/**
 * assets/css/style.css — ธีมขาว–น้ำเงิน มินิมอล/โมเดิร์น, font Kanit (§2, §9)
 * แสง/เงานุ่มๆ + hover animation ทุกปุ่ม/การ์ด ตามที่ขอ
 * ไม่ใช้ letter-spacing กว้าง/uppercase กับตัวอักษรไทย
 */

:root {
  /* โทนสีอ้างอิงจาก lib.alvis.ink_mockup.html (ค่าจริงที่ได้จาก getComputedStyle) */
  --blue-900: #0f172a;
  --blue-800: #1e2f5c;
  --blue-700: #2b4dbf;
  --blue-600: #3d63dd;
  --blue-500: #3d63dd;
  --blue-400: #6b8ff2;
  --blue-100: #dce4fb;
  --blue-50: #eef2fd;
  --border: #e4e9f2;
  --tag-bg: #f1f4f9;
  --text: #0f172a;
  --text-muted: #3a4256;
  --danger: #9b1c1c;
  --success: #14632f;
  --diff-add-bg: #e3f4ea;
  --diff-add-text: #14632f;
  --diff-remove-bg: #fde8e8;
  --diff-remove-text: #9b1c1c;
  --radius: 18px;
  --radius-sm: 10px;
  --radius-lg: 22px;
  --max-width: 1200px;

  --shadow-xs: 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow-sm: 0 6px 20px rgba(15, 23, 42, 0.05);
  --shadow-md: 0 10px 28px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 18px 44px rgba(15, 23, 42, 0.12);
  --glow-blue: 0 4px 14px rgba(61, 99, 221, 0.25);

  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: #f6f8fc;
  color: var(--text);
  font-family: 'Kanit', sans-serif;
  font-size: 15px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--blue-600); text-decoration: none; transition: color 0.18s var(--ease); }
a:hover { color: var(--blue-800); text-decoration: none; }

h1, h2, h3 { color: var(--blue-900); font-weight: 600; margin: 0 0 12px; letter-spacing: -0.01em; }

::selection { background: var(--blue-100); color: var(--blue-900); }

/* ---------------------------------------------------------------------
   ปุ่ม / form ทั่วไป — hover/active animation ทุกปุ่ม
--------------------------------------------------------------------- */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: inherit;
  font-size: 14px;
  font-weight: 500;
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: transform 0.18s var(--ease), box-shadow 0.22s var(--ease), background 0.18s var(--ease), color 0.18s var(--ease), border-color 0.18s var(--ease);
  will-change: transform;
}
.btn:active { transform: translateY(1px) scale(0.98); }

.btn-primary {
  background: linear-gradient(135deg, var(--blue-600), var(--blue-700));
  color: #fff;
  box-shadow: var(--shadow-sm);
}
.btn-primary:hover {
  color: #fff;
  transform: translateY(-2px);
  box-shadow: var(--glow-blue);
}

.btn-secondary {
  background: var(--blue-100);
  color: var(--blue-800);
  box-shadow: var(--shadow-xs);
}
.btn-secondary:hover { background: #dde6fb; transform: translateY(-2px); box-shadow: var(--shadow-sm); }

.btn-ghost {
  background: #fff;
  color: var(--blue-800);
  border-color: var(--border);
}
.btn-ghost:hover {
  border-color: var(--blue-500);
  box-shadow: var(--shadow-sm);
  transform: translateY(-2px);
  color: var(--blue-800);
}

.btn-text { background: transparent; color: var(--text-muted); padding: 9px 8px; }
.btn-text:hover { color: var(--blue-700); background: var(--blue-50); }

.btn-danger { background: #fdecea; color: var(--danger); }
.btn-danger:hover { background: #fbdad6; transform: translateY(-2px); box-shadow: 0 6px 18px rgba(211, 57, 42, 0.18); }

.btn-lg { padding: 13px 26px; font-size: 16px; border-radius: var(--radius-sm); }
.btn-sm { padding: 6px 12px; font-size: 13px; }
.btn-block { display: flex; width: 100%; justify-content: center; margin-bottom: 8px; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; transform: none !important; box-shadow: none !important; }

