/* ==========================================================================
   Modern Personal Portfolio Design System & Stylesheet
   Default: Light Mode
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. CSS Reset & Variables (Design Tokens)
   -------------------------------------------------------------------------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  /* Default: Light Theme */
  --bg-body: #f8fafc;
  --bg-surface: #ffffff;
  --bg-surface-elevated: #ffffff;
  --bg-subtle: #f1f5f9;
  --bg-muted: #e2e8f0;
  
  --text-main: #0f172a;
  --text-body: #334155;
  --text-muted: #64748b;
  --text-subtle: #94a3b8;
  --text-inverse: #ffffff;

  --primary: #059669;
  --primary-hover: #047857;
  --primary-light: #ecfdf5;
  --primary-border: #a7f3d0;

  --accent: #0d9488;
  --accent-light: #f0fdfa;
  --gradient-primary: linear-gradient(135deg, #059669 0%, #10b981 100%);
  --gradient-subtle: linear-gradient(135deg, #ecfdf5 0%, #f0fdfa 100%);

  --border-color: #e2e8f0;
  --border-subtle: #cbd5e1;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
  --shadow-hover: 0 20px 30px -10px rgba(5, 150, 105, 0.2), 0 10px 15px -5px rgba(0, 0, 0, 0.06);

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  --nav-height: 72px;
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark Theme Tokens */
[data-theme="dark"] {
  --bg-body: #0b0f19;
  --bg-surface: #111827;
  --bg-surface-elevated: #1f2937;
  --bg-subtle: #1a2234;
  --bg-muted: #2d3748;

  --text-main: #f8fafc;
  --text-body: #cbd5e1;
  --text-muted: #94a3b8;
  --text-subtle: #64748b;
  --text-inverse: #0f172a;

  --primary: #34d399;
  --primary-hover: #6ee7b7;
  --primary-light: rgba(52, 211, 153, 0.15);
  --primary-border: rgba(52, 211, 153, 0.3);

  --accent: #2dd4bf;
  --accent-light: rgba(45, 212, 191, 0.15);
  --gradient-primary: linear-gradient(135deg, #34d399 0%, #2dd4bf 100%);
  --gradient-subtle: linear-gradient(135deg, rgba(52, 211, 153, 0.1) 0%, rgba(45, 212, 191, 0.1) 100%);

  --border-color: #1e293b;
  --border-subtle: #334155;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.5), 0 2px 4px -2px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.55), 0 8px 10px -6px rgba(0, 0, 0, 0.4);
  --shadow-hover: 0 20px 30px -10px rgba(52, 211, 153, 0.25), 0 10px 15px -5px rgba(0, 0, 0, 0.5);
}

/* --------------------------------------------------------------------------
   2. Base Styles
   -------------------------------------------------------------------------- */
html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: 'Plus Jakarta Sans', 'Noto Sans KR', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background-color: var(--bg-body);
  color: var(--text-body);
  line-height: 1.7;
  overflow-x: hidden;
  transition: background-color var(--transition-slow), color var(--transition-slow);
  -webkit-font-smoothing: antialiased;
}

/* Scroll Progress Bar */
.scroll-progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: var(--gradient-primary);
  z-index: 1001;
  transition: width 0.1s ease-out;
}

/* Typography Helpers */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-main);
  font-weight: 700;
  line-height: 1.3;
}

a {
  color: inherit;
  text-decoration: none;
  transition: var(--transition);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

button, input, textarea {
  font-family: inherit;
  font-size: inherit;
  border: none;
  outline: none;
}

/* Container */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section {
  padding: 6rem 0;
}

@media (max-width: 768px) {
  .section {
    padding: 4rem 0;
  }
}

/* Section Header */
.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 4rem auto;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 1rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--primary);
  background-color: var(--primary-light);
  border: 1px solid var(--primary-border);
  border-radius: var(--radius-full);
  margin-bottom: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.section-title {
  font-size: 2.25rem;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

.section-desc {
  font-size: 1.1rem;
  color: var(--text-muted);
}

/* --------------------------------------------------------------------------
   3. Navigation (Header)
   -------------------------------------------------------------------------- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background-color: rgba(248, 250, 252, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
  transition: var(--transition);
}

[data-theme="dark"] .navbar {
  background-color: rgba(11, 15, 25, 0.85);
}

.navbar.scrolled {
  box-shadow: var(--shadow-sm);
  height: 64px;
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.logo-symbol {
  width: 34px;
  height: 34px;
  background: var(--gradient-primary);
  color: #ffffff;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1.1rem;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-muted);
  position: relative;
  padding: 0.5rem 0;
}

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

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: var(--primary);
  border-radius: var(--radius-full);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* Theme Toggle Button */
.theme-toggle-btn {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.theme-toggle-btn:hover {
  background-color: var(--bg-subtle);
  transform: rotate(15deg);
}

.theme-toggle-btn svg {
  width: 20px;
  height: 20px;
  stroke-width: 2;
}

.sun-icon {
  display: none;
}
.moon-icon {
  display: block;
}

[data-theme="dark"] .sun-icon {
  display: block;
}
[data-theme="dark"] .moon-icon {
  display: none;
}

/* Mobile Toggle */
.mobile-toggle-btn {
  display: none;
  background: none;
  border: none;
  color: var(--text-main);
  cursor: pointer;
  padding: 0.5rem;
}

.mobile-toggle-btn svg {
  width: 26px;
  height: 26px;
}

/* --------------------------------------------------------------------------
   4. Hero Section
   -------------------------------------------------------------------------- */
.hero-section {
  padding-top: calc(var(--nav-height) + 4rem);
  padding-bottom: 6rem;
  position: relative;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  align-items: center;
  gap: 3.5rem;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.4rem 1rem;
  background-color: var(--primary-light);
  border: 1px solid var(--primary-border);
  color: var(--primary);
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  margin-bottom: 1.5rem;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: #10b981;
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.25);
  animation: pulse-dot 2s infinite;
}

@keyframes pulse-dot {
  0% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.4); }
  70% { box-shadow: 0 0 0 8px rgba(16, 185, 129, 0); }
  100% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.hero-title {
  font-size: 3.25rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.25;
  margin-bottom: 1.5rem;
}

.highlight-gradient {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.hero-description {
  font-size: 1.2rem;
  color: var(--text-muted);
  line-height: 1.8;
  margin-bottom: 2.25rem;
  max-width: 580px;
}

.hero-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 2.5rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  padding: 0.85rem 1.8rem;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
}

.btn-primary {
  background: var(--gradient-primary);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.45);
}

.btn-outline {
  background-color: var(--bg-surface);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}

.btn-outline:hover {
  background-color: var(--bg-subtle);
  border-color: var(--border-subtle);
  transform: translateY(-2px);
}

.social-links {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.social-label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-subtle);
}

.social-icon-btn {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-full);
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.social-icon-btn:hover {
  color: var(--primary);
  border-color: var(--primary);
  transform: translateY(-2px);
}

.social-icon-btn svg {
  width: 20px;
  height: 20px;
}

/* Hero Visual Box */
.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
}

.hero-card {
  width: 100%;
  max-width: 420px;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 2.25rem 2rem;
  box-shadow: var(--shadow-lg);
  position: relative;
  overflow: hidden;
}

.hero-avatar-wrap {
  position: relative;
  width: 130px;
  height: 130px;
  margin: 0 auto 1.5rem auto;
}

.hero-avatar {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  background: var(--gradient-subtle);
  border: 4px solid var(--bg-surface);
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
}

.hero-avatar svg {
  width: 64px;
  height: 64px;
}

.avatar-badge {
  position: absolute;
  bottom: 4px;
  right: 4px;
  background: #10b981;
  color: #fff;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 2px solid var(--bg-surface);
}

