/* style.css — TripForge Design Tokens + Component Styles */

/* ===== TYPE SCALE ===== */
:root {
  --text-xs:   clamp(0.75rem,  0.7rem  + 0.25vw, 0.875rem);
  --text-sm:   clamp(0.875rem, 0.8rem  + 0.35vw, 1rem);
  --text-base: clamp(1rem,     0.9rem  + 0.5vw,  1.125rem);
  --text-lg:   clamp(1.125rem, 0.95rem + 0.85vw, 1.5rem);
  --text-xl:   clamp(1.5rem,   1rem    + 1.5vw,  2.25rem);
  --text-2xl:  clamp(2rem,     1.2rem  + 2.5vw,  3.5rem);
  --text-3xl:  clamp(2.5rem,   1rem    + 4vw,    5rem);
  --text-hero: clamp(3rem,     0.5rem  + 7vw,    8rem);
}

/* ===== SPACING (4px grid) ===== */
:root {
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;
}

/* ===== FONT FAMILIES ===== */
:root {
  --font-display: 'Sora', 'Inter', sans-serif;
  --font-body: 'Inter', 'Helvetica Neue', sans-serif;
}

/* ===== RADII ===== */
:root {
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;
}

/* ===== TRANSITIONS ===== */
:root {
  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);
}

/* ===== CONTENT WIDTHS ===== */
:root {
  --content-narrow: 640px;
  --content-default: 960px;
  --content-wide: 1200px;
  --content-full: 100%;
}

/* ============================================
   LIGHT MODE — TripForge Custom Palette
   ============================================ */
:root, [data-theme="light"] {
  --color-bg:               #f5f7fa;
  --color-surface:          #ffffff;
  --color-surface-2:        #f8fafb;
  --color-surface-offset:   #eef1f5;
  --color-surface-offset-2: #e4e8ee;
  --color-surface-dynamic:  #dce1e8;
  --color-divider:          #d0d6df;
  --color-border:           #c2c9d4;

  --color-text:             #1a2332;
  --color-text-muted:       #5c6b7e;
  --color-text-faint:       #9aa5b4;
  --color-text-inverse:     #f5f7fa;

  --color-primary:          #0b4f6c;
  --color-primary-hover:    #083d54;
  --color-primary-active:   #062d3e;
  --color-primary-highlight: #d0e6f0;

  --color-accent:           #e8613a;
  --color-accent-hover:     #d04e28;
  --color-accent-active:    #b8401e;
  --color-accent-highlight: #fde4db;

  --color-secondary:        #2aa5a0;
  --color-secondary-hover:  #1f8b87;
  --color-secondary-active: #17726e;
  --color-secondary-highlight: #d4efed;

  --color-success:          #2d8a4e;
  --color-success-hover:    #1f6e3a;
  --color-success-highlight: #d4eed8;

  --color-warning:          #c67f18;
  --color-warning-hover:    #a66812;
  --color-warning-highlight: #f5e9ce;

  --color-error:            #c5303e;
  --color-error-hover:      #a82430;
  --color-error-highlight:  #f5d3d6;

  --shadow-sm: 0 1px 2px oklch(0.25 0.02 250 / 0.06);
  --shadow-md: 0 4px 12px oklch(0.25 0.02 250 / 0.08);
  --shadow-lg: 0 12px 32px oklch(0.25 0.02 250 / 0.12);
}

/* ============================================
   DARK MODE
   ============================================ */
[data-theme="dark"] {
  --color-bg:               #0f1621;
  --color-surface:          #162030;
  --color-surface-2:        #1b2740;
  --color-surface-offset:   #141c2b;
  --color-surface-offset-2: #1e2a3e;
  --color-surface-dynamic:  #283650;
  --color-divider:          #243044;
  --color-border:           #2e3e55;

  --color-text:             #d6dce5;
  --color-text-muted:       #8696ab;
  --color-text-faint:       #506074;
  --color-text-inverse:     #1a2332;

  --color-primary:          #4dadd0;
  --color-primary-hover:    #3796bb;
  --color-primary-active:   #2880a3;
  --color-primary-highlight: #1d3344;

  --color-accent:           #f08c6d;
  --color-accent-hover:     #e87552;
  --color-accent-active:    #e05e38;
  --color-accent-highlight: #3d2a22;

  --color-secondary:        #56c8c2;
  --color-secondary-hover:  #3fb5af;
  --color-secondary-active: #2da09b;
  --color-secondary-highlight: #1c3635;

  --color-success:          #5ec97c;
  --color-success-hover:    #42b262;
  --color-success-highlight: #1d3628;

