/* Professional Portfolio - Main Styles */
:root {
  --primary: #0A192F;
  --secondary: #3b82f6;
  --accent: #64FFDA;
  --text-dark: #1f2937;
  --text-medium: #4b5563;
  --white: #ffffff;
  --background: #F8F9FA;
  --card-bg: #ffffff;
  --border-color: #e5e7eb;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
  --gradient-secondary: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
  --gradient-accent: linear-gradient(135deg, #64FFDA 0%, #00D9B5 100%);
  --border-radius: 12px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body.dark-mode {
  /* Higher-contrast dark theme: brighter body text and clearer borders */
  --primary: #061321;            /* deep navy for primary surfaces */
  --secondary: #3b82f6;         /* keep blue accent */
  --accent: #64FFDA;            /* bright teal accent preserved */
  --text-dark: #ffffff;         /* maximum contrast for body text */
  --text-medium: #cbd5e1;       /* lighter secondary text for clarity */
  --white: #ffffff;             /* white remains white */
  --background: #04060a;        /* near-black background for max contrast */
  --card-bg: #071526;           /* slightly lighter card surface */
  --border-color: rgba(255,255,255,0.12); /* stronger subtle borders */
  /* adjusted shadows for dark surfaces */
  --shadow: 0 8px 22px rgba(2,6,23,0.72);
  --shadow-lg: 0 14px 36px rgba(2,6,23,0.72);
  --shadow-xl: 0 24px 48px rgba(2,6,23,0.78);
  /* keep gradients but tuned for dark backgrounds */
  --gradient-secondary: linear-gradient(135deg, #1e90ff 0%, #2563eb 100%);
  --gradient-accent: linear-gradient(135deg, #64FFDA 0%, #00D9B5 100%);
}

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

body {
  font-family: 'Poppins', sans-serif;
  background: var(--background);
  color: var(--text-dark);
  line-height: 1.7;
  overflow-x: hidden;
  transition: background-color 0.3s ease;
}

#loader {
  position: fixed;
  inset: 0;
  background: var(--background);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
}

.spinner {
  width: 60px;
  height: 60px;
  border: 4px solid var(--border-color);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

header {
  background: var(--card-bg);
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.header-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 1.25rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

.logo {
  font-size: 1.75rem;
  font-weight: 800;
  background: var(--gradient-accent);
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  cursor: pointer;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-tabs {
  display: flex;
  gap: 0.5rem;
}

.tab-btn {
  padding: 0.75rem 1.5rem;
  background: transparent;
  border: none;
  color: var(--text-medium);
  font-weight: 500;
  cursor: pointer;
  border-radius: 8px;
  transition: var(--transition);
  font-family: inherit;
}

.tab-btn:hover {
  background: rgba(100, 255, 218, 0.1);
  color: var(--accent);
}

.tab-btn.active {
  background: var(--gradient-secondary);
  color: var(--white);
}

.theme-toggle {
  background: var(--card-bg);
  border: 2px solid var(--border-color);
  border-radius: 50px;
  padding: 0.5rem 1rem;
  cursor: pointer;
  transition: var(--transition);
  font-size: 1.1rem;
  color: var(--accent);
}

.theme-toggle:hover {
  border-color: var(--accent);
  transform: scale(1.05);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 1.75rem;
  color: var(--accent);
  cursor: pointer;
}

.tab-content-wrapper {
  max-width: 1400px;
  margin: 0 auto;
  padding: 3rem 2rem;
  min-height: calc(100vh - 200px);
}

.tab-content {
  display: none;
  animation: fadeInUp 0.6s ease;
}

.tab-content.active {
  display: block;
}

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

.home-section {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 4rem;
  align-items: center;
  padding: 2rem 0;
}

.home-text h1 {
  font-size: 3.5rem;
  font-weight: 800;
  margin-bottom: 1rem;
  line-height: 1.2;
}

.home-text .subtitle {
  font-size: 1.5rem;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.home-text .tagline {
  font-size: 1.4rem;
  color: var(--secondary);
  font-weight: 600;
  margin-bottom: 1.5rem;
  min-height: 2rem;
}

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

.btn {
  padding: 1rem 2rem;
  border-radius: var(--border-radius);
  font-weight: 600;
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  border: none;
  cursor: pointer;
}

.btn-primary {
  background: var(--gradient-secondary);
  color: var(--white);
  box-shadow: var(--shadow-lg);
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-xl);
}

.btn-secondary {
  background: transparent;
  color: var(--accent);
  border: 2px solid var(--accent);
}

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

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

.social-links a {
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--card-bg);
  border: 2px solid var(--border-color);
  border-radius: 50%;
  color: var(--text-medium);
  transition: var(--transition);
  font-size: 1.3rem;
}

.social-links a:hover {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-5px);
}

.profile-img {
  width: 100%;
  max-width: 450px;
  height: 450px;
  object-fit: cover;
  border-radius: 20px;
  box-shadow: var(--shadow-xl);
  border: 4px solid var(--accent);
  transition: var(--transition);
}

