/* ============================================
   Praveen Kumar Kancharla - Personal Website
   Clean, modern light theme for readability
   ============================================ */

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

:root {
  --color-bg: #faf9f6;
  --color-surface: #f2f0eb;
  --color-surface-2: #eae7e0;
  --color-border: #d8d4cc;
  --color-text: #1a1a1a;
  --color-text-muted: #555555;
  --color-text-dim: #888888;
  --color-accent: #1a1a1a;
  --color-accent-soft: rgba(26, 26, 26, 0.06);
  --color-accent-hover: #333333;
  --color-green: #059669;
  --color-amber: #d97706;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --max-width: 1200px;
  --section-pad: 80px;
  --transition: 0.3s ease;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

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

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

/* --- Navigation --- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 20px 0;
  transition: all var(--transition);
  background: transparent;
}

.navbar.scrolled {
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  padding: 12px 0;
  border-bottom: 1px solid var(--color-border);
}

.nav-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.02em;
  padding: 6px 14px;
  border: 2px solid var(--color-accent);
  border-radius: 8px;
  transition: all var(--transition);
}

.nav-logo:hover {
  background: var(--color-accent);
  color: var(--color-bg);
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 8px;
}

.nav-links a {
  color: var(--color-text-muted);
  font-size: 0.875rem;
  font-weight: 500;
  padding: 8px 16px;
  border-radius: 6px;
  transition: all var(--transition);
}

.nav-links a:hover {
  color: var(--color-text);
  background: var(--color-surface-2);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  transition: all var(--transition);
}

/* --- Hero Section --- */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 120px 24px 80px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(26, 26, 26, 0.02) 0%, transparent 70%);
  pointer-events: none;
}

.hero-content {
  max-width: var(--max-width);
  margin: 0 auto;
  width: 100%;
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 80px;
  align-items: center;
}

.hero-greeting {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--color-accent);
  margin-bottom: 16px;
  letter-spacing: 0.05em;
}

.hero-name {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
  color: var(--color-text);
}

.hero-title {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: 12px;
}

.hero-subtitle {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: 36px;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  padding: 14px 28px;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  font-family: var(--font-body);
  cursor: pointer;
  transition: all var(--transition);
  border: none;
}

.btn-primary {
  background: var(--color-accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--color-accent-hover);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(26, 26, 26, 0.15);
}

.btn-outline {
  background: transparent;
  color: var(--color-text);
  border: 1.5px solid var(--color-border);
}

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

/* Hero Photo */
.hero-photo {
  display: flex;
  justify-content: center;
  margin-bottom: 24px;
}

.hero-photo img {
  width: 100%;
  max-width: 280px;
  height: auto;
  border-radius: 16px;
  object-fit: contain;
  border: 3px solid var(--color-accent);
  box-shadow: 0 8px 32px rgba(26, 26, 26, 0.08);
  transition: all var(--transition);
}

.hero-photo img:hover {
  transform: scale(1.02);
  box-shadow: 0 12px 40px rgba(26, 26, 26, 0.12);
}

/* Hero Stats */
.hero-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.stat-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 28px 24px;
  text-align: center;
  transition: all var(--transition);
}

.stat-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.08);
}

.stat-number {
  display: block;
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-accent);
  letter-spacing: -0.02em;
}

.stat-label {
  display: block;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-top: 4px;
}

/* Scroll Indicator */
.scroll-indicator {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--color-text-dim);
  font-size: 0.75rem;
  font-family: var(--font-mono);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  animation: fadeInUp 2s ease infinite;
}

.scroll-line {
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, var(--color-text-dim), transparent);
}

@keyframes fadeInUp {
  0%, 100% { opacity: 0.4; transform: translateX(-50%) translateY(0); }
  50% { opacity: 1; transform: translateX(-50%) translateY(8px); }
}

/* --- Section Styles --- */
.section {
  padding: var(--section-pad) 0;
}

.section-title {
  font-size: clamp(1.8rem, 3vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 16px;
  text-align: center;
}

.section-subtitle {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  text-align: center;
  max-width: 600px;
  margin: 0 auto 60px;
  line-height: 1.7;
}

/* --- About Section --- */
.about {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.about-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 80px;
  margin-top: 60px;
}

.about-lead {
  font-size: 1.15rem;
  color: var(--color-text);
  line-height: 1.8;
  margin-bottom: 20px;
  font-weight: 400;
}

.about-story p {
  color: var(--color-text-muted);
  margin-bottom: 16px;
  line-height: 1.8;
}

.about-timeline h3 {
  font-size: 1rem;
  color: var(--color-text-muted);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 32px;
}

/* Timeline */
.timeline {
  position: relative;
  padding-left: 28px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--color-border);
}

.timeline-item {
  position: relative;
  margin-bottom: 32px;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -33px;
  top: 6px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-border);
  border: 2px solid var(--color-bg);
}

.timeline-item.active::before {
  background: var(--color-accent);
  box-shadow: 0 0 0 4px var(--color-accent-soft);
}

.timeline-year {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-accent);
  font-weight: 500;
}

.timeline-content h4 {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-text);
  margin: 4px 0 2px;
}

.timeline-content p {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-bottom: 0;
}

/* --- What I Work On Section --- */
.work-on-intro {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  line-height: 1.8;
  max-width: 800px;
  margin: 0 auto 32px;
  text-align: center;
}

.work-on-list {
  max-width: 800px;
  margin: 0 auto;
  list-style: none;
  padding: 0;
}

.work-on-list li {
  font-size: 0.95rem;
  color: var(--color-text-muted);
  line-height: 1.8;
  padding: 12px 0;
  border-bottom: 1px solid var(--color-border);
}

.work-on-list li:last-child {
  border-bottom: none;
}

.work-on-list li strong {
  color: var(--color-text);
  font-weight: 600;
}

/* --- Deliverables Section --- */
.role-details {
  margin-bottom: 8px;
  border: 1px solid var(--color-border);
  border-radius: 12px;
  overflow: hidden;
}

.role-details[open] {
  margin-bottom: 24px;
}

.role-details summary {
  cursor: pointer;
  list-style: none;
}

.role-details summary::-webkit-details-marker {
  display: none;
}

.role-details summary::after {
  content: '+';
  float: right;
  font-size: 1.2rem;
  font-weight: 300;
  color: var(--color-text-muted);
  transition: transform var(--transition);
}

.role-details[open] summary::after {
  content: '-';
}

.role-heading {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--color-text);
  margin: 0;
  padding: 16px 20px;
  border-bottom: none;
  letter-spacing: -0.01em;
  background: var(--color-surface);
  transition: background var(--transition);
}

.role-heading:hover {
  background: var(--color-surface-2);
}

.role-period {
  font-size: 0.85rem;
  font-weight: 400;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
}

.deliverables-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.deliverable-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 16px;
  padding: 32px;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.deliverable-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: transparent;
  transition: background var(--transition);
}

.deliverable-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-4px);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.08);
}

.deliverable-card:hover::before {
  background: var(--color-accent);
}

.deliverable-card.featured {
  grid-column: span 2;
  background: linear-gradient(135deg, var(--color-surface) 0%, var(--color-surface-2) 100%);
}

.deliverable-card.featured::before {
  background: var(--color-accent);
}

.card-icon {
  width: 44px;
  height: 44px;
  background: var(--color-accent-soft);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}

.card-icon svg {
  width: 22px;
  height: 22px;
  color: var(--color-accent);
}

.deliverable-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 12px;
  letter-spacing: -0.01em;
}

.deliverable-card p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: 20px;
}

.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.card-tags span {
  font-size: 0.75rem;
  font-family: var(--font-mono);
  color: var(--color-accent);
  background: var(--color-accent-soft);
  padding: 4px 10px;
  border-radius: 6px;
  font-weight: 500;
}

/* --- Skills Section --- */
.skills {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 40px;
  margin-top: 60px;
}

.skill-category h3 {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 16px;
}

.skill-items {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.skill-chip {
  display: inline-block;
  font-size: 0.85rem;
  color: var(--color-text);
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  padding: 6px 14px;
  border-radius: 20px;
  transition: all var(--transition);
}

.skill-chip:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: var(--color-accent-soft);
}

/* --- Passions Section --- */
.passions-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 60px;
}

.passion-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 16px;
  padding: 36px 28px;
  transition: all var(--transition);
}

.passion-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-4px);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.08);
}

.passion-icon {
  width: 48px;
  height: 48px;
  background: var(--color-accent-soft);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}

.passion-icon svg {
  width: 24px;
  height: 24px;
  color: var(--color-accent);
}

.passion-card h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.passion-card p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* --- Impact Section --- */
.impact {
  background: var(--color-bg);
}

.impact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 24px;
  margin-top: 60px;
}

.impact-item {
  text-align: center;
  padding: 32px 12px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  transition: all var(--transition);
}

.impact-item:hover {
  border-color: var(--color-accent);
  transform: translateY(-4px);
}

.impact-number {
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-accent);
  letter-spacing: -0.02em;
}

.impact-suffix {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--color-accent);
}

.impact-label {
  display: block;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-top: 8px;
  line-height: 1.4;
}

/* --- Contact Section --- */
.contact {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 60px;
}

.contact-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: 16px;
  padding: 40px 28px;
  transition: all var(--transition);
  text-decoration: none;
}

.contact-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-4px);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.08);
}

.contact-card svg {
  width: 32px;
  height: 32px;
  color: var(--color-accent);
  margin-bottom: 16px;
}

.contact-label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 4px;
}

.contact-value {
  font-size: 0.95rem;
  color: var(--color-text);
  font-weight: 500;
}

/* --- Footer --- */
.footer {
  padding: 40px 0;
  text-align: center;
  border-top: 1px solid var(--color-border);
}

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

.footer-quote {
  font-style: italic;
  color: var(--color-text-muted);
  margin-top: 8px;
  font-size: 0.85rem;
}

/* --- Animations --- */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* --- Responsive --- */
@media (max-width: 1024px) {
  .hero-content {
    grid-template-columns: 1fr;
    gap: 60px;
  }

  .hero-stats {
    max-width: 400px;
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: 60px;
  }

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

  .deliverable-card.featured {
    grid-column: span 2;
  }

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

  .impact-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 768px) {
  :root {
    --section-pad: 60px;
  }

  .nav-links {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.98);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 16px;
    z-index: 999;
  }

  .nav-links.active {
    display: flex;
  }

  .nav-links a {
    font-size: 1.2rem;
    padding: 12px 24px;
  }

  .nav-toggle {
    display: flex;
    z-index: 1001;
  }

  .hero {
    padding: 100px 24px 60px;
  }

  .hero-name {
    font-size: 2.2rem;
  }

  .hero-cta {
    flex-direction: column;
  }

  .btn {
    text-align: center;
    justify-content: center;
  }

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

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

  .deliverable-card.featured {
    grid-column: span 1;
  }

  .skills-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

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

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

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

  .scroll-indicator {
    display: none;
  }
}

@media (max-width: 480px) {
  .hero-stats {
    grid-template-columns: 1fr 1fr;
    gap: 12px;
  }

  .stat-card {
    padding: 20px 16px;
  }

  .impact-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }

  .impact-item {
    padding: 24px 8px;
  }

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