/* ==========================================================================
   Design tokens
   ========================================================================== */

:root {
  --color-bg: #0f0f12;
  --color-bg-alt: #16161c;
  --color-bg-card: #1a1a22;
  --color-bg-card-hover: #1f1f28;
  --color-border: #2a2a35;
  --color-border-hover: #3d3d4f;
  --color-text: #e8e8ed;
  --color-text-muted: #9898a8;
  --color-text-subtle: #6b6b7b;
  --color-accent: #7c8aff;
  --color-accent-dim: rgba(124, 138, 255, 0.15);
  --color-accent-glow: rgba(124, 138, 255, 0.25);

  --font-sans: "Inter", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;

  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2.5rem;
  --space-xl: 4rem;
  --space-2xl: 6rem;

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.3);
  --shadow-card-hover: 0 8px 32px rgba(0, 0, 0, 0.45), 0 0 0 1px var(--color-border-hover);

  --header-height: 4rem;
  --container-max: 1100px;

  --transition: 0.2s ease;
  --transition-slow: 0.4s ease;
}

/* ==========================================================================
   Reset & base
   ========================================================================== */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

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

a:hover {
  text-decoration: underline;
}

ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

h1, h2, h3 {
  line-height: 1.2;
  margin: 0;
}

p {
  margin: 0 0 var(--space-sm);
}

p:last-child {
  margin-bottom: 0;
}

strong {
  color: var(--color-text);
  font-weight: 600;
}

/* ==========================================================================
   Utilities
   ========================================================================== */

.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-md);
}

.section {
  padding-block: var(--space-xl);
}

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

.section--contact {
  padding-bottom: var(--space-2xl);
}

.section-heading {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  margin-bottom: var(--space-lg);
  letter-spacing: -0.02em;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-sm);
  z-index: 1000;
  padding: var(--space-xs) var(--space-sm);
  background: var(--color-accent);
  color: var(--color-bg);
  border-radius: var(--radius-sm);
  font-weight: 600;
}

.skip-link:focus {
  top: var(--space-sm);
  outline: 2px solid var(--color-text);
  outline-offset: 2px;
}

/* Scroll reveal */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
  }
}

/* ==========================================================================
   Header & navigation
   ========================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background: rgba(15, 15, 18, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
}

.logo {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: -0.02em;
}

.logo:hover {
  color: var(--color-accent);
  text-decoration: none;
}

.site-nav ul {
  display: flex;
  gap: var(--space-md);
}

.site-nav a {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  transition: color var(--transition);
}

.site-nav a:hover,
.site-nav a:focus-visible {
  color: var(--color-text);
  text-decoration: none;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 2.5rem;
  height: 2.5rem;
  padding: 0;
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
}

.nav-toggle-bar {
  display: block;
  width: 18px;
  height: 2px;
  margin-inline: auto;
  background: var(--color-text);
  border-radius: 1px;
  transition: transform var(--transition), opacity var(--transition);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

@media (max-width: 639px) {
  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: var(--color-bg-alt);
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-sm) var(--space-md) var(--space-md);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: transform var(--transition), opacity var(--transition), visibility var(--transition);
  }

  .site-nav.is-open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .site-nav ul {
    flex-direction: column;
    gap: var(--space-xs);
  }

  .site-nav a {
    display: block;
    padding: var(--space-xs) 0;
    font-size: 1rem;
  }
}

/* ==========================================================================
   Hero
   ========================================================================== */

.hero {
  position: relative;
  padding-block: var(--space-2xl) var(--space-xl);
  overflow: hidden;
  min-height: calc(100vh - var(--header-height));
  min-height: calc(100dvh - var(--header-height));
  display: flex;
  align-items: center;
}

.hero-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
}

.hero-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.4;
}

.hero-orb--1 {
  width: 400px;
  height: 400px;
  top: -100px;
  right: -100px;
  background: radial-gradient(circle, var(--color-accent) 0%, transparent 70%);
}

.hero-orb--2 {
  width: 300px;
  height: 300px;
  bottom: -50px;
  left: -80px;
  background: radial-gradient(circle, #5eead4 0%, transparent 70%);
  opacity: 0.2;
}

.hero-grid {
  position: absolute;
  top: 50%;
  right: -10%;
  width: 500px;
  height: 500px;
  transform: translateY(-50%) rotate(15deg);
  color: var(--color-border);
  opacity: 0.5;
}

