/* ==========================================================================
   Static Site — Design System
   ========================================================================== */

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

/* --------------------------------------------------------------------------
   CSS Variables
   -------------------------------------------------------------------------- */
:root {
  --bg: #0e0e0e;
  --bg-surface: #161616;
  --bg-raised: #1f1f1f;
  --border: #2a2a2a;
  --text: #e8e8e8;
  --text-muted: #6b6b6b;
  --accent: #c8ff00;
  --danger: #ff4444;

  --font-display: 'IBM Plex Mono', monospace;
  --font-body: 'DM Sans', sans-serif;

  --max-width: 720px;
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
}

/* --------------------------------------------------------------------------
   Base
   -------------------------------------------------------------------------- */
html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background-color: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 500;
  line-height: 1.3;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 1.75rem; }
h3 { font-size: 1.25rem; }

@media (min-width: 640px) {
  h1 { font-size: 3rem; }
  h2 { font-size: 2rem; }
  h3 { font-size: 1.5rem; }
}

a {
  color: var(--text);
  text-decoration: none;
  transition: color 0.2s ease;
}

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

p {
  margin-bottom: var(--spacing-sm);
}

ul, ol {
  padding-left: var(--spacing-md);
}

li {
  margin-bottom: var(--spacing-xs);
}

/* --------------------------------------------------------------------------
   Layout
   -------------------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.page {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main {
  flex: 1;
  padding: var(--spacing-xl) 0;
}

/* --------------------------------------------------------------------------
   Skip Link (Accessibility)
   -------------------------------------------------------------------------- */
.skip-link {
  position: absolute;
  top: -100%;
  left: 0;
  background: var(--accent);
  color: var(--bg);
  padding: var(--spacing-xs) var(--spacing-sm);
  z-index: 1000;
  font-family: var(--font-display);
  font-size: 0.875rem;
}

.skip-link:focus {
  top: 0;
}

/* --------------------------------------------------------------------------
   Navigation
   -------------------------------------------------------------------------- */
.nav {
  padding: var(--spacing-md) 0;
  border-bottom: 1px solid var(--border);
}

.nav__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

.nav__logo {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 500;
  color: var(--text);
}

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

.nav__links {
  display: flex;
  gap: var(--spacing-md);
  list-style: none;
  padding: 0;
  margin: 0;
}

.nav__link {
  font-family: var(--font-display);
  font-size: 0.875rem;
  color: var(--text-muted);
  padding: 0.25rem 0;
  position: relative;
  transition: color 0.2s ease;
}

.nav__link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--accent);
  transition: width 0.2s ease;
}

.nav__link:hover::after,
.nav__link--active::after {
  width: 100%;
}

.nav__link:hover,
.nav__link--active {
  color: var(--accent);
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
.footer {
  padding: var(--spacing-lg) 0;
  border-top: 1px solid var(--border);
}

.footer__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

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

.footer__links {
  display: flex;
  gap: var(--spacing-md);
}

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

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

/* --------------------------------------------------------------------------
   Contact
   -------------------------------------------------------------------------- */
.contact-links {
  display: grid;
  gap: var(--spacing-md);
}

.contact-link {
  font-family: var(--font-display);
  font-size: 1rem;
  color: var(--accent);
  transition: color 0.2s ease;
}

.contact-link:hover {
  color: var(--text);
}

/* --------------------------------------------------------------------------
   Project Cards (GitHub style)
   -------------------------------------------------------------------------- */
.project-card {
  display: block;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  padding: var(--spacing-md);
  margin-bottom: var(--spacing-md);
  transition: border-color 0.2s ease, background-color 0.2s ease, transform 0.2s ease;
  text-decoration: none;
}

.project-card:hover {
  border-color: var(--accent);
  background: var(--bg-raised);
  transform: translateY(-2px);
}

.project-card__header {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-sm);
}

.project-card__icon {
  color: var(--text-muted);
  flex-shrink: 0;
}

.project-card:hover .project-card__icon {
  color: var(--accent);
}

.project-card__title {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 500;
  color: var(--accent);
  margin: 0;
  transition: color 0.2s ease;
}

.project-card__subtitle {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin: 0;
}

.project-card__description {
  color: var(--text-muted);
  font-size: 0.9375rem;
  margin-bottom: var(--spacing-md);
}

.project-card__footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

.project-card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
}

.project-card__link-text {
  font-family: var(--font-display);
  font-size: 0.875rem;
  color: var(--text-muted);
  transition: color 0.2s ease;
}

