:root {
  --bg-primary: #050510;
  --bg-secondary: #0b0b18;
  --bg-card: #111122;
  --text-primary: #f9fafb;
  --text-secondary: #a5b4fc;
  --accent: #6366f1;
  --accent-soft: rgba(99, 102, 241, 0.18);
  --border: #2d3148;
  --gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 45%, #ec4899 100%);
}

[data-theme="light"] {
  --bg-primary: #ffffff;
  --bg-secondary: #f9fafb;
  --bg-card: #ffffff;
  --text-primary: #111827;
  --text-secondary: #4b5563;
  --accent: #6366f1;
  --accent-soft: rgba(99, 102, 241, 0.12);
  --border: #e5e7eb;
  --gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #ec4899 100%);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: radial-gradient(circle at top, #111827 0, var(--bg-primary) 40%, #020617 100%);
  color: var(--text-primary);
  transition: background 0.3s ease, color 0.3s ease;
}

/* NAVBAR */

.navbar {
  display: flex;
  justify-content: center;
  background: rgba(5, 5, 16, 0.96);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 1000;
}

[data-theme="light"] .navbar {
  background: rgba(249, 250, 251, 0.96);
}

.nav-container {
  width: 100%;
  max-width: 1100px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.8rem 1.5rem;
  gap: 0.75rem;
}

.logo {
  font-size: 1.1rem;
  font-weight: 700;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 0.9rem;
  flex-wrap: wrap;
  justify-content: center;
}

.nav-link {
  text-decoration: none;
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.95rem;
  padding-bottom: 2px;
  transition: color 0.2s ease, border-color 0.2s ease;
  border-bottom: 2px solid transparent;
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
}

.nav-link span.nav-emoji {
  font-size: 1rem;
}

.nav-link.active,
.nav-link:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.theme-toggle {
  cursor: pointer;
  font-size: 1.1rem;
  border: none;
  background: var(--bg-card);
  color: var(--text-primary);
  padding: 0.4rem 0.9rem;
  border-radius: 999px;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
  box-shadow: 0 0 0 1px var(--border);
}

.theme-toggle:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.35);
}

/* LAYOUT */

.main-content {
  padding: 2.2rem 1.6rem 3rem;
  max-width: 1100px;
  margin: 0 auto;
}

.section {
  margin-bottom: 3rem;
  animation: fadeIn 0.25s ease;
}

.section h2 {
  font-size: 2rem;
  margin-bottom: 1.5rem;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.section-subtitle {
  margin-top: -0.25rem;
  margin-bottom: 2.2rem;
  font-size: 0.95rem;
  color: var(--text-secondary);
  text-align: center;
}

/* HERO (HOME) */

.hero {
  text-align: center;
}

.hero-inner {
  display: grid;
  grid-template-columns: minmax(220px, 280px) minmax(260px, 1fr);
  gap: 2.2rem;
  align-items: center;
}

.profile-column {
  text-align: center;
}

.about-column {
  text-align: left;
}

.profile-pic {
  width: 210px;
  height: 210px;
  border-radius: 50%;
  object-fit: cover;
  border: 4px solid transparent;
  background: var(--gradient);
  padding: 4px;
  margin-bottom: 0.9rem;
  box-shadow: 0 18px 55px rgba(15, 23, 42, 0.9);
}

.hero-title {
  font-size: 2.4rem;
  margin: 0;
}

.hero-title span {
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-role {
  font-size: 1rem;
  color: var(--text-secondary);
  margin: 0.3rem 0 1rem;
}

.subtitle {
  color: var(--text-secondary);
  margin-bottom: 1rem;
  line-height: 1.5;
  font-size: 0.98rem;
}

.about-box {
  background: radial-gradient(circle at top left, var(--accent-soft), var(--bg-card));
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.1rem 1.2rem;
  margin: 1.1rem 0 1.4rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* BUTTONS */

.cta-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
}

.btn {
  padding: 0.6rem 1.4rem;
  border-radius: 999px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.25s ease;
  text-decoration: none;
  display: inline-block;
  text-align: center;
  font-size: 0.95rem;
}

.btn-primary {
  background: var(--gradient);
  color: #ffffff;
  border: none;
  box-shadow: 0 10px 25px rgba(99, 102, 241, 0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 30px rgba(99, 102, 241, 0.45);
}

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

.btn-secondary:hover {
  border-color: var(--accent);
  background: var(--accent);
  color: #ffffff;
}

/* TIMELINE (EXPERIENCE) */

.timeline-section {
  text-align: center;
}

.timeline {
  position: relative;
  margin: 2rem 0;
  padding-bottom: 2rem;
}

.timeline-line {
  position: absolute;
  top: 0.5rem;
  bottom: 0;
  left: 50%;
  width: 2px;
  background: var(--border);
}

.timeline-item {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  margin: 2.4rem 0;
}

.timeline-dot {
  position: absolute;
  left: 50%;
  transform: translate(-50%, 0);
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.45);
  font-size: 1rem;
}

.timeline-card {
  background: radial-gradient(circle at top left, var(--accent-soft), var(--bg-card));
  border-radius: 16px;
  border: 1px solid var(--border);
  padding: 1rem 1.2rem;
  max-width: 420px;
  text-align: left;
  box-shadow: 0 18px 45px rgba(0, 0, 0, 0.6);
}