.hero-inner {
  position: relative;
  z-index: 1;
}

.hero-content {
  max-width: 640px;
}

.avatar {
  width: 96px;
  height: 96px;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, var(--color-accent-dim), var(--color-bg-card));
  border: 2px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-accent);
  letter-spacing: -0.03em;
  margin-bottom: var(--space-md);
}

img.avatar {
  object-fit: cover;
}

.hero-eyebrow {
  font-size: 0.875rem;
  color: var(--color-text-subtle);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-xs);
}

.hero-content h1 {
  font-size: clamp(2.5rem, 6vw, 3.75rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-xs);
}

.hero-title {
  font-size: clamp(1.125rem, 2.5vw, 1.375rem);
  color: var(--color-accent);
  font-weight: 500;
  margin-bottom: var(--space-sm);
}

.hero-tagline {
  font-size: clamp(1rem, 2vw, 1.125rem);
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: var(--space-lg);
  max-width: 52ch;
}

.hero-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.625rem 1.25rem;
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: background var(--transition), border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
}

.btn:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.btn--primary {
  background: var(--color-accent);
  color: var(--color-bg);
  border-color: var(--color-accent);
}

.btn--primary:hover {
  background: #929dff;
  border-color: #929dff;
  box-shadow: 0 4px 16px var(--color-accent-glow);
}

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

.btn--secondary:hover {
  background: var(--color-bg-card);
  border-color: var(--color-border-hover);
}

.btn--large {
  padding: 0.875rem 1.5rem;
  font-size: 1rem;
}

/* ==========================================================================
   About
   ========================================================================== */

.about-content {
  max-width: 68ch;
}

.about-content p {
  color: var(--color-text-muted);
  font-size: 1.0625rem;
  line-height: 1.75;
  margin-bottom: var(--space-md);
}

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

/* ==========================================================================
   Projects
   ========================================================================== */

.projects-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
}

@media (min-width: 640px) {
  .projects-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .projects-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.project-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition), background var(--transition);
}

.project-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
  border-color: var(--color-border-hover);
  background: var(--color-bg-card-hover);
}

.project-card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-sm);
}

.project-title {
  font-size: 1.125rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.project-link {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  color: var(--color-text-muted);
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
}

.project-link:hover {
  color: var(--color-accent);
  background: var(--color-accent-dim);
  text-decoration: none;
}

.project-badge {
  flex-shrink: 0;
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-subtle);
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-full);
}

.project-desc {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  line-height: 1.65;
  flex: 1;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.375rem;
  margin-top: auto;
  padding-top: var(--space-xs);
}

.tags li {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--color-accent);
  background: var(--color-accent-dim);
  padding: 0.25rem 0.625rem;
  border-radius: var(--radius-full);
}

/* ==========================================================================
   Experience timeline
   ========================================================================== */

.timeline {
  position: relative;
  padding-left: var(--space-lg);
  margin: 0 0 var(--space-lg);
  list-style: none;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--color-border);
}

.timeline-item {
  position: relative;
  padding-bottom: var(--space-lg);
}

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

.timeline-marker {
  position: absolute;
  left: calc(-1 * var(--space-lg) + 2px);
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: var(--radius-full);
  background: var(--color-accent);
  border: 2px solid var(--color-bg);
  box-shadow: 0 0 0 2px var(--color-accent-dim);
}

.timeline-item--secondary .timeline-marker {
  background: var(--color-text-subtle);
  box-shadow: 0 0 0 2px var(--color-border);
}

.timeline-content h3 {
  font-size: 1.0625rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.timeline-role {
  font-size: 0.9375rem;
  color: var(--color-accent);
  font-weight: 500;
  margin-bottom: 0.375rem;
}

.timeline-note {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  line-height: 1.6;
}

.education {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  padding-top: var(--space-md);
  border-top: 1px solid var(--color-border);
}

.education-detail {
  color: var(--color-text-subtle);
}

/* ==========================================================================
   Contact
   ========================================================================== */

.contact-lead {
  font-size: 1.0625rem;
  color: var(--color-text-muted);
  max-width: 52ch;
  margin-bottom: var(--space-lg);
  line-height: 1.7;
}

.contact-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

/* ==========================================================================
   Footer
   ========================================================================== */

.site-footer {
  border-top: 1px solid var(--color-border);
  padding-block: var(--space-md);
}

.site-footer p {
  font-size: 0.8125rem;
  color: var(--color-text-subtle);
  text-align: center;
  margin: 0;
}