/* ========================================
   Portfolio Site - Global Styles
   Minimalist black & white design
   ======================================== */

/* CSS Variables for consistent theming */
:root {
  --color-background: #ffffff;
  --color-foreground: #000000;
  --color-gray-100: #f7f7f7;
  --color-gray-200: #e5e5e5;
  --color-gray-400: #a3a3a3;
  --color-gray-600: #525252;
  
  --font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  
  --border-radius: 9999px;
  --transition-default: all 0.2s ease;
  
  --max-width-content: 700px;
}

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  background-color: var(--color-background);
  color: var(--color-foreground);
  font-family: var(--font-family);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Typography */
h1 {
  font-size: 3rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

h2 {
  font-size: 2rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

p {
  font-size: 1.125rem;
  color: var(--color-gray-600);
  font-weight: 300;
}

/* Layout */
.page-container {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: var(--spacing-sm);
}

.content-wrapper {
  width: 100%;
  max-width: var(--max-width-content);
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* Spacers */
.spacer-sm { height: var(--spacing-sm); }
.spacer-md { height: var(--spacing-md); }
.spacer-lg { height: var(--spacing-lg); }
.spacer-xl { height: var(--spacing-xl); }

/* Header */
.header {
  text-align: center;
  padding-top: var(--spacing-xl);
}

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

.header__subtitle {
  font-size: 1.125rem;
}

/* Navigation Pills */
.nav-pills {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  width: 100%;
  padding: var(--spacing-lg) 0;
}

.nav-pill {
  display: block;
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  background-color: var(--color-background);
  color: var(--color-foreground);
  text-decoration: none;
  text-align: center;
  font-size: 1rem;
  font-weight: 500;
  border: 2px solid var(--color-foreground);
  border-radius: var(--border-radius);
  transition: var(--transition-default);
}

.nav-pill:hover {
  background-color: var(--color-foreground);
  color: var(--color-background);
}

.nav-pill:focus {
  outline: none;
  box-shadow: 0 0 0 3px var(--color-gray-400);
}

/* Page Content */
.page-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--spacing-lg);
}

.page-content__title {
  margin-bottom: var(--spacing-sm);
}

.page-content__text {
  max-width: 500px;
}

/* Back Link */
.back-link {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  color: var(--color-gray-600);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--border-radius);
  transition: var(--transition-default);
  margin-top: var(--spacing-lg);
}

.back-link:hover {
  color: var(--color-foreground);
  background-color: var(--color-gray-100);
}

.back-link::before {
  content: '←';
}

/* Footer */
.footer {
  width: 100%;
  border-top: 1px solid var(--color-gray-200);
  padding: var(--spacing-sm);
  margin-top: auto;
}

.footer__content {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--spacing-lg);
  flex-wrap: wrap;
}

.footer__link {
  color: var(--color-gray-600);
  text-decoration: none;
  font-size: 0.875rem;
  transition: var(--transition-default);
}

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

.footer__copyright {
  color: var(--color-gray-600);
  font-size: 0.875rem;
}

/* Animations */
@keyframes fade-in {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.animate-fade-in {
  animation: fade-in 0.4s ease-out;
}

.nav-pill {
  animation: fade-in 0.4s ease-out backwards;
}

.nav-pill:nth-child(1) { animation-delay: 0.1s; }
.nav-pill:nth-child(2) { animation-delay: 0.15s; }
.nav-pill:nth-child(3) { animation-delay: 0.2s; }
.nav-pill:nth-child(4) { animation-delay: 0.25s; }
.nav-pill:nth-child(5) { animation-delay: 0.3s; }

/* Article List (Blog, Reviews, etc.) */
.article-list {
  width: 100%;
  max-width: var(--max-width-content);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
  padding: var(--spacing-lg) 0;
}

.article-list__item {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) 0;
  border-bottom: 1px solid var(--color-gray-200);
  text-decoration: none;
  color: inherit;
  transition: var(--transition-default);
}

.article-list__item:first-child {
  border-top: 1px solid var(--color-gray-200);
}

.article-list__item:hover {
  background-color: var(--color-gray-100);
  padding-left: var(--spacing-sm);
  padding-right: var(--spacing-sm);
  margin-left: calc(-1 * var(--spacing-sm));
  margin-right: calc(-1 * var(--spacing-sm));
}

.article-list__title {
  flex: 1;
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-foreground);
}

.article-list__topic {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--color-gray-400);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  white-space: nowrap;
  text-align: right;
}

.article-list__date {
  font-size: 0.875rem;
  color: var(--color-gray-400);
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
  width: 6.5rem;
  text-align: right;
}

.article-list__empty {
  text-align: center;
  color: var(--color-gray-600);
  font-size: 1rem;
  padding: var(--spacing-lg) 0;
}

/* External Link Indicator (reusable) */
.external {
  font-size: 0.75rem;
  font-weight: 400;
  color: var(--color-gray-400);
  margin-left: var(--spacing-xs);
}