.avatar-badge svg {
  width: 16px;
  height: 16px;
}

.profile-name {
  text-align: center;
  font-size: 1.35rem;
  margin-bottom: 0.25rem;
}

.profile-role {
  text-align: center;
  color: var(--primary);
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
}

.profile-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: center;
}

.tag {
  font-size: 0.8rem;
  font-weight: 600;
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-full);
  background-color: var(--bg-subtle);
  color: var(--text-muted);
}

/* Floating Badges */
.floating-stat-box {
  position: absolute;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  padding: 0.85rem 1.25rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  gap: 0.75rem;
  backdrop-filter: blur(10px);
}

.box-top-right {
  top: -10px;
  right: -20px;
}

.box-bottom-left {
  bottom: 20px;
  left: -20px;
}

.stat-icon-wrap {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  background-color: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
}

.stat-icon-wrap svg {
  width: 20px;
  height: 20px;
}

.floating-text-num {
  font-weight: 800;
  font-size: 1.1rem;
  color: var(--text-main);
  line-height: 1.2;
}

.floating-text-label {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* --------------------------------------------------------------------------
   5. About Section
   -------------------------------------------------------------------------- */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.about-lead {
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--text-main);
  line-height: 1.6;
  margin-bottom: 1.5rem;
}

.about-text {
  color: var(--text-muted);
  font-size: 1.05rem;
  margin-bottom: 2rem;
}

.stats-counter-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.stat-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  padding: 1.5rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.stat-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary-border);
  box-shadow: var(--shadow-md);
}

.stat-number {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--primary);
  line-height: 1.1;
  margin-bottom: 0.25rem;
}

.stat-title {
  font-size: 0.9rem;
  color: var(--text-muted);
  font-weight: 500;
}

.values-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.value-item {
  display: flex;
  gap: 1.25rem;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  padding: 1.5rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.value-item:hover {
  transform: translateY(-3px);
  border-color: var(--primary-border);
  box-shadow: var(--shadow-md);
}

.value-icon {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: var(--gradient-subtle);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
}

.value-icon svg {
  width: 24px;
  height: 24px;
}

.value-content h3 {
  font-size: 1.15rem;
  margin-bottom: 0.4rem;
}

.value-content p {
  font-size: 0.95rem;
  color: var(--text-muted);
}

/* --------------------------------------------------------------------------
   6. Skills Section
   -------------------------------------------------------------------------- */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.skill-category-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 2.25rem;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.skill-category-card:hover {
  transform: translateY(-5px);
  border-color: var(--primary-border);
  box-shadow: var(--shadow-hover);
}

.category-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.75rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
}

.category-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
}

.category-icon svg {
  width: 22px;
  height: 22px;
}

.category-header h3 {
  font-size: 1.25rem;
}

.skill-items {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.skill-row {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.skill-info {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.skill-name {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text-main);
}

.skill-percent {
  font-size: 0.85rem;
  color: var(--primary);
  font-weight: 700;
}

.skill-bar-bg {
  width: 100%;
  height: 7px;
  background-color: var(--bg-subtle);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.skill-bar-fill {
  height: 100%;
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  width: 0%;
  transition: width 1s ease-out;
}

/* --------------------------------------------------------------------------
   7. Projects Section & Filtering
   -------------------------------------------------------------------------- */
.projects-filter-wrap {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 3rem;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 0.6rem 1.4rem;
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  background-color: var(--bg-surface);
  color: var(--text-muted);
  border: 1px solid var(--border-color);
  cursor: pointer;
  transition: var(--transition);
}

.filter-btn:hover {
  color: var(--primary);
  border-color: var(--primary-border);
}

.filter-btn.active {
  background: var(--gradient-primary);
  color: #ffffff;
  border-color: transparent;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.project-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  transition: var(--transition);
  opacity: 1;
  transform: scale(1);
}

.project-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
  border-color: var(--primary-border);
}

.project-card.hidden {
  display: none;
}

.project-thumb {
  position: relative;
  width: 100%;
  height: 210px;
  background: var(--gradient-subtle);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.project-graphic-svg {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.project-card:hover .project-graphic-svg {
  transform: scale(1.04);
}

