/* ===================================================
   大橘子的家 — Modern Bird Watching Site
   birds.css
   =================================================== */

/* --- Design Tokens --- */
:root {
  --color-forest:    #2d5a27;
  --color-moss:      #4a7c40;
  --color-fern:      #6b9e5e;
  --color-bark:      #5c4033;
  --color-soil:      #8b6347;
  --color-cream:     #faf6ef;
  --color-parchment: #f0e8d8;
  --color-stone:     #e8ddd0;
  --color-charcoal:  #2c2c2c;
  --color-sky:       #4a8fa8;
  --color-sky-hover: #2d6b85;

  --font-serif: 'Noto Serif TC', '標楷體', Georgia, serif;
  --font-sans:  'Noto Sans TC', '微軟正黑體', system-ui, sans-serif;

  --space-1:  4px;
  --space-2:  8px;
  --space-3:  12px;
  --space-4:  16px;
  --space-6:  24px;
  --space-8:  32px;
  --space-12: 48px;

  --sidebar-width: 200px;
  --radius: 6px;
}

/* --- Reset & Base --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-sans);
  background: var(--color-cream);
  color: var(--color-charcoal);
  line-height: 1.7;
  min-height: 100vh;
}

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

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

ul { list-style: none; }

/* ===================================================
   BREADCRUMB
   =================================================== */
.breadcrumb {
  background: var(--color-parchment);
  border-bottom: 1px solid var(--color-stone);
  padding: var(--space-2) var(--space-4);
  font-size: 0.8rem;
  font-family: var(--font-sans);
  white-space: nowrap;
  overflow-x: auto;
  display: flex;
  align-items: center;
  gap: var(--space-1);
  flex-wrap: wrap;
}
.breadcrumb a { color: var(--color-sky); }
.breadcrumb a:hover { color: var(--color-sky-hover); }
.breadcrumb-current {
  color: var(--color-bark);
  font-weight: 700;
}
.breadcrumb-sep {
  color: var(--color-fern);
  margin: 0 2px;
}
.breadcrumb-nav-links {
  margin-left: var(--space-2);
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
}
.breadcrumb-nav-links a {
  background: var(--color-stone);
  border-radius: 3px;
  padding: 1px 6px;
  font-size: 0.75rem;
}
.breadcrumb-nav-links a:hover {
  background: var(--color-forest);
  color: white;
  text-decoration: none;
}

/* ===================================================
   TWO-COLUMN LAYOUT
   =================================================== */
.layout {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  grid-template-areas: "toggle toggle" "sidebar content";
  min-height: calc(100vh - 42px);
}

/* Hamburger button (hidden on desktop) */
.sidebar-toggle {
  display: none;
  grid-area: toggle;
  background: var(--color-forest);
  color: white;
  border: none;
  padding: var(--space-2) var(--space-4);
  font-size: 1.2rem;
  cursor: pointer;
  text-align: left;
  font-family: var(--font-sans);
  letter-spacing: 0.05em;
}
.sidebar-toggle:hover { background: var(--color-moss); }

/* Sidebar */
.sidebar {
  grid-area: sidebar;
  background: var(--color-parchment);
  border-right: 2px solid var(--color-stone);
  padding: var(--space-4) var(--space-3);
  font-size: 0.85rem;
  line-height: 2;
  position: sticky;
  top: 0;
  max-height: 100vh;
  overflow-y: auto;
}
.sidebar a {
  display: block;
  padding: 0 var(--space-2);
  border-radius: 3px;
  color: var(--color-sky);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.sidebar a:hover {
  background: var(--color-stone);
  text-decoration: none;
}
.sidebar b, .sidebar strong {
  display: block;
  padding: 0 var(--space-2);
  padding-left: var(--space-3);
  border-left: 3px solid var(--color-fern);
  color: var(--color-bark);
  font-weight: 700;
  font-family: var(--font-serif);
}
.sidebar hr {
  border: none;
  border-top: 1px solid var(--color-stone);
  margin: var(--space-2) 0;
}
.sidebar-section-title {
  font-size: 0.75rem;
  color: var(--color-soil);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: var(--space-2) var(--space-2) 0;
  margin-top: var(--space-2);
}

/* Main content area */
.content {
  grid-area: content;
  padding: var(--space-6) var(--space-8);
  max-width: 900px;
}

/* ===================================================
   SEASON INDEX PAGE  (.page-season)
   =================================================== */
.page-season .content h1,
.page-season .season-title {
  font-family: var(--font-serif);
  color: var(--color-bark);
  font-size: 1.4rem;
  margin-bottom: var(--space-4);
  padding-bottom: var(--space-2);
  border-bottom: 2px solid var(--color-fern);
}

.page-season .content ul {
  margin-top: var(--space-2);
}

.page-season .content li {
  border-left: 3px solid transparent;
  padding: var(--space-2) var(--space-3);
  border-radius: 0 var(--radius) var(--radius) 0;
  transition: background 150ms, border-color 150ms;
  line-height: 1.5;
}
.page-season .content li:hover {
  background: var(--color-parchment);
  border-left-color: var(--color-fern);
}
.page-season .content li a {
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-sky);
}
.page-season .content li a:hover {
  color: var(--color-sky-hover);
}

/* ===================================================
   BIRD SPECIES PAGE  (.page-bird)
   =================================================== */
.page-bird .content p:first-child,
.page-bird .bird-name {
  font-family: var(--font-serif);
  color: var(--color-bark);
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: var(--space-2);
}

.bird-meta {
  color: var(--color-soil);
  font-size: 0.875rem;
  margin-bottom: var(--space-4);
}

.bird-photo {
  border-radius: var(--radius);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
  margin: var(--space-4) 0;
  width: auto;
  max-width: 100%;
}

/* Extra images on the same page */
.page-bird .content p img {
  border-radius: var(--radius);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.12);
  margin: var(--space-3) 0;
}

/* ===================================================
   ALL.HTM  (.page-all)
   =================================================== */
.page-all .content h2,
.page-all .content > p > a {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  color: var(--color-bark);
  font-weight: 700;
  margin-top: var(--space-6);
  margin-bottom: var(--space-1);
  display: block;
}
.page-all .content > p:first-child > a { margin-top: 0; }

.page-all .content ul {
  margin-bottom: var(--space-2);
}
.page-all .content li {
  border-left: 3px solid transparent;
  padding: 2px var(--space-3);
  border-radius: 0 var(--radius) var(--radius) 0;
  transition: background 120ms, border-color 120ms;
  font-size: 0.95rem;
}
.page-all .content li:hover {
  background: var(--color-parchment);
  border-left-color: var(--color-fern);
}

/* ===================================================
   HOMEPAGE  (.page-index)
   =================================================== */

/* Site header */
.site-header {
  background: var(--color-forest);
  background: linear-gradient(135deg, var(--color-forest) 0%, #1e3d1a 100%);
  padding: var(--space-8) var(--space-8) var(--space-6);
  color: white;
}
.site-header h1 {
  font-family: var(--font-serif);
  font-size: 2rem;
  letter-spacing: 0.08em;
  color: white;
  margin-bottom: var(--space-2);
}
.site-welcome {
  font-size: 1rem;
  color: rgba(255, 255, 255, 0.85);
  font-family: var(--font-sans);
}

/* Top nav bar */
.home-nav {
  background: var(--color-moss);
  padding: var(--space-2) var(--space-8);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1) var(--space-3);
  align-items: center;
  font-size: 0.8rem;
}
.home-nav a {
  color: rgba(255, 255, 255, 0.9);
  padding: 2px 6px;
  border-radius: 3px;
  transition: background 150ms;
}
.home-nav a:hover {
  background: rgba(255, 255, 255, 0.2);
  color: white;
  text-decoration: none;
}
.home-nav-sep {
  color: rgba(255, 255, 255, 0.4);
  user-select: none;
}

/* Season grid */
.season-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--space-6);
  padding: var(--space-8);
  max-width: 1280px;
  margin: 0 auto;
}

.season-card {
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.12);
  background: white;
  transition: transform 200ms ease, box-shadow 200ms ease;
  text-decoration: none;
  display: block;
  color: inherit;
}
.season-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.18);
  text-decoration: none;
}
.season-thumb {
  width: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  display: block;
}
.season-card-label {
  padding: var(--space-3) var(--space-4);
  font-family: var(--font-serif);
  font-size: 1.05rem;
  color: var(--color-bark);
  border-top: 1px solid var(--color-stone);
  background: white;
}

/* Site footer */
.site-footer {
  text-align: center;
  padding: var(--space-8);
  font-size: 0.8rem;
  color: var(--color-soil);
  border-top: 1px solid var(--color-stone);
  margin-top: var(--space-8);
}
.site-footer a { color: var(--color-soil); }

/* ===================================================
   SPECIAL / LINK / ABOUT PAGES  (.page-other)
   =================================================== */
.page-other .content {
  padding: var(--space-6) var(--space-8);
}
.page-other .content p {
  margin-bottom: var(--space-3);
  line-height: 1.8;
}

/* ===================================================
   RESPONSIVE
   =================================================== */
@media (max-width: 640px) {
  .layout {
    grid-template-columns: 1fr;
    grid-template-areas: "toggle" "content";
  }

  /* Show hamburger */
  .sidebar-toggle { display: block; }

  /* Sidebar slides in as overlay */
  .sidebar {
    grid-area: unset;
    position: fixed;
    top: 0;
    left: -270px;
    width: 260px;
    height: 100vh;
    z-index: 200;
    box-shadow: 4px 0 20px rgba(0, 0, 0, 0.25);
    transition: left 250ms ease;
  }
  .sidebar.is-open { left: 0; }

  /* Overlay backdrop */
  .sidebar-backdrop {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    z-index: 199;
  }
  .sidebar-backdrop.is-open { display: block; }

  .content {
    grid-area: content;
    padding: var(--space-4);
  }

  .season-grid {
    grid-template-columns: 1fr;
    padding: var(--space-4);
    gap: var(--space-4);
  }

  .site-header { padding: var(--space-6) var(--space-4) var(--space-4); }
  .site-header h1 { font-size: 1.5rem; }
  .home-nav { padding: var(--space-2) var(--space-4); }
}

@media (min-width: 641px) and (max-width: 1024px) {
  :root { --sidebar-width: 160px; }
  .content { padding: var(--space-4) var(--space-6); }
}

@media (min-width: 1400px) {
  .season-grid {
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  }
}

/* ===================================================
   SEARCH BOX (injected into every page via birds.js)
   =================================================== */
.site-search {
  display: flex;
  align-items: center;
  gap: 0;
  border-radius: 6px;
  overflow: hidden;
  box-shadow: 0 1px 6px rgba(0,0,0,0.15);
}
.site-search input[type="search"] {
  border: none;
  padding: 6px 12px;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  width: 180px;
  outline: none;
  background: rgba(255,255,255,0.95);
  color: var(--color-charcoal);
}
.site-search input[type="search"]::placeholder { color: #aaa; }
.site-search button {
  background: var(--color-moss);
  color: white;
  border: none;
  padding: 6px 12px;
  cursor: pointer;
  font-size: 0.9rem;
  transition: background 150ms;
  white-space: nowrap;
}
.site-search button:hover { background: var(--color-fern); }

/* Placed inside .site-header on homepage */
.site-header .site-search { margin-top: var(--space-4); }

/* Placed inside .breadcrumb on other pages */
.breadcrumb .site-search { margin-left: auto; }
.breadcrumb .site-search input[type="search"] {
  background: white;
  font-size: 0.8rem;
  width: 150px;
  padding: 3px 8px;
}
.breadcrumb .site-search button { padding: 3px 8px; font-size: 0.8rem; }

@media (max-width: 640px) {
  .site-search input[type="search"] { width: 120px; }
  .breadcrumb .site-search input[type="search"] { width: 100px; }
}

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