primary-700);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background: transparent;
  color: var(--color-primary);
  border: 1.5px solid var(--color-primary);
}

.btn-secondary:hover {
  background: var(--color-primary);
  color: white;
}

.hero-image {
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}

.profile-card-stack {
  position: relative;
  width: 100%;
  max-width: 400px;
  height: 500px;
}

.profile-card-layer {
  position: absolute;
  width: 100%;
  height: 100%;
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  overflow: hidden;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.profile-card-layer.layer-1 {
  z-index: 3;
  cursor: pointer;
  transform: translate(0, 0) rotate(-1deg);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12), 0 2px 8px rgba(0, 0, 0, 0.08);
  border: 1px solid rgba(0, 0, 0, 0.04);
}

.profile-card-layer.layer-1:hover {
  transform: translate(0, -4px) rotate(-1deg);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.16), 0 4px 12px rgba(0, 0, 0, 0.1);
}

.profile-card-layer.layer-2 {
  z-index: 2;
  transform: translate(16px, 16px) rotate(2deg);
  opacity: 0.8;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.1), 0 2px 6px rgba(0, 0, 0, 0.06);
  border: 1px solid rgba(0, 0, 0, 0.03);
  background: rgba(255, 255, 255, 0.98);
}

.profile-card-layer.layer-3 {
  z-index: 1;
  transform: translate(32px, 32px) rotate(-2deg);
  opacity: 0.6;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08), 0 1px 4px rgba(0, 0, 0, 0.04);
  border: 1px solid rgba(0, 0, 0, 0.02);
  background: rgba(255, 255, 255, 0.95);
}

.hero-profile-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: opacity 0.3s ease;
  display: block;
}

/* Scroll Indicator */
.scroll-indicator {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 10;
  animation: scrollBounce 2s ease-in-out infinite;
}

.scroll-arrow {
  width: 24px;
  height: 24px;
  border-right: 2px solid var(--color-primary);
  border-bottom: 2px solid var(--color-primary);
  transform: rotate(45deg);
  opacity: 0.7;
  transition: opacity 0.3s ease;
}

.scroll-indicator:hover .scroll-arrow {
  opacity: 1;
}

@keyframes scrollBounce {
  0%,
  100% {
    transform: translateX(-50%) translateY(0);
  }
  50% {
    transform: translateX(-50%) translateY(10px);
  }
}

/* Section Styles */
section {
  padding: 60px 0;
}

.section-header {
  text-align: center;
  margin-bottom: 40px;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 32px;
  position: relative;
  letter-spacing: -0.03em;
}

.section-title::after {
  display: none;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--color-muted);
  max-width: 600px;
  margin: 0 auto;
  letter-spacing: -0.01em;
}

/* About Section */
.about {
  background: var(--color-bg);
}

.about-content {
  display: flex;
  justify-content: center;
  align-items: center;
}

.about-text {
  max-width: 800px;
  margin: 0 auto;
}

.about-text h3 {
  font-size: 2rem;
  color: #2c3e50;
  margin-bottom: 30px;
}

.about-text p {
  font-size: 1.1rem;
  color: #5a6c7d;
  line-height: 1.8;
  margin-bottom: 40px;
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.stat {
  text-align: center;
  padding: 20px;
  background: white;
  border-radius: 15px;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
  transition: transform 0.3s ease;
}

.stat:hover {
  transform: translateY(-5px);
}

.stat h4 {
  font-size: 2.5rem;
  color: #3498db;
  font-weight: 700;
  margin-bottom: 10px;
}

.stat p {
  color: #7f8c8d;
  font-weight: 500;
}

/* Simple About Section Styles */
.intro-text {
  margin-bottom: 40px;
  text-align: left;
}

.intro-text h3 {
  font-size: 1.75rem;
  color: var(--color-text);
  margin-bottom: 20px;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.intro-text p {
  color: var(--color-text);
  font-size: 1.05rem;
  line-height: 1.75;
  margin: 0;
  letter-spacing: -0.01em;
}

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

.simple-title {
  color: var(--color-text);
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 24px;
  position: relative;
  letter-spacing: -0.01em;
}

.simple-item {
  display: flex;
  gap: 32px;
  margin-bottom: 24px;
}

.simple-period {
  color: #7f8c8d;
  font-size: 0.95rem;
  font-weight: 500;
  min-width: 120px;
  flex-shrink: 0;
  margin-top: 2px;
}