.project-category-badge {
  position: absolute;
  top: 1rem;
  left: 1rem;
  background-color: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(8px);
  color: var(--primary);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.3rem 0.75rem;
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-sm);
}

[data-theme="dark"] .project-category-badge {
  background-color: rgba(17, 24, 39, 0.9);
}

.project-body {
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.project-title {
  font-size: 1.25rem;
  margin-bottom: 0.6rem;
}

.project-desc {
  font-size: 0.925rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 1.25rem;
  flex-grow: 1;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 1.5rem;
}

.project-tag {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-sm);
  background-color: var(--bg-subtle);
  color: var(--text-muted);
}

.project-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 1rem;
  border-top: 1px solid var(--border-color);
}

.btn-detail {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--primary);
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.4rem 0;
}

.btn-detail:hover {
  text-decoration: underline;
}

.project-links {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.icon-link {
  color: var(--text-muted);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-md);
  background-color: var(--bg-subtle);
  transition: var(--transition);
}

.icon-link:hover {
  color: var(--primary);
  background-color: var(--primary-light);
}

.icon-link svg {
  width: 16px;
  height: 16px;
}

/* --------------------------------------------------------------------------
   8. Experience Section (Timeline)
   -------------------------------------------------------------------------- */
.timeline {
  max-width: 800px;
  margin: 0 auto;
  position: relative;
}

.timeline::before {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: 20px;
  width: 2px;
  background-color: var(--border-color);
}

.timeline-item {
  position: relative;
  padding-left: 60px;
  margin-bottom: 3rem;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-dot {
  position: absolute;
  left: 10px;
  top: 4px;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background-color: var(--bg-surface);
  border: 4px solid var(--primary);
  box-shadow: 0 0 0 4px var(--primary-light);
}

.timeline-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 1.75rem 2rem;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.timeline-card:hover {
  transform: translateX(4px);
  border-color: var(--primary-border);
  box-shadow: var(--shadow-md);
}

.timeline-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.5rem;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.timeline-period {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--primary);
  background-color: var(--primary-light);
  padding: 0.2rem 0.75rem;
  border-radius: var(--radius-full);
}

.timeline-role {
  font-size: 1.25rem;
  margin-bottom: 0.25rem;
}

.timeline-company {
  font-size: 0.95rem;
  color: var(--text-muted);
  font-weight: 600;
  margin-bottom: 0.85rem;
}

.timeline-desc {
  font-size: 0.95rem;
  color: var(--text-body);
  line-height: 1.6;
}

.timeline-desc ul {
  padding-left: 1.2rem;
  margin-top: 0.5rem;
}

.timeline-desc li {
  margin-bottom: 0.35rem;
}

/* --------------------------------------------------------------------------
   9. Contact Section
   -------------------------------------------------------------------------- */
.contact-grid {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 3rem;
}

.contact-info-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.contact-info-title {
  font-size: 1.5rem;
  margin-bottom: 0.75rem;
}

.contact-info-desc {
  color: var(--text-muted);
  font-size: 1rem;
  margin-bottom: 2rem;
}

.contact-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.contact-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background-color: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.contact-icon svg {
  width: 22px;
  height: 22px;
}

.contact-meta-label {
  font-size: 0.8rem;
  color: var(--text-subtle);
  font-weight: 500;
}

.contact-meta-value {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-main);
}

.contact-meta-value:hover {
  color: var(--primary);
}

/* Contact Form */
.contact-form-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
}

.form-group-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-bottom: 1.5rem;
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 0.5rem;
}

.form-input, .form-textarea {
  width: 100%;
  padding: 0.85rem 1.1rem;
  background-color: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-main);
  font-size: 0.95rem;
  transition: var(--transition);
}

.form-input:focus, .form-textarea:focus {
  background-color: var(--bg-surface);
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-light);
}

.form-textarea {
  resize: vertical;
  min-height: 140px;
}

.btn-submit {
  width: 100%;
  padding: 1rem;
  font-size: 1rem;
}

/* --------------------------------------------------------------------------
   10. Footer & Back to Top
   -------------------------------------------------------------------------- */
.footer {
  background-color: var(--bg-surface);
  border-top: 1px solid var(--border-color);
  padding: 3rem 0;
  margin-top: 4rem;
}

.footer-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.footer-brand {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text-main);
}

.footer-copy {
  font-size: 0.875rem;
  color: var(--text-muted);
}

.back-to-top-btn {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 46px;
  height: 46px;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transition: var(--transition);
  z-index: 99;
}

.back-to-top-btn.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top-btn:hover {
  background: var(--gradient-primary);
  color: #ffffff;
  transform: translateY(-3px);
  box-shadow: var(--shadow-hover);
}

/* --------------------------------------------------------------------------
   11. Modal Popup
   -------------------------------------------------------------------------- */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.65);
  backdrop-filter: blur(6px);
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.modal-overlay.open {
  opacity: 1;
  visibility: visible;
}

.modal-content {
  background-color: var(--bg-surface);
  border-radius: var(--radius-xl);
  max-width: 720px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.35);
  border: 1px solid var(--border-color);
  position: relative;
  transform: scale(0.95);
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.modal-overlay.open .modal-content {
  transform: scale(1);
}

.modal-close-btn {
  position: absolute;
  top: 1.25rem;
  right: 1.25rem;
  background: var(--bg-subtle);
  border: none;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  color: var(--text-main);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
  z-index: 10;
}

.modal-close-btn:hover {
  background-color: var(--primary);
  color: #fff;
}

.modal-body {
  padding: 2.5rem;
}

.modal-tag {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--primary);
  background-color: var(--primary-light);
  padding: 0.3rem 0.8rem;
  border-radius: var(--radius-full);
  margin-bottom: 0.75rem;
}

.modal-title {
  font-size: 1.75rem;
  margin-bottom: 1rem;
}

.modal-meta-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-bottom: 1.75rem;
  padding: 1.25rem;
  background-color: var(--bg-subtle);
  border-radius: var(--radius-md);
}

.modal-meta-item strong {
  display: block;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.2rem;
}

.modal-meta-item span {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-main);
}

.modal-section-title {
  font-size: 1.15rem;
  margin: 1.5rem 0 0.75rem 0;
}

.modal-list {
  padding-left: 1.25rem;
  color: var(--text-body);
  margin-bottom: 1.5rem;
}

.modal-list li {
  margin-bottom: 0.5rem;
}

.modal-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 2rem;
}

.modal-actions {
  display: flex;
  gap: 1rem;
}

/* --------------------------------------------------------------------------
   12. Toast Notification
   -------------------------------------------------------------------------- */
.toast-container {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 3000;
  pointer-events: none;
}

.toast {
  background-color: #10b981;
  color: #ffffff;
  padding: 0.85rem 1.75rem;
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 600;
  font-size: 0.95rem;
  opacity: 0;
  transform: translateY(20px);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  pointer-events: auto;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
}

/* --------------------------------------------------------------------------
   13. Responsive Media Queries
   -------------------------------------------------------------------------- */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-description {
    margin-left: auto;
    margin-right: auto;
  }

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

  .social-links {
    justify-content: center;
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

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

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

  .contact-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .mobile-toggle-btn {
    display: block;
  }

  .nav-menu {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background-color: var(--bg-surface);
    flex-direction: column;
    padding: 2rem;
    gap: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
    transform: translateY(-120%);
    opacity: 0;
    visibility: hidden;
    transition: transform 0.3s ease, opacity 0.3s ease;
  }

  .nav-menu.open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .hero-title {
    font-size: 2.35rem;
  }

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

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

  .form-group-row {
    grid-template-columns: 1fr;
  }

  .modal-meta-grid {
    grid-template-columns: 1fr;
  }
}