/* ============================================
   THE SILENT CURATOR — Design System CSS
   Based on DESIGN.md & Google Stitch Export
   ============================================ */

/* --- CSS Custom Properties (Design Tokens) --- */
:root {
  /* Primary palette */
  --primary: #00647c;
  --primary-container: #007f9d;
  --on-primary: #ffffff;
  --on-primary-container: #fafdff;
  --primary-fixed: #b7eaff;
  --primary-fixed-dim: #6cd3f7;
  --inverse-primary: #6cd3f7;

  /* Surface / Background */
  --surface: #faf9f8;
  --surface-dim: #dbdad9;
  --surface-bright: #faf9f8;
  --surface-container-lowest: #ffffff;
  --surface-container-low: #f4f3f3;
  --surface-container: #efeeed;
  --surface-container-high: #e9e8e7;
  --surface-container-highest: #e3e2e2;
  --surface-variant: #e3e2e2;
  --surface-tint: #006780;
  --background: #faf9f8;

  /* On Surface */
  --on-surface: #1b1c1c;
  --on-surface-variant: #3e484d;
  --on-background: #1b1c1c;
  --inverse-surface: #2f3131;
  --inverse-on-surface: #f2f0f0;

  /* Secondary */
  --secondary: #5e5e5e;
  --secondary-container: #e3e2e2;
  --on-secondary: #ffffff;
  --on-secondary-container: #646464;

  /* Tertiary */
  --tertiary: #615b55;
  --tertiary-container: #7a736d;
  --on-tertiary: #ffffff;
  --on-tertiary-container: #fffbff;
  --tertiary-fixed: #eae1d9;

  /* Outline */
  --outline: #6e797e;
  --outline-variant: #bdc8ce;

  /* Error */
  --error: #ba1a1a;
  --error-container: #ffdad6;
  --on-error: #ffffff;
  --on-error-container: #93000a;

  /* Spacing scale */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Border radius */
  --radius-sm: 0.125rem;
  --radius-md: 0.25rem;
  --radius-lg: 0.5rem;
  --radius-xl: 0.75rem;

  /* Typography sizes */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;
  --text-6xl: 3.75rem;
  --text-7xl: 4.5rem;
}


/* --- 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;
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background-color: var(--surface);
  color: var(--on-surface);
  line-height: 1.6;
}

::selection {
  background-color: var(--primary-fixed);
  color: #001f28;
}

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

a {
  color: inherit;
  text-decoration: none;
}


/* --- Typography --- */
.font-headline {
  font-family: 'Noto Serif', Georgia, 'Times New Roman', serif;
}

.font-body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

.font-label {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

.label {
  font-size: var(--text-xs);
  font-family: 'Inter', sans-serif;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--tertiary);
}


/* --- Layout: Homepage Split --- */
.split-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  min-height: 100vh;
  width: 100%;
}

.split-layout__image {
  position: relative;
  width: 100%;
  height: 100vh;
  overflow: hidden;
  position: sticky;
  top: 0;
}

.split-layout__image img {
  transition: opacity 0.3s ease;
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.split-layout__image::after {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--primary);
  opacity: 0.05;
  mix-blend-mode: multiply;
}

.split-layout__content {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: flex-start;
  padding: var(--space-12) var(--space-24);
  background-color: var(--surface);
}

@media (max-width: 768px) {
  .split-layout {
    grid-template-columns: 1fr;
  }
  .split-layout__image {
    height: 50vh;
    position: relative;
  }
  .split-layout__content {
    padding: var(--space-8) var(--space-6);
  }
}


/* --- Navigation --- */
.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: var(--space-6) var(--space-8);
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(250, 249, 248, 0.8);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.site-nav__logo {
  font-family: 'Noto Serif', serif;
  font-size: var(--text-lg);
  color: var(--on-surface);
  letter-spacing: 0.05em;
}

.site-nav__links {
  display: flex;
  gap: var(--space-8);
  list-style: none;
}

.site-nav__links a {
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--tertiary);
  transition: color 0.4s ease;
}

.site-nav__links a:hover {
  color: var(--primary);
}


/* --- Article Index (Homepage) --- */
.article-index {
  list-style: none;
  padding: 0;
}

.article-index__item {
  margin-bottom: var(--space-8);
}

.article-index__link {
  display: block;
  font-family: 'Noto Serif', serif;
  font-size: var(--text-2xl);
  font-weight: 400;
  color: var(--secondary);
  letter-spacing: 0.1em;
  line-height: 1.3;
  transition: color 0.5s ease;
}

