/* ============================================================
   BLEAM BLOG — shared styles
   Built to match /index.html exactly: same design tokens,
   same dark/light theme system, same nav + footer markup/CSS.
   Reference this file from blog.html and blog/posts/*.html.
   ============================================================ */

/* ============================================================
   DESIGN TOKENS (copied from the main site)
   ============================================================ */
:root {
  --cyan-50:  #e6fafa;
  --cyan-100: #b3f0f0;
  --cyan-400: #2dd4cc;
  --cyan-500: #0dcfcf;
  --cyan-600: #00b8b8;
  --cyan-700: #008f8f;

  --navy-950: #060d14;
  --navy-900: #0a1628;
  --navy-800: #0f2040;
  --navy-700: #1a2f52;

  --slate-700: #334155;
  --slate-500: #64748b;
  --slate-400: #94a3b8;
  --slate-200: #e2e8f0;
  --slate-100: #f1f5f9;
  --slate-50:  #f8fafc;

  --white: #ffffff;
  --amber: #f59e0b;

  --font-primary: 'Plus Jakarta Sans', -apple-system, sans-serif;
  --font-body:    'Inter', -apple-system, sans-serif;
  --font-mono:    'IBM Plex Mono', ui-monospace, monospace;

  --space-1:  4px;
  --space-2:  8px;
  --space-3:  12px;
  --space-4:  16px;
  --space-5:  20px;
  --space-6:  24px;
  --space-8:  32px;
  --space-10: 40px;
  --space-12: 48px;
  --space-16: 64px;
  --space-20: 80px;
  --space-24: 96px;
  --space-32: 128px;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  --shadow-sm:  0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
  --shadow-md:  0 4px 16px rgba(0,0,0,.08), 0 2px 6px rgba(0,0,0,.05);
  --shadow-lg:  0 12px 40px rgba(0,0,0,.12), 0 4px 12px rgba(0,0,0,.06);
  --shadow-xl:  0 24px 64px rgba(0,0,0,.16);
  --shadow-cyan: 0 0 32px rgba(13,207,207,.18);

  --transition-fast:   150ms cubic-bezier(.4,0,.2,1);
  --transition-base:   250ms cubic-bezier(.4,0,.2,1);
  --transition-slow:   400ms cubic-bezier(.4,0,.2,1);

  --max-w: 1200px;
  --nav-h: 72px;
}

[data-theme="dark"] {
  --th-bg-page:      var(--navy-950);
  --th-bg-section:   var(--white);
  --th-bg-alt:       var(--slate-50);
  --th-text-body:    var(--navy-900);
  --th-border:       var(--slate-200);

  --th-nav-scrolled-bg:     rgba(255,255,255,.92);
  --th-nav-scrolled-border: var(--slate-200);
  --th-nav-logo-color:      var(--navy-900);
  --th-nav-link-color:      var(--slate-700);
  --th-nav-link-hover-bg:   var(--cyan-50);
  --th-nav-link-hover-text: var(--cyan-600);
  --th-hamburger-color:     var(--navy-900);

  --th-toggle-bg:     rgba(255,255,255,.06);
  --th-toggle-border: rgba(255,255,255,.14);
  --th-toggle-color:  var(--slate-400);
  --th-toggle-hover:  rgba(255,255,255,.1);

  --th-page-hero-bg:    var(--navy-950);
  --th-page-hero-title: var(--white);
  --th-page-hero-sub:   var(--slate-400);

  --th-card-bg:     var(--white);
  --th-card-border: var(--slate-200);
  --th-code-bg:     var(--navy-950);
}

[data-theme="light"] {
  --th-bg-page:      var(--white);
  --th-bg-section:   var(--white);
  --th-bg-alt:       var(--slate-50);
  --th-text-body:    var(--navy-900);
  --th-border:       var(--slate-200);

  --th-nav-scrolled-bg:     rgba(255,255,255,.95);
  --th-nav-scrolled-border: var(--slate-200);
  --th-nav-logo-color:      var(--navy-900);
  --th-nav-link-color:      var(--slate-700);
  --th-nav-link-hover-bg:   var(--cyan-50);
  --th-nav-link-hover-text: var(--cyan-700);
  --th-hamburger-color:     var(--navy-900);

  --th-toggle-bg:     rgba(13,207,207,.08);
  --th-toggle-border: rgba(13,207,207,.25);
  --th-toggle-color:  var(--cyan-700);
  --th-toggle-hover:  rgba(13,207,207,.15);

  --th-page-hero-bg:    #f0fbfb;
  --th-page-hero-title: var(--navy-900);
  --th-page-hero-sub:   var(--slate-500);