.nav-pill .external {
  font-size: 0.7rem;
}

.nav-pill:hover .external {
  color: var(--color-gray-200);
}

/* Staggered animation for article list items */
.article-list__item {
  animation: fade-in 0.4s ease-out backwards;
}

.article-list__item:nth-child(1) { animation-delay: 0.1s; }
.article-list__item:nth-child(2) { animation-delay: 0.15s; }
.article-list__item:nth-child(3) { animation-delay: 0.2s; }
.article-list__item:nth-child(4) { animation-delay: 0.25s; }
.article-list__item:nth-child(5) { animation-delay: 0.3s; }
.article-list__item:nth-child(6) { animation-delay: 0.35s; }
.article-list__item:nth-child(7) { animation-delay: 0.4s; }
.article-list__item:nth-child(8) { animation-delay: 0.45s; }
.article-list__item:nth-child(9) { animation-delay: 0.5s; }
.article-list__item:nth-child(10) { animation-delay: 0.55s; }

/* Blog Post / Article Page */
.article {
  width: 100%;
  max-width: var(--max-width-content);
  padding: var(--spacing-lg) 0;
}

.article__header {
  text-align: center;
  margin-bottom: var(--spacing-lg);
}

.article__title {
  font-size: 2rem;
  margin-bottom: var(--spacing-xs);
}

.article__date {
  font-size: 0.875rem;
  color: var(--color-gray-400);
}

/* Article Meta (date + views) */
.article__meta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  flex-wrap: wrap;
  margin-top: 0.25rem;
}

.article__meta-separator {
  color: var(--color-gray-400);
  font-size: 0.875rem;
}

.article__views {
  font-size: 0.875rem;
  color: var(--color-gray-400);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.article__views--loaded {
  opacity: 1;
}

.article__content {
  line-height: 1.8;
}

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

.article__content h2 {
  font-size: 1.5rem;
  margin-top: var(--spacing-lg);
  margin-bottom: var(--spacing-sm);
}

.article__content a {
  color: var(--color-foreground);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.article__content a:hover {
  text-decoration-thickness: 2px;
}

.article__content ul,
.article__content ol {
  margin-bottom: var(--spacing-md);
  padding-left: var(--spacing-md);
  color: var(--color-gray-600);
}

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

.article__content blockquote {
  border-left: 3px solid var(--color-gray-200);
  padding-left: var(--spacing-md);
  margin: var(--spacing-md) 0;
  font-style: italic;
  color: var(--color-gray-600);
}

.article__content sup {
  font-size: 0.75rem;
  color: var(--color-gray-400);
}

.article__divider {
  border: none;
  border-top: 1px solid var(--color-gray-200);
  margin: var(--spacing-lg) 0;
}

.article__references {
  font-size: 0.875rem;
  color: var(--color-gray-600);
}

.article__references p {
  font-size: 0.875rem;
  margin-bottom: var(--spacing-xs);
  line-height: 1.5;
}

/* Project List */
.project-list {
  width: 100%;
  max-width: var(--max-width-content);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  padding: var(--spacing-lg) 0;
}

.project-item {
  display: flex;
  align-items: center;
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  background-color: var(--color-background);
  color: var(--color-foreground);
  text-decoration: none;
  font-size: 1rem;
  font-weight: 500;
  border: 2px solid var(--color-foreground);
  border-radius: var(--border-radius);
  transition: var(--transition-default);
  position: relative;
}

.project-item:hover {
  background-color: var(--color-foreground);
  color: var(--color-background);
}

.project-item__title {
  flex: 1;
  text-align: center;
}

.project-item__info {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 1.25rem;
  height: 1.25rem;
  border-radius: 50%;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-gray-400);
  border: 1.5px solid var(--color-gray-400);
  cursor: help;
  flex-shrink: 0;
  transition: var(--transition-default);
}

.project-item:hover .project-item__info {
  color: var(--color-gray-200);
  border-color: var(--color-gray-200);
}

.project-item__tooltip {
  position: absolute;
  right: 0;
  top: calc(100% + 0.5rem);
  width: 280px;
  padding: var(--spacing-sm);
  background-color: var(--color-foreground);
  color: var(--color-background);
  font-size: 0.875rem;
  font-weight: 400;
  line-height: 1.5;
  border-radius: 0.5rem;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.2s ease, visibility 0.2s ease;
  z-index: 100;
  text-align: left;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.project-item__tooltip::before {
  content: '';
  position: absolute;
  top: -6px;
  right: 0.5rem;
  border-left: 6px solid transparent;
  border-right: 6px solid transparent;
  border-bottom: 6px solid var(--color-foreground);
}

.project-item__info:hover .project-item__tooltip,
.project-item__info:focus .project-item__tooltip {
  opacity: 1;
  visibility: visible;
}

/* Staggered animation for project items */
.project-item {
  animation: fade-in 0.4s ease-out backwards;
}

.project-item:nth-child(1) { animation-delay: 0.1s; }
.project-item:nth-child(2) { animation-delay: 0.15s; }
.project-item:nth-child(3) { animation-delay: 0.2s; }
.project-item:nth-child(4) { animation-delay: 0.25s; }
.project-item:nth-child(5) { animation-delay: 0.3s; }

/* Book Review Pills */
.review-list {
  width: 100%;
  max-width: var(--max-width-content);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  padding: var(--spacing-lg) 0;
}

.review-pill {
  display: flex;
  flex-direction: column;
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  background-color: var(--color-background);
  color: var(--color-foreground);
  text-decoration: none;
  border: 2px solid var(--color-foreground);
  border-radius: var(--border-radius);
  transition: var(--transition-default);
  text-align: left;
}

.review-pill:hover {
  background-color: var(--color-foreground);
  color: var(--color-background);
}

.review-pill:focus {
  outline: none;
  box-shadow: 0 0 0 3px var(--color-gray-400);
}

.review-pill__header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: var(--spacing-sm);
  width: 100%;
}

.review-pill__title {
  font-size: 1rem;
  font-weight: 500;
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.review-pill__rating {
  font-size: 0.875rem;
  font-weight: 400;
  color: var(--color-gray-600);
  white-space: nowrap;
  letter-spacing: 0.05em;
}

.review-pill:hover .review-pill__rating {
  color: var(--color-gray-200);
}

.review-pill__author {
  font-size: 0.875rem;
  font-weight: 400;
  color: var(--color-gray-600);
  margin-top: 0.125rem;
}

.review-pill:hover .review-pill__author {
  color: var(--color-gray-200);
}

/* Staggered animation for review pills */
.review-pill {
  animation: fade-in 0.4s ease-out backwards;
}

.review-pill:nth-child(1) { animation-delay: 0.1s; }
.review-pill:nth-child(2) { animation-delay: 0.15s; }
.review-pill:nth-child(3) { animation-delay: 0.2s; }
.review-pill:nth-child(4) { animation-delay: 0.25s; }
.review-pill:nth-child(5) { animation-delay: 0.3s; }
.review-pill:nth-child(6) { animation-delay: 0.35s; }
.review-pill:nth-child(7) { animation-delay: 0.4s; }
.review-pill:nth-child(8) { animation-delay: 0.45s; }
.review-pill:nth-child(9) { animation-delay: 0.5s; }
.review-pill:nth-child(10) { animation-delay: 0.55s; }
.review-pill:nth-child(11) { animation-delay: 0.6s; }
.review-pill:nth-child(12) { animation-delay: 0.65s; }

/* Book Review Article Styles */
.book-review__meta {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.25rem;
  margin-bottom: var(--spacing-xs);
}

.book-review__author {
  font-size: 1.125rem;
  color: var(--color-gray-600);
  font-weight: 400;
}

.book-review__rating {
  font-size: 1.25rem;
  letter-spacing: 0.1em;
  color: var(--color-foreground);
}

/* Read count link */
.read-count-link {
  color: var(--color-gray-600);
  text-decoration: underline;
  text-underline-offset: 2px;
  font-size: 1.125rem;
  font-weight: 400;
  transition: var(--transition-default);
}

.read-count-link:hover {
  color: var(--color-foreground);
}

/* Header description */
.header__description {
  font-size: 1rem;
  color: var(--color-gray-600);
  font-weight: 300;
  margin-top: var(--spacing-sm);
}

/* Reviews note */
.reviews-note {
  text-align: center;
  margin-top: var(--spacing-sm);
}

/* Comments Section (Giscus) */
.comments-section {
  width: 100%;
  max-width: var(--max-width-content);
  margin-top: var(--spacing-lg);
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--color-gray-200);
}

.giscus {
  max-width: 100%;
}

/* RSS Link */
.rss-link {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  margin-top: var(--spacing-sm);
  padding: 0.375rem 0.75rem;
  font-size: 0.75rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-gray-600);
  text-decoration: none;
  border: 1.5px solid var(--color-gray-400);
  border-radius: var(--border-radius);
  transition: var(--transition-default);
}

.rss-link:hover {
  color: var(--color-foreground);
  border-color: var(--color-foreground);
}

.rss-icon {
  width: 14px;
  height: 14px;
}

/* Responsive */
@media (max-width: 480px) {
  h1 {
    font-size: 2.5rem;
  }
  
  .header {
    padding-top: var(--spacing-lg);
  }
  
  .footer__content {
    flex-direction: column;
    gap: var(--spacing-sm);
  }
  
  .review-pill__header {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.25rem;
  }
  
  .review-pill__title {
    white-space: normal;
  }
  
  .review-pill__date {
    font-size: 0.7rem;
  }
}