.article-index__link:hover {
  color: var(--primary);
}

.article-index__meta {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-top: var(--space-2);
}

.article-index__tag {
  font-size: var(--text-xs);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--tertiary);
}

.article-index__date {
  font-size: var(--text-xs);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--tertiary);
}

.article-index__dot {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--outline-variant);
}


/* --- Article Page --- */
.article {
  max-width: 48rem;
  margin: 0 auto;
  padding: var(--space-24) var(--space-6) var(--space-32);
}

.article__back {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: 10px;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--tertiary);
  transition: color 0.4s ease;
  margin-bottom: var(--space-16);
}

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

.article__meta {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-bottom: var(--space-6);
}

.article__title {
  font-family: 'Noto Serif', serif;
  font-size: var(--text-5xl);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--on-surface);
  margin-bottom: var(--space-8);
}

.article__subtitle {
  font-family: 'Noto Serif', serif;
  font-size: var(--text-xl);
  font-style: italic;
  color: var(--tertiary);
  line-height: 1.6;
  max-width: 40rem;
}

@media (min-width: 768px) {
  .article__title {
    font-size: var(--text-6xl);
  }
}


/* --- Article Hero Image (Full Bleed) --- */
.article__hero {
  position: relative;
  width: 100vw;
  left: 50%;
  right: 50%;
  margin-left: -50vw;
  margin-right: -50vw;
  margin-top: var(--space-16);
  margin-bottom: var(--space-20);
  overflow: hidden;
  background: var(--surface-container-low);
}

.article__hero img {
  width: 100%;
  height: 614px;
  object-fit: cover;
  opacity: 0.9;
  transition: transform 1s ease;
}

.article__hero img:hover {
  transform: scale(1.05);
}


/* --- Article Body Content --- */
.article__body {
  font-size: var(--text-lg);
  color: var(--on-surface-variant);
  line-height: 1.8;
}

.article__body p {
  margin-bottom: var(--space-12);
}

.article__body p:first-of-type::first-letter {
  font-family: 'Noto Serif', serif;
  font-size: var(--text-7xl);
  float: left;
  margin-right: var(--space-4);
  line-height: 0.85;
  color: var(--primary);
}

@media (min-width: 768px) {
  .article__body {
    font-size: var(--text-xl);
  }
}


/* --- Blockquote (Asymmetric) --- */
.article__quote {
  position: relative;
  padding: var(--space-12) 0 var(--space-12) var(--space-8);
  margin: var(--space-16) 0;
  border-left: 2px solid rgba(0, 100, 124, 0.2);
}

.article__quote blockquote {
  font-family: 'Noto Serif', serif;
  font-size: var(--text-2xl);
  font-style: italic;
  color: var(--on-surface);
  line-height: 1.4;
}

.article__quote cite {
  display: block;
  margin-top: var(--space-4);
  font-size: var(--text-xs);
  font-style: normal;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--tertiary);
}

@media (min-width: 768px) {
  .article__quote {
    margin-left: var(--space-12);
  }
  .article__quote blockquote {
    font-size: var(--text-3xl);
  }
}


/* --- Code Blocks (Tech Blog Essential) --- */
.article__body pre {
  background: var(--inverse-surface);
  color: var(--inverse-on-surface);
  padding: var(--space-6);
  border-radius: var(--radius-xl);
  overflow-x: auto;
  margin: var(--space-8) 0 var(--space-12);
  font-size: var(--text-sm);
  line-height: 1.7;
}

.article__body code {
  font-family: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
  font-size: 0.9em;
}

.article__body p code,
.article__body li code {
  background: var(--surface-container-low);
  padding: 0.15em 0.4em;
  border-radius: var(--radius-md);
  color: var(--primary);
}


/* --- Image Grid --- */
.article__image-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-12);
  margin: var(--space-20) 0;
}

.article__image-grid img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: var(--radius-xl);
}

@media (min-width: 768px) {
  .article__image-grid {
    grid-template-columns: 1fr 1fr;
  }
}


/* --- Reading Progress Rail --- */
.reading-progress {
  position: fixed;
  left: 2rem;
  top: 50%;
  transform: translateY(-50%);
  width: 1px;
  height: 200px;
  background-color: rgba(189, 200, 206, 0.2);
  display: none;
}

.reading-progress__fill {
  width: 100%;
  height: 0%;
  background-color: var(--primary);
  transition: height 0.15s ease-out;
}