.btn-icon {
  background: #fff; border: 1px solid var(--border); border-radius: 999px;
  padding: 9px 14px; cursor: pointer; font-family: inherit; font-size: 14px; color: var(--text);
  display: inline-flex; align-items: center; gap: 6px;
  transition: transform 0.18s var(--ease), box-shadow 0.22s var(--ease), background 0.18s var(--ease), border-color 0.18s var(--ease), color 0.18s var(--ease);
}
.btn-icon:hover { transform: translateY(-2px) scale(1.03); box-shadow: var(--shadow-sm); border-color: var(--blue-400); }
.btn-icon.active { background: var(--blue-100); color: var(--blue-800); border-color: var(--blue-500); box-shadow: var(--glow-blue); }
#likeBtn.active { color: var(--danger); border-color: #f3c9c9; background: var(--diff-remove-bg); }
#likeBtn.active .icon-heart { fill: currentColor; }
#copyLinkBtn.active { color: var(--success); border-color: #bfe3cc; background: var(--diff-add-bg); }

input[type="text"], input[type="email"], input[type="url"], input[type="search"],
input[type="number"], input[type="password"], textarea, select {
  font-family: inherit;
  font-size: 14px;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  width: 100%;
  margin-bottom: 12px;
  background: #fff;
  color: var(--text);
  transition: border-color 0.18s var(--ease), box-shadow 0.18s var(--ease);
}
input:hover, textarea:hover, select:hover { border-color: #c7d3ef; }
input:focus, textarea:focus, select:focus {
  outline: none; border-color: var(--blue-500);
  box-shadow: 0 0 0 4px rgba(63, 107, 234, 0.14);
}

label { display: block; font-weight: 500; margin-bottom: 4px; color: var(--blue-900); font-size: 13px; }
.form-error { color: var(--danger); background: #fdecea; border-radius: var(--radius-sm); padding: 10px 14px; margin: 10px 0; }
.hint { color: var(--text-muted); font-size: 13px; }
.muted-note { color: var(--text-muted); font-size: 14px; }
.empty-state { color: var(--text-muted); padding: 32px 24px; text-align: center; }

/* ---------------------------------------------------------------------
   Header — glass effect
--------------------------------------------------------------------- */

.site-header {
  background: rgba(255, 255, 255, 0.82);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 20;
}
.site-header-inner {
  max-width: var(--max-width); margin: 0 auto; padding: 14px 20px;
  display: flex; align-items: center; gap: 24px;
}
.brand { font-size: 21px; font-weight: 700; color: var(--blue-900); transition: transform 0.18s var(--ease); display: inline-flex; align-items: center; gap: 8px; }
.brand:hover { transform: translateY(-1px); color: var(--blue-900); }
.brand-icon {
  display: inline-flex; align-items: center; justify-content: center;
  width: 30px; height: 30px; border-radius: 10px; flex: none;
  background: linear-gradient(135deg, var(--blue-600), var(--blue-700)); color: #fff;
  box-shadow: var(--shadow-sm);
}
.brand-lib {
  background: linear-gradient(135deg, var(--blue-600), var(--blue-400));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.brand-dot { color: var(--blue-900); }
.main-nav { display: flex; gap: 22px; flex: 1; }
.main-nav a { color: var(--text); font-weight: 500; position: relative; padding: 4px 0; display: inline-flex; align-items: center; gap: 6px; }
.main-nav a svg { opacity: 0.75; transition: opacity 0.18s var(--ease); }
.main-nav a:hover svg, .main-nav a.nav-active svg { opacity: 1; }
.main-nav a::after {
  content: ''; position: absolute; left: 0; right: 100%; bottom: -2px; height: 2px;
  background: var(--blue-600); border-radius: 2px; transition: right 0.22s var(--ease);
}
.main-nav a:hover::after, .main-nav a.nav-active::after { right: 0; }
.header-actions { display: flex; align-items: center; gap: 10px; }
.header-actions .btn svg { flex: none; }
.user-chip {
  display: flex; align-items: center; gap: 8px; color: var(--text); font-weight: 500;
  padding: 6px 12px 6px 6px; border-radius: 999px; transition: background 0.18s var(--ease), transform 0.18s var(--ease);
}
.user-chip:hover { background: var(--blue-50); transform: translateY(-1px); color: var(--text); }
.user-chip .avatar { width: 30px; height: 30px; border-radius: 50%; box-shadow: 0 0 0 2px #fff, 0 0 0 3px var(--blue-100); }
.avatar-initial {
  display: inline-flex; align-items: center; justify-content: center; flex: none;
  background: var(--blue-100); color: var(--blue-700); border-radius: 50%; font-weight: 600;
  box-shadow: 0 0 0 2px #fff, 0 0 0 3px var(--blue-100);
}
.user-chip-inline { display: inline-flex; align-items: center; gap: 6px; }
.user-chip-inline .avatar-img { width: 22px; height: 22px; border-radius: 50%; }
.guest-banner {
  background: var(--blue-50); color: var(--blue-800); text-align: center;
  padding: 9px 16px; font-size: 13px; border-top: 1px solid var(--border);
  display: flex; align-items: center; justify-content: center; gap: 6px;
}

/* ---------------------------------------------------------------------
   Main layout
--------------------------------------------------------------------- */

.site-main { max-width: var(--max-width); margin: 0 auto; padding: 28px 20px 90px; }
.page-heading { font-size: 23px; margin-bottom: 18px; display: flex; align-items: center; gap: 10px; }
.breadcrumb { font-size: 13px; color: var(--text-muted); margin-bottom: 14px; }
.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--blue-700); }

.site-footer { border-top: 1px solid var(--border); margin-top: 48px; }
.site-footer-inner {
  max-width: var(--max-width); margin: 0 auto; padding: 22px 20px;
  display: flex; justify-content: space-between; color: var(--text-muted); font-size: 13px;
}
.footer-nav { display: flex; gap: 16px; }
.footer-nav a { color: var(--text-muted); }
.footer-nav a:hover { color: var(--blue-700); }

.mobile-nav { display: none; }

/* ---------------------------------------------------------------------
   หน้าแรก: ค้นหา + filter + grid
--------------------------------------------------------------------- */

.hero-search { margin-bottom: 18px; }
.search-form { display: flex; gap: 8px; }
.search-form input { margin-bottom: 0; flex: 1; }

.filter-bar { display: flex; flex-direction: column; gap: 10px; margin-bottom: 24px; }
.pill-group { display: flex; flex-wrap: wrap; gap: 8px; }
.pill {
  background: #fff; border: 1px solid var(--border); border-radius: 999px;
  padding: 8px 18px; font-size: 13px; color: var(--text); white-space: nowrap;
  transition: transform 0.18s var(--ease), box-shadow 0.2s var(--ease), background 0.18s var(--ease), border-color 0.18s var(--ease), color 0.18s var(--ease);
}
.pill:hover { text-decoration: none; border-color: var(--blue-400); transform: translateY(-2px); box-shadow: var(--shadow-sm); color: var(--blue-800); }
.pill-sm { padding: 6px 14px; font-size: 12px; }
.pill-active { background: linear-gradient(135deg, var(--blue-600), var(--blue-700)); color: #fff; border-color: var(--blue-700); box-shadow: var(--shadow-sm); }
.pill-active:hover { color: #fff; box-shadow: var(--glow-blue); }

.post-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.post-row-scroll { display: flex; gap: 18px; overflow-x: auto; padding: 4px 4px 12px; scroll-snap-type: x proximity; }
.post-row-scroll .post-card { min-width: 240px; flex: 0 0 240px; scroll-snap-align: start; }

.post-card {
  display: block; border: 1px solid var(--border); border-radius: var(--radius);
  overflow: hidden; color: var(--text); background: #fff;
  box-shadow: var(--shadow-xs);
  transition: box-shadow 0.28s var(--ease), transform 0.28s var(--ease), border-color 0.28s var(--ease);
}
.post-card:hover {
  box-shadow: var(--shadow-lg);
  text-decoration: none;
  transform: translateY(-6px);
  border-color: #d3ddf7;
}
.post-card-thumb {
  position: relative; height: 124px; background: var(--blue-50);
  display: flex; align-items: center; justify-content: center; overflow: hidden;
}
.post-card-thumb::before {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(120px 80px at 30% 20%, rgba(255,255,255,0.6), transparent 70%);
  opacity: 0; transition: opacity 0.28s var(--ease);
}
.post-card:hover .post-card-thumb::before { opacity: 1; }
.post-card-thumb-video { background: linear-gradient(135deg, #e8edfc, #d6e0fa); }
.post-card-thumb-file { background: linear-gradient(135deg, #f4f7fe, #e8edfc); }
.post-card-thumb-html { background: linear-gradient(135deg, #eaf2ff, #dbe6ff); }
.post-type-icon {
  color: var(--blue-700); opacity: 0.4; transition: transform 0.28s var(--ease), opacity 0.28s var(--ease);
  display: inline-flex;
}
.post-card:hover .post-type-icon { transform: scale(1.12) rotate(-4deg); opacity: 0.55; }
.post-type-badge {
  position: absolute; top: 10px; left: 10px; background: rgba(15, 23, 42, 0.85); color: #fff;
  font-size: 11px; padding: 4px 10px; border-radius: 999px; backdrop-filter: blur(4px);
}
.post-lock-icon {
  position: absolute; top: 10px; right: 10px; color: #fff;
  display: inline-flex; filter: drop-shadow(0 1px 2px rgba(0,0,0,0.35));
}
.post-card-body { padding: 14px 16px; }
.post-card-title { font-size: 15px; margin: 0 0 8px; color: var(--blue-900); line-height: 1.4; }
.post-card-meta { display: flex; gap: 6px; font-size: 12px; color: var(--text-muted); margin-bottom: 10px; align-items: center; flex-wrap: wrap; }
.grade-badge { background: var(--blue-100); color: var(--blue-800); padding: 3px 9px; border-radius: 999px; font-size: 11px; font-weight: 500; }
.post-card-footer { display: flex; justify-content: space-between; font-size: 12px; color: var(--text-muted); }

.pagination { display: flex; gap: 6px; justify-content: center; margin-top: 24px; }
.page-link {
  border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 7px 13px; color: var(--text);
  transition: transform 0.18s var(--ease), box-shadow 0.18s var(--ease), background 0.18s var(--ease);
}
.page-link:hover { transform: translateY(-2px); box-shadow: var(--shadow-sm); }
.page-active { background: linear-gradient(135deg, var(--blue-600), var(--blue-700)); color: #fff; border-color: var(--blue-700); }
.page-active:hover { color: #fff; }

/* ---------------------------------------------------------------------
   หน้าวิชา
--------------------------------------------------------------------- */

.topic-row { margin-bottom: 32px; }
.topic-row-title { font-size: 16px; margin-bottom: 12px; }
.grade-section { margin-bottom: 32px; }
.subject-chip-list { display: flex; flex-wrap: wrap; gap: 8px; }
.subject-chip {
  background: var(--blue-50); border: 1px solid var(--border); border-radius: var(--radius-sm);
  padding: 9px 16px; font-size: 13px; color: var(--blue-800);
  transition: transform 0.18s var(--ease), box-shadow 0.18s var(--ease), background 0.18s var(--ease);
}
.subject-chip:hover { transform: translateY(-2px); box-shadow: var(--shadow-sm); background: #eaf0fd; color: var(--blue-800); }

/* ---------------------------------------------------------------------
   หน้าสร้าง/แก้ไขโพสต์
--------------------------------------------------------------------- */

.type-picker { display: flex; gap: 14px; margin-bottom: 22px; }
.type-card {
  flex: 1; background: #fff; border: 2px solid var(--border); border-radius: var(--radius);
  padding: 22px; text-align: center; cursor: pointer; font-family: inherit; display: flex;
  flex-direction: column; gap: 6px; align-items: center;
  transition: transform 0.22s var(--ease), box-shadow 0.22s var(--ease), border-color 0.22s var(--ease);
}
.type-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: var(--blue-400); }
.type-card-icon { display: inline-flex; color: var(--blue-600); transition: transform 0.22s var(--ease); }
.type-card:hover .type-card-icon { transform: scale(1.15); }
.type-card small { color: var(--text-muted); }
.type-card-active { border-color: var(--blue-600); background: var(--blue-50); box-shadow: var(--glow-blue); }

.post-form-grid { display: grid; grid-template-columns: 1fr 1.3fr; gap: 28px; align-items: start; }
.type-panel { display: none; }
.type-panel-enter { animation: panel-enter 0.32s var(--ease); }
@keyframes panel-enter {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.visibility-toggle { display: flex; align-items: center; gap: 8px; font-weight: normal; color: var(--text); margin: 10px 0; }
.visibility-toggle input { width: auto; margin: 0; }

.topic-input { position: relative; margin-bottom: 12px; }
.topic-chips { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 6px; }
.chip {
  background: var(--blue-100); color: var(--blue-800); border-radius: 999px; padding: 5px 12px;
  font-size: 12px; display: inline-flex; align-items: center; gap: 4px;
  transition: transform 0.16s var(--ease), box-shadow 0.16s var(--ease);
}
.chip:hover { transform: translateY(-1px); box-shadow: var(--shadow-xs); }
.chip-static { background: var(--blue-50); }
.chip-remove { background: none; border: none; color: var(--blue-800); cursor: pointer; font-size: 14px; line-height: 1; transition: transform 0.16s var(--ease); }
.chip-remove:hover { transform: scale(1.25); }
.topic-suggestions { display: flex; flex-wrap: wrap; gap: 6px; }
.topic-suggestion {
  background: #fff; border: 1px dashed var(--border); border-radius: 999px; padding: 5px 12px;
  font-size: 12px; cursor: pointer; color: var(--text-muted);
  transition: transform 0.16s var(--ease), border-color 0.16s var(--ease), color 0.16s var(--ease);
}
.topic-suggestion:hover { transform: translateY(-2px); border-color: var(--blue-400); border-style: solid; color: var(--blue-700); }

.video-preview iframe { width: 100%; aspect-ratio: 16/9; border: 0; border-radius: var(--radius-sm); margin-top: 8px; box-shadow: var(--shadow-sm); }
.file-list { list-style: none; padding: 0; margin: 8px 0; }
.file-list li {
  display: flex; justify-content: space-between; padding: 8px 12px; background: var(--blue-50);
  border-radius: var(--radius-sm); margin-bottom: 6px; font-size: 13px;
  transition: transform 0.16s var(--ease), box-shadow 0.16s var(--ease);
}
.file-list li:hover { transform: translateX(2px); box-shadow: var(--shadow-xs); }

.html-mode-toggle { display: flex; gap: 8px; margin-bottom: 12px; }
.mode-btn {
  flex: 1; padding: 9px; border: 1px solid var(--border); background: #fff; border-radius: var(--radius-sm);
  cursor: pointer; font-family: inherit; transition: transform 0.18s var(--ease), box-shadow 0.18s var(--ease), background 0.18s var(--ease), color 0.18s var(--ease), border-color 0.18s var(--ease);
}
.mode-btn:hover { transform: translateY(-2px); box-shadow: var(--shadow-sm); border-color: var(--blue-400); }
.mode-btn-active { background: linear-gradient(135deg, var(--blue-600), var(--blue-700)); color: #fff; border-color: var(--blue-700); }
.mode-btn-active:hover { color: #fff; box-shadow: var(--glow-blue); }

.studio-editor, .studio-standalone .studio-editor { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; height: 480px; }
.studio-code textarea {
  width: 100%; height: 100%; font-family: 'Fira Code', ui-monospace, monospace; font-size: 13px;
  background: #0f1626; color: #e6ebff; border-radius: var(--radius); resize: none; margin: 0;
  border: 1px solid #223061; box-shadow: var(--shadow-sm);
}
.studio-code textarea:focus { border-color: var(--blue-500); box-shadow: var(--glow-blue); }
.studio-preview { display: flex; flex-direction: column; border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-sm); }
.studio-preview-toolbar { display: flex; justify-content: space-between; align-items: center; padding: 8px 10px; background: var(--blue-50); }
.studio-tabs { display: none; gap: 4px; }
.studio-tab { padding: 5px 12px; border: 1px solid var(--border); background: #fff; border-radius: 999px; font-family: inherit; cursor: pointer; font-size: 12px; transition: all 0.18s var(--ease); }
.studio-tab:hover { transform: translateY(-1px); box-shadow: var(--shadow-xs); }
.studio-tab-active { background: var(--blue-800); color: #fff; }
#previewFrame, #standaloneFrame { flex: 1; border: 0; background: #fff; }
.studio-standalone { margin-top: 12px; }

/* ---------------------------------------------------------------------
   หน้าโพสต์
--------------------------------------------------------------------- */

