/* ============================================================
   sepsad.github.io — personal site
   Vintage minimal: parchment · EB Garamond · Courier Prime
   ============================================================ */

/* --- Variables -------------------------------------------- */

:root {
  --font-serif: 'EB Garamond', Georgia, serif;
  --font-mono:  'Courier Prime', 'Courier New', monospace;

  --color-bg:     #f4efe6;
  --color-text:   #1c1c1c;
  --color-accent: #7a3b2e;
  --color-muted:  #6b6560;
  --color-rule:   #c9c1b5;

  --size-name:  clamp(2.4rem, 5vw, 3.8rem);
  --size-h2:    1.05rem;
  --size-body:  1.1rem;
  --size-meta:  0.82rem;
  --size-small: 0.92rem;

  --line-height: 1.75;

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

  --content-width: 660px;
  --header-h: 3rem;
}

/* --- Reset ------------------------------------------------- */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
img  { display: block; max-width: 100%; }
ul, ol { list-style: none; }

/* --- Base -------------------------------------------------- */

body {
  font-family:      var(--font-serif);
  font-size:        var(--size-body);
  line-height:      var(--line-height);
  color:            var(--color-text);
  background-color: var(--color-bg);
}

a {
  color: var(--color-text);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--color-rule);
  transition: color 0.1s ease, text-decoration-color 0.1s ease;
}

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

/* --- Header / Nav ----------------------------------------- */

header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-bg);
  border-bottom: 1px solid var(--color-rule);
  height: var(--header-h);
}

.nav-inner {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-name {
  font-family: var(--font-mono);
  font-size: var(--size-meta);
  color: var(--color-muted);
  text-decoration: none;
  letter-spacing: 0.08em;
}

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

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

.nav-links a {
  font-family: var(--font-mono);
  font-size: var(--size-meta);
  color: var(--color-muted);
  text-decoration: none;
  letter-spacing: 0.05em;
}

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

/* --- Active nav link -------------------------------------- */

.nav-links a.nav-active {
  color: var(--color-accent);
}

/* --- Main container --------------------------------------- */

main {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

/* --- Masthead --------------------------------------------- */

.masthead {
  padding: var(--space-xl) 0 var(--space-md);
}

/* Home landing: extra vertical breathing room */
.masthead--home {
  padding: var(--space-xl) 0 var(--space-xl);
}

.name-display {
  font-family: var(--font-serif);
  font-size: var(--size-name);
  font-weight: 400;
  line-height: 1.1;
  letter-spacing: -0.01em;
}

/* Sub-page title (smaller than home name) */
.page-title {
  font-family: var(--font-serif);
  font-size: clamp(1.6rem, 3.5vw, 2.2rem);
  font-weight: 400;
  line-height: 1.2;
}

.error-code {
  font-family: var(--font-mono);
  font-size: var(--size-meta);
  color: var(--color-muted);
  letter-spacing: 0.1em;
  margin-bottom: var(--space-xs);
}

.tagline {
  margin-top: var(--space-sm);
  font-style: italic;
  color: var(--color-muted);
  font-size: var(--size-small);
}

hr.ruled-line {
  border: none;
  border-top: 1px solid var(--color-rule);
  margin: var(--space-md) 0 0;
}

/* --- Home nav (below masthead hr) ------------------------- */

.home-nav {
  margin-top: var(--space-md);
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
  align-items: flex-start;
}

.home-nav a {
  font-family: var(--font-mono);
  font-size: var(--size-meta);
  color: var(--color-muted);
  text-decoration: none;
  letter-spacing: 0.05em;
}

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

.home-nav-sep {
  display: none;
}

/* --- Home identity (name + photo row) --------------------- */

.home-identity {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-md);
}

.home-identity-text {
  flex: 1;
  min-width: 0;
}

/* Wrapper div owns the fixed size — immune to global img max-width: 100% */
.home-photo-wrap {
  flex-shrink: 0;
  width: 110px;
  height: 110px;
  overflow: hidden;
  border: 1px solid var(--color-rule);
}

.home-photo {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center top;
  display: block;
}

@media (max-width: 520px) {
  .home-identity    { flex-direction: column; gap: var(--space-sm); }
  .home-photo-wrap  { width: 80px; height: 80px; }
}

/* --- Section --------------------------------------------- */

.section {
  padding-top: var(--space-lg);
  margin-bottom: var(--space-lg);
}

.section-heading {
  font-family: var(--font-mono);
  font-size: var(--size-h2);
  font-weight: 400;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--color-muted);
  border-bottom: 1px solid var(--color-rule);
  padding-bottom: 0.4em;
  margin-bottom: var(--space-md);
}

/* targeted by anchor nav */
section:target .section-heading {
  color: var(--color-accent);
}

/* Ornamental divider */
.divider {
  text-align: center;
  color: var(--color-rule);
  font-family: var(--font-serif);
  letter-spacing: 0.5em;
  font-size: 0.9rem;
  user-select: none;
  margin: var(--space-lg) 0;
}

