@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

/* ─── Design Tokens — Infrared Palette ─── */
/* Brand: Nhiệt huyết · Rực rỡ · Sang · Trẻ   */
/* ADR-0003: UI Brand Guidelines               */
:root {
  --bg:          #FAFAFA;
  --white:       #FFFFFF;
  --border:      #E8E8E8;
  --border-soft: #F0F0F0;
  --ink:         #0D1117;   /* Base · Ink — premium near-black    */
  --ink-2:       #1F2937;
  --muted:       #6B7280;
  --muted-2:     #9CA3AF;

  /* ── Infrared Brand Colors ── */
  /* Primary — Crimson: nhiệt huyết, passion   */
  --primary:       #E8002D;
  --primary-soft:  #FFF0F2;
  --primary-deep:  #B8001F;
  --primary-glow:  rgba(232,0,45,.18);

  /* Energy — Tangerine: rực rỡ, young energy  */
  --energy:        #FF6B35;
  --energy-soft:   #FFF3EE;
  --energy-deep:   #D94E1A;

  /* Accent — Gold: sang, premium highlight    */
  --accent:        #FFB200;
  --accent-soft:   #FFF8E1;
  --accent-deep:   #D99200;

  /* Base — Ink: foundation dark               */
  --base:          #0D1117;
  --base-mid:      #1F2937;

  /* Legacy aliases (keeps chip/button classes working) */
  --teal:        var(--primary);
  --teal-soft:   var(--primary-soft);
  --teal-deep:   var(--primary-deep);
  --sage:        var(--energy);
  --sage-soft:   var(--energy-soft);
  --sage-deep:   var(--energy-deep);
  --coral:       var(--primary);
  --coral-soft:  var(--primary-soft);
  --coral-deep:  var(--primary-deep);
  --amber:       var(--accent);
  --amber-soft:  var(--accent-soft);
  --ig-blue:     var(--primary);

  --shadow-sm:   0 1px 3px rgba(0,0,0,.08);
  --shadow-md:   0 4px 16px rgba(0,0,0,.10);
  --transition:  160ms cubic-bezier(.4,0,.2,1);
  --r-sm:  4px;
  --r-md:  8px;
  --r-lg:  12px;
  --r-full: 9999px;
}

/* ─── Reset ─── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--ink);
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 14px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}
img { display: block; max-width: 100%; }
button, input, textarea { font: inherit; }
a { color: inherit; text-decoration: none; }

/* ─── Navbar ─── */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 clamp(16px, 3vw, 40px);
  height: 60px;
  background: var(--white);
  border-bottom: 1px solid var(--border);
}

.nav-logo {
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--ink);
  flex-shrink: 0;
  font-style: italic;
}

.nav-logo span { color: var(--teal); }

.nav-search-wrap {
  flex: 1;
  max-width: 280px;
  margin: 0 auto;
  position: relative;
}

.nav-search-input {
  width: 100%;
  height: 36px;
  padding: 0 12px 0 34px;
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  background: var(--bg);
  color: var(--ink);
  font-size: 13px;
  outline: none;
  text-align: center;
  transition: border-color var(--transition), background var(--transition);
}

.nav-search-input:focus {
  background: var(--white);
  border-color: var(--muted);
  text-align: left;
}

.nav-search-input::placeholder { color: var(--muted); font-weight: 500; }

.nav-search-icon {
  position: absolute;
  left: 10px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--muted);
  pointer-events: none;
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
  margin-left: auto;
}

.badge-chip {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 4px 10px;
  border-radius: var(--r-full);
  font-size: 12px;
  font-weight: 600;
}

.badge-chip.sage  { background: var(--sage-soft);  color: var(--sage-deep); }
.badge-chip.teal  { background: var(--teal-soft);  color: var(--teal-deep); }
.badge-chip.coral { background: var(--coral-soft); color: var(--coral-deep); }
.badge-chip.amber { background: var(--amber-soft); color: var(--amber); }
.badge-chip.muted { background: #F3F4F6; color: var(--muted); }
.badge-chip.bib   {
  background: var(--teal-soft);
  color: var(--teal);
  font-family: 'SF Mono', 'Fira Code', monospace;
  font-size: 11px;
  letter-spacing: .02em;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 7px 16px;
  border-radius: var(--r-md);
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  border: 0;
  transition: opacity var(--transition), transform var(--transition);
}

