/* Clean, minimal theme inspired by Blowfish */

:root {
  /* System fonts - soft and native */
  --font-sans: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", Monaco, "Cascadia Code", "Roboto Mono", Menlo, Consolas, monospace;

  /* Colors - light mode */
  --color-bg: #fafafa;
  --color-bg-secondary: #ffffff;
  --color-text: #0a0a0a;
  --color-text-secondary: #525252;
  --color-accent: #2563eb;
  --color-accent-hover: #1d4ed8;
  --color-border: #e5e5e5;
  --color-code-bg: #f5f5f5;
  --color-card-bg: #ffffff;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #09090b;
    --color-bg-secondary: #18181b;
    --color-text: #fafafa;
    --color-text-secondary: #a1a1aa;
    --color-accent: #60a5fa;
    --color-accent-hover: #3b82f6;
    --color-border: #27272a;
    --color-code-bg: #18181b;
    --color-card-bg: #18181b;
  }
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

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

/* Layout */
.container {
  max-width: 72rem;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Header */
header {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg-secondary);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 1rem 0;
  margin-bottom: 3rem;
  box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.03);
}

@media (prefers-color-scheme: dark) {
  header {
    background: rgba(24, 24, 27, 0.8);
  }
}

header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.site-title {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: -0.025em;
  transition: color 0.2s;
}

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

nav ul {
  list-style: none;
  display: flex;
  gap: 0.5rem;
}

nav a {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.9375rem;
  padding: 0.5rem 1rem;
  border-radius: 0.5rem;
  transition: all 0.2s;
}

nav a:hover {
  color: var(--color-text);
  background-color: var(--color-bg);
}

/* Main content */
main {
  min-height: calc(100vh - 200px);
  padding-bottom: 4rem;
}

.intro-text {
  color: var(--color-text-secondary);
  font-size: 1.0625rem;
  line-height: 1.75;
  margin-bottom: 3rem;
  max-width: 42rem;
}

.section-heading {
  font-size: 1.375rem;
  font-weight: 700;
  margin-top: 3rem;
  margin-bottom: 1.5rem;
  color: var(--color-text);
  letter-spacing: -0.025em;
  position: relative;
  display: inline-block;
}

.section-heading::after {
  content: '';
  position: absolute;
  bottom: -0.375rem;
  left: 0;
  width: 2rem;
  height: 0.25rem;
  background: var(--color-accent);
  border-radius: 2px;
}

/* Tag Filters */
.tag-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--color-border);
}

.filter-tag {
  padding: 0.5rem 1rem;
  border: 1px solid var(--color-border);
  background-color: var(--color-card-bg);
  color: var(--color-text-secondary);
  border-radius: 0.5rem;
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  font-family: var(--font-sans);
}

.filter-tag:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background-color: rgba(37, 99, 235, 0.05);
}

.filter-tag.active {
  background-color: var(--color-accent);
  color: white;
  border-color: var(--color-accent);
}

@media (prefers-color-scheme: dark) {
  .filter-tag:hover {
    background-color: rgba(96, 165, 250, 0.1);
  }
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.3;
  margin-bottom: 1rem;
  color: var(--color-text);
}

h1 {
  font-size: 2.25rem;
  margin-bottom: 1.25rem;
  font-weight: 800;
  letter-spacing: -0.035em;
  background: linear-gradient(135deg, var(--color-text) 0%, var(--color-text-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

h2 {
  font-size: 1.875rem;
  margin-top: 2.5rem;
  margin-bottom: 1rem;
}

h3 {
  font-size: 1.5rem;
  margin-top: 2rem;
}

h4 {
  font-size: 1.25rem;
  margin-top: 1.5rem;
}

p {
  margin-bottom: 1.25rem;
  color: var(--color-text);
}

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

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

/* Lists */
ul, ol {
  margin-bottom: 1.25rem;
  padding-left: 1.5rem;
}

li {
  margin-bottom: 0.5rem;
}

/* Code */
code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background-color: var(--color-code-bg);
  padding: 0.2em 0.4em;
  border-radius: 0.25rem;
  color: var(--color-text);
}

pre {
  background-color: var(--color-code-bg);
  padding: 1rem;
  border-radius: 0.5rem;
  overflow-x: auto;
  margin-bottom: 1.5rem;
  border: 1px solid var(--color-border);
}

pre code {
  background-color: transparent;
  padding: 0;
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--color-text);
}

/* Syntax highlighting - Light mode */
.highlight .c,    /* Comment */
.highlight .cm,   /* Comment.Multiline */
.highlight .c1,   /* Comment.Single */
.highlight .cs {  /* Comment.Special */
  color: #6a737d;
  font-style: italic;
}

.highlight .k,    /* Keyword */
.highlight .kd,   /* Keyword.Declaration */
.highlight .kn,   /* Keyword.Namespace */
.highlight .kp,   /* Keyword.Pseudo */
.highlight .kr,   /* Keyword.Reserved */
.highlight .kt {  /* Keyword.Type */
  color: #d73a49;
}

.highlight .s,    /* String */
.highlight .s1,   /* String.Single */
.highlight .s2,   /* String.Double */
.highlight .sb,   /* String.Backtick */
.highlight .sc,   /* String.Char */
.highlight .sd,   /* String.Doc */
.highlight .se,   /* String.Escape */
.highlight .sh {  /* String.Heredoc */
  color: #22863a;
}

.highlight .n,    /* Name */
.highlight .na,   /* Name.Attribute */
.highlight .nb,   /* Name.Builtin */
.highlight .nc,   /* Name.Class */
.highlight .nf,   /* Name.Function */
.highlight .nn {  /* Name.Namespace */
  color: #6f42c1;
}