/* --- Profile photo (About section) ----------------------- */

.about-photo {
  float: left;
  width: 130px;
  height: 130px;
  object-fit: cover;
  margin: 0 var(--space-md) var(--space-sm) 0;
  border: 1px solid var(--color-rule);
  display: block;
}

.about-body { overflow: hidden; }

.about-photo-secondary-wrap {
  margin-top: var(--space-lg);
}

.about-photo-secondary {
  width: 100%;
  max-height: 420px;
  object-fit: cover;
  object-position: center;
  border: 1px solid var(--color-rule);
  display: block;
}

/* --- Markdown content styling ---------------------------- */

.md-content p {
  margin-bottom: 0;
  font-size: var(--size-body);
  line-height: var(--line-height);
}

.md-content p + p {
  text-indent: 1.5em;
}

/* First paragraph after heading: no indent */
.md-content h1 + p,
.md-content h2 + p,
.md-content h3 + p {
  text-indent: 0;
}

.md-content h1, .md-content h2, .md-content h3 {
  font-family: var(--font-serif);
  font-weight: 600;
}

.md-content h2 {
  font-size: 1.1rem;
  font-style: italic;
  font-weight: 400;
  color: var(--color-text);
  margin: var(--space-md) 0 var(--space-xs);
}

.md-content h3 {
  font-family: var(--font-mono);
  font-size: var(--size-meta);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-muted);
  font-weight: 400;
  margin: var(--space-md) 0 var(--space-sm);
  border-bottom: 1px solid var(--color-rule);
  padding-bottom: 0.3em;
}

.md-content a {
  color: var(--color-text);
  text-underline-offset: 3px;
  text-decoration-color: var(--color-rule);
}

.md-content a:hover {
  color: var(--color-accent);
  text-decoration-color: var(--color-accent);
}

.md-content a[href^="https://doi"],
.md-content a[href^="http://doi"] {
  font-family: var(--font-mono);
  font-size: var(--size-meta);
  color: var(--color-accent);
  text-decoration: none;
}

.md-content a[href^="https://doi"]:hover,
.md-content a[href^="http://doi"]:hover {
  text-decoration: underline;
  text-underline-offset: 3px;
}

.md-content strong { font-weight: 600; }
.md-content em     { font-style: italic; }

.md-content ul,
.md-content ol {
  padding-left: var(--space-md);
  list-style: initial;
}

.md-content ol { list-style: decimal; }

.md-content li {
  margin-bottom: var(--space-xs);
  line-height: var(--line-height);
}

/* Research entries: left border rule */
.md-content blockquote {
  border-left: 1px solid var(--color-rule);
  padding-left: var(--space-sm);
  margin: var(--space-sm) 0;
  color: var(--color-muted);
  font-style: italic;
}

/* Horizontal rules within markdown */
.md-content hr {
  border: none;
  border-top: 1px solid var(--color-rule);
  margin: var(--space-md) 0;
}

/* --- Writing preview (index) ----------------------------- */

.writing-list {
  margin-top: var(--space-sm);
}

.writing-item {
  display: flex;
  gap: var(--space-sm);
  align-items: baseline;
  margin-bottom: var(--space-sm);
}

.writing-date {
  font-family: var(--font-mono);
  font-size: var(--size-meta);
  color: var(--color-muted);
  white-space: nowrap;
  flex-shrink: 0;
}

.writing-title {
  font-style: italic;
  text-underline-offset: 3px;
}

.writing-desc {
  font-size: var(--size-small);
  color: var(--color-muted);
  margin-top: 0.15rem;
  font-style: normal;
}

.all-posts-link {
  display: inline-block;
  margin-top: var(--space-md);
  font-family: var(--font-mono);
  font-size: var(--size-meta);
  color: var(--color-muted);
  text-decoration: none;
  letter-spacing: 0.04em;
}

.all-posts-link:hover { color: var(--color-accent); }

/* --- Contact --------------------------------------------- */

.contact-grid {
  display: grid;
  grid-template-columns: 5.5rem 1fr;
  row-gap: var(--space-xs);
  align-items: baseline;
}

.contact-label {
  font-family: var(--font-mono);
  font-size: var(--size-meta);
  color: var(--color-muted);
  letter-spacing: 0.04em;
}

/* --- Footer ---------------------------------------------- */

footer {
  padding: var(--space-lg) 0 var(--space-md);
  text-align: center;
  max-width: var(--content-width);
  margin: 0 auto;
}

.footer-note {
  font-family: var(--font-mono);
  font-size: var(--size-meta);
  color: var(--color-muted);
}

/* ==========================================================
   BLOG PAGE
   ========================================================== */

.blog-layout-wrapper {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.blog-layout {
  display: flex;
  gap: var(--space-xl);
  padding-top: var(--space-lg);
  align-items: flex-start;
}

