/* ============================================
   PORTFOLIO WEBSITE - STYLE.CSS
   Premium Portfolio for Software Developer
   & UI/UX Designer
   ============================================ */

/* ============================================
   1. CSS CUSTOM PROPERTIES (THEME SYSTEM)
   ============================================ */
:root {
  /* Light Mode Colors (Default) */
  --bg-primary: #FFFFFF;
  --bg-secondary: #F8FAFC;
  --bg-tertiary: #F1F5F9;
  --bg-card: #FFFFFF;
  --bg-card-hover: #F8FAFC;
  --bg-navbar: rgba(255, 255, 255, 0.85);
  --bg-modal: rgba(0, 0, 0, 0.6);

  --text-primary: #111111;
  --text-secondary: #555555;
  --text-tertiary: #94A3B8;
  --text-inverse: #FFFFFF;

  --primary: #2563EB;
  --primary-hover: #1D4ED8;
  --primary-light: rgba(37, 99, 235, 0.1);
  --primary-glow: rgba(37, 99, 235, 0.15);

  --border-color: #E2E8F0;
  --border-light: #F1F5F9;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.08);
  --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.1);
  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.04), 0 4px 12px rgba(0, 0, 0, 0.03);
  --shadow-card-hover: 0 8px 30px rgba(0, 0, 0, 0.08);

  /* Typography */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Consolas', monospace;

  /* Spacing */
  --section-padding: 100px 0;
  --container-width: 1200px;
  --container-padding: 0 24px;

  /* Border Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 50%;

  /* Transitions */
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-spring: 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);

  /* Timeline */
  --timeline-line: #E2E8F0;
  --timeline-dot: #2563EB;

  /* Scrollbar */
  --scrollbar-bg: #F1F5F9;
  --scrollbar-thumb: #CBD5E1;
}

/* Dark Mode */
[data-theme="dark"] {
  --bg-primary: #0F172A;
  --bg-secondary: #1E293B;
  --bg-tertiary: #334155;
  --bg-card: #1E293B;
  --bg-card-hover: #263548;
  --bg-navbar: rgba(15, 23, 42, 0.9);
  --bg-modal: rgba(0, 0, 0, 0.75);

  --text-primary: #F8FAFC;
  --text-secondary: #CBD5E1;
  --text-tertiary: #64748B;
  --text-inverse: #0F172A;

  --primary: #3B82F6;
  --primary-hover: #60A5FA;
  --primary-light: rgba(59, 130, 246, 0.12);
  --primary-glow: rgba(59, 130, 246, 0.2);

  --border-color: #334155;
  --border-light: #1E293B;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.35);
  --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.4);
  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.2), 0 4px 12px rgba(0, 0, 0, 0.15);
  --shadow-card-hover: 0 8px 30px rgba(0, 0, 0, 0.3);

  --timeline-line: #334155;
  --timeline-dot: #3B82F6;

  --scrollbar-bg: #1E293B;
  --scrollbar-thumb: #475569;
}

/* ============================================
   2. RESET & BASE STYLES
   ============================================ */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-primary);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  transition: background-color var(--transition-base), color var(--transition-base);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

button {
  border: none;
  background: none;
  cursor: pointer;
  font-family: inherit;
  font-size: inherit;
}

ul, ol {
  list-style: none;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--scrollbar-bg);
}

::-webkit-scrollbar-thumb {
  background: var(--scrollbar-thumb);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-tertiary);
}

/* Selection */
::selection {
  background: var(--primary);
  color: var(--text-inverse);
}

/* ============================================
   3. UTILITY CLASSES
   ============================================ */
.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: var(--container-padding);
}

.section {
  padding: var(--section-padding);
}

.section-header {
  text-align: center;
  margin-bottom: 64px;
}

.section-label {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--primary);
  margin-bottom: 12px;
  padding: 6px 16px;
  background: var(--primary-light);
  border-radius: 20px;
}

.section-title {
  font-size: clamp(2rem, 4vw, 2.75rem);
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.section-subtitle {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 16px auto 0;
  line-height: 1.7;
}