.simple-content h5 {
  color: #2c3e50;
  font-size: 1.3rem;
  font-weight: 600;
  margin: 0 0 8px 0;
}

.simple-content > p {
  color: #5a6c7d;
  font-size: 1rem;
  margin: 0 0 15px 0;
}

.simple-details {
  list-style: none;
  padding: 0;
  margin: 0;
}

.simple-details li {
  color: #5a6c7d;
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 8px;
  padding-left: 15px;
  position: relative;
}

.simple-details li::before {
  content: "•";
  color: #3498db;
  position: absolute;
  left: 0;
  font-weight: bold;
}

/* Blog Links */
.blog-links {
  display: flex;
  gap: 25px;
  margin-bottom: 30px;
  flex-wrap: wrap;
  justify-content: center;
}

.simple-blog-link {
  display: flex;
  align-items: center;
  gap: 15px;
  padding: 16px 24px;
  background: var(--color-surface);
  border: 1px solid rgba(0, 0, 0, 0.06);
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: all 0.2s ease;
  box-shadow: var(--shadow-sm);
  min-width: 280px;
  justify-content: space-between;
}

.simple-blog-link:hover {
  box-shadow: var(--shadow-md);
  border-color: rgba(0, 0, 0, 0.1);
}

.blog-name {
  color: var(--color-text);
  font-weight: 600;
  font-size: 1rem;
  flex: 1;
  letter-spacing: -0.01em;
}

.blog-platform {
  background: var(--color-bg);
  color: var(--color-muted);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  font-weight: 500;
  border: 1px solid rgba(0, 0, 0, 0.06);
}

.simple-blog-link:last-child {
  background: var(--color-surface);
  box-shadow: var(--shadow-sm);
}

.simple-blog-link:last-child:hover {
  box-shadow: var(--shadow-md);
}

.blog-desc {
  color: #5a6c7d;
  font-size: 0.95rem;
  line-height: 1.6;
  margin: 0;
}

/* Skills Section */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 32px;
}

.skill-category {
  text-align: left;
}

.skill-category h3 {
  font-size: 1.8rem;
  color: #2c3e50;
  margin-bottom: 25px;
  font-weight: 700;
  position: relative;
  padding-bottom: 10px;
}

.skill-category h3::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 50px;
  height: 3px;
  background: linear-gradient(90deg, #3498db, #2980b9);
  border-radius: 2px;
}

.skill-items {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.skill-item {
  background: #f8f9fa;
  color: #2c3e50;
  padding: 10px 18px;
  border-radius: 25px;
  font-size: 0.95rem;
  font-weight: 600;
  transition: all 0.3s ease;
  border: 2px solid transparent;
  cursor: pointer;
}

.skill-item:hover {
  background: #3498db;
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(52, 152, 219, 0.3);
}

/* Projects Section */
.projects {
  background: var(--color-bg);
}
@media (prefers-color-scheme: dark) {
  .projects {
    background: #0f1115;
  }
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 32px 24px;
}

/* remove zigzag layout */

.project-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: all 0.2s ease;
  border: 1px solid rgba(0, 0, 0, 0.04);
}

.project-card:hover {
  box-shadow: var(--shadow-md);
  border-color: rgba(0, 0, 0, 0.08);
}

/* no special hover offset per position */

.project-image {
  height: 200px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  position: relative;
  overflow: hidden;
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}

/* 프로젝트별 배경 이미지 */
.project-image.xai-aml-bg {
  background-image: linear-gradient(rgba(0, 0, 0, 0.3), rgba(0, 0, 0, 0.3)),
    url("../images/proj-xai.jpg?v=2");
}

.project-image.dividend-bg {
  background-image: linear-gradient(rgba(0, 0, 0, 0.3), rgba(0, 0, 0, 0.3)),
    url("../images/proj-dividend.jpg?v=2");
}

.project-image.blog-dapp-bg {
  background-image: linear-gradient(rgba(0, 0, 0, 0.3), rgba(0, 0, 0, 0.3)),
    url("../images/proj-blogdapp.jpg?v=2");
}

.project-image.caria-bg {
  background-image: linear-gradient(rgba(0, 0, 0, 0.3), rgba(0, 0, 0, 0.3)),
    url("../images/proj-caria.jpg?v=2");
}

/* TRACE-X background */
.project-image.tracex-bg {
  background-image: linear-gradient(rgba(0, 0, 0, 0.35), rgba(0, 0, 0, 0.35)),
    url("../images/이상거래탐지데모사진.jpg?v=2");
}