  --th-card-bg:     var(--white);
  --th-card-border: var(--slate-200);
  --th-code-bg:     var(--navy-950);
}

/* ============================================================
   RESET + BASE
   ============================================================ */
* { box-sizing: border-box; }

html {
  color-scheme: dark;
  scroll-behavior: smooth;
  transition: background-color .35s ease, color .35s ease;
}
[data-theme="light"] { color-scheme: light; }

body {
  margin: 0;
  font-family: var(--font-body);
  color: var(--navy-900);
  background: var(--white);
  overflow-x: hidden;
  line-height: 1.6;
}
img, video, canvas, svg { display: block; max-width: 100%; }
a { text-decoration: none; color: inherit; }
ul, ol { list-style: none; margin: 0; padding: 0; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }

.container {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--space-6);
}
@media (min-width: 768px) { .container { padding: 0 var(--space-8); } }
@media (min-width: 1024px) { .container { padding: 0 var(--space-12); } }

.section { padding: var(--space-24) 0; }
.section--light { background: var(--slate-50); }

.label {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-primary);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--cyan-600);
  margin-bottom: var(--space-4);
}
.label::before {
  content: '';
  width: 20px;
  height: 2px;
  background: var(--cyan-500);
  border-radius: 2px;
}

.section-heading {
  font-family: var(--font-primary);
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -.02em;
  color: var(--navy-900);
  max-width: 720px;
}
.section-subheading {
  margin-top: var(--space-4);
  font-size: 17px;
  line-height: 1.7;
  color: var(--slate-500);
  max-width: 580px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-primary);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: .01em;
  border-radius: var(--radius-md);
  padding: 13px 26px;
  transition: var(--transition-base);
  white-space: nowrap;
}
.btn-primary { background: var(--cyan-500); color: var(--white); }
.btn-primary:hover { background: var(--cyan-600); box-shadow: var(--shadow-cyan); transform: translateY(-1px); }
.btn-outline { border: 1.5px solid var(--slate-200); color: var(--navy-900); background: transparent; }
.btn-outline:hover { border-color: var(--cyan-400); color: var(--cyan-600); background: var(--cyan-50); }
.btn-arrow::after { content: '→'; transition: transform var(--transition-fast); }
.btn-arrow:hover::after { transform: translateX(4px); }

.reveal { opacity: 0; transform: translateY(24px); transition: opacity .6s cubic-bezier(.4,0,.2,1), transform .6s cubic-bezier(.4,0,.2,1); }
.reveal.visible { opacity: 1; transform: none; }
.reveal-delay-1 { transition-delay: .1s; }
.reveal-delay-2 { transition-delay: .2s; }
.reveal-delay-3 { transition-delay: .3s; }

/* ============================================================
   THEME TOGGLE
   ============================================================ */
.theme-toggle {
  display: flex; align-items: center; justify-content: center;
  width: 38px; height: 38px;
  border-radius: var(--radius-md);
  background: var(--th-toggle-bg);
  border: 1px solid var(--th-toggle-border);
  color: var(--th-toggle-color);
  transition: background var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast);
  flex-shrink: 0;
  position: relative;
  overflow: hidden;
}
.theme-toggle:hover { background: var(--th-toggle-hover); transform: scale(1.05); }
.theme-toggle:active { transform: scale(.96); }
.theme-toggle svg { width: 16px; height: 16px; position: absolute; transition: opacity var(--transition-base), transform var(--transition-base); }
.theme-toggle .icon-sun  { opacity: 0; transform: rotate(90deg) scale(.6); }
.theme-toggle .icon-moon { opacity: 1; transform: rotate(0deg) scale(1); }
[data-theme="light"] .theme-toggle .icon-sun  { opacity: 1; transform: rotate(0deg) scale(1); }
[data-theme="light"] .theme-toggle .icon-moon { opacity: 0; transform: rotate(-90deg) scale(.6); }

/* ============================================================
   NAVIGATION (structurally identical to the main site)
   ============================================================ */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  height: var(--nav-h);
  transition: background var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
  border-bottom: 1px solid transparent;
}
.nav.scrolled {
  background: var(--th-nav-scrolled-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-color: var(--th-nav-scrolled-border);
  box-shadow: var(--shadow-sm);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: var(--nav-h); }
.nav-logo { display: flex; align-items: center; gap: var(--space-3); }
.nav-logo-text { font-family: var(--font-primary); font-size: 20px; font-weight: 800; color: var(--th-nav-logo-color); letter-spacing: -.03em; }
.nav-links { display: none; align-items: center; gap: var(--space-1); }
@media (min-width: 900px) { .nav-links { display: flex; } }
.nav-link { font-size: 14px; font-weight: 500; color: var(--th-nav-link-color); padding: var(--space-2) var(--space-3); border-radius: var(--radius-sm); transition: var(--transition-fast); }
.nav-link:hover { color: var(--th-nav-link-hover-text); background: var(--th-nav-link-hover-bg); }
.nav-link.active { color: var(--cyan-600); }
.nav-actions { display: flex; align-items: center; gap: var(--space-3); }

