/* -------------------------------------------------------------------------- */
/*                               DESIGN TOKENS                                */
/* -------------------------------------------------------------------------- */
:root {
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  
  /* Transition timings */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s cubic-bezier(0.16, 1, 0.3, 1);

  /* Border radius */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;
}

/* Dark Theme (Default) */
html[data-theme="dark"] {
  --bg-primary: #090d16;
  --bg-surface: #101726;
  --bg-surface-elevated: #162033;
  --bg-card: rgba(16, 23, 38, 0.85);
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(255, 255, 255, 0.18);
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --text-subtle: #64748b;
  --accent: #38bdf8;
  --accent-soft: rgba(56, 189, 248, 0.12);
  --accent-glow: rgba(56, 189, 248, 0.25);
  --gradient-text: linear-gradient(135deg, #f8fafc 0%, #cbd5e1 50%, #38bdf8 100%);
  --ambient-bg: radial-gradient(circle at 50% 0%, rgba(56, 189, 248, 0.12) 0%, transparent 65%);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 10px 30px -10px rgba(0, 0, 0, 0.6);
  --bg-header: rgba(9, 13, 22, 0.82);
}

/* Light Theme */
html[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-surface: #ffffff;
  --bg-surface-elevated: #f1f5f9;
  --bg-card: rgba(255, 255, 255, 0.9);
  --border-subtle: rgba(15, 23, 42, 0.08);
  --border-hover: rgba(15, 23, 42, 0.18);
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-subtle: #94a3b8;
  --accent: #0284c7;
  --accent-soft: rgba(2, 132, 199, 0.08);
  --accent-glow: rgba(2, 132, 199, 0.2);
  --gradient-text: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #0284c7 100%);
  --ambient-bg: radial-gradient(circle at 50% 0%, rgba(2, 132, 199, 0.08) 0%, transparent 65%);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 10px 30px -10px rgba(0, 0, 0, 0.08);
  --bg-header: rgba(248, 250, 252, 0.85);
}

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

html {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  scroll-behavior: smooth;
  background-color: var(--bg-primary);
  color: var(--text-main);
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

body {
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* Ambient backdrop */
.ambient-glow {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 500px;
  background: var(--ambient-bg);
  pointer-events: none;
  z-index: 0;
}

.container {
  max-width: 780px;
  margin: 0 auto;
  padding: 0 1.5rem;
  position: relative;
  z-index: 1;
}

/* -------------------------------------------------------------------------- */
/*                               HEADER / NAV                                 */
/* -------------------------------------------------------------------------- */
.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.75rem 0;
  border-bottom: 1px solid var(--border-subtle);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  position: sticky;
  top: 0;
  background: var(--bg-header);
  z-index: 50;
}

.brand-logo {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  color: var(--text-main);
  font-weight: 600;
  font-size: 1.05rem;
  letter-spacing: -0.02em;
}

.logo-dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 10px var(--accent);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-muted);
  font-size: 0.92rem;
  font-weight: 500;
  transition: color var(--transition-fast);
}

.nav-links a:hover {
  color: var(--text-main);
}

.theme-btn {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  padding: 0.45rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.theme-btn:hover {
  color: var(--text-main);
  border-color: var(--border-hover);
  background: var(--bg-surface-elevated);
}

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

/* -------------------------------------------------------------------------- */
/*                               HERO SECTION                                 */
/* -------------------------------------------------------------------------- */
.hero-section {
  padding: 3.5rem 0 2.5rem;
}

.availability-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  background: var(--accent-soft);
  color: var(--accent);
  border: 1px solid rgba(56, 189, 248, 0.2);
  border-radius: var(--radius-full);
  padding: 0.35rem 0.85rem;
  font-size: 0.8rem;
  font-weight: 500;
  margin-bottom: 1.5rem;
}

.status-indicator {
  width: 7px;
  height: 7px;
  background-color: #10b981;
  border-radius: 50%;
  box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.6);
  animation: pulse-ring 2s infinite cubic-bezier(0.45, 0, 0.55, 1);
}