/* X-mas background */
.project-image.xmas-bg {
  background-image: linear-gradient(rgba(0, 0, 0, 0.35), rgba(0, 0, 0, 0.35)),
    url("../images/크리스마스 롤링 페이퍼 프로젝트.jpeg?v=2");
}

.project-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity 0.3s ease;
}

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

.project-links {
  display: flex;
  gap: 20px;
}

.project-link {
  width: 50px;
  height: 50px;
  background: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #3498db;
  text-decoration: none;
  font-size: 1.2rem;
  transition: all 0.3s ease;
}

.project-link:hover {
  background: #3498db;
  color: white;
  transform: scale(1.1);
}

.project-content {
  padding: 30px;
}

.project-content h3 {
  font-size: 1.5rem;
  color: #2c3e50;
  margin-bottom: 15px;
}

.project-content p {
  color: #7f8c8d;
  margin-bottom: 20px;
  line-height: 1.6;
}

.project-tech {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tech-tag {
  background: #e3f2fd;
  color: #3498db;
  padding: 5px 15px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
}

/* Awards Section - Toss Style */
.awards {
  background: var(--color-bg);
}

.awards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 20px;
  max-width: 1200px;
  margin: 0 auto;
}

.award-card {
  background: var(--color-surface);
  border-radius: 16px;
  padding: 28px;
  border: 1px solid rgba(0, 0, 0, 0.04);
  transition: all 0.2s ease;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
  position: relative;
  overflow: hidden;
}

@media (prefers-color-scheme: dark) {
  .award-card {
    border-color: rgba(255, 255, 255, 0.06);
  }
}

.award-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  opacity: 0;
  transition: opacity 0.2s ease;
}

.award-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  border-color: rgba(0, 0, 0, 0.08);
}

.award-card:hover::before {
  opacity: 1;
}

@media (prefers-color-scheme: dark) {
  .award-card:hover {
    border-color: rgba(255, 255, 255, 0.1);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
  }
}

.award-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 16px;
  gap: 16px;
}

.award-content {
  flex: 1;
}

.award-content h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 8px;
  line-height: 1.4;
  letter-spacing: -0.02em;
}

.award-content h3 a {
  color: var(--color-text);
  text-decoration: none;
  transition: color 0.2s ease;
}

.award-content h3 a:hover {
  color: var(--color-primary);
  text-decoration: underline;
}

.award-meta {
  display: flex;
  flex-direction: column;
  gap: 8px;
  align-items: flex-start;
  margin-bottom: 16px;
}

.award-organization {
  color: var(--color-muted);
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: -0.01em;
}

.award-date {
  color: var(--color-muted);
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: -0.01em;
}

.award-level {
  margin: 0;
}

.award-badge {
  display: inline-flex;
  align-items: center;
  padding: 6px 12px;
  border-radius: 6px;
  background: rgba(49, 130, 246, 0.1);
  color: var(--color-primary);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

@media (prefers-color-scheme: dark) {
  .award-badge {
    background: rgba(74, 163, 255, 0.15);
    color: #9cc9ff;
  }
}

.award-description {
  color: var(--color-text);
  margin-top: 16px;
}

.award-description ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.award-description li {
  position: relative;
  padding-left: 20px;
  margin-bottom: 10px;
  line-height: 1.6;
  font-size: 0.9375rem;
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.award-description li::before {
  content: "·";
  position: absolute;
  left: 8px;
  color: var(--color-muted);
  font-weight: bold;
  font-size: 1.2rem;
  line-height: 1;
}

.award-description li:last-child {
  margin-bottom: 0;
}

/* Activities Section - Toss Style */
.activities {
  background: var(--color-bg);
}

.activities-timeline {
  max-width: 900px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.activity-timeline-item {
  background: var(--color-surface);
  border-radius: 16px;
  padding: 28px;
  border: 1px solid rgba(0, 0, 0, 0.04);
  transition: all 0.2s ease;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
  position: relative;
  overflow: hidden;
}

@media (prefers-color-scheme: dark) {
  .activity-timeline-item {
    border-color: rgba(255, 255, 255, 0.06);
  }
}

.activity-timeline-item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  opacity: 0;
  transition: opacity 0.2s ease;
}

.activity-timeline-item:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  border-color: rgba(0, 0, 0, 0.08);
}