@media (min-width: 1024px) {
  .reading-progress {
    display: block;
  }
}


/* --- Footer --- */
.site-footer {
  padding: var(--space-24) var(--space-6);
  text-align: center;
}

.site-footer__copyright {
  font-size: 10px;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--tertiary);
  opacity: 0.5;
}


/* --- Utility Classes --- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.container {
  max-width: 48rem;
  margin: 0 auto;
  padding: 0 var(--space-6);
}


/* --- Article Tags --- */
.article__tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin-top: var(--space-16);
  padding-top: var(--space-8);
}

.article__tag {
  font-size: var(--text-xs);
  font-family: 'Inter', sans-serif;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--tertiary);
  padding: var(--space-2) var(--space-4);
  background: var(--surface-container-low);
  border-radius: var(--radius-xl);
  transition: color 0.4s ease, background-color 0.4s ease;
}

.article__tag:hover {
  color: var(--on-primary);
  background: linear-gradient(135deg, var(--primary), var(--primary-container));
}


/* --- Hugo Syntax Highlighting (chroma) --- */
.highlight {
  margin: var(--space-8) 0 var(--space-12);
  border-radius: var(--radius-xl);
  overflow: hidden;
}

.highlight pre {
  background: var(--inverse-surface) !important;
  color: var(--inverse-on-surface) !important;
  padding: var(--space-6);
  overflow-x: auto;
  font-size: var(--text-sm);
  line-height: 1.7;
  margin: 0;
  border-radius: var(--radius-xl);
}

.highlight pre code {
  font-family: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
  background: none;
  padding: 0;
  color: inherit;
}

/* Chroma token colors (monokailight-inspired, warm) */
.highlight .k,
.highlight .kd,
.highlight .kn,
.highlight .kp,
.highlight .kr { color: #6cd3f7; }          /* keywords */
.highlight .s,
.highlight .s1,
.highlight .s2,
.highlight .se { color: #cdc5bd; }          /* strings */
.highlight .mi,
.highlight .mf,
.highlight .mh { color: #b7eaff; }          /* numbers */
.highlight .c,
.highlight .c1,
.highlight .cm,
.highlight .cp { color: #6e797e; font-style: italic; } /* comments */
.highlight .nf,
.highlight .nx { color: #ffffff; }           /* functions */
.highlight .o,
.highlight .p { color: #bdc8ce; }           /* operators/punctuation */


/* --- Article Body Headings (from Markdown) --- */
.article__body h2 {
  font-family: 'Noto Serif', serif;
  font-size: var(--text-3xl);
  color: var(--on-surface);
  margin-top: var(--space-16);
  margin-bottom: var(--space-6);
  line-height: 1.2;
}

.article__body h3 {
  font-family: 'Noto Serif', serif;
  font-size: var(--text-2xl);
  color: var(--on-surface);
  margin-top: var(--space-12);
  margin-bottom: var(--space-6);
  line-height: 1.3;
}

.article__body h4 {
  font-family: 'Inter', sans-serif;
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--on-surface);
  margin-top: var(--space-10);
  margin-bottom: var(--space-4);
}


/* --- Article Body Lists --- */
.article__body ul,
.article__body ol {
  padding-left: var(--space-8);
  margin-bottom: var(--space-8);
}

.article__body li {
  margin-bottom: var(--space-3);
}


/* --- Article Body Links --- */
.article__body a {
  color: var(--primary);
  text-decoration: underline;
  text-decoration-color: rgba(0, 100, 124, 0.3);
  text-underline-offset: 3px;
  transition: text-decoration-color 0.4s ease;
}

.article__body a:hover {
  text-decoration-color: var(--primary);
}


/* --- Blockquote from Markdown --- */
.article__body blockquote {
  position: relative;
  padding: var(--space-8) 0 var(--space-8) var(--space-8);
  margin: var(--space-12) 0;
  border-left: 2px solid rgba(0, 100, 124, 0.2);
  font-family: 'Noto Serif', serif;
  font-size: var(--text-xl);
  font-style: italic;
  color: var(--on-surface);
  line-height: 1.5;
}

.article__body blockquote p {
  margin-bottom: 0;
}

@media (min-width: 768px) {
  .article__body blockquote {
    margin-left: var(--space-12);
    font-size: var(--text-2xl);
  }
}


/* --- Article Body Images --- */
.article__body img {
  border-radius: var(--radius-xl);
  margin: var(--space-8) 0;
}


/* --- Horizontal Rule --- */
.article__body hr {
  border: none;
  height: 1px;
  background: var(--surface-container-highest);
  margin: var(--space-16) 0;
}