.hamburger { display: flex; flex-direction: column; gap: 5px; padding: var(--space-2); }
@media (min-width: 900px) { .hamburger { display: none; } }
.hamburger span { display: block; width: 22px; height: 2px; background: var(--th-hamburger-color); border-radius: 2px; transition: var(--transition-base); }

.mobile-menu {
  position: fixed; inset: 0; background: var(--white); z-index: 999;
  padding: var(--space-24) var(--space-6) var(--space-8);
  display: flex; flex-direction: column; gap: var(--space-4);
  transform: translateX(100%);
  transition: transform var(--transition-slow);
}
[data-theme="dark"] .mobile-menu { background: var(--navy-900); }
.mobile-menu.open { transform: translateX(0); }
.mobile-menu-link { font-family: var(--font-primary); font-size: 22px; font-weight: 700; color: var(--th-text-body); padding: var(--space-3) 0; border-bottom: 1px solid var(--slate-100); }
[data-theme="dark"] .mobile-menu-link { color: var(--white); border-bottom-color: rgba(255,255,255,.08); }

/* Since the blog always renders in daylight sections, nav sits on a
   light-on-scroll background from the top on this page (unlike the
   homepage hero, which starts transparent-on-dark). */
.nav:not(.scrolled) .nav-logo-text,
.nav:not(.scrolled) .nav-link,
.nav:not(.scrolled) .hamburger span { color: var(--navy-900); }
[data-theme="dark"] .nav:not(.scrolled) .nav-logo-text,
[data-theme="dark"] .nav:not(.scrolled) .nav-link,
[data-theme="dark"] .nav:not(.scrolled) .hamburger span { color: var(--white); }
[data-theme="dark"] .nav:not(.scrolled) .nav-link:hover { background: rgba(13,207,207,.12); }

/* ============================================================
   PAGE HERO (blog index + post header)
   ============================================================ */
.page-hero {
  padding: calc(var(--nav-h) + var(--space-16)) 0 var(--space-16);
  background: var(--th-page-hero-bg);
  border-bottom: 1px solid var(--th-border);
}
[data-theme="dark"] .page-hero { border-bottom-color: rgba(255,255,255,.06); }
.page-hero h1 {
  font-family: var(--font-primary);
  font-size: clamp(30px, 4.5vw, 48px);
  font-weight: 800;
  letter-spacing: -.02em;
  line-height: 1.12;
  color: var(--th-page-hero-title);
  max-width: 700px;
  margin: 0 0 var(--space-4);
}
.page-hero p { font-size: 17px; line-height: 1.7; color: var(--th-page-hero-sub); max-width: 560px; margin: 0; }

/* ============================================================
   POST LIST / CARDS
   ============================================================ */
.post-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
  padding: var(--space-16) 0 var(--space-24);
}
@media (min-width: 768px) { .post-grid { grid-template-columns: 1fr 1fr; } }

.post-card {
  background: var(--th-card-bg);
  border: 1px solid var(--th-card-border);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  transition: box-shadow var(--transition-base), border-color var(--transition-base), transform var(--transition-base);
  position: relative;
  overflow: hidden;
}
.post-card::before {
  content: '';
  position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba(13,207,207,.04) 0%, transparent 60%);
  opacity: 0;
  transition: opacity var(--transition-base);
}
.post-card:hover { box-shadow: var(--shadow-lg); border-color: var(--cyan-400); transform: translateY(-3px); }
.post-card:hover::before { opacity: 1; }
.post-card-meta {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--slate-500);
  text-transform: uppercase;
  letter-spacing: .06em;
}
.post-card h2 { font-family: var(--font-primary); font-size: 20px; font-weight: 700; letter-spacing: -.01em; color: var(--navy-900); margin: 0; }
.post-card:hover h2 { color: var(--cyan-700); }
.post-card p { font-size: 14px; line-height: 1.7; color: var(--slate-500); margin: 0; }
.post-card-tags { display: flex; gap: var(--space-2); flex-wrap: wrap; margin-top: var(--space-2); }
.post-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--cyan-700);
  background: var(--cyan-50);
  border: 1px solid var(--cyan-100);
  border-radius: var(--radius-sm);
  padding: 3px 9px;
}
.post-card-read { display: inline-flex; align-items: center; gap: var(--space-1); font-size: 13px; font-weight: 600; color: var(--cyan-600); margin-top: var(--space-2); transition: gap var(--transition-fast); }
.post-card:hover .post-card-read { gap: var(--space-3); }

/* ============================================================
   ARTICLE (single post page)
   ============================================================ */
.article-wrap { max-width: 720px; margin: 0 auto; padding: var(--space-16) var(--space-6) var(--space-24); }
@media (min-width: 768px) { .article-wrap { padding-left: var(--space-8); padding-right: var(--space-8); } }

.back-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: 13px;
  font-weight: 600;
  color: var(--cyan-600);
  margin-bottom: var(--space-8);
}
.back-link:hover { gap: var(--space-3); }

article.post-body h2 {
  font-family: var(--font-primary);
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -.01em;
  color: var(--navy-900);
  margin: var(--space-12) 0 var(--space-4);
  padding-top: var(--space-8);
  border-top: 1px solid var(--slate-100);
}
article.post-body h2:first-of-type { border-top: none; padding-top: 0; margin-top: var(--space-6); }
article.post-body p { font-size: 17px; line-height: 1.75; color: var(--slate-700); margin: 0 0 var(--space-5); }
article.post-body strong { color: var(--navy-900); }
article.post-body ul, article.post-body ol { margin: 0 0 var(--space-5); padding-left: 22px; }
article.post-body li { list-style: disc; font-size: 16px; line-height: 1.7; color: var(--slate-700); margin-bottom: var(--space-2); }
article.post-body code {
  font-family: var(--font-mono);
  background: var(--cyan-50);
  color: var(--cyan-700);
  padding: 2px 7px;
  border-radius: 5px;
  font-size: .88em;
}
article.post-body pre {
  background: var(--th-code-bg);
  color: #dff8f8;
  padding: var(--space-6);
  border-radius: var(--radius-md);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 14px;
  line-height: 1.65;
  margin: 0 0 var(--space-6);
  border-left: 3px solid var(--cyan-500);
}
article.post-body pre code { background: none; color: inherit; padding: 0; }
article.post-body blockquote {
  margin: 0 0 var(--space-6);
  padding: var(--space-1) 0 var(--space-1) var(--space-5);
  border-left: 3px solid var(--cyan-400);
  color: var(--slate-500);
  font-style: italic;
}

.post-header { margin-bottom: var(--space-2); }
.post-header .label { margin-bottom: var(--space-3); }
.post-header h1 {
  font-family: var(--font-primary);
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 800;
  letter-spacing: -.02em;
  line-height: 1.15;
  color: var(--navy-900);
  margin: 0 0 var(--space-4);
}
.post-meta { font-family: var(--font-mono); font-size: 13px; color: var(--slate-500); }

/* ============================================================
   FOOTER (identical markup/CSS to the main site)
   ============================================================ */
.footer { background: var(--navy-950); border-top: 1px solid rgba(255,255,255,.06); padding: var(--space-16) 0 var(--space-8); }
.footer-grid { display: grid; grid-template-columns: 1fr; gap: var(--space-10); margin-bottom: var(--space-12); }
@media (min-width: 768px) { .footer-grid { grid-template-columns: 1.5fr 1fr 1fr 1fr; } }
.footer-brand { display: flex; flex-direction: column; gap: var(--space-4); }
.footer-logo { font-family: var(--font-primary); font-size: 22px; font-weight: 800; color: var(--white); letter-spacing: -.03em; display: flex; align-items: center; gap: var(--space-3); }
.footer-logo-icon { width: 32px; height: 32px; background: var(--cyan-500); border-radius: var(--radius-sm); display: flex; align-items: center; justify-content: center; }
.footer-tagline { font-size: 14px; color: var(--slate-500); line-height: 1.6; max-width: 280px; }
.footer-col-title { font-family: var(--font-primary); font-size: 12px; font-weight: 700; text-transform: uppercase; letter-spacing: .08em; color: var(--slate-500); margin-bottom: var(--space-5); }
.footer-links { display: flex; flex-direction: column; gap: var(--space-3); }
.footer-link { font-size: 14px; color: var(--slate-400); transition: color var(--transition-fast); }
.footer-link:hover { color: var(--cyan-400); }
.footer-bottom { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: var(--space-4); padding-top: var(--space-8); border-top: 1px solid rgba(255,255,255,.06); }
.footer-copy { font-size: 13px; color: var(--slate-500); }
.footer-legal { display: flex; gap: var(--space-6); }
.footer-legal a { font-size: 13px; color: var(--slate-500); transition: color var(--transition-fast); }
.footer-legal a:hover { color: var(--cyan-400); }

@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }