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

:root {
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --max-width: 1060px;
  --nav-height: 64px;
  --radius: 8px;
  --transition: 0.25s ease;
}

/* ===== Theme Colors ===== */
[data-theme="dark"] {
  --bg: #0f0f0f;
  --bg-alt: #171717;
  --surface: #1e1e1e;
  --border: #2a2a2a;
  --text: #e4e4e7;
  --text-muted: #a1a1aa;
  --heading: #fafafa;
  --accent: #60a5fa;
  --accent-hover: #93c5fd;
  --tag-bg: #1e293b;
  --tag-text: #93c5fd;
  --card-shadow: 0 1px 3px rgba(0,0,0,0.4);
}

[data-theme="light"] {
  --bg: #fafafa;
  --bg-alt: #f4f4f5;
  --surface: #ffffff;
  --border: #e4e4e7;
  --text: #3f3f46;
  --text-muted: #71717a;
  --heading: #18181b;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --tag-bg: #eff6ff;
  --tag-text: #1d4ed8;
  --card-shadow: 0 1px 3px rgba(0,0,0,0.08);
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
}

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 16px;
  transition: background var(--transition), color var(--transition);
}

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

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

h1, h2, h3 {
  color: var(--heading);
  line-height: 1.3;
}

strong {
  color: var(--heading);
}

ul {
  list-style: none;
}

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

/* ===== Navigation ===== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: color-mix(in srgb, var(--bg) 80%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
  transition: background var(--transition), border-color var(--transition);
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--heading);
  letter-spacing: -0.5px;
}

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

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-links a {
  color: var(--text-muted);
  font-size: 0.875rem;
  font-weight: 500;
  transition: color var(--transition);
  position: relative;
}

.nav-links a.active {
  color: var(--heading);
}

.nav-links a.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--accent);
  border-radius: 1px;
}

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

.btn-resume {
  padding: 6px 14px;
  border: 1px solid var(--accent);
  border-radius: var(--radius);
  color: var(--accent) !important;
  font-size: 0.8rem !important;
  font-weight: 600 !important;
  transition: all var(--transition) !important;
}

.btn-resume:hover {
  background: var(--accent);
  color: var(--bg) !important;
}

.download-icon {
  font-size: 0.75rem;
}

/* Theme toggle */
.theme-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: 50%;
  width: 36px;
  height: 36px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: border-color var(--transition);
}

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

.toggle-icon {
  color: var(--text);
}

.toggle-icon::after {
  font-size: 1rem;
}

[data-theme="dark"] .toggle-icon::after {
  content: "\2600"; /* sun */
}

[data-theme="light"] .toggle-icon::after {
  content: "\263D"; /* moon */
}

/* Mobile menu */
.nav-mobile-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

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

@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 24px;
    gap: 20px;
    transform: translateY(-120%);
    opacity: 0;
    transition: transform 0.3s ease, opacity 0.3s ease;
  }

  .nav-links.active {
    transform: translateY(0);
    opacity: 1;
  }

  .nav-mobile-toggle {
    display: flex;
  }
}

/* ===== Hero ===== */
.hero {
  padding-top: calc(var(--nav-height) + 80px);
  padding-bottom: 80px;
}

.hero-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 48px;
}

.hero-text {
  flex: 1;
}

.hero-photo {
  flex-shrink: 0;
}

.hero-photo img {
  width: 280px;
  height: 280px;
  border-radius: 50%;
  object-fit: cover;
  object-position: center 15%;
  border: 3px solid var(--border);
  transition: border-color var(--transition);
}

.hero-photo img:hover {
  border-color: var(--border);
}

@media (max-width: 640px) {
  .hero-container {
    flex-direction: column-reverse;
    text-align: center;
  }

  .hero-photo img {
    width: 160px;
    height: 160px;
  }

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

.hero-greeting {
  font-size: 1rem;
  color: var(--accent);
  font-weight: 500;
  margin-bottom: 8px;
}

.hero-name {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  letter-spacing: -1.5px;
  margin-bottom: 12px;
}

.hero-tagline {
  font-size: 1.25rem;
  color: var(--text-muted);
  font-weight: 400;
  margin-bottom: 20px;
}

.hero-sub {
  font-size: 1.05rem;
  color: var(--text);
  max-width: 540px;
  margin-bottom: 32px;
}

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

.hero-link {
  padding: 10px 22px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font-size: 0.9rem;
  font-weight: 500;
  transition: all var(--transition);
}

.hero-link:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ===== Sections ===== */
.section {
  padding: 80px 0;
}

.section-alt {
  background: var(--bg-alt);
  transition: background var(--transition);
}

.section-title {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 40px;
  letter-spacing: -0.5px;
}

.section-title::after {
  content: '';
  display: block;
  width: 40px;
  height: 3px;
  background: var(--accent);
  margin-top: 12px;
  border-radius: 2px;
}

/* ===== About ===== */
.about-content p {
  margin-bottom: 16px;
  font-size: 1rem;
}

.about-content p:last-child {
  margin-bottom: 0;
}

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

.timeline::before {
  content: '';
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--border);
}