@keyframes pulse-ring {
  0% {
    box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7);
  }
  70% {
    box-shadow: 0 0 0 6px rgba(16, 185, 129, 0);
  }
  100% {
    box-shadow: 0 0 0 0 rgba(16, 185, 129, 0);
  }
}

.hero-title {
  font-size: clamp(2.2rem, 5vw, 3rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 1rem;
}

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

.hero-subtitle {
  font-size: 1.1rem;
  color: var(--text-muted);
  line-height: 1.6;
  max-width: 650px;
  margin-bottom: 1.5rem;
}

.semibold {
  font-weight: 600;
  color: var(--text-main);
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 2rem;
}

.meta-item {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
}

.meta-link {
  color: var(--text-muted);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.meta-link:hover {
  color: var(--accent);
  text-decoration: underline;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  align-items: center;
}

/* -------------------------------------------------------------------------- */
/*                               BUTTONS                                      */
/* -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
  font-weight: 500;
  padding: 0.65rem 1.15rem;
  border-radius: var(--radius-md);
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all var(--transition-fast);
}

.btn-primary {
  background: var(--accent);
  color: #04101d;
  font-weight: 600;
  box-shadow: 0 4px 14px var(--accent-glow);
}

.btn-primary:hover {
  transform: translateY(-1px);
  filter: brightness(1.1);
}

.btn-secondary {
  background: var(--bg-surface);
  border-color: var(--border-subtle);
  color: var(--text-main);
}

.btn-secondary:hover {
  background: var(--bg-surface-elevated);
  border-color: var(--border-hover);
  transform: translateY(-1px);
}

.btn-ghost {
  background: transparent;
  border-color: var(--border-subtle);
  color: var(--text-muted);
}

.btn-ghost:hover {
  color: var(--text-main);
  background: var(--bg-surface);
  border-color: var(--border-hover);
}

/* -------------------------------------------------------------------------- */
/*                               SECTIONS                                     */
/* -------------------------------------------------------------------------- */
.section {
  padding: 2.75rem 0;
  border-top: 1px solid var(--border-subtle);
}

.section-heading {
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 1.5rem;
  color: var(--text-main);
}

.section-header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.5rem;
}

.section-header-row .section-heading {
  margin-bottom: 0;
}

.section-sub-tag {
  font-size: 0.8rem;
  color: var(--text-subtle);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-weight: 600;
}

/* -------------------------------------------------------------------------- */
/*                               CARDS & ABOUT                                */
/* -------------------------------------------------------------------------- */
.card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
}

.about-card p {
  color: var(--text-muted);
  font-size: 0.98rem;
  line-height: 1.7;
  margin-bottom: 1rem;
}

.about-card strong {
  color: var(--text-main);
}

.about-highlights {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 1.25rem;
}

.highlight-chip {
  background: var(--accent-soft);
  color: var(--accent);
  border: 1px solid rgba(56, 189, 248, 0.2);
  border-radius: var(--radius-sm);
  padding: 0.35rem 0.75rem;
  font-size: 0.85rem;
  font-weight: 500;
}

/* -------------------------------------------------------------------------- */
/*                               PROJECTS                                     */
/* -------------------------------------------------------------------------- */
.projects-grid {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.project-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.6rem;
  transition: all var(--transition-normal);
  position: relative;
}

.project-card:hover {
  border-color: var(--border-hover);
  background: var(--bg-surface-elevated);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.project-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 1rem;
}

.project-tag {
  display: inline-block;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.project-title {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text-main);
  margin-bottom: 0.2rem;
}

.project-tagline {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.project-links {
  display: flex;
  gap: 0.5rem;
}

.icon-link {
  color: var(--text-muted);
  padding: 0.4rem;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.icon-link:hover {
  color: var(--text-main);
  background: var(--border-subtle);
}

.project-bullets {
  list-style: none;
  margin-bottom: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}

.project-bullets li {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.55;
  position: relative;
  padding-left: 1.2rem;
}

.project-bullets li::before {
  content: "•";
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: bold;
}

.tech-stack-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.tech-pill {
  font-size: 0.78rem;
  background: var(--bg-primary);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-weight: 500;
}