.activity-timeline-item:hover::before {
  opacity: 1;
}

@media (prefers-color-scheme: dark) {
  .activity-timeline-item:hover {
    border-color: rgba(255, 255, 255, 0.1);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
  }
}

.activity-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 16px;
  gap: 16px;
}

.activity-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: 6px;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  flex-shrink: 0;
}

.activity-badge.active {
  background: rgba(49, 130, 246, 0.1);
  color: var(--color-primary);
}

.activity-badge.completed {
  background: rgba(139, 149, 161, 0.1);
  color: var(--color-muted);
}

@media (prefers-color-scheme: dark) {
  .activity-badge.active {
    background: rgba(74, 163, 255, 0.15);
    color: #9cc9ff;
  }

  .activity-badge.completed {
    background: rgba(154, 167, 177, 0.15);
    color: var(--color-muted);
  }
}

.activity-badge i {
  font-size: 0.7rem;
}

.activity-year {
  font-size: 0.75rem;
}

.activity-timeline-details {
  flex: 1;
}

.activity-timeline-details h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 12px;
  line-height: 1.4;
  letter-spacing: -0.02em;
}

.activity-org {
  color: var(--color-muted);
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 16px;
  letter-spacing: -0.01em;
}

.activity-points {
  list-style: none;
  padding: 0;
  margin: 0;
}

.activity-points li {
  position: relative;
  padding-left: 20px;
  margin-bottom: 10px;
  color: var(--color-text);
  line-height: 1.6;
  font-size: 0.9375rem;
  letter-spacing: -0.01em;
}

.activity-points li::before {
  content: "·";
  position: absolute;
  left: 8px;
  color: var(--color-muted);
  font-weight: bold;
  font-size: 1.2rem;
  line-height: 1;
}

.activity-points li:last-child {
  margin-bottom: 0;
}

/* Contact Section */
.contact-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 30px;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 20px;
  background: var(--color-surface);
  border-radius: 15px;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
  transition: transform 0.3s ease;
}

.contact-item:hover {
  transform: translateY(-5px);
}

.contact-item i {
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, #3498db, #2980b9);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
}

.contact-item h4 {
  color: #2c3e50;
  margin-bottom: 5px;
}

.contact-item p {
  color: #7f8c8d;
}

.contact-form {
  background: white;
  padding: 40px;
  border-radius: 20px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.form-group {
  margin-bottom: 25px;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 15px;
  border: 2px solid #e9ecef;
  border-radius: 10px;
  font-size: 1rem;
  transition: border-color 0.3s ease;
  font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: #3498db;
}

.form-group textarea {
  resize: vertical;
  min-height: 120px;
}

/* Footer */
.footer {
  background: #2c3e50;
  color: white;
  padding: 40px 0;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 20px;
}

.social-links {
  display: flex;
  gap: 20px;
}

.social-link {
  width: 36px;
  height: 36px;
  background: rgba(255, 255, 255, 0.1);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  transition: all 0.3s ease;
}

.social-link img {
  width: 18px;
  height: 18px;
  display: block;
}

.social-link i {
  font-size: 1rem;
}

.social-link:hover {
  background: #3498db;
  transform: translateY(-3px);
}

/* Inline notification styles (used by JS) */
.notification {
  position: fixed;
  top: 100px;
  right: 20px;
  color: white;
  padding: 15px 25px;
  border-radius: 10px;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
  z-index: 10000;
  transform: translateX(400px);
  transition: transform 0.3s ease;
  font-weight: 500;
  max-width: 300px;
}

.notification-info {
  background: #3498db;
}
.notification-success {
  background: #27ae60;
}
.notification-error {
  background: #e74c3c;
}

/* Scroll to top button */
.scroll-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, #3498db, #2980b9);
  color: white;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  font-size: 1.2rem;
  box-shadow: 0 5px 15px rgba(52, 152, 219, 0.3);
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  z-index: 1000;
}

.scroll-to-top:hover {
  transform: scale(1.1);
}

/* Skip link */
.skip-link {
  position: absolute;
  left: -9999px;
  top: auto;
  width: 1px;
  height: 1px;
  overflow: hidden;
}
.skip-link:focus {
  position: fixed;
  left: 20px;
  top: 20px;
  width: auto;
  height: auto;
  padding: 10px 14px;
  background: var(--color-primary);
  color: #fff;
  border-radius: 8px;
  z-index: 1100;
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
  * {
    animation: none !important;
    transition: none !important;
  }
}