.btn:hover  { opacity: .88; }
.btn:active { transform: scale(.98); }

.btn-teal    { background: linear-gradient(135deg, var(--primary), var(--energy)); color: #fff; box-shadow: 0 2px 12px var(--primary-glow); }
.btn-black   { background: var(--base); color: #fff; }
.btn-outline { background: transparent; border: 1.5px solid var(--border); color: var(--ink-2); }
.btn-outline:hover { background: var(--bg); border-color: var(--primary); color: var(--primary); opacity: 1; }
.btn-ghost   { background: transparent; color: var(--primary); border: 0; font-size: 13px; font-weight: 700; padding: 4px 0; }

.btn-sm { padding: 5px 12px; font-size: 12px; }

/* ─── Main Layout (A1) ─── */
.main-layout {
  display: grid;
  grid-template-columns: 300px 1fr;
  min-height: calc(100vh - 60px);
}

/* ─── Sidebar ─── */
.sidebar {
  background: var(--white);
  border-right: 1px solid var(--border);
  padding: 24px 16px;
  display: flex;
  flex-direction: column;
  gap: 24px;
  position: sticky;
  top: 60px;
  height: calc(100vh - 60px);
  overflow-y: auto;
}

.sidebar-profile {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 0 4px;
}

.avatar {
  width: 56px;
  height: 56px;
  border-radius: var(--r-full);
  background: linear-gradient(135deg, var(--primary), var(--energy));
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 18px;
  font-weight: 800;
  flex-shrink: 0;
}

.avatar-sm {
  width: 32px;
  height: 32px;
  font-size: 12px;
}

.sidebar-profile-name { font-size: 14px; font-weight: 700; }
.sidebar-profile-sub  { font-size: 12px; color: var(--muted); margin-top: 2px; }

.sidebar-section-label {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--muted);
  padding: 0 8px;
  margin-bottom: 4px;
}

.sidebar-nav { display: flex; flex-direction: column; gap: 2px; }

.sidebar-nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 10px;
  border-radius: var(--r-md);
  font-size: 13px;
  font-weight: 500;
  color: var(--ink-2);
  cursor: pointer;
  transition: background var(--transition), color var(--transition);
  border: 0;
  background: transparent;
  text-align: left;
  width: 100%;
}

.sidebar-nav-item:hover    { background: var(--bg); }
.sidebar-nav-item.active   { background: var(--primary-soft); color: var(--primary); font-weight: 700; }
.sidebar-nav-item .nav-ico { font-size: 15px; width: 20px; text-align: center; }

.sidebar-divider { height: 1px; background: var(--border-soft); }

.sidebar-form { display: flex; flex-direction: column; gap: 10px; }

.form-field { display: flex; flex-direction: column; gap: 5px; }
.form-field-label { font-size: 11px; font-weight: 700; color: var(--muted); text-transform: uppercase; letter-spacing: .06em; }

.text-input {
  width: 100%;
  height: 40px;
  padding: 0 12px;
  border: 1.5px solid var(--border);
  border-radius: var(--r-md);
  background: var(--white);
  font-size: 14px;
  font-weight: 600;
  color: var(--ink);
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
  letter-spacing: .02em;
}

.text-input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-glow);
}

.text-input::placeholder { font-weight: 400; color: var(--muted-2); font-size: 13px; }

.dropzone {
  border: 1.5px dashed var(--border);
  border-radius: var(--r-md);
  padding: 20px 12px;
  text-align: center;
  cursor: pointer;
  position: relative;
  transition: border-color var(--transition), background var(--transition);
  background: var(--white);
}

.dropzone:hover, .dropzone.over { border-color: var(--primary); background: var(--primary-soft); }
.dropzone input { position: absolute; inset: 0; opacity: 0; cursor: pointer; }
.dropzone-icon { font-size: 22px; margin-bottom: 4px; }
.dropzone-text { font-size: 12px; color: var(--muted); line-height: 1.4; }
.dropzone-text strong { color: var(--primary); }

.slider-row { display: flex; align-items: center; gap: 8px; }
.slider-row input[type="range"] { flex: 1; accent-color: var(--primary); }
.slider-val { font-size: 12px; font-weight: 700; color: var(--primary); min-width: 32px; text-align: right; }

/* Filter chips */
.filter-chips { display: flex; flex-wrap: wrap; gap: 6px; }
.filter-chip {
  padding: 4px 10px;
  border-radius: var(--r-full);
  font-size: 12px;
  font-weight: 600;
  border: 1.5px solid var(--border);
  background: var(--white);
  color: var(--ink-2);
  cursor: pointer;
  transition: all var(--transition);
}
.filter-chip:hover  { border-color: var(--primary); color: var(--primary); }
.filter-chip.active { background: linear-gradient(135deg, var(--primary), var(--energy)); border-color: var(--primary); color: #fff; }

/* ─── Content Area (A1) ─── */
.content {
  min-width: 0;
  padding: 0;
}

.content-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 20px 14px;
  border-bottom: 1px solid var(--border-soft);
}

.content-title { font-size: 16px; font-weight: 700; }
.content-sub   { font-size: 13px; color: var(--muted); margin-top: 2px; }

.content-header-right {
  display: flex;
  align-items: center;
  gap: 10px;
}

/* ─── Photo Grid — Instagram 3-col ─── */
.photo-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 3px;
}

.photo-grid-wide { grid-column: span 2; }

.photo-card {
  position: relative;
  cursor: pointer;
  overflow: hidden;
  background: #E5E7EB;
  aspect-ratio: 1;
}

.photo-card-wide { aspect-ratio: 2/1; }

.photo-card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 300ms ease;
}

.photo-card:hover img { transform: scale(1.04); }

.photo-card-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,.38);
  opacity: 0;
  transition: opacity var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  color: #fff;
}

.photo-card:hover .photo-card-overlay { opacity: 1; }

.photo-overlay-stat {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 14px;
  font-weight: 700;
}

.photo-card-badges {
  position: absolute;
  bottom: 8px;
  left: 8px;
  display: flex;
  gap: 4px;
  opacity: 0;
  transition: opacity var(--transition);
}

.photo-card:hover .photo-card-badges { opacity: 1; }

/* Date group header */
.date-group {
  padding: 16px 20px 10px;
  font-size: 13px;
  font-weight: 700;
  color: var(--ink-2);
  border-top: 1px solid var(--border-soft);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.date-group:first-child { border-top: 0; }

/* Status bar */
.status-bar {
  padding: 14px 20px;
  border-top: 1px solid var(--border-soft);
  font-size: 12px;
  color: var(--muted);
  text-align: center;
}

/* Message */
.msg {
  min-height: 24px;
  font-size: 13px;
  color: var(--muted);
  padding: 8px 20px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.msg.error   { color: var(--coral-deep); }
.msg.loading { color: var(--primary); }
.msg.loading::before {
  content: '';
  display: inline-block;
  width: 12px; height: 12px;
  border: 2px solid var(--primary-soft);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin .7s linear infinite;
  flex-shrink: 0;
}

@keyframes spin { to { transform: rotate(360deg); } }

/* Empty state */
.empty-state {
  grid-column: 1 / -1;
  padding: 80px 20px;
  text-align: center;
  color: var(--muted);
}

.empty-icon { font-size: 48px; margin-bottom: 12px; }
.empty-text { font-size: 14px; line-height: 1.6; }

/* ─── Detail Page (A2) ─── */
.detail-layout {
  display: grid;
  grid-template-columns: 1fr 405px;
  min-height: calc(100vh - 60px);
}

.detail-photo-col {
  background: var(--white);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
}

.detail-photo-main {
  flex: 1;
  background: #111;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.detail-photo-main img {
  max-width: 100%;
  max-height: calc(100vh - 60px - 56px - 100px);
  object-fit: contain;
}

.detail-photo-actions {
  border-top: 1px solid var(--border);
  padding: 12px 16px;
}

.detail-action-row {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-bottom: 10px;
}

.detail-action-btn {
  background: transparent;
  border: 0;
  cursor: pointer;
  padding: 6px;
  border-radius: var(--r-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--ink);
  transition: opacity var(--transition);
}

.detail-action-btn:hover { opacity: .6; }
.detail-action-btn.right { margin-left: auto; }
.detail-action-btn svg   { width: 24px; height: 24px; }

.detail-likes-count { font-size: 14px; font-weight: 700; margin-bottom: 4px; }
.detail-date        { font-size: 11px; color: var(--muted); margin-bottom: 12px; }

.detail-filmstrip {
  display: flex;
  gap: 3px;
  overflow-x: auto;
  scrollbar-width: none;
  padding-bottom: 2px;
}

.detail-filmstrip::-webkit-scrollbar { display: none; }

.filmstrip-thumb {
  width: 72px;
  height: 72px;
  flex-shrink: 0;
  border-radius: var(--r-sm);
  overflow: hidden;
  border: 2px solid transparent;
  cursor: pointer;
  transition: border-color var(--transition);
}

.filmstrip-thumb.active { border-color: var(--primary); }
.filmstrip-thumb img { width: 100%; height: 100%; object-fit: cover; }

/* Detail info panel */
.detail-info-col {
  background: var(--white);
  display: flex;
  flex-direction: column;
  height: calc(100vh - 60px);
  overflow-y: auto;
}

.detail-info-header {
  padding: 16px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 12px;
}

.detail-username    { font-size: 14px; font-weight: 700; }
.detail-follow-btn  {
  margin-left: auto;
  padding: 5px 14px;
  border: 1.5px solid var(--border);
  border-radius: var(--r-sm);
  font-size: 13px;
  font-weight: 700;
  background: transparent;
  cursor: pointer;
  color: var(--ig-blue);
  transition: background var(--transition);
}

.detail-follow-btn:hover { background: var(--primary-soft); color: var(--primary-deep); }

.detail-comments { flex: 1; overflow-y: auto; }

.comment-row {
  display: flex;
  gap: 12px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border-soft);
}

.comment-avatar {
  width: 32px;
  height: 32px;
  border-radius: var(--r-full);
  background: linear-gradient(135deg, var(--primary), var(--energy));
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 11px;
  font-weight: 700;
}

.comment-avatar.coral-bg { background: linear-gradient(135deg, var(--energy), var(--accent)); }
.comment-avatar.sage-bg  { background: linear-gradient(135deg, var(--accent), var(--energy)); }

.comment-body { flex: 1; min-width: 0; }
.comment-user { font-size: 13px; font-weight: 700; display: inline; }
.comment-text { font-size: 13px; display: inline; margin-left: 4px; color: var(--ink-2); }
.comment-chips { display: flex; flex-wrap: wrap; gap: 4px; margin-top: 6px; }
.comment-time  { font-size: 11px; color: var(--muted); margin-top: 4px; }

.detail-actions-panel {
  padding: 16px;
  border-top: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.detail-more-label {
  padding: 12px 16px 8px;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .07em;
  color: var(--muted);
  border-top: 1px solid var(--border-soft);
}

.detail-more-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 3px;
  padding: 0 0 16px;
}

.detail-more-grid .photo-card { aspect-ratio: 1; border-radius: var(--r-sm); overflow: hidden; }

/* ─── Breadcrumb ─── */
.breadcrumb {
  padding: 10px clamp(16px, 3vw, 40px);
  font-size: 13px;
  color: var(--muted);
  border-bottom: 1px solid var(--border-soft);
  background: var(--white);
  display: flex;
  align-items: center;
  gap: 6px;
}

.breadcrumb a { color: var(--teal); font-weight: 600; }
.breadcrumb a:hover { text-decoration: underline; }
.breadcrumb-sep { color: var(--muted-2); }

/* ─── Responsive ─── */
@media (max-width: 980px) {
  .main-layout { grid-template-columns: 240px 1fr; }
}

@media (max-width: 768px) {
  .main-layout { grid-template-columns: 1fr; }
  .sidebar { position: static; height: auto; border-right: 0; border-bottom: 1px solid var(--border); }
  .photo-grid { grid-template-columns: repeat(2, 1fr); }
  .detail-layout { grid-template-columns: 1fr; }
  .detail-info-col { height: auto; }
}

@media (max-width: 480px) {
  .photo-grid { grid-template-columns: repeat(2, 1fr); }
  .photo-grid-wide { grid-column: span 2; }
}

/* ─── Utility ─── */
.hidden  { display: none !important; }
.fade-in { animation: fadeIn 220ms ease both; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: none; } }