/* --- Blog Panel ------------------------------------------ */

.blog-panel {
  flex: 0 0 200px;
  position: sticky;
  top: calc(var(--header-h) + var(--space-md));
  max-height: calc(100vh - var(--header-h) - var(--space-md) * 2);
  overflow-y: auto;
  border-right: 1px solid var(--color-rule);
  padding-right: var(--space-md);
}

.panel-heading {
  font-family: var(--font-mono);
  font-size: var(--size-meta);
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--color-muted);
  margin-bottom: var(--space-sm);
}

.panel-list { margin-top: var(--space-xs); }

.panel-item {
  display: block;
  padding: var(--space-xs) 0;
  border-bottom: 1px solid var(--color-rule);
  cursor: pointer;
  text-decoration: none;
}

.panel-item-date {
  font-family: var(--font-mono);
  font-size: calc(var(--size-meta) * 0.95);
  color: var(--color-muted);
  display: block;
  margin-bottom: 0.1rem;
}

.panel-item-title {
  font-style: italic;
  font-size: var(--size-small);
  color: var(--color-text);
  display: block;
  line-height: 1.4;
}

.panel-item:hover .panel-item-title,
.panel-item.active .panel-item-title {
  color: var(--color-accent);
}

.panel-item.active { border-left: 2px solid var(--color-accent); padding-left: var(--space-xs); }

/* --- Blog Content ---------------------------------------- */

.blog-content {
  flex: 1;
  min-width: 0;
  max-width: var(--content-width);
}

.post-header {
  margin-bottom: var(--space-lg);
  border-bottom: 1px solid var(--color-rule);
  padding-bottom: var(--space-md);
}

.post-title-display {
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 3.5vw, 2rem);
  font-weight: 400;
  font-style: italic;
  line-height: 1.2;
  margin-bottom: var(--space-xs);
}

.post-meta-display {
  font-family: var(--font-mono);
  font-size: var(--size-meta);
  color: var(--color-muted);
}

.post-body p { margin-bottom: 0; }
.post-body p + p { text-indent: 1.5em; }
.post-body p:first-child { text-indent: 0; }

.post-body h2 {
  font-family: var(--font-mono);
  font-size: var(--size-meta);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-muted);
  font-weight: 400;
  margin: var(--space-md) 0 var(--space-sm);
  border-bottom: 1px solid var(--color-rule);
  padding-bottom: 0.3em;
}

.post-body ul,
.post-body ol {
  padding-left: var(--space-md);
  list-style: initial;
  margin: var(--space-sm) 0;
}

.post-body ol { list-style: decimal; }
.post-body li { margin-bottom: var(--space-xs); }

.post-body a {
  color: var(--color-text);
  text-underline-offset: 3px;
  text-decoration-color: var(--color-rule);
}

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

.back-link {
  display: inline-block;
  margin-top: var(--space-lg);
  font-family: var(--font-mono);
  font-size: var(--size-meta);
  color: var(--color-muted);
  text-decoration: none;
  letter-spacing: 0.04em;
}

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

/* Blog footer is inside .blog-layout-wrapper */
.blog-footer {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

/* Blog "empty state" */
.blog-empty {
  font-style: italic;
  color: var(--color-muted);
  margin-top: var(--space-md);
}

/* ==========================================================
   RESPONSIVE
   ========================================================== */

/* Tablet: nav may crowd */
@media (max-width: 680px) {
  .nav-inner { padding: 0 var(--space-sm); }
  main        { padding: 0 var(--space-sm); }

  .about-photo {
    float: none;
    margin: 0 0 var(--space-md);
  }
}

/* Mobile */
@media (max-width: 520px) {
  .nav-inner {
    flex-direction: column;
    height: auto;
    padding: var(--space-xs) var(--space-sm);
    gap: var(--space-xs);
    align-items: flex-start;
  }

  header { height: auto; }

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

  .writing-item { flex-direction: column; gap: 0.1rem; }

  .contact-grid { grid-template-columns: 1fr; }
  .contact-label::after { content: ": "; }

  .masthead { padding: var(--space-lg) 0 var(--space-sm); }
}

/* Blog mobile */
@media (max-width: 640px) {
  .blog-layout { flex-direction: column; gap: var(--space-md); }

  .blog-panel {
    position: static;
    max-height: none;
    border-right: none;
    border-bottom: 1px solid var(--color-rule);
    padding-right: 0;
    padding-bottom: var(--space-md);
    flex: none;
    width: 100%;
  }

  .blog-layout-wrapper { padding: 0 var(--space-sm); }
}

/* ==========================================================
   PRINT
   ========================================================== */

@media print {
  header         { position: static; border-bottom: none; }
  .nav-links     { display: none; }
  .divider       { color: #aaa; }
  a              { color: var(--color-text); text-decoration: none; }
  a[href^="http"]::after {
    content: " (" attr(href) ")";
    font-size: 0.72rem;
    color: var(--color-muted);
    font-family: var(--font-mono);
  }
  .blog-panel    { display: none; }
  .blog-content  { max-width: 100%; }
}