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

:root {
  --color-text: #3a4550;
  --color-heading: #1a3a5c;
  --color-muted: #6b7f8e;
  --color-link: #2e78c2;
  --color-link-hover: #1a5a9e;
  --color-border: #c8d6e0;
  --color-bg-gradient-1: #dae8f5;
  --color-bg-gradient-2: #f0f4f8;
  --color-bg-gradient-3: #ffffff;
  --color-surface: rgba(255, 255, 255, 0.97);
  --color-header-bg: rgba(255, 255, 255, 0.92);
  --color-code-bg: #eef3f8;
  --color-pre-bg: #f6f9fc;
}

[data-theme="dark"] {
  --color-text: #c8d6e0;
  --color-heading: #e2ecf4;
  --color-muted: #8a9baa;
  --color-link: #5ba3e6;
  --color-link-hover: #7dbcf5;
  --color-border: #2e3d4d;
  --color-bg-gradient-1: #0f1923;
  --color-bg-gradient-2: #141e2a;
  --color-bg-gradient-3: #1a2433;
  --color-surface: rgba(22, 33, 46, 0.97);
  --color-header-bg: rgba(15, 25, 35, 0.92);
  --color-code-bg: #1c2a38;
  --color-pre-bg: #172130;
}

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

@import url("https://fonts.googleapis.com/css?family=Source+Sans+Pro:300,400,600");

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  height: 100%;
}

body {
  font-family: "Source Sans Pro", system-ui, sans-serif;
  font-weight: 300;
  line-height: 1.8;
  letter-spacing: 0.12em;
  color: var(--color-text);
  background:
    linear-gradient(135deg, var(--color-bg-gradient-1) 0%, var(--color-bg-gradient-2) 40%, var(--color-bg-gradient-3) 100%);
  background-attachment: fixed;
  min-height: 100vh;
}

/* -------------------------------------------------
   Header / Navigation
------------------------------------------------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.5rem 2rem;
  background: var(--color-header-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.site-brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  text-decoration: none;
  color: var(--color-heading);
  white-space: nowrap;
}

.site-brand:hover {
  text-decoration: none;
  color: var(--color-link);
}

.site-photo {
  height: 44px;
  border-radius: 4px;
  object-fit: cover;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.12);
}

.site-title {
  font-size: 1.2rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.22em;
}

.site-desc {
  font-size: 0.75rem;
  font-weight: 300;
  color: var(--color-muted);
  letter-spacing: 0.1em;
  text-transform: none;
}

.site-header nav {
  display: flex;
  align-items: center;
  gap: 0.1rem;
  margin-left: auto;
  flex-wrap: wrap;
}

.site-header nav a {
  padding: 0.3rem 0.7rem;
  text-decoration: none;
  text-transform: uppercase;
  font-size: 0.85rem;
  letter-spacing: 0.15em;
  color: var(--color-text);
  border-radius: 4px;
  transition: color 0.2s ease;
}

.site-header nav a:hover {
  color: var(--color-link);
  text-decoration: none;
}

/* Dropdown */

.nav-item {
  position: relative;
}

.nav-item > a {
  cursor: pointer;
}

.dropdown {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 12rem;
  padding: 0.4rem 0;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  z-index: 200;
}

.dropdown a {
  display: block;
  padding: 0.4rem 1rem;
  font-size: 0.82rem;
  white-space: nowrap;
}

.dropdown a:hover {
  background: var(--color-code-bg);
}

.nav-item:hover .dropdown {
  display: block;
}

/* Theme toggle */

#theme-toggle {
  background: none;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  cursor: pointer;
  padding: 0.3rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-muted);
  transition: color 0.2s ease, border-color 0.2s ease;
  margin-left: 0.5rem;
}

#theme-toggle:hover {
  color: var(--color-link);
  border-color: var(--color-link);
}

#theme-toggle .icon-sun {
  display: none;
}

[data-theme="dark"] #theme-toggle .icon-sun {
  display: block;
}

[data-theme="dark"] #theme-toggle .icon-moon {
  display: none;
}

/* -------------------------------------------------
   Main content
------------------------------------------------- */

main {
  max-width: 800px;
  margin: 2rem auto;
  padding: 2.5rem 3rem;
  background: var(--color-surface);
  border-radius: 4px;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.06);
}

h1, h2, h3 {
  color: var(--color-heading);
  line-height: 1.4;
  font-weight: 400;
}

h1 {
  margin-top: 0;
  font-size: 1.85em;
  letter-spacing: 0.22em;
  text-transform: uppercase;
}

h2 {
  font-size: 1.25em;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

h3 {
  font-size: 1em;
}

a {
  color: var(--color-link);
  text-decoration: none;
  transition: color 0.2s ease;
}

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

strong, b {
  font-weight: 600;
  color: var(--color-heading);
}

hr {
  border: none;
  border-bottom: 1px solid var(--color-border);
  margin: 2em 0;
}

/* -------------------------------------------------
   Breadcrumb
------------------------------------------------- */

.breadcrumb {
  margin-bottom: 1.5rem;
  font-size: 0.85rem;
  letter-spacing: 0.1em;
}

.breadcrumb a {
  color: var(--color-muted);
}

.breadcrumb a:hover {
  color: var(--color-link);
}

.breadcrumb .sep {
  margin: 0 0.3em;
  color: var(--color-border);
}

.breadcrumb .current {
  color: var(--color-heading);
  font-weight: 600;
}

/* -------------------------------------------------
   Hero photo (homepage)
------------------------------------------------- */

.hero-photo {
  width: 100%;
  max-height: 300px;
  object-fit: cover;
  object-position: center -30px;
  border-radius: 4px;
  margin-bottom: 1.5rem;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

/* -------------------------------------------------
   Cards
------------------------------------------------- */

.card {
  border: 1px solid var(--color-border);
  border-radius: 4px;
  padding: 1.2rem;
  margin: 1.2rem 0;
}

.card h2 {
  font-size: 1.1em;
}

/* -------------------------------------------------
   Utilities
------------------------------------------------- */

.muted {
  color: var(--color-muted);
  font-size: 0.85rem;
}

/* -------------------------------------------------
   Language switch
------------------------------------------------- */

.lang-switch {
  margin: 0 0 1.5rem 0;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
}

.lang-switch a {
  margin-right: 0.5rem;
  color: var(--color-muted);
}

.lang-switch a:hover {
  color: var(--color-link);
}

.lang-current {
  margin-right: 0.5rem;
  font-weight: 600;
  color: var(--color-heading);
}

/* -------------------------------------------------
   Code blocks
------------------------------------------------- */

code, pre {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  letter-spacing: 0;
  text-transform: none;
}

code {
  font-size: 0.9em;
  background: var(--color-code-bg);
  padding: 0.15em 0.4em;
  border-radius: 3px;
}

pre {
  padding: 1rem;
  overflow-x: auto;
  border-radius: 4px;
  border: 1px solid var(--color-border);
  background: var(--color-pre-bg);
  line-height: 1.5;
}

pre code {
  background: none;
  padding: 0;
}

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

footer {
  margin-top: 3rem;
  padding-top: 1rem;
  border-top: 1px solid var(--color-border);
  font-size: 0.85rem;
  color: var(--color-muted);
  text-transform: uppercase;
  letter-spacing: 0.15em;
}

/* -------------------------------------------------
   Responsive
------------------------------------------------- */

@media (max-width: 736px) {
  body {
    font-size: 11pt;
  }

  .site-header {
    padding: 0.5rem 1rem;
    flex-wrap: wrap;
  }

  .site-header nav {
    margin-left: 0;
    width: 100%;
    gap: 0;
  }

  .site-header nav a {
    font-size: 0.8rem;
    padding: 0.25rem 0.5rem;
  }

  main {
    margin: 1rem 0.5rem;
    padding: 2rem 1.5rem;
  }

  h1 {
    font-size: 1.5em;
  }
}

@media (max-width: 480px) {
  body {
    font-size: 10pt;
  }

  main {
    margin: 0;
    border-radius: 0;
    box-shadow: none;
    padding: 1.5rem 1rem;
  }

  h1 {
    font-size: 1.3em;
    letter-spacing: 0.15em;
  }
}