/* ============================================
   4. ANIMATION CLASSES
   ============================================ */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s cubic-bezier(0.4, 0, 0.2, 1),
              transform 0.7s cubic-bezier(0.4, 0, 0.2, 1);
}

.animate-on-scroll.visible {
  opacity: 1;
  transform: translateY(0);
}

.fade-up {
  opacity: 0;
  transform: translateY(40px);
}

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

.fade-in {
  opacity: 0;
}

.fade-in.visible {
  opacity: 1;
}

.slide-left {
  opacity: 0;
  transform: translateX(-50px);
}

.slide-left.visible {
  opacity: 1;
  transform: translateX(0);
}

.slide-right {
  opacity: 0;
  transform: translateX(50px);
}

.slide-right.visible {
  opacity: 1;
  transform: translateX(0);
}

/* Stagger animation delays */
.delay-1 { transition-delay: 0.1s; }
.delay-2 { transition-delay: 0.2s; }
.delay-3 { transition-delay: 0.3s; }
.delay-4 { transition-delay: 0.4s; }
.delay-5 { transition-delay: 0.5s; }
.delay-6 { transition-delay: 0.6s; }

/* ============================================
   5. NAVBAR
   ============================================ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--bg-navbar);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  transition: background-color var(--transition-base), 
              border-color var(--transition-base),
              box-shadow var(--transition-base);
  height: 72px;
}

.navbar.scrolled {
  box-shadow: var(--shadow-md);
}

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

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

.nav-logo img {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-links a {
  padding: 8px 16px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast), background-color var(--transition-fast);
  position: relative;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--primary);
  background: var(--primary-light);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Language Switch */
.lang-switch {
  display: flex;
  align-items: center;
  background: var(--bg-tertiary);
  border-radius: 20px;
  padding: 3px;
  gap: 2px;
}

.lang-btn {
  padding: 5px 12px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
  border-radius: 18px;
  transition: all var(--transition-fast);
}

.lang-btn.active {
  background: var(--primary);
  color: #FFFFFF;
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.3);
}

/* Theme Toggle */
.theme-toggle {
  width: 42px;
  height: 42px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  font-size: 1.15rem;
  transition: all var(--transition-fast);
}

.theme-toggle:hover {
  background: var(--primary-light);
  color: var(--primary);
  transform: rotate(15deg);
}

/* Mobile Menu Toggle */
.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  cursor: pointer;
}

.mobile-menu-btn span {
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all var(--transition-base);
  display: block;
}

.mobile-menu-btn.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-btn.active span:nth-child(2) {
  opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ============================================
   6. HERO SECTION
   ============================================ */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 72px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -30%;
  width: 700px;
  height: 700px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--primary-glow) 0%, transparent 70%);
  pointer-events: none;
  animation: pulse-glow 6s ease-in-out infinite;
}

@keyframes pulse-glow {
  0%, 100% { transform: scale(1); opacity: 0.5; }
  50% { transform: scale(1.15); opacity: 0.8; }
}

.hero .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 60px;
  position: relative;
  z-index: 1;
}

.hero-content {
  flex: 1;
  max-width: 600px;
}

.hero-greeting {
  font-size: 1.05rem;
  color: var(--primary);
  font-weight: 600;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.hero-greeting::before {
  content: '';
  width: 32px;
  height: 2px;
  background: var(--primary);
  border-radius: 2px;
}

.hero-name {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.hero-title {
  font-size: clamp(1.25rem, 3vw, 1.75rem);
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 20px;
  line-height: 1.3;
}

.hero-description {
  font-size: 1.1rem;
  color: var(--text-secondary);
  line-height: 1.8;
  max-width: 480px;
  margin-bottom: 36px;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
  cursor: pointer;
}

.btn-primary {
  background: var(--primary);
  color: #FFFFFF;
  box-shadow: 0 4px 16px rgba(37, 99, 235, 0.3);
}

.btn-primary:hover {
  background: var(--primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(37, 99, 235, 0.4);
}