  --color-warning:          #e8a84a;
  --color-warning-hover:    #d8952f;
  --color-warning-highlight: #3b3020;

  --color-error:            #e86674;
  --color-error-hover:      #d44e5c;
  --color-error-highlight:  #3d2228;

  --shadow-sm: 0 1px 2px oklch(0 0 0 / 0.25);
  --shadow-md: 0 4px 12px oklch(0 0 0 / 0.35);
  --shadow-lg: 0 12px 32px oklch(0 0 0 / 0.45);
}

/* System preference fallback */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --color-bg:               #0f1621;
    --color-surface:          #162030;
    --color-surface-2:        #1b2740;
    --color-surface-offset:   #141c2b;
    --color-surface-offset-2: #1e2a3e;
    --color-surface-dynamic:  #283650;
    --color-divider:          #243044;
    --color-border:           #2e3e55;
    --color-text:             #d6dce5;
    --color-text-muted:       #8696ab;
    --color-text-faint:       #506074;
    --color-text-inverse:     #1a2332;
    --color-primary:          #4dadd0;
    --color-primary-hover:    #3796bb;
    --color-primary-active:   #2880a3;
    --color-primary-highlight: #1d3344;
    --color-accent:           #f08c6d;
    --color-accent-hover:     #e87552;
    --color-accent-active:    #e05e38;
    --color-accent-highlight: #3d2a22;
    --color-secondary:        #56c8c2;
    --color-secondary-hover:  #3fb5af;
    --color-secondary-active: #2da09b;
    --color-secondary-highlight: #1c3635;
    --color-success:          #5ec97c;
    --color-success-hover:    #42b262;
    --color-success-highlight: #1d3628;
    --color-warning:          #e8a84a;
    --color-warning-hover:    #d8952f;
    --color-warning-highlight: #3b3020;
    --color-error:            #e86674;
    --color-error-hover:      #d44e5c;
    --color-error-highlight:  #3d2228;
    --shadow-sm: 0 1px 2px oklch(0 0 0 / 0.25);
    --shadow-md: 0 4px 12px oklch(0 0 0 / 0.35);
    --shadow-lg: 0 12px 32px oklch(0 0 0 / 0.45);
  }
}


/* ============================================
   COMPONENT STYLES
   ============================================ */

/* ===== TOP BAR ===== */
.topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-surface);
  border-bottom: 1px solid oklch(from var(--color-text) l c h / 0.08);
  box-shadow: var(--shadow-sm);
}

.topbar__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--content-wide);
  margin-inline: auto;
  padding: var(--space-3) var(--space-4);
  gap: var(--space-4);
}

.topbar__left {
  display: flex;
  align-items: center;
  gap: var(--space-6);
}

.topbar__logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
  color: var(--color-primary);
  transition: color var(--transition-interactive);
}
.topbar__logo:hover { color: var(--color-primary-hover); }

.logo-icon { color: var(--color-primary); flex-shrink: 0; }
.logo-text {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.topbar__nav {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.topbar__link {
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: none;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  transition: color var(--transition-interactive), background var(--transition-interactive);
}
.topbar__link:hover { color: var(--color-text); background: var(--color-surface-offset); }
.topbar__link--active { color: var(--color-primary); font-weight: 600; }

.topbar__right {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.icon-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
  transition: color var(--transition-interactive), background var(--transition-interactive);
}
.icon-btn:hover { color: var(--color-text); background: var(--color-surface-offset); }
.icon-btn:active { background: var(--color-surface-offset-2); }

/* Avatar */
.avatar {
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--color-text-inverse);
  background: var(--color-primary);
  flex-shrink: 0;
}
.avatar--sm { width: 36px; height: 36px; font-size: var(--text-sm); }
.avatar--member {
  width: 36px;
  height: 36px;
  font-size: var(--text-sm);
  background: var(--avatar-color, var(--color-primary));
  border: 2px solid var(--color-surface);
}

/* ===== TRIP BANNER ===== */
.trip-banner {
  position: relative;
  overflow: hidden;
  border-radius: 0;
}

.trip-banner__bg {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg,
    var(--color-primary) 0%,
    oklch(from var(--color-primary) calc(l + 0.1) c h) 40%,
    var(--color-secondary) 100%
  );
}

.trip-banner__pattern {
  position: absolute;
  inset: 0;
  opacity: 0.12;
  background-image:
    radial-gradient(circle at 20% 80%, var(--color-accent) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, var(--color-secondary) 0%, transparent 40%),
    repeating-linear-gradient(
      45deg,
      transparent 0px,
      transparent 20px,
      oklch(1 0 0 / 0.05) 20px,
      oklch(1 0 0 / 0.05) 21px
    );
}