.highlight .m,    /* Number */
.highlight .mf,   /* Number.Float */
.highlight .mh,   /* Number.Hex */
.highlight .mi,   /* Number.Integer */
.highlight .mo {  /* Number.Oct */
  color: #005cc5;
}

.highlight .o,    /* Operator */
.highlight .ow {  /* Operator.Word */
  color: #d73a49;
}

.highlight .p {   /* Punctuation */
  color: #24292e;
}

/* Syntax highlighting - Dark mode */
@media (prefers-color-scheme: dark) {
  .highlight .c,
  .highlight .cm,
  .highlight .c1,
  .highlight .cs {
    color: #8b949e;
  }

  .highlight .k,
  .highlight .kd,
  .highlight .kn,
  .highlight .kp,
  .highlight .kr,
  .highlight .kt {
    color: #ff7b72;
  }

  .highlight .s,
  .highlight .s1,
  .highlight .s2,
  .highlight .sb,
  .highlight .sc,
  .highlight .sd,
  .highlight .se,
  .highlight .sh {
    color: #a5d6ff;
  }

  .highlight .n,
  .highlight .na,
  .highlight .nb,
  .highlight .nc,
  .highlight .nf,
  .highlight .nn {
    color: #d2a8ff;
  }

  .highlight .m,
  .highlight .mf,
  .highlight .mh,
  .highlight .mi,
  .highlight .mo {
    color: #79c0ff;
  }

  .highlight .o,
  .highlight .ow {
    color: #ff7b72;
  }

  .highlight .p {
    color: #c9d1d9;
  }
}

/* Writeups list */
.writeups-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1rem;
  margin-top: 2rem;
}

.writeup-card {
  padding: 1.25rem;
  border: 1px solid var(--color-border);
  border-radius: 0.75rem;
  background-color: var(--color-card-bg);
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.2s ease, transform 0.2s ease;
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  height: 100%;
  opacity: 1;
  transform: translateY(0);
}

.writeup-card::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--color-accent);
  transform: scaleY(0);
  transition: transform 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

.writeup-card:hover {
  border-color: var(--color-accent);
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.08);
  transform: translateY(-4px);
}

@media (prefers-color-scheme: dark) {
  .writeup-card:hover {
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.4);
  }
}

.writeup-card:hover::before {
  transform: scaleY(1);
}

.writeup-card h3 {
  margin-top: 0;
  margin-bottom: 0.5rem;
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -0.015em;
  line-height: 1.4;
}

.writeup-card h3 a {
  color: var(--color-text);
  text-decoration: none;
  transition: color 0.2s;
  display: block;
}

.writeup-card h3 a:hover {
  color: var(--color-accent);
}

.writeup-meta {
  color: var(--color-text-secondary);
  font-size: 0.8125rem;
  margin-top: auto;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.writeup-summary {
  color: var(--color-text-secondary);
  line-height: 1.5;
  font-size: 0.9375rem;
  display: none;
}

/* Tags */
.tags {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 0.375rem;
  align-items: center;
}

.tag {
  background-color: rgba(37, 99, 235, 0.1);
  color: var(--color-accent);
  padding: 0.125rem 0.625rem;
  border-radius: 0.375rem;
  font-size: 0.75rem;
  font-weight: 600;
  line-height: 1.5;
  border: 1px solid rgba(37, 99, 235, 0.2);
  transition: all 0.2s;
  cursor: pointer;
  user-select: none;
}

@media (prefers-color-scheme: dark) {
  .tag {
    background-color: rgba(96, 165, 250, 0.15);
    border-color: rgba(96, 165, 250, 0.25);
  }
}

.tag:hover {
  background-color: rgba(37, 99, 235, 0.2);
  border-color: rgba(37, 99, 235, 0.4);
  transform: translateY(-1px);
}

@media (prefers-color-scheme: dark) {
  .tag:hover {
    background-color: rgba(96, 165, 250, 0.25);
    border-color: rgba(96, 165, 250, 0.4);
  }
}

/* Footer */
footer {
  border-top: 1px solid var(--color-border);
  padding: 2.5rem 0;
  margin-top: 6rem;
  text-align: center;
  color: var(--color-text-secondary);
  font-size: 0.875rem;
  background-color: var(--color-bg-secondary);
}

footer p {
  margin-bottom: 0;
}

/* Article page */
.article-header {
  margin-bottom: 3rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--color-border);
}

.article-header h1 {
  margin-bottom: 1rem;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--color-text-secondary);
  font-size: 0.9375rem;
  flex-wrap: wrap;
}

.article-content {
  max-width: 48rem;
}

.article-content img {
  max-width: 100%;
  height: auto;
  border-radius: 0.5rem;
  margin: 2rem 0;
}

.article-content blockquote {
  border-left: 3px solid var(--color-accent);
  padding-left: 1.5rem;
  margin: 2rem 0;
  color: var(--color-text-secondary);
  font-style: italic;
}

.article-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 2rem 0;
}

.article-content th,
.article-content td {
  border: 1px solid var(--color-border);
  padding: 0.75rem;
  text-align: left;
}

.article-content th {
  background-color: var(--color-bg-secondary);
  font-weight: 600;
}

/* Responsive */
@media (max-width: 768px) {
  header .container {
    flex-direction: column;
    gap: 1rem;
  }

  nav ul {
    gap: 0.25rem;
  }

  h1 {
    font-size: 1.875rem;
  }

  h2 {
    font-size: 1.5rem;
  }

  h3 {
    font-size: 1.25rem;
  }

  .writeups-list {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }

  .container {
    padding: 0 1rem;
  }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .writeups-list {
    grid-template-columns: repeat(2, 1fr);
  }
}