.btn-outline {
  background: transparent;
  color: var(--text-primary);
  border: 2px solid var(--border-color);
}

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

.hero-image {
  flex: 0 0 auto;
  position: relative;
}

.hero-image-wrapper {
  width: 380px;
  height: 380px;
  border-radius: var(--radius-xl);
  overflow: hidden;
  position: relative;
  animation: float 6s ease-in-out infinite;
  box-shadow: var(--shadow-xl);
}

.hero-image-wrapper::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-xl);
  border: 2px solid var(--primary-glow);
  pointer-events: none;
}

.hero-image-wrapper img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

@keyframes float {
  0%, 100% { transform: translateY(0px); }
  50% { transform: translateY(-20px); }
}

/* Decorative dots */
.hero-dots {
  position: absolute;
  width: 120px;
  height: 120px;
  bottom: -20px;
  right: -20px;
  background-image: radial-gradient(circle, var(--primary) 1.5px, transparent 1.5px);
  background-size: 16px 16px;
  opacity: 0.2;
  z-index: -1;
}

/* ============================================
   7. ABOUT SECTION
   ============================================ */
.about {
  background: var(--bg-secondary);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.about-image-container {
  position: relative;
}

.about-image {
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.about-image img {
  width: 100%;
  height: 420px;
  object-fit: cover;
}

.about-stats {
  position: absolute;
  bottom: -30px;
  right: -20px;
  display: flex;
  gap: 12px;
}

.stat-card {
  background: var(--bg-card);
  padding: 18px 22px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  text-align: center;
  border: 1px solid var(--border-color);
}

.stat-number {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--primary);
  line-height: 1;
}

.stat-label {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-top: 4px;
  font-weight: 500;
}

.about-content h3 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 16px;
}

.about-text {
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 24px;
}

.about-details {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 32px;
}

.about-detail-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  background: var(--bg-tertiary);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
}

.about-detail-icon {
  font-size: 1.2rem;
}

.about-detail-text strong {
  display: block;
  font-size: 0.75rem;
  color: var(--text-tertiary);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.about-detail-text span {
  color: var(--text-primary);
  font-weight: 600;
}

/* ============================================
   8. SKILLS SECTION
   ============================================ */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.skill-category {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.skill-category::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--primary-hover));
  transform: scaleX(0);
  transition: transform var(--transition-base);
  transform-origin: left;
}

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

.skill-category:hover::before {
  transform: scaleX(1);
}

.skill-category-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--primary-light);
  border-radius: var(--radius-md);
  font-size: 1.5rem;
  margin-bottom: 20px;
}

.skill-category-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 16px;
}

.skill-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.skill-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.skill-name {
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.skill-bar-container {
  flex: 1;
  max-width: 100px;
  height: 4px;
  background: var(--bg-tertiary);
  border-radius: 2px;
  overflow: hidden;
}

.skill-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--primary), var(--primary-hover));
  border-radius: 2px;
  width: 0%;
  transition: width 1.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.skill-category:hover .skill-bar,
.skill-bar.animated {
  /* Width is set via inline style */
}

/* ============================================
   9. PROJECTS SECTION
   ============================================ */
.projects {
  background: var(--bg-secondary);
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--transition-base);
  position: relative;
}

.project-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-card-hover);
}

.project-image {
  position: relative;
  overflow: hidden;
  height: 240px;
}

.project-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

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

.project-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(0, 0, 0, 0.7) 0%, transparent 50%);
  opacity: 0;
  transition: opacity var(--transition-base);
  display: flex;
  align-items: flex-end;
  justify-content: center;
  padding: 24px;
  gap: 12px;
}

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

.project-overlay-btn {
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 600;
  transition: all var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.project-overlay-btn.github {
  background: rgba(255, 255, 255, 0.15);
  color: #FFFFFF;
  border: 1px solid rgba(255, 255, 255, 0.3);
  backdrop-filter: blur(8px);
}

.project-overlay-btn.demo {
  background: var(--primary);
  color: #FFFFFF;
}

.project-overlay-btn:hover {
  transform: translateY(-2px);
}

.project-content {
  padding: 24px;
}

.project-name {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.project-description {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 16px;
}

.project-tech {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.project-tech span {
  padding: 4px 12px;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--primary);
  background: var(--primary-light);
  border-radius: 20px;
}

/* ============================================
   10. EXPERIENCE TIMELINE
   ============================================ */
.timeline {
  position: relative;
  max-width: 700px;
  margin: 0 auto;
  padding: 20px 0;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--timeline-line);
  transform: translateX(-50%);
}

.timeline-item {
  position: relative;
  margin-bottom: 48px;
  width: 50%;
}

.timeline-item:nth-child(odd) {
  padding-right: 48px;
  text-align: right;
}

.timeline-item:nth-child(even) {
  left: 50%;
  padding-left: 48px;
}

.timeline-dot {
  position: absolute;
  top: 24px;
  width: 16px;
  height: 16px;
  border-radius: var(--radius-full);
  background: var(--primary);
  border: 3px solid var(--bg-primary);
  box-shadow: 0 0 0 4px var(--primary-light);
  z-index: 1;
  transition: background-color var(--transition-base), border-color var(--transition-base);
}

.timeline-item:nth-child(odd) .timeline-dot {
  right: -8px;
}

.timeline-item:nth-child(even) .timeline-dot {
  left: -8px;
}

.timeline-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  transition: all var(--transition-base);
}

.timeline-card:hover {
  box-shadow: var(--shadow-card-hover);
  transform: translateY(-3px);
}

.timeline-year {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--primary);
  background: var(--primary-light);
  padding: 4px 14px;
  border-radius: 20px;
  margin-bottom: 12px;
}

.timeline-position {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.timeline-company {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
  font-weight: 500;
}

.timeline-description {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ============================================
   11. CERTIFICATES SECTION
   ============================================ */
.certificates {
  background: var(--bg-secondary);
}

.certificates-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
  max-width: 800px;
  margin: 0 auto;
}

.certificate-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  cursor: pointer;
  transition: all var(--transition-base);
}

.certificate-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-card-hover);
}

.certificate-image {
  position: relative;
  overflow: hidden;
  height: 220px;
}

.certificate-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.certificate-card:hover .certificate-image img {
  transform: scale(1.05);
}

.certificate-zoom {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity var(--transition-base);
}

.certificate-card:hover .certificate-zoom {
  opacity: 1;
}

.certificate-zoom-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  color: #FFFFFF;
}

.certificate-info {
  padding: 20px;
}

.certificate-name {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.certificate-issuer {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* Certificate Modal */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: var(--bg-modal);
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
  backdrop-filter: blur(8px);
}

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

.modal-content {
  max-width: 90vw;
  max-height: 90vh;
  position: relative;
  transform: scale(0.9);
  transition: transform var(--transition-base);
}

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

.modal-content img {
  max-width: 100%;
  max-height: 85vh;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
}

.modal-close {
  position: absolute;
  top: -16px;
  right: -16px;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  background: var(--bg-card);
  color: var(--text-primary);
  font-size: 1.2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-fast);
  border: 1px solid var(--border-color);
}

.modal-close:hover {
  background: var(--primary);
  color: #FFFFFF;
  transform: rotate(90deg);
}

/* ============================================
   12. CONTACT SECTION
   ============================================ */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}

.contact-info h3 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 16px;
}

.contact-info p {
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 32px;
}

.contact-links {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.contact-link {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 16px 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
}

.contact-link:hover {
  border-color: var(--primary);
  background: var(--primary-light);
  transform: translateX(5px);
}

.contact-link-icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--primary-light);
  color: var(--primary);
  border-radius: var(--radius-sm);
  font-size: 1.2rem;
  flex-shrink: 0;
}

.contact-link-text strong {
  display: block;
  font-size: 0.9rem;
  color: var(--text-primary);
}

.contact-link-text span {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* Contact Form */
.contact-form {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px;
}

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

.form-label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.form-input,
.form-textarea {
  width: 100%;
  padding: 14px 18px;
  font-size: 0.95rem;
  font-family: var(--font-primary);
  color: var(--text-primary);
  background: var(--bg-tertiary);
  border: 2px solid transparent;
  border-radius: var(--radius-sm);
  outline: none;
  transition: all var(--transition-fast);
}

.form-input:focus,
.form-textarea:focus {
  border-color: var(--primary);
  background: var(--bg-primary);
  box-shadow: 0 0 0 4px var(--primary-light);
}

.form-input::placeholder,
.form-textarea::placeholder {
  color: var(--text-tertiary);
}

.form-textarea {
  resize: vertical;
  min-height: 130px;
}

.form-error {
  font-size: 0.8rem;
  color: #EF4444;
  margin-top: 6px;
  display: none;
}

.form-group.error .form-input,
.form-group.error .form-textarea {
  border-color: #EF4444;
}

.form-group.error .form-error {
  display: block;
}

.form-submit {
  width: 100%;
  padding: 16px;
  font-size: 1rem;
  font-weight: 600;
  color: #FFFFFF;
  background: var(--primary);
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-base);
}

.form-submit:hover {
  background: var(--primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(37, 99, 235, 0.3);
}

.form-success {
  display: none;
  text-align: center;
  padding: 20px;
  background: rgba(34, 197, 94, 0.1);
  border: 1px solid rgba(34, 197, 94, 0.3);
  border-radius: var(--radius-sm);
  color: #22C55E;
  font-weight: 600;
  margin-top: 16px;
}

.form-success.show {
  display: block;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ============================================
   13. FOOTER
   ============================================ */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 48px 0 24px;
}

.footer-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 32px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
}

.footer-logo img {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
}

.footer-social {
  display: flex;
  gap: 12px;
}

.footer-social-link {
  width: 42px;
  height: 42px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  font-size: 1.1rem;
  transition: all var(--transition-base);
}

.footer-social-link:hover {
  background: var(--primary);
  color: #FFFFFF;
  transform: translateY(-3px);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.footer-bottom {
  text-align: center;
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
}

.footer-copyright {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* ============================================
   14. BACK TO TOP BUTTON
   ============================================ */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  border-radius: var(--radius-full);
  background: var(--primary);
  color: #FFFFFF;
  font-size: 1.2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 16px rgba(37, 99, 235, 0.3);
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all var(--transition-base);
  z-index: 900;
  cursor: pointer;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--primary-hover);
  transform: translateY(-3px);
}

/* ============================================
   15. RESPONSIVE DESIGN
   ============================================ */

/* Large Desktop (1200px+) - Default styles above */

/* Laptop / Small Desktop */
@media (max-width: 1200px) {
  .skills-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .hero-image-wrapper {
    width: 320px;
    height: 320px;
  }
}

/* Tablet */
@media (max-width: 992px) {
  .nav-links {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--bg-primary);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transform: translateX(100%);
    transition: transform var(--transition-base);
    z-index: 999;
  }

  .nav-links.active {
    transform: translateX(0);
  }

  .nav-links a {
    font-size: 1.1rem;
    padding: 12px 24px;
  }

  .mobile-menu-btn {
    display: flex;
  }

  .hero .container {
    flex-direction: column-reverse;
    text-align: center;
    gap: 24px;
  }

  .hero-content {
    max-width: 100%;
  }

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

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

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

  .hero-image-wrapper {
    width: 200px;
    height: 200px;
  }

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

  .about-image img {
    height: 280px;
  }

  .about-stats {
    position: static;
    margin-top: 20px;
    justify-content: center;
  }

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

  .timeline::before {
    left: 20px;
  }

  .timeline-item,
  .timeline-item:nth-child(even) {
    width: 100%;
    left: 0;
    padding-left: 56px;
    padding-right: 0;
    text-align: left;
  }

  .timeline-item:nth-child(odd) {
    padding-right: 0;
    padding-left: 56px;
    text-align: left;
  }