.post-page-grid { display: grid; grid-template-columns: 1fr 300px; gap: 36px; align-items: start; }
.post-title { font-size: 25px; margin-bottom: 14px; }
.old-revision-banner { background: #fff8e1; border: 1px solid #f0c96b; border-radius: var(--radius-sm); padding: 10px 14px; margin-bottom: 14px; font-size: 13px; }
.post-content-area { margin-bottom: 22px; }
.content-locked {
  background: linear-gradient(160deg, var(--blue-50), #fff); border-radius: var(--radius-lg); padding: 64px 20px; text-align: center;
  display: flex; flex-direction: column; align-items: center; gap: 12px; border: 1px solid var(--border); box-shadow: var(--shadow-sm);
}
.lock-icon {
  display: inline-flex; align-items: center; justify-content: center;
  width: 64px; height: 64px; border-radius: 50%; color: var(--blue-700);
  background: var(--blue-100); box-shadow: var(--shadow-sm);
}
.video-embed-wrap { position: relative; aspect-ratio: 16/9; border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-md); }
.video-embed-wrap iframe { width: 100%; height: 100%; border: 0; }
.sandbox-frame-wrap { border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-md); }
.sandbox-frame-wrap iframe { width: 100%; height: 640px; border: 0; }
.pdf-viewer-list { display: flex; flex-direction: column; gap: 22px; }
.file-viewer-box { border: 1px solid var(--border); border-radius: var(--radius); padding: 14px; box-shadow: var(--shadow-xs); transition: box-shadow 0.22s var(--ease); }
.file-viewer-box:hover { box-shadow: var(--shadow-sm); }
.file-viewer-box img { max-width: 100%; border-radius: var(--radius-sm); }
.pdf-page-canvas { max-width: 100%; display: block; margin: 0 auto 12px; border-radius: 4px; box-shadow: var(--shadow-sm); }
.post-description { color: var(--text); margin-bottom: 18px; }
.topic-chip-row { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 22px; }

.post-sidebar { display: flex; flex-direction: column; gap: 12px; }
.social-actions { display: flex; gap: 8px; }
.post-meta { font-size: 13px; background: var(--blue-50); border-radius: var(--radius); padding: 14px 16px; }
.post-meta dt { color: var(--text-muted); margin-top: 8px; }
.post-meta dd { margin: 0 0 4px; color: var(--text); font-weight: 500; }
.related-posts { border-top: 1px solid var(--border); padding-top: 14px; }
.related-post-link { display: block; padding: 7px 4px; font-size: 13px; border-radius: var(--radius-sm); transition: background 0.16s var(--ease), transform 0.16s var(--ease), padding-left 0.16s var(--ease); }
.related-post-link:hover { background: var(--blue-50); padding-left: 10px; color: var(--blue-800); }

/* ---------------------------------------------------------------------
   ประวัติ/diff
--------------------------------------------------------------------- */

.history-grid { display: grid; grid-template-columns: 280px 1fr; gap: 24px; }
.revision-list { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 8px; }
.revision-item {
  border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 11px 13px;
  transition: transform 0.18s var(--ease), box-shadow 0.18s var(--ease), border-color 0.18s var(--ease);
}
.revision-item:hover { transform: translateX(2px); box-shadow: var(--shadow-sm); border-color: var(--blue-400); }
.revision-item a { color: var(--text); }
.revision-selected { border-color: var(--blue-600); background: var(--blue-50); box-shadow: var(--shadow-xs); }
.revision-meta { color: var(--text-muted); font-size: 12px; margin-top: 4px; }
.revision-note { font-size: 12px; color: var(--blue-800); margin-top: 4px; }
.badge-current, .badge-restore, .badge, .badge-warn {
  display: inline-block; font-size: 10px; padding: 2px 7px; border-radius: 999px; margin-left: 6px;
}
.badge-current { background: var(--success); color: #fff; }
.badge-restore { background: var(--blue-500); color: #fff; }
.badge { background: var(--blue-100); color: var(--blue-800); }
.badge-warn { background: #fdecea; color: var(--danger); }
.diff-box { background: var(--blue-50); border-radius: var(--radius-sm); padding: 14px; margin-bottom: 18px; line-height: 1.8; }
.diff-add, ins.diff-add { background: var(--diff-add-bg); text-decoration: none; color: var(--diff-add-text); border-radius: 3px; padding: 0 2px; }
.diff-del, del.diff-del { background: var(--diff-remove-bg); color: var(--diff-remove-text); border-radius: 3px; padding: 0 2px; }
.diff-summary { color: var(--text-muted); font-size: 13px; }
.revision-actions { display: flex; gap: 10px; margin-top: 18px; }

/* ---------------------------------------------------------------------
   โปรไฟล์
--------------------------------------------------------------------- */

.profile-header { display: flex; align-items: center; gap: 14px; margin-bottom: 10px; }
.profile-avatar { width: 58px; height: 58px; border-radius: 50%; box-shadow: 0 0 0 3px #fff, 0 0 0 5px var(--blue-100); }
.profile-tabs { display: flex; gap: 22px; border-bottom: 1px solid var(--border); margin-bottom: 22px; }
.profile-tabs .tab { padding: 11px 4px; color: var(--text-muted); border-bottom: 2px solid transparent; transition: color 0.18s var(--ease), border-color 0.18s var(--ease); }
.profile-tabs .tab:hover { color: var(--blue-700); }
.tab-active { color: var(--blue-800) !important; border-color: var(--blue-700) !important; font-weight: 500; }

/* ---------------------------------------------------------------------
   Admin
--------------------------------------------------------------------- */

.admin-nav { display: flex; gap: 18px; border-bottom: 1px solid var(--border); margin-bottom: 22px; flex-wrap: wrap; }
.admin-nav-item { padding: 9px 4px; color: var(--text-muted); border-bottom: 2px solid transparent; transition: color 0.18s var(--ease), border-color 0.18s var(--ease); }
.admin-nav-item:hover { color: var(--blue-700); }
.admin-nav-item.active { color: var(--blue-800); border-color: var(--blue-700); font-weight: 500; }
.admin-table { width: 100%; border-collapse: separate; border-spacing: 0; margin-bottom: 26px; font-size: 13px; }
.admin-table th, .admin-table td { text-align: left; padding: 11px; border-bottom: 1px solid var(--border); }
.admin-table th { color: var(--text-muted); font-weight: 500; }
.admin-table tbody tr { transition: background 0.16s var(--ease); }
.admin-table tbody tr:hover { background: var(--blue-50); }
.admin-actions { display: flex; gap: 6px; flex-wrap: wrap; }
.row-suspicious { background: #fff8e1; }
.admin-add-form { margin-bottom: 22px; }
.admin-add-form summary { cursor: pointer; margin-bottom: 10px; list-style: none; }
.admin-add-form form { max-width: 420px; border: 1px solid var(--border); border-radius: var(--radius); padding: 18px; box-shadow: var(--shadow-sm); }
.admin-filter-form { max-width: 420px; margin-bottom: 18px; }
.admin-inline-form { display: flex; gap: 10px; align-items: flex-end; flex-wrap: wrap; max-width: 640px; margin-bottom: 26px; }
.admin-inline-form label { margin-bottom: 4px; }
.admin-inline-form > * { margin-bottom: 0; }
.stats-cards { display: flex; gap: 16px; margin-bottom: 26px; flex-wrap: wrap; }
.stat-card {
  background: linear-gradient(160deg, var(--blue-50), #fff); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px 26px; text-align: center; min-width: 130px;
  box-shadow: var(--shadow-xs); transition: transform 0.2s var(--ease), box-shadow 0.2s var(--ease);
}
.stat-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-md); }
.stat-card strong { display: block; font-size: 26px; color: var(--blue-800); }
.stat-card span { font-size: 12px; color: var(--text-muted); }

/* ---------------------------------------------------------------------
   วิธีใช้ / auth
--------------------------------------------------------------------- */

.help-content h2 { font-size: 16px; margin-top: 22px; }
.auth-card { max-width: 420px; margin: 60px auto; padding: 26px; border: 1px solid var(--border); border-radius: var(--radius-lg); box-shadow: var(--shadow-md); }

/* ---------------------------------------------------------------------
   Responsive / mobile (§9)
--------------------------------------------------------------------- */

@media (max-width: 900px) {
  .main-nav { display: none; }
  .post-grid { grid-template-columns: repeat(2, 1fr); }
  .post-form-grid { grid-template-columns: 1fr; }
  .post-page-grid { grid-template-columns: 1fr; }
  .history-grid { grid-template-columns: 1fr; }
  .studio-editor { grid-template-columns: 1fr; height: auto; }
  .studio-code, .studio-preview { height: 320px; }
  .studio-tabs { display: flex; }
  .studio-preview { display: none; }
  .site-main { padding-bottom: 96px; }

  .mobile-nav {
    display: flex; position: fixed; bottom: 0; left: 0; right: 0; background: rgba(255,255,255,0.9);
    backdrop-filter: blur(10px); border-top: 1px solid var(--border); z-index: 30;
    box-shadow: 0 -4px 20px rgba(23,51,122,0.08);
  }
  .mobile-nav-item {
    flex: 1; display: flex; flex-direction: column; align-items: center; gap: 2px;
    text-align: center; padding: 8px 0 10px; font-size: 11px; color: var(--text-muted);
    transition: color 0.18s var(--ease), transform 0.18s var(--ease);
  }
  .mobile-nav-item:hover, .mobile-nav-item.nav-active { color: var(--blue-700); transform: translateY(-2px); }
  .mobile-nav-cta { color: var(--blue-800); font-weight: 600; }
}

@media (min-width: 901px) {
  .mobile-only { display: none !important; }
}

@media (max-width: 600px) {
  .post-grid { grid-template-columns: 1fr; }
  .type-picker { flex-direction: column; }
  .stats-cards { flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition-duration: 0.001ms !important; animation-duration: 0.001ms !important; }
}

/* ---------------------------------------------------------------------
   ปุ่มเลือกไฟล์ที่แต่งเอง (แทน "เลือกไฟล์" ของเบราว์เซอร์)
--------------------------------------------------------------------- */

.file-input-wrap {
  display: inline-flex; align-items: center; gap: 10px; cursor: pointer;
  margin-bottom: 10px; max-width: 100%;
}
.file-input-native {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0;
}
.file-input-button {
  display: inline-flex; align-items: center; gap: 7px; flex: none;
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius-sm);
  padding: 9px 15px; font-size: 13px; font-weight: 500; color: var(--blue-800);
  transition: transform 0.18s var(--ease), box-shadow 0.2s var(--ease), border-color 0.18s var(--ease);
}
.file-input-wrap:hover .file-input-button {
  transform: translateY(-2px); box-shadow: var(--shadow-sm); border-color: var(--blue-400);
}
.file-input-native:focus-visible ~ .file-input-button {
  outline: none; border-color: var(--blue-500); box-shadow: 0 0 0 4px rgba(63, 107, 234, 0.14);
}
.file-input-name {
  font-size: 13px; color: var(--text-muted); overflow: hidden; text-overflow: ellipsis;
  white-space: nowrap; max-width: 220px;
}

/* ---------------------------------------------------------------------
   Toast + dialog ของเว็บเอง (แทน alert()/confirm()/prompt() ของเบราว์เซอร์)
--------------------------------------------------------------------- */

.ui-toast-host {
  position: fixed; top: 18px; left: 50%; transform: translateX(-50%);
  z-index: 100; display: flex; flex-direction: column; gap: 8px;
  width: min(92vw, 420px); pointer-events: none;
}
.ui-toast {
  pointer-events: auto; cursor: pointer;
  background: var(--blue-900); color: #fff; border-radius: var(--radius-sm);
  padding: 12px 16px; font-size: 13.5px; line-height: 1.5; box-shadow: var(--shadow-lg);
  opacity: 0; transform: translateY(-10px) scale(0.98);
  transition: opacity 0.22s var(--ease), transform 0.22s var(--ease);
}
.ui-toast-in { opacity: 1; transform: translateY(0) scale(1); }
.ui-toast-out { opacity: 0; transform: translateY(-6px) scale(0.98); }
.ui-toast-error { background: #3a1418; border: 1px solid #6b2530; }
.ui-toast-success { background: #113322; border: 1px solid #1f6b3f; }
.ui-toast-info { background: var(--blue-900); }

.ui-dialog-overlay {
  position: fixed; inset: 0; z-index: 110; display: flex; align-items: center; justify-content: center;
  padding: 20px; background: rgba(15, 23, 42, 0);
  opacity: 0; visibility: hidden; pointer-events: none;
  transition: opacity 0.18s var(--ease), background 0.18s var(--ease);
}
.ui-dialog-overlay-open {
  opacity: 1; visibility: visible; pointer-events: auto; background: rgba(15, 23, 42, 0.45);
  backdrop-filter: blur(2px);
}
.ui-dialog {
  background: #fff; border-radius: var(--radius-lg); box-shadow: var(--shadow-lg);
  padding: 24px; width: min(92vw, 420px);
  transform: translateY(8px) scale(0.98); transition: transform 0.2s var(--ease);
}
.ui-dialog-overlay-open .ui-dialog { transform: translateY(0) scale(1); }
.ui-dialog-message { margin: 0 0 16px; color: var(--text); line-height: 1.6; white-space: pre-line; }
.ui-dialog-input {
  width: 100%; font-family: inherit; font-size: 14px; padding: 10px 14px;
  border: 1px solid var(--border); border-radius: var(--radius-sm); margin-bottom: 16px; resize: vertical;
}
.ui-dialog-input:focus { outline: none; border-color: var(--blue-500); box-shadow: 0 0 0 4px rgba(63, 107, 234, 0.14); }
.ui-dialog-actions { display: flex; justify-content: flex-end; gap: 10px; }