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

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

/* PDF Print Styles */
@media print {
  * {
    -webkit-print-color-adjust: exact !important;
    print-color-adjust: exact !important;
  }

  body {
    font-size: 12pt;
    line-height: 1.4;
    background: white !important;
  }

  .navbar {
    display: none !important;
  }

  .hero {
    page-break-inside: avoid;
    margin-bottom: 20pt;
  }

  .profile-cards {
    position: relative !important;
    height: auto !important;
    display: flex !important;
    flex-direction: row !important;
    gap: 20pt !important;
    justify-content: center !important;
  }

  .profile-card {
    position: relative !important;
    left: auto !important;
    margin-left: auto !important;
    page-break-inside: avoid;
    max-width: 200pt;
  }

  .section {
    page-break-inside: avoid;
    margin-bottom: 30pt;
  }

  .project-card,
  .activity-card,
  .award-card {
    page-break-inside: avoid;
    margin-bottom: 15pt;
    box-shadow: none !important;
    border: 1pt solid #ddd;
  }

  h1 {
    font-size: 24pt;
  }
  h2 {
    font-size: 18pt;
    page-break-after: avoid;
  }
  h3 {
    font-size: 14pt;
    page-break-after: avoid;
  }
  h4 {
    font-size: 12pt;
    page-break-after: avoid;
  }
}

/* Responsive Design */
/* Tablet styles */
@media (max-width: 1024px) and (min-width: 769px) {
  .hero-container {
    gap: 40px;
  }

  .hero-title {
    font-size: 3rem;
  }

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

  .awards-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .profile-card-stack {
    max-width: 350px;
    height: 450px;
  }
}

@media (max-width: 768px) {
  .hamburger {
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .nav-menu {
    position: fixed;
    left: -100%;
    top: 70px;
    flex-direction: column;
    background-color: var(--color-surface);
    width: 100%;
    text-align: center;
    transition: 0.3s;
    box-shadow: 0 10px 27px rgba(0, 0, 0, 0.05);
    padding: 20px 0;
    z-index: 999;
    max-height: calc(100vh - 70px);
    overflow-y: auto;
  }

  @media (prefers-color-scheme: dark) {
    .nav-menu {
      background-color: var(--color-surface);
      box-shadow: 0 10px 27px rgba(0, 0, 0, 0.3);
    }
  }

  .nav-menu.active {
    left: 0;
  }

  .nav-item {
    margin: 10px 0;
  }

  .nav-link {
    padding: 10px 20px;
    display: block;
  }

  .hero {
    min-height: auto;
    padding: 100px 0 60px;
  }

  .hero-container {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 40px;
    padding: 0 20px;
  }

  .hero-title {
    font-size: 2.5rem;
    line-height: 1.2;
    text-align: center;
  }

  .hero-title br {
    display: block;
    margin: 0;
    line-height: 0.3;
    height: 0.3em;
  }

  .hero-keywords {
    justify-content: center;
    gap: 8px;
  }

  .keyword-tag {
    padding: 8px 14px;
    font-size: 0.85rem;
  }

  .profile-card-stack {
    max-width: 240px;
    height: 300px;
    margin: 0 auto;
  }

  .profile-card-layer {
    transform: none !important;
  }

  .profile-card-layer.layer-1 {
    transform: translate(0, 0) rotate(0deg) !important;
  }

  .profile-card-layer.layer-2,
  .profile-card-layer.layer-3 {
    display: none;
  }

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

  .simple-item {
    flex-direction: column;
    gap: 12px;
  }

  .simple-period {
    min-width: auto;
    margin-top: 0;
  }

  .blog-links {
    flex-direction: column;
    gap: 15px;
  }

  .simple-blog-link {
    min-width: auto;
    width: 100%;
  }

  .about-stats {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .projects-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .project-content {
    padding: 20px;
  }

  .project-content h3 {
    font-size: 1.3rem;
  }

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

  .award-card {
    padding: 20px;
  }

  .award-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }

  .award-content h3 {
    font-size: 1.125rem;
  }

  .award-meta {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }

  .activities-timeline {
    gap: 12px;
  }

  .activity-timeline-item {
    padding: 20px;
  }

  .activity-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }

  .activity-timeline-details h3 {
    font-size: 1.125rem;
  }

  .skills-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }

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

  .contact-form {
    padding: 25px;
  }

  .footer-content {
    flex-direction: column;
    text-align: center;
  }

  .hero-buttons {
    justify-content: center;
  }

  .btn {
    padding: 12px 24px;
    font-size: 0.9rem;
  }

  .section {
    padding: 40px 0;
  }

  .section-title {
    font-size: 1.75rem;
    margin-bottom: 24px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 15px;
  }