.timeline-item {
  position: relative;
  margin-bottom: 40px;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-marker {
  position: absolute;
  left: -28px;
  top: 8px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg);
  z-index: 1;
}

.section-alt .timeline-marker {
  border-color: var(--bg-alt);
}

.timeline-content {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--card-shadow);
  transition: background var(--transition), border-color var(--transition);
  position: relative;
  overflow: hidden;
}

.timeline-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}

.timeline-header h3 {
  font-size: 1.1rem;
  font-weight: 600;
}

.timeline-company {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-top: 2px;
}

.timeline-date {
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 600;
  white-space: nowrap;
  font-family: var(--font-mono);
}

.timeline-content ul {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.timeline-content li {
  font-size: 0.925rem;
  color: var(--text);
  padding-left: 16px;
  position: relative;
}

.timeline-content li::before {
  content: '\2013';
  position: absolute;
  left: 0;
  color: var(--text-muted);
}

/* ===== Skills ===== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 28px;
}

.skill-group h3 {
  font-size: 0.9rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-muted);
  margin-bottom: 12px;
}

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

.tag {
  background: var(--tag-bg);
  color: var(--tag-text);
  padding: 5px 12px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 500;
  transition: background var(--transition), color var(--transition);
}

/* ===== Awards ===== */
.awards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.award-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--card-shadow);
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.award-card:hover {
  transform: translateY(-2px);
}

[data-theme="dark"] .award-card:hover {
  border-color: var(--accent);
}

.award-icon {
  font-size: 1.75rem;
  margin-bottom: 12px;
}

.award-card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 6px;
}

.award-card p {
  color: var(--text-muted);
  font-size: 0.875rem;
}

/* ===== Education ===== */
.education-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--card-shadow);
  transition: background var(--transition), border-color var(--transition);
}

.education-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
  margin-bottom: 12px;
  flex-wrap: wrap;
}

.education-header h3 {
  font-size: 1.2rem;
  font-weight: 600;
}

.education-sub {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-top: 2px;
}

.education-card p {
  margin-bottom: 4px;
  font-size: 0.95rem;
}

/* ===== Contact ===== */
.contact-text {
  font-size: 1.05rem;
  color: var(--text-muted);
  margin-bottom: 28px;
  max-width: 480px;
}

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

.contact-link {
  padding: 12px 24px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-weight: 500;
  font-size: 0.95rem;
  transition: all var(--transition);
}

.contact-link:hover {
  border-color: var(--accent);
  background: var(--accent);
  color: var(--bg);
}

/* ===== Footer ===== */
.footer {
  border-top: 1px solid var(--border);
  padding: 24px 0;
  text-align: center;
  transition: border-color var(--transition);
}

.footer p {
  color: var(--text-muted);
  font-size: 0.8rem;
}

/* ===== Scroll Animations ===== */
.timeline-item,
.skill-group,
.award-card,
.education-card,
.about-content {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.timeline-item.visible,
.skill-group.visible,
.award-card.visible,
.education-card.visible,
.about-content.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger animation for timeline items */
.timeline-item:nth-child(2).visible { transition-delay: 0.1s; }
.timeline-item:nth-child(3).visible { transition-delay: 0.2s; }
.timeline-item:nth-child(4).visible { transition-delay: 0.3s; }

.skill-group:nth-child(2).visible { transition-delay: 0.1s; }
.skill-group:nth-child(3).visible { transition-delay: 0.1s; }
.skill-group:nth-child(4).visible { transition-delay: 0.15s; }

.award-card:nth-child(2).visible { transition-delay: 0.1s; }
.award-card:nth-child(3).visible { transition-delay: 0.2s; }

/* ===== Responsive ===== */
@media (max-width: 640px) {
  .hero {
    padding-top: calc(var(--nav-height) + 48px);
    padding-bottom: 48px;
  }

  .section {
    padding: 56px 0;
  }

  .timeline-header {
    flex-direction: column;
    gap: 4px;
  }

  .education-header {
    flex-direction: column;
    gap: 4px;
  }

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

/* ===== Typewriter ===== */
.terminal-prompt {
  color: var(--accent);
  font-family: var(--font-mono);
  margin-right: 4px;
}

.typewriter {
  color: var(--accent);
  font-weight: 700;
}

.typewriter-cursor {
  color: var(--accent);
  font-weight: 300;
  animation: blink 0.8s step-end infinite;
}

@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

/* ===== Card Glow ===== */
.card-glow {
  position: absolute;
  width: 250px;
  height: 250px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--accent) 0%, transparent 70%);
  opacity: 0;
  pointer-events: none;
  transform: translate(-50%, -50%);
  transition: opacity 0.3s ease;
  z-index: 0;
}

[data-theme="dark"] .card-glow {
  opacity: 0.06;
}

[data-theme="light"] .card-glow {
  opacity: 0.08;
}

.timeline-content > *:not(.card-glow),
.award-card > *:not(.card-glow) {
  position: relative;
  z-index: 1;
}