.project-card:hover .project-card__link-text {
  color: var(--accent);
}

/* --------------------------------------------------------------------------
   Blog Post List
   -------------------------------------------------------------------------- */
.blog-post {
  display: block;
  padding: var(--spacing-md);
  margin-bottom: var(--spacing-md);
  border: 1px solid var(--border);
  background: var(--bg-surface);
  text-decoration: none;
  transition: border-color 0.2s ease, background-color 0.2s ease, transform 0.2s ease;
}

.blog-post:hover {
  border-color: var(--accent);
  background: var(--bg-raised);
  transform: translateY(-2px);
}

.blog-post__header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-xs);
}

.blog-post__title {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--text);
  margin: 0;
  transition: color 0.2s ease;
}

.blog-post:hover .blog-post__title {
  color: var(--accent);
}

.blog-post__date {
  font-family: var(--font-display);
  font-size: 0.875rem;
  color: var(--text-muted);
}

.blog-post__excerpt {
  color: var(--text-muted);
  font-size: 0.9375rem;
  margin: 0;
}

/* --------------------------------------------------------------------------
   Article (Individual Blog Post)
   -------------------------------------------------------------------------- */
.article {
  max-width: var(--max-width);
}

.article__header {
  margin-bottom: var(--spacing-xl);
}

.article__back {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: var(--spacing-md);
  transition: color 0.2s ease;
}

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

.article__title {
  font-size: 2.5rem;
  margin-bottom: var(--spacing-sm);
}

@media (min-width: 640px) {
  .article__title {
    font-size: 3rem;
  }
}

.article__meta {
  font-family: var(--font-display);
  font-size: 0.875rem;
  color: var(--text-muted);
  margin: 0;
}

.article__content {
  line-height: 1.8;
}

.article__content h2 {
  margin-top: var(--spacing-xl);
  margin-bottom: var(--spacing-md);
  padding-bottom: var(--spacing-xs);
  border-bottom: 1px solid var(--border);
}

.article__content h3 {
  margin-top: var(--spacing-lg);
  margin-bottom: var(--spacing-sm);
}

.article__content p {
  margin-bottom: var(--spacing-md);
}

.article__content ul,
.article__content ol {
  margin-bottom: var(--spacing-md);
  padding-left: var(--spacing-lg);
}

.article__content li {
  margin-bottom: var(--spacing-xs);
}

.article__content code {
  font-family: var(--font-display);
  font-size: 0.875em;
  background: var(--bg-surface);
  padding: 0.125rem 0.375rem;
  border: 1px solid var(--border);
}

.article__content pre {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  padding: var(--spacing-md);
  overflow-x: auto;
  margin-bottom: var(--spacing-md);
}

.article__content pre code {
  background: none;
  border: none;
  padding: 0;
}

.article__content blockquote {
  border-left: 3px solid var(--accent);
  padding: var(--spacing-sm) var(--spacing-md);
  margin: 0 0 var(--spacing-md) 0;
  background: var(--bg-surface);
  color: var(--text-muted);
  font-size: 0.9375rem;
  line-height: 1.7;
}

/* --------------------------------------------------------------------------
   Hero
   -------------------------------------------------------------------------- */
.hero {
  padding: var(--spacing-2xl) 0;
}

.hero__title {
  margin-bottom: var(--spacing-sm);
  animation: fadeUp 0.6s ease both;
}

.hero__subtitle {
  font-family: var(--font-display);
  font-size: 1.125rem;
  color: var(--accent);
  margin-bottom: var(--spacing-lg);
  animation: fadeUp 0.6s ease 0.1s both;
}

.hero__description {
  color: var(--text-muted);
  max-width: 560px;
  animation: fadeUp 0.6s ease 0.2s both;
}

.hero__cta {
  display: flex;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-lg);
  animation: fadeUp 0.6s ease 0.3s both;
}

/* --------------------------------------------------------------------------
   Section
   -------------------------------------------------------------------------- */
.section {
  margin-bottom: var(--spacing-2xl);
}

.section__title {
  margin-bottom: var(--spacing-lg);
  padding-bottom: var(--spacing-sm);
  border-bottom: 1px solid var(--border);
}

.subsection__title {
  font-family: var(--font-display);
  font-size: 1rem;
  color: var(--text-muted);
  margin-top: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
}