  .timeline-dot,
  .timeline-item:nth-child(odd) .timeline-dot,
  .timeline-item:nth-child(even) .timeline-dot {
    left: 12px;
    right: auto;
  }
}

/* Large Mobile */
@media (max-width: 768px) {
  :root {
    --section-padding: 60px 0;
  }

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

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

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

  .hero {
    min-height: auto;
    padding-top: 72px;
    padding-bottom: 40px;
  }

  .hero .container {
    gap: 20px;
  }

  .hero-image-wrapper {
    width: 160px;
    height: 160px;
  }

  .hero-name {
    font-size: 2rem;
  }

  .hero-title {
    font-size: 1.15rem;
    margin-bottom: 12px;
  }

  .hero-description {
    font-size: 0.95rem;
    margin-bottom: 24px;
    line-height: 1.7;
  }

  .hero::before {
    width: 400px;
    height: 400px;
  }

  .about-image img {
    height: 220px;
  }

  .about-content h3 {
    font-size: 1.25rem;
  }

  .about-text {
    font-size: 0.95rem;
    margin-bottom: 16px;
  }

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

  .skill-category {
    padding: 24px 20px;
  }

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

  .project-description {
    font-size: 0.9rem;
  }

  .timeline-card {
    padding: 20px;
  }

  .timeline-position {
    font-size: 1rem;
  }

  .timeline-description {
    font-size: 0.9rem;
  }

  .certificates-grid {
    grid-template-columns: 1fr;
    max-width: 400px;
  }

  .contact-info h3 {
    font-size: 1.25rem;
  }

  .contact-form {
    padding: 24px;
  }

  .footer-content {
    flex-direction: column;
    gap: 20px;
  }
}

/* Small Mobile */
@media (max-width: 576px) {
  :root {
    --section-padding: 48px 0;
    --container-padding: 0 16px;
  }

  .navbar {
    height: 64px;
  }

  .nav-links {
    top: 64px;
  }

  html {
    scroll-padding-top: 64px;
  }

  .hero {
    padding-top: 64px;
    padding-bottom: 32px;
  }

  .hero .container {
    gap: 16px;
  }

  .hero-image-wrapper {
    width: 130px;
    height: 130px;
    border-radius: var(--radius-lg);
  }

  .hero-name {
    font-size: 1.75rem;
  }

  .hero-title {
    font-size: 1.05rem;
  }

  .hero-description {
    font-size: 0.9rem;
    margin-bottom: 20px;
  }

  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }

  .btn {
    width: 100%;
    justify-content: center;
    padding: 12px 24px;
    font-size: 0.9rem;
  }

  .about-image img {
    height: 180px;
  }

  .about-details {
    grid-template-columns: 1fr;
  }

  .stat-card {
    padding: 14px 18px;
  }

  .stat-number {
    font-size: 1.5rem;
  }

  .timeline-item,
  .timeline-item:nth-child(even),
  .timeline-item:nth-child(odd) {
    padding-left: 44px;
  }

  .timeline::before {
    left: 14px;
  }

  .timeline-dot,
  .timeline-item:nth-child(odd) .timeline-dot,
  .timeline-item:nth-child(even) .timeline-dot {
    left: 6px;
    width: 16px;
    height: 16px;
  }

  .timeline-card {
    padding: 16px;
  }

  .contact-link {
    padding: 14px 16px;
  }

  .contact-form {
    padding: 20px;
  }

  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 42px;
    height: 42px;
  }

  .modal-close {
    top: -12px;
    right: -6px;
    width: 36px;
    height: 36px;
  }

  .lang-switch {
    display: none;
  }
}

/* ============================================
   16. PRINT STYLES
   ============================================ */
@media print {
  .navbar,
  .back-to-top,
  .modal-overlay,
  .theme-toggle,
  .lang-switch,
  .mobile-menu-btn {
    display: none !important;
  }

  body {
    color: #000;
    background: #fff;
  }

  .section {
    padding: 32px 0;
    page-break-inside: avoid;
  }
}