/* ==========================================================================
   Emoji Alchemist - PWA & Native App Stylesheet
   - Strict Viewport Lockdown (100dvh, zero page scroll)
   - Anti-Frustration UI (Disabled pull-to-refresh & callout menu)
   - Pinned Mobile Inventory Dock & Responsive Scaling
   - Milestone Tiers, Feedback System, & Celebration Toasts
   ========================================================================== */

:root {
  --bg-primary: #0d1117;
  --bg-secondary: #161b22;
  --bg-tertiary: #21262d;
  --bg-canvas: #090d13;
  --border-color: #30363d;
  --border-focus: #58a6ff;
  --text-primary: #f0f6fc;
  --text-secondary: #8b949e;
  --text-muted: #6e7681;
  --accent-purple: #8957e5;
  --accent-blue: #388bfd;
  --accent-gold: #f1e05a;
  --accent-green: #3fb950;
  --accent-red: #f85149;
  --sidebar-width: 320px;
  --header-height: 56px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --shadow-main: 0 8px 24px rgba(0, 0, 0, 0.5);
  --font-main: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-user-select: none;
  user-select: none;
  -webkit-touch-callout: none;
  -webkit-tap-highlight-color: transparent;
}

/* 1. Native App Behavior & Viewport Lockdown */
html, body {
  font-family: var(--font-main);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  height: 100%;
  height: 100dvh;
  width: 100vw;
  overflow: hidden;
  position: fixed;
  overscroll-behavior: none;
  overscroll-behavior-y: none;
  touch-action: none;
}

#app-root {
  display: flex;
  flex-direction: column;
  height: 100%;
  height: 100dvh;
  width: 100vw;
  overflow: hidden;
  position: relative;
}

/* Allow text selection specifically in inputs and textareas */
input, textarea {
  -webkit-user-select: text !important;
  user-select: text !important;
}

/* ==========================================================================
   Psychological Engagement Banner
   ========================================================================== */
.engagement-banner {
  background: linear-gradient(90deg, #1b2838 0%, #1f1f38 50%, #291a38 100%);
  border-bottom: 1px solid rgba(137, 87, 229, 0.35);
  padding: 6px 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  font-size: 0.8rem;
  z-index: 60;
  flex-shrink: 0;
  animation: bannerSlideDown 0.3s ease-out;
}

.engagement-banner.hidden {
  display: none !important;
}

.banner-content {
  display: flex;
  align-items: center;
  gap: 10px;
  overflow: hidden;
}

.banner-badge {
  background: rgba(63, 185, 80, 0.18);
  border: 1px solid var(--accent-green);
  color: #7ee787;
  font-size: 0.68rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 9999px;
  white-space: nowrap;
  letter-spacing: 0.02em;
}

.banner-text {
  color: var(--text-primary);
  font-size: 0.78rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.banner-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.btn-banner-action {
  background: var(--accent-purple);
  color: #fff;
  border: none;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 600;
  cursor: pointer;
  box-shadow: 0 0 10px rgba(137, 87, 229, 0.4);
}

.btn-banner-action:hover {
  background: #9a68f7;
  box-shadow: 0 0 14px rgba(137, 87, 229, 0.7);
}

.btn-icon-close {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 4px 6px;
  font-size: 0.85rem;
  border-radius: 4px;
}

.btn-icon-close:hover {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.1);
}

@keyframes bannerSlideDown {
  from { transform: translateY(-100%); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

/* ==========================================================================
   App Header
   ========================================================================== */
#app-header {
  height: var(--header-height);
  background: linear-gradient(180deg, #161b22 0%, #0d1117 100%);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  z-index: 50;
  flex-shrink: 0;
}

.brand-section {
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand-logo {
  font-size: 1.6rem;
  filter: drop-shadow(0 0 10px rgba(137, 87, 229, 0.6));
  animation: floatSlow 3s ease-in-out infinite;
}

.brand-titles h1 {
  font-size: 1.12rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  background: linear-gradient(90deg, #ffffff 0%, #c9d1d9 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.brand-subtitle {
  font-size: 0.68rem;
  color: #7ee787;
  letter-spacing: 0.04em;
  font-weight: 600;
  display: block;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 6px;
}

/* Tier Discovery Badge */
.stats-badge {
  display: flex;
  align-items: center;
  gap: 6px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  padding: 5px 10px;
  border-radius: 9999px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  cursor: pointer;
  transition: all 0.15s ease;
}

.stats-badge:hover {
  border-color: #58a6ff;
  background: #2b313a;
}

.stats-badge .counter-highlight {
  color: #58a6ff;
}

/* General Button Styles */
.btn {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  font-weight: 500;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 5px;
  transition: all 0.15s ease;
  white-space: nowrap;
  touch-action: manipulation;
}