  .nav-container {
    padding: 0 15px;
  }

  .nav-logo a {
    font-size: 18px;
  }

  .hero {
    padding: 90px 0 50px;
  }

  .hero-container {
    padding: 0 15px;
    gap: 30px;
  }

  .hero-title {
    font-size: 2rem;
    line-height: 1.2;
    text-align: center;
  }

  .hero-title br {
    display: block;
    margin: 0;
    line-height: 0.3;
    height: 0.3em;
  }

  .hero-keywords {
    gap: 6px;
  }

  .keyword-tag {
    padding: 6px 12px;
    font-size: 0.8rem;
  }

  .profile-card-stack {
    max-width: 200px;
    height: 250px;
  }

  .section {
    padding: 30px 0;
  }

  .section-title {
    font-size: 1.5rem;
    margin-bottom: 20px;
  }

  .section-subtitle {
    font-size: 0.95rem;
  }

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

  .project-content {
    padding: 15px;
  }

  .project-content h3 {
    font-size: 1.2rem;
    margin-bottom: 12px;
  }

  .project-content p {
    font-size: 0.9rem;
    margin-bottom: 15px;
  }

  .tech-tag {
    padding: 4px 12px;
    font-size: 0.75rem;
  }

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

  .skill-category h3 {
    font-size: 1.5rem;
    margin-bottom: 20px;
  }

  .skill-item {
    padding: 8px 14px;
    font-size: 0.85rem;
  }

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

  .award-card {
    padding: 16px;
  }

  .award-content h3 {
    font-size: 1rem;
    margin-bottom: 8px;
  }

  .award-meta {
    gap: 6px;
    margin-bottom: 12px;
  }

  .award-organization,
  .award-date {
    font-size: 0.8125rem;
  }

  .award-badge {
    padding: 4px 10px;
    font-size: 0.6875rem;
  }

  .award-description {
    margin-top: 12px;
  }

  .award-description li {
    font-size: 0.875rem;
    margin-bottom: 8px;
    padding-left: 18px;
  }

  .activities-timeline {
    gap: 12px;
  }

  .activity-timeline-item {
    padding: 16px;
  }

  .activity-timeline-details h3 {
    font-size: 1rem;
    margin-bottom: 10px;
  }

  .activity-org {
    font-size: 0.8125rem;
    margin-bottom: 12px;
  }

  .activity-points li {
    font-size: 0.875rem;
    margin-bottom: 8px;
    padding-left: 18px;
  }

  .activity-badge {
    padding: 4px 10px;
    font-size: 0.6875rem;
  }

  .simple-section {
    margin-bottom: 24px;
  }

  .simple-title {
    font-size: 1.05rem;
    margin-bottom: 16px;
  }

  .simple-content h5 {
    font-size: 1.15rem;
  }

  .simple-content > p {
    font-size: 0.9rem;
  }

  .simple-details li {
    font-size: 0.85rem;
  }

  .blog-links {
    gap: 12px;
  }

  .simple-blog-link {
    padding: 12px 16px;
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }

  .blog-name {
    font-size: 0.9rem;
  }

  .blog-platform {
    font-size: 0.75rem;
    padding: 4px 10px;
  }

  .contact-content {
    gap: 30px;
  }

  .contact-item {
    padding: 15px;
    gap: 15px;
  }

  .contact-item i {
    width: 40px;
    height: 40px;
    font-size: 1rem;
  }

  .contact-item h4 {
    font-size: 0.95rem;
  }

  .contact-item p {
    font-size: 0.85rem;
  }

  .contact-form {
    padding: 20px;
  }

  .form-group {
    margin-bottom: 20px;
  }

  .form-group input,
  .form-group textarea {
    padding: 12px;
    font-size: 0.9rem;
  }

  .intro-text p {
    font-size: 0.95rem;
    line-height: 1.7;
  }

  .footer {
    padding: 30px 0;
  }

  .footer-content {
    gap: 15px;
  }

  .social-links {
    gap: 15px;
  }

  .social-link {
    width: 32px;
    height: 32px;
  }

  .social-link img {
    width: 16px;
    height: 16px;
  }
}