.trip-banner__content {
  position: relative;
  z-index: 1;
  max-width: var(--content-wide);
  margin-inline: auto;
  padding: var(--space-8) var(--space-4) var(--space-6);
  color: var(--color-text-inverse);
}

[data-theme="dark"] .trip-banner__content { color: var(--color-text); }

.trip-banner__top {
  margin-bottom: var(--space-3);
}

.trip-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-1) var(--space-3);
  background: oklch(1 0 0 / 0.18);
  backdrop-filter: blur(8px);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.02em;
}

.trip-banner__title {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-3);
  text-shadow: 0 2px 8px oklch(0 0 0 / 0.2);
}

.trip-banner__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  font-weight: 500;
  opacity: 0.9;
}

.trip-meta-item {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
}

.trip-meta-divider { opacity: 0.5; }

/* Trip Members */
.trip-members {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-top: var(--space-5);
}

.trip-members__avatars {
  display: flex;
}
.trip-members__avatars .avatar--member {
  margin-left: -8px;
}
.trip-members__avatars .avatar--member:first-child {
  margin-left: 0;
}

.invite-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background: oklch(1 0 0 / 0.18);
  backdrop-filter: blur(8px);
  border: 1px solid oklch(1 0 0 / 0.25);
  border-radius: var(--radius-full);
  color: inherit;
  font-size: var(--text-xs);
  font-weight: 600;
  transition: background var(--transition-interactive);
}
.invite-btn:hover { background: oklch(1 0 0 / 0.28); }
.invite-btn:active { background: oklch(1 0 0 / 0.15); }

/* ===== CONTENT AREA ===== */
.content-area {
  display: grid;
  grid-template-columns: 1fr;
  max-width: var(--content-wide);
  margin-inline: auto;
  padding: 0 var(--space-4);
  gap: var(--space-6);
}

@media (min-width: 1024px) {
  .content-area {
    grid-template-columns: 1fr 320px;
    padding: 0 var(--space-6);
  }
}

/* ===== MAIN COLUMN ===== */
.main-col {
  min-width: 0;
}

/* ===== DAY TABS ===== */
.day-tabs {
  position: sticky;
  top: 60px;
  z-index: 50;
  background: var(--color-bg);
  padding: var(--space-4) 0;
  margin-bottom: var(--space-4);
}

.day-tabs__scroll {
  display: flex;
  gap: var(--space-2);
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
  padding-bottom: var(--space-1);
}
.day-tabs__scroll::-webkit-scrollbar { display: none; }

.day-tab {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  border: 1px solid oklch(from var(--color-text) l c h / 0.08);
  min-width: 72px;
  flex-shrink: 0;
  transition: background var(--transition-interactive), border-color var(--transition-interactive), box-shadow var(--transition-interactive);
}

.day-tab__num {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text);
}
.day-tab__date {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

.day-tab:hover {
  border-color: var(--color-primary-highlight);
  background: var(--color-surface-2);
}
.day-tab:active {
  background: var(--color-surface-offset);
}

.day-tab--active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
}
.day-tab--active .day-tab__num { color: var(--color-text-inverse); }
.day-tab--active .day-tab__date { color: oklch(from var(--color-text-inverse) l c h / 0.75); }
.day-tab--active:hover { background: var(--color-primary-hover); border-color: var(--color-primary-hover); }

/* ===== DAY PANEL ===== */
.day-panel {
  padding-bottom: var(--space-8);
}
.day-panel--hidden { display: none; }

.day-header {
  margin-bottom: var(--space-6);
}
.day-header__title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.02em;
}
.day-header__subtitle {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-top: var(--space-1);
  display: block;
}

/* ===== TIMELINE ===== */
.timeline {
  list-style: none;
  position: relative;
  padding: 0;
}

.timeline-item {
  display: grid;
  grid-template-columns: 24px 1fr;
  gap: var(--space-4);
  position: relative;
  padding-bottom: var(--space-6);
}

/* Timeline connecting line */
.timeline-item::before {
  content: '';
  position: absolute;
  left: 11px;
  top: 24px;
  bottom: 0;
  width: 2px;
  background: var(--color-divider);
}
.timeline-item--last::before { display: none; }

.timeline-item__marker {
  display: flex;
  justify-content: center;
  padding-top: var(--space-4);
  z-index: 1;
}

.timeline-dot {
  width: 12px;
  height: 12px;
  border-radius: var(--radius-full);
  border: 2px solid var(--color-surface);
  flex-shrink: 0;
  box-shadow: 0 0 0 2px var(--color-divider);
}

.timeline-dot--transport { background: var(--color-warning); box-shadow: 0 0 0 2px var(--color-warning-highlight); }
.timeline-dot--hotel { background: var(--color-primary); box-shadow: 0 0 0 2px var(--color-primary-highlight); }
.timeline-dot--food { background: var(--color-accent); box-shadow: 0 0 0 2px var(--color-accent-highlight); }
.timeline-dot--activity { background: var(--color-secondary); box-shadow: 0 0 0 2px var(--color-secondary-highlight); }
.timeline-dot--shopping { background: var(--color-error); box-shadow: 0 0 0 2px var(--color-error-highlight); }

/* Timeline Card */
.timeline-card {
  background: var(--color-surface);
  border: 1px solid oklch(from var(--color-text) l c h / 0.08);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-interactive), border-color var(--transition-interactive);
}
.timeline-card:hover {
  box-shadow: var(--shadow-md);
  border-color: oklch(from var(--color-text) l c h / 0.14);
}

.timeline-card__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-2);
  gap: var(--space-2);
}

.timeline-time {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-primary);
  font-variant-numeric: tabular-nums lining-nums;
}

.timeline-category {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.timeline-card__title {
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-2);
  letter-spacing: -0.01em;
}

.timeline-card__desc {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
  margin-bottom: var(--space-3);
}

.timeline-card__footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-4);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-weight: 500;
  padding-top: var(--space-3);
  border-top: 1px solid oklch(from var(--color-text) l c h / 0.06);
}

.timeline-cost, .timeline-duration {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
}

.timeline-cost--free {
  color: var(--color-success);
  font-weight: 600;
}

.timeline-rating {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
}
.star-filled { color: var(--color-warning); fill: var(--color-warning); }

/* Add Activity Button */
.add-activity-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  width: 100%;
  padding: var(--space-4);
  border: 2px dashed var(--color-border);
  border-radius: var(--radius-lg);
  color: var(--color-text-muted);
  font-size: var(--text-sm);
  font-weight: 600;
  transition: border-color var(--transition-interactive), color var(--transition-interactive), background var(--transition-interactive);
}
.add-activity-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-primary-highlight);
}
.add-activity-btn:active {
  background: oklch(from var(--color-primary) l c h / 0.12);
}

/* ===== SIDEBAR ===== */
.sidebar {
  display: none;
}

@media (min-width: 1024px) {
  .sidebar {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
    padding-top: var(--space-4);
    position: sticky;
    top: 76px;
    max-height: calc(100dvh - 80px);
    overflow-y: auto;
    overscroll-behavior: contain;
  }
}

.sidebar__card {
  background: var(--color-surface);
  border: 1px solid oklch(from var(--color-text) l c h / 0.08);
  border-radius: var(--radius-xl);
  padding: var(--space-5);
  box-shadow: var(--shadow-sm);
}

.sidebar__title {
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-4);
  letter-spacing: -0.01em;
}

/* Budget Summary */
.budget-summary {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  margin-bottom: var(--space-5);
}

.budget-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.budget-label {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.budget-value {
  font-family: var(--font-display);
  font-weight: 700;
  font-variant-numeric: tabular-nums lining-nums;
}
.budget-value--total { font-size: var(--text-lg); color: var(--color-text); }
.budget-value--spent { font-size: var(--text-base); color: var(--color-accent); }
.budget-value--remaining { font-size: var(--text-base); color: var(--color-success); }

/* Progress Bar */
.budget-progress {
  margin-bottom: var(--space-5);
}

.budget-progress__track {
  height: 8px;
  background: var(--color-surface-offset);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-bottom: var(--space-2);
}

.budget-progress__fill {
  height: 100%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  border-radius: var(--radius-full);
  transition: width 600ms cubic-bezier(0.16, 1, 0.3, 1);
  min-width: 4px;
}

.budget-progress__label {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  font-weight: 500;
}

/* Category Breakdown */
.budget-categories__title {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text-faint);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: var(--space-3);
}

.category-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.category-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.category-item__info {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-text);
}

.category-dot {
  width: 10px;
  height: 10px;
  border-radius: var(--radius-full);
  background: var(--dot-color);
  flex-shrink: 0;
}

.category-item__right {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.category-pct {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text-muted);
  font-variant-numeric: tabular-nums;
}

.category-amt {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text);
  font-variant-numeric: tabular-nums;
  min-width: 52px;
  text-align: right;
}

/* Category Stacked Bar */
.category-bars {
  display: flex;
  height: 8px;
  border-radius: var(--radius-full);
  overflow: hidden;
  gap: 2px;
}

.category-bar {
  height: 100%;
  width: var(--bar-width);
  background: var(--bar-color);
  border-radius: var(--radius-full);
}