.btn:hover {
  background: #2b313a;
  border-color: #58a6ff;
  transform: translateY(-1px);
}

.btn:active {
  transform: translateY(0);
}

.btn-primary {
  background: #238636;
  border-color: rgba(240, 246, 252, 0.1);
  color: #fff;
}

.btn-primary:hover {
  background: #2ea043;
  border-color: #3fb950;
  box-shadow: 0 0 10px rgba(63, 185, 80, 0.4);
}

.btn-icon {
  padding: 6px;
  width: 34px;
  height: 34px;
  justify-content: center;
}

.btn-hint {
  background: rgba(241, 224, 90, 0.12);
  border-color: rgba(241, 224, 90, 0.35);
  color: #fff48f;
}

.btn-hint:hover {
  background: rgba(241, 224, 90, 0.22);
  border-color: var(--accent-gold);
  box-shadow: 0 0 12px rgba(241, 224, 90, 0.3);
}

.btn-feedback {
  background: rgba(88, 166, 255, 0.12);
  border-color: rgba(88, 166, 255, 0.35);
  color: #79c0ff;
}

.btn-feedback:hover {
  background: rgba(88, 166, 255, 0.22);
  border-color: var(--accent-blue);
  box-shadow: 0 0 12px rgba(88, 166, 255, 0.3);
}

.btn-hint-mobile {
  display: none;
}

.btn-danger-hover:hover {
  border-color: var(--accent-red);
  color: var(--accent-red);
  background: rgba(248, 81, 73, 0.1);
}

/* ==========================================================================
   Main Application Layout (Zero-Scroll Strict Viewport Fit)
   ========================================================================== */
#app-layout {
  flex: 1;
  display: flex;
  position: relative;
  overflow: hidden;
  min-height: 0;
}

/* ==========================================================================
   Sidebar: Inventory
   ========================================================================== */
#sidebar {
  width: var(--sidebar-width);
  background: var(--bg-secondary);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  z-index: 30;
  flex-shrink: 0;
  min-height: 0;
}

.sidebar-header {
  padding: 12px 14px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex-shrink: 0;
}

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

.sidebar-title {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 6px;
}

.inventory-badge {
  font-size: 0.72rem;
  color: var(--text-secondary);
  background: var(--bg-tertiary);
  padding: 2px 8px;
  border-radius: 9999px;
  border: 1px solid var(--border-color);
}

/* Progress bar inside sidebar */
.progress-container {
  width: 100%;
  background: var(--bg-tertiary);
  height: 5px;
  border-radius: 9999px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, #388bfd 0%, #8957e5 100%);
  border-radius: 9999px;
  transition: width 0.4s ease;
}

/* Search bar */
.search-box {
  position: relative;
  display: flex;
  align-items: center;
}

.search-icon {
  position: absolute;
  left: 10px;
  color: var(--text-muted);
  font-size: 0.8rem;
  pointer-events: none;
}

.search-input {
  width: 100%;
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 7px 12px 7px 30px;
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.search-input:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 2px rgba(88, 166, 255, 0.2);
}

.clear-search-btn {
  position: absolute;
  right: 8px;
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 0.78rem;
  padding: 2px 6px;
  display: none;
}

.search-input:not(:placeholder-shown) + .clear-search-btn {
  display: block;
}

/* Inventory Items Grid */
.inventory-scroll {
  flex: 1;
  overflow-y: auto;
  padding: 10px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  align-content: start;
  touch-action: pan-y;
  min-height: 0;
}

.inventory-scroll::-webkit-scrollbar {
  width: 6px;
}
.inventory-scroll::-webkit-scrollbar-track {
  background: transparent;
}
.inventory-scroll::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 4px;
}

/* Individual Inventory Item Tile */
.inventory-item {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 8px 4px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  cursor: grab;
  transition: transform 0.15s ease, border-color 0.15s ease, box-shadow 0.15s ease;
  position: relative;
  touch-action: none;
  min-height: 70px;
}

.inventory-item:hover {
  background: #282e37;
  border-color: #58a6ff;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.inventory-item:active {
  cursor: grabbing;
}

.inventory-item .item-emoji {
  font-size: 1.65rem;
  line-height: 1;
  pointer-events: none;
}

.inventory-item .item-name {
  font-size: 0.7rem;
  color: var(--text-secondary);
  text-align: center;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 95%;
  pointer-events: none;
}

.inventory-item.base-element::after {
  content: "★";
  position: absolute;
  top: 3px;
  right: 5px;
  font-size: 0.62rem;
  color: var(--accent-gold);
  opacity: 0.6;
}