.timeline-item:nth-child(odd) .timeline-card {
  grid-column: 2;
  justify-self: flex-start;
}

.timeline-item:nth-child(even) .timeline-card {
  grid-column: 1;
  justify-self: flex-end;
}

.timeline-date {
  font-size: 0.85rem;
  color: #facc15;
  margin: 0 0 0.3rem;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.timeline-role {
  margin: 0 0 0.1rem;
  font-size: 1.1rem;
}

.timeline-company {
  margin: 0 0 0.6rem;
  font-size: 0.92rem;
  color: var(--text-secondary);
}

.timeline-card ul {
  margin: 0 0 0.6rem;
  padding-left: 1.1rem;
}

.timeline-card li {
  margin-bottom: 0.35rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.timeline-tags {
  margin-top: 0.5rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

/* PROJECTS – STACKED CARDS */

.filter-controls {
  margin-bottom: 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.filter-btn {
  padding: 0.4rem 1rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 0.85rem;
  transition: all 0.25s ease;
}

.filter-btn.active,
.filter-btn:hover {
  background: var(--accent);
  color: #ffffff;
  border-color: var(--accent);
}

.projects-grid {
  display: flex;
  flex-direction: column;
  gap: 1.4rem;
  max-width: 720px;
  margin: 0 auto;
}

.project-card {
  background: radial-gradient(circle at top left, var(--accent-soft), var(--bg-card));
  border-radius: 16px;
  border: 1px solid var(--border);
  text-decoration: none;
  color: inherit;
  padding: 0.9rem;
  transition: all 0.25s ease;
  display: flex;
  flex-direction: column;
}

.project-card:hover {
  transform: translateY(-4px) translateZ(0);
  box-shadow: 0 14px 40px rgba(0, 0, 0, 0.55);
  border-color: var(--accent);
}

.project-thumb {
  width: 100%;
  height: 160px;
  border-radius: 12px;
  margin-bottom: 0.8rem;
  background-color: #020617;
  background-image: radial-gradient(circle at top left, rgba(96, 165, 250, 0.3), rgba(15, 23, 42, 0.9));
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}

.project-info h3 {
  margin: 0 0 0.4rem 0;
  font-size: 1rem;
}

.project-info p {
  margin: 0 0 0.7rem 0;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.project-topics {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.lang-tag {
  background: var(--accent);
  color: #ffffff;
  padding: 0.18rem 0.7rem;
  border-radius: 999px;
  font-size: 0.75rem;
}

.project-topics .lang-tag {
  background: #10b981;
}

/* CONTACT */

.contact-form {
  max-width: 550px;
  margin: 1.5rem 0;
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
}

.contact-form input,
.contact-form textarea {
  padding: 0.9rem;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-primary);
  font-size: 0.95rem;
}

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

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

.about-box a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
}

.about-box a:hover {
  text-decoration: underline;
}

/* EDUCATION */

.education-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.4rem;
}

.education-card {
  background: radial-gradient(circle at top left, var(--accent-soft), var(--bg-card));
  border-radius: 16px;
  border: 1px solid var(--border);
  padding: 1rem 1.2rem;
  color: var(--text-secondary);
  font-size: 0.94rem;
}

.edu-header {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  margin-bottom: 0.6rem;
}

.edu-icon {
  width: 34px;
  height: 34px;
  border-radius: 999px;
  background: var(--gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  color: #ffffff;
  font-weight: 700;
  flex-shrink: 0;
}

.edu-header h3 {
  margin: 0;
  font-size: 1rem;
  color: var(--text-primary);
}

.edu-degree {
  margin: 0.05rem 0;
  font-weight: 500;
}

.edu-meta {
  margin: 0;
  font-size: 0.8rem;
  opacity: 0.85;
}

.edu-description {
  margin: 0.5rem 0;
}

.edu-list {
  margin: 0.4rem 0 0.3rem;
  padding-left: 1.1rem;
}

.edu-list li {
  margin-bottom: 0.2rem;
}

.edu-extra {
  margin-top: 0.4rem;
  font-size: 0.85rem;
  opacity: 0.95;
}

/* LOADING */

.spinner {
  width: 36px;
  height: 36px;
  border-radius: 999px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  animation: spin 1s linear infinite;
  margin: 1rem auto;
}

.loading {
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* ANIMATIONS */

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

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

/* RESPONSIVE */

@media (max-width: 768px) {
  .nav-container {
    flex-wrap: wrap;
    justify-content: center;
  }

  .hero-inner {
    grid-template-columns: 1fr;
  }

  .about-column {
    text-align: center;
  }

  .about-box {
    text-align: left;
  }

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

  /* timeline becomes left-aligned */
  .timeline-line {
    left: 22px;
  }

  .timeline-item {
    grid-template-columns: 1fr;
    margin: 2rem 0;
    padding-left: 2.8rem;
  }

  .timeline-item:nth-child(odd) .timeline-card,
  .timeline-item:nth-child(even) .timeline-card {
    grid-column: 1;
    justify-self: stretch;
  }

  .timeline-dot {
    left: 22px;
  }

  .timeline-card {
    max-width: 100%;
  }
}