/* Quick Actions */
.quick-actions {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.quick-action-btn {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  transition: background var(--transition-interactive), color var(--transition-interactive);
}
.quick-action-btn:hover { background: var(--color-surface-offset); color: var(--color-text); }
.quick-action-btn:active { background: var(--color-surface-offset-2); }

/* ===== MOBILE BOTTOM TAB BAR ===== */
.mobile-tab-bar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 100;
  display: flex;
  justify-content: space-around;
  align-items: center;
  background: var(--color-surface);
  border-top: 1px solid oklch(from var(--color-text) l c h / 0.08);
  padding: var(--space-2) 0;
  padding-bottom: calc(var(--space-2) + env(safe-area-inset-bottom));
  box-shadow: 0 -2px 12px oklch(0 0 0 / 0.06);
}

.mobile-tab {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-1) var(--space-2);
  min-width: 48px;
  min-height: 44px;
  color: var(--color-text-faint);
  font-size: 10px;
  font-weight: 500;
  border-radius: var(--radius-md);
  transition: color var(--transition-interactive);
}
.mobile-tab:active { color: var(--color-primary); }
.mobile-tab--active { color: var(--color-primary); font-weight: 600; }

@media (min-width: 1024px) {
  .mobile-tab-bar { display: none; }
}

/* ===== EMPTY STATE ===== */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: var(--space-12) var(--space-4);
  color: var(--color-text-muted);
}
.empty-state__icon {
  color: var(--color-text-faint);
  margin-bottom: var(--space-4);
  animation: gentle-float 3s ease-in-out infinite;
}
.empty-state h3 {
  font-family: var(--font-display);
  color: var(--color-text);
  margin-bottom: var(--space-2);
}
.empty-state p {
  max-width: 36ch;
  font-size: var(--text-sm);
  margin-bottom: var(--space-6);
}

@keyframes gentle-float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-6px); }
}

/* Skeletons */
.skeleton-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  width: 100%;
  max-width: 400px;
}

@keyframes shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

.skeleton {
  background: linear-gradient(
    90deg,
    var(--color-surface-offset) 25%,
    var(--color-surface-dynamic) 50%,
    var(--color-surface-offset) 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s ease-in-out infinite;
  border-radius: var(--radius-lg);
}

.skeleton-card { height: 80px; }

/* ===== FOOTER ===== */
.app-footer {
  text-align: center;
  padding: var(--space-6) var(--space-4);
  padding-bottom: calc(var(--space-6) + 80px); /* clear mobile tab bar */
}

@media (min-width: 1024px) {
  .app-footer {
    padding-bottom: var(--space-6);
  }
}

.footer-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  text-decoration: none;
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-full);
  border: 1px solid oklch(from var(--color-text) l c h / 0.06);
  transition: color var(--transition-interactive), border-color var(--transition-interactive);
}
.footer-badge:hover {
  color: var(--color-text-muted);
  border-color: oklch(from var(--color-text) l c h / 0.12);
}
.footer-badge strong { font-weight: 600; }

/* ===== SKIP LINK ===== */
.skip-link {
  position: absolute;
  top: var(--space-2);
  left: var(--space-2);
  z-index: 1000;
  padding: var(--space-2) var(--space-4);
  background: var(--color-primary);
  color: var(--color-text-inverse);
  border-radius: var(--radius-md);
  text-decoration: none;
  font-weight: 600;
  font-size: var(--text-sm);
  transform: translateY(-120%);
  transition: transform var(--transition-interactive);
}
.skip-link:focus {
  transform: translateY(0);
}

/* ===== DESKTOP NAV ===== */
.topbar__link--desktop { display: none; }
@media (min-width: 768px) {
  .topbar__link--desktop { display: inline-flex; }
}

/* ===== SCROLL FADE-IN ANIMATION ===== */
.fade-in { opacity: 1; }

@supports (animation-timeline: scroll()) {
  .fade-in {
    opacity: 0;
    animation: reveal-fade linear both;
    animation-timeline: view();
    animation-range: entry 0% entry 80%;
  }
}

@keyframes reveal-fade {
  to { opacity: 1; }
}

/* ===== RESPONSIVE ADJUSTMENTS ===== */
@media (max-width: 767px) {
  .trip-banner__title {
    font-size: var(--text-xl);
  }
  .trip-banner__content {
    padding: var(--space-6) var(--space-4) var(--space-5);
  }
}

@media (max-width: 599px) {
  .topbar__nav {
    display: none;
  }
}

@media (max-width: 480px) {
  .trip-banner__meta {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-1);
  }
  .trip-meta-divider { display: none; }
}