/* Hint Pulsing Highlight */
.inventory-item.hint-pulse,
.canvas-element.hint-pulse {
  animation: hintGlow 1.2s infinite alternate ease-in-out !important;
  border-color: var(--accent-gold) !important;
  z-index: 40;
}

@keyframes hintGlow {
  0% {
    box-shadow: 0 0 6px rgba(241, 224, 90, 0.5), inset 0 0 6px rgba(241, 224, 90, 0.2);
    transform: scale(1);
  }
  100% {
    box-shadow: 0 0 20px rgba(241, 224, 90, 0.9), inset 0 0 10px rgba(241, 224, 90, 0.4);
    transform: scale(1.06);
  }
}

/* Empty search state */
.empty-inventory-msg {
  grid-column: 1 / -1;
  text-align: center;
  padding: 30px 12px;
  color: var(--text-muted);
  font-size: 0.82rem;
}

/* ==========================================================================
   Canvas (Crafting Area)
   ========================================================================== */
#canvas-container {
  flex: 1;
  position: relative;
  background-color: var(--bg-canvas);
  background-image: 
    radial-gradient(circle at 1px 1px, rgba(255, 255, 255, 0.05) 1px, transparent 0);
  background-size: 24px 24px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  touch-action: none;
  min-height: 0;
}

#crafting-canvas {
  width: 100%;
  height: 100%;
  position: relative;
  overflow: hidden;
  touch-action: none;
}

/* Canvas Overlay Controls Toolbar */
.canvas-toolbar {
  position: absolute;
  top: 14px;
  right: 14px;
  display: flex;
  align-items: center;
  gap: 6px;
  z-index: 40;
  background: rgba(22, 27, 34, 0.88);
  backdrop-filter: blur(8px);
  padding: 5px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-main);
}

.canvas-hint-pill {
  position: absolute;
  bottom: 16px;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(22, 27, 34, 0.85);
  backdrop-filter: blur(8px);
  border: 1px solid var(--border-color);
  padding: 6px 14px;
  border-radius: 9999px;
  font-size: 0.76rem;
  color: var(--text-secondary);
  pointer-events: none;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: opacity 0.3s ease;
  white-space: nowrap;
}

/* Canvas Placed Element Card */
.canvas-element {
  position: absolute;
  width: 76px;
  height: 76px;
  background: rgba(33, 38, 45, 0.95);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  cursor: grab;
  touch-action: none;
  z-index: 10;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.4);
  transition: transform 0.05s ease, box-shadow 0.15s ease, border-color 0.15s ease;
}

.canvas-element:hover {
  border-color: #58a6ff;
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.6);
}

.canvas-element.dragging {
  cursor: grabbing;
  z-index: 100;
  transform: scale(1.12);
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.7), 0 0 15px rgba(88, 166, 255, 0.4);
  border-color: var(--accent-blue);
  opacity: 0.95;
}

.canvas-element.hover-combine-target {
  border-color: var(--accent-purple);
  box-shadow: 0 0 22px rgba(137, 87, 229, 0.85);
  transform: scale(1.08);
  animation: pulseCombine 0.8s infinite alternate ease-in-out;
}

.canvas-element .elem-emoji {
  font-size: 2.1rem;
  line-height: 1;
  pointer-events: none;
}

.canvas-element .elem-name {
  font-size: 0.68rem;
  color: var(--text-primary);
  font-weight: 500;
  pointer-events: none;
  text-align: center;
  max-width: 90%;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Animations */
@keyframes popSpawn {
  0% { transform: scale(0.2) rotate(-15deg); opacity: 0; }
  60% { transform: scale(1.22) rotate(4deg); opacity: 1; }
  85% { transform: scale(0.96) rotate(-2deg); }
  100% { transform: scale(1) rotate(0deg); }
}

.canvas-element.pop-animation {
  animation: popSpawn 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

@keyframes wiggleFail {
  0%, 100% { transform: translateX(0); }
  20%, 60% { transform: translateX(-6px) rotate(-3deg); }
  40%, 80% { transform: translateX(6px) rotate(3deg); }
}

.canvas-element.wiggle-fail {
  animation: wiggleFail 0.35s ease-in-out;
  border-color: var(--accent-red);
}

@keyframes pulseCombine {
  from { box-shadow: 0 0 12px rgba(137, 87, 229, 0.4); }
  to { box-shadow: 0 0 24px rgba(137, 87, 229, 0.9); }
}

@keyframes floatSlow {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-3px); }
}

/* Sparkle Particle Burst Effect */
.sparkle-burst {
  position: absolute;
  pointer-events: none;
  width: 120px;
  height: 120px;
  z-index: 150;
  transform: translate(-50%, -50%);
}