/* -------------------------------------------------------------------------- */
/*                               SKILLS GRID                                  */
/* -------------------------------------------------------------------------- */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
}

.skill-category-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.35rem;
  transition: border-color var(--transition-fast);
}

.skill-category-card:hover {
  border-color: var(--border-hover);
}

.skill-category-title {
  font-size: 0.98rem;
  font-weight: 600;
  margin-bottom: 0.85rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-main);
}

.skill-icon {
  font-size: 1.05rem;
}

.skill-badge-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.skill-badge {
  font-size: 0.82rem;
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  padding: 0.3rem 0.7rem;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.skill-badge:hover {
  color: var(--text-main);
  border-color: var(--accent);
}

/* -------------------------------------------------------------------------- */
/*                               EDUCATION TIMELINE                           */
/* -------------------------------------------------------------------------- */
.timeline {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  margin-bottom: 2.5rem;
  position: relative;
}

.timeline::before {
  content: "";
  position: absolute;
  top: 10px;
  bottom: 10px;
  left: 6px;
  width: 2px;
  background: var(--border-subtle);
}

.timeline-item {
  position: relative;
  padding-left: 2rem;
}

.timeline-marker {
  position: absolute;
  top: 6px;
  left: 2px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 4px var(--bg-primary);
}

.timeline-header {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.15rem 1.25rem;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1rem;
}

.timeline-title {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 0.25rem;
}

.timeline-subtitle {
  font-size: 0.88rem;
  color: var(--text-muted);
}

.timeline-badge-wrap {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 0.35rem;
  white-space: nowrap;
}

.timeline-period {
  font-size: 0.82rem;
  color: var(--text-subtle);
  font-weight: 500;
}

.score-badge {
  font-size: 0.78rem;
  font-weight: 600;
  background: var(--accent-soft);
  color: var(--accent);
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(56, 189, 248, 0.2);
}

/* -------------------------------------------------------------------------- */
/*                               CERTIFICATIONS                               */
/* -------------------------------------------------------------------------- */
.sub-heading {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 1rem;
}

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

.cert-card {
  display: flex;
  align-items: center;
  gap: 1rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  transition: border-color var(--transition-fast);
}

.cert-card:hover {
  border-color: var(--border-hover);
}

.cert-icon {
  font-size: 1.5rem;
}

.cert-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 0.15rem;
}

.cert-issuer {
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* -------------------------------------------------------------------------- */
/*                               CONTACT BOX                                  */
/* -------------------------------------------------------------------------- */
.contact-box {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 2.25rem 2rem;
  text-align: center;
}

.contact-box h2 {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.75rem;
  color: var(--text-main);
}

.contact-box p {
  color: var(--text-muted);
  max-width: 500px;
  margin: 0 auto 1.5rem;
  font-size: 0.95rem;
}

.contact-cta-row {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

/* -------------------------------------------------------------------------- */
/*                               FOOTER                                       */
/* -------------------------------------------------------------------------- */
.site-footer {
  padding: 2.5rem 0 3.5rem;
  border-top: 1px solid var(--border-subtle);
  margin-top: 2rem;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.85rem;
  color: var(--text-subtle);
}

.footer-links {
  display: flex;
  gap: 1.25rem;
}

.footer-links a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--accent);
}

/* -------------------------------------------------------------------------- */
/*                               TOAST NOTIFICATION                           */
/* -------------------------------------------------------------------------- */
.toast {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--text-main);
  color: var(--bg-primary);
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 500;
  box-shadow: var(--shadow-md);
  opacity: 0;
  pointer-events: none;
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.3s ease;
  z-index: 100;
}

.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

/* -------------------------------------------------------------------------- */
/*                               RESPONSIVENESS                               */
/* -------------------------------------------------------------------------- */
@media (max-width: 640px) {
  .site-header {
    padding: 1.25rem 0;
  }

  .nav-links {
    gap: 0.85rem;
  }

  .nav-links a {
    font-size: 0.85rem;
  }

  .hero-section {
    padding: 2.5rem 0 2rem;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .hero-actions .btn {
    justify-content: center;
  }

  .timeline-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .timeline-badge-wrap {
    align-items: flex-start;
  }

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