.profile-img:hover {
  transform: scale(1.02);
}

.section-title {
  font-size: 2.75rem;
  font-weight: 800;
  margin-bottom: 3rem;
  text-align: center;
  position: relative;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -12px;
  left: 50%;
  transform: translateX(-50%);
  width: 80px;
  height: 5px;
  background: var(--gradient-accent);
  border-radius: 3px;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 2rem;
}

.stat-card {
  background: var(--card-bg);
  padding: 2.5rem 2rem;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow);
  text-align: center;
  transition: var(--transition);
  border: 2px solid var(--border-color);
}

.stat-card:hover {
  transform: translateY(-8px);
  border-color: var(--accent);
}

.stat-card h3 {
  font-size: 3rem;
  font-weight: 800;
  background: var(--gradient-secondary);
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 0.75rem;
}

.timeline-item {
  background: var(--card-bg);
  padding: 2.5rem;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow);
  margin-bottom: 2rem;
  border-left: 5px solid var(--accent);
  transition: var(--transition);
}

.timeline-item:hover {
  transform: translateX(8px);
  box-shadow: var(--shadow-lg);
}

.timeline-header {
  display: flex;
  gap: 1.5rem;
  margin-bottom: 1.5rem;
}

.company-logo {
  width: 96px;
  height: 96px;
  object-fit: contain;
  border-radius: 10px;
  background: var(--white);
  padding: 10px;
}

#education .company-logo {
  width: 120px;
  height: 120px;
}

.timeline-date {
  display: inline-block;
  background: var(--gradient-accent);
  color: var(--primary);
  padding: 0.4rem 1rem;
  border-radius: 20px;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.tech-badge {
  background: var(--secondary);
  color: var(--white);
  padding: 0.3rem 0.8rem;
  border-radius: 15px;
  font-size: 0.85rem;
  margin-right: 0.5rem;
  margin-bottom: 0.5rem;
  display: inline-block;
}

.timeline-item li {
  padding-left: 1.75rem;
  margin-bottom: 1rem;
  position: relative;
  color: var(--text-medium);
}

.timeline-item li::before {
  content: '▹';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-size: 1.2rem;
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(380px, 1fr));
  gap: 2.5rem;
}

.project-card {
  background: var(--card-bg);
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  transition: var(--transition);
  border: 2px solid var(--border-color);
}

.project-card:hover {
  transform: translateY(-10px);
  border-color: var(--accent);
}

.project-card img {
  width: 100%;
  height: 240px;
  object-fit: cover;
}

.project-badge {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: var(--gradient-accent);
  color: var(--primary);
  padding: 0.4rem 1rem;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 700;
}

.project-info {
  padding: 2rem;
}

.tag {
  background: linear-gradient(135deg, #3b82f6, #2563eb);
  color: var(--white);
  padding: 0.35rem 0.9rem;
  border-radius: 15px;
  font-size: 0.8rem;
  margin-right: 0.5rem;
  margin-bottom: 0.5rem;
  display: inline-block;
}

.skill-category h3 {
  font-size: 1.8rem;
  margin-bottom: 2rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.skill-category h3 i {
  color: var(--accent);
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 1.5rem;
}

.skill-item {
  background: var(--background);
  padding: 1.75rem 1rem;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow);
  text-align: center;
  transition: var(--transition);
  border: 2px solid var(--border-color);
}

.skill-item:hover {
  transform: translateY(-8px);
  border-color: var(--accent);
}

.skill-icon {
  width: 55px;
  height: 55px;
  margin-bottom: 1rem;
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
}

.contact-form {
  background: var(--card-bg);
  padding: 2.5rem;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-lg);
}

.form-group {
  margin-bottom: 1.75rem;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 1rem;
  border: 2px solid var(--border-color);
  border-radius: var(--border-radius);
  font-family: inherit;
  background: var(--background);
  color: var(--text-dark);
  transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
}

footer {
  background: var(--primary);
  color: var(--white);
  text-align: center;
  padding: 2.5rem;
  margin-top: 5rem;
}

.scroll-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 50px;
  height: 50px;
  background: var(--gradient-accent);
  color: var(--primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition);
  z-index: 999;
}

.scroll-top.show {
  opacity: 1;
  visibility: visible;
}

@media (max-width: 1024px) {
  .home-section,
  .contact-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .nav-tabs {
    display: none;
    position: fixed;
    top: 75px;
    left: 0;
    right: 0;
    background: var(--card-bg);
    flex-direction: column;
    padding: 1rem;
    z-index: 999;
  }
  
  .nav-tabs.mobile-active {
    display: flex;
  }
  
  .mobile-menu-btn {
    display: block;
  }
  
  .tab-btn {
    width: 100%;
    text-align: left;
  }
  
  .home-text h1 {
    font-size: 2.5rem;
  }
  
  .projects-grid {
    grid-template-columns: 1fr;
  }
}