.subsection__title:first-of-type {
  margin-top: 0;
}

/* --------------------------------------------------------------------------
   Cards
   -------------------------------------------------------------------------- */
.card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  padding: var(--spacing-md);
  margin-bottom: var(--spacing-md);
  transition: border-color 0.2s ease, background-color 0.2s ease, transform 0.2s ease;
}

.card:hover {
  border-color: var(--accent);
  background: var(--bg-raised);
  transform: translateY(-2px);
}

.card:hover .card__title {
  color: var(--accent);
}

.card__header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
  margin-bottom: var(--spacing-sm);
}

.card__title {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 500;
  transition: color 0.2s ease;
}

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

.card__meta {
  font-family: var(--font-display);
  font-size: 0.75rem;
  color: var(--text-muted);
}

a.card--link {
  display: block;
  text-decoration: none;
  color: inherit;
}

.card__header-with-logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.card__logo {
  width: 48px;
  height: 48px;
  object-fit: contain;
  flex-shrink: 0;
}

.card__school {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--text);
  margin: 0;
  transition: color 0.2s ease;
}

.card:hover .card__school {
  color: var(--accent);
}

.card__description {
  color: var(--text-muted);
  font-size: 0.9375rem;
}

.card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
  margin-top: var(--spacing-sm);
}

/* --------------------------------------------------------------------------
   Tags
   -------------------------------------------------------------------------- */
.tag {
  font-family: var(--font-display);
  font-size: 0.75rem;
  color: var(--accent);
  background: transparent;
  border: 1px solid var(--border);
  padding: 0.25rem 0.5rem;
  transition: background-color 0.2s ease, border-color 0.2s ease;
}

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

/* --------------------------------------------------------------------------
   Timeline
   -------------------------------------------------------------------------- */
.timeline {
  position: relative;
  padding-left: var(--spacing-md);
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 1px;
  background: var(--border);
}

.timeline__item {
  position: relative;
  margin-bottom: var(--spacing-lg);
}

.timeline__item::before {
  content: '';
  position: absolute;
  left: calc(-1 * var(--spacing-md) - 3px);
  top: 0.5rem;
  width: 7px;
  height: 7px;
  background: var(--accent);
  border-radius: 50%;
}

/* --------------------------------------------------------------------------
   Skills Grid
   -------------------------------------------------------------------------- */
.skills {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--spacing-md);
}

.skills__category {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  padding: var(--spacing-md);
  transition: border-color 0.2s ease, transform 0.2s ease;
}

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

.skills__title {
  font-family: var(--font-display);
  font-size: 0.875rem;
  color: var(--accent);
  margin-bottom: var(--spacing-sm);
}

.skills__list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.skills__item {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: var(--spacing-xs);
}

/* --------------------------------------------------------------------------
   Buttons
   -------------------------------------------------------------------------- */
.btn {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 0.875rem;
  padding: 0.75rem 1.5rem;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text);
  cursor: pointer;
  transition: border-color 0.2s ease, color 0.2s ease;
}

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

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

.btn--primary:hover {
  background: transparent;
  color: var(--accent);
}

/* --------------------------------------------------------------------------
   Empty State
   -------------------------------------------------------------------------- */
.empty-state {
  text-align: center;
  padding: var(--spacing-2xl) var(--spacing-md);
  color: var(--text-muted);
}

.empty-state__title {
  font-family: var(--font-display);
  font-size: 1.25rem;
  margin-bottom: var(--spacing-sm);
  color: var(--text);
}

/* --------------------------------------------------------------------------
   Error Page
   -------------------------------------------------------------------------- */
.error-page {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 60vh;
  text-align: center;
}

.error-page__code {
  font-family: var(--font-display);
  font-size: 6rem;
  color: var(--accent);
  line-height: 1;
  margin-bottom: var(--spacing-sm);
}

.error-page__message {
  font-size: 1.25rem;
  color: var(--text-muted);
  margin-bottom: var(--spacing-lg);
}

/* --------------------------------------------------------------------------
   Animations
   -------------------------------------------------------------------------- */
@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-up {
  animation: fadeUp 0.6s ease both;
}

.fade-up-1 { animation-delay: 0.1s; }
.fade-up-2 { animation-delay: 0.2s; }
.fade-up-3 { animation-delay: 0.3s; }
.fade-up-4 { animation-delay: 0.4s; }
.fade-up-5 { animation-delay: 0.5s; }

/* --------------------------------------------------------------------------
   Utilities
   -------------------------------------------------------------------------- */
.text-muted {
  color: var(--text-muted);
}

.text-accent {
  color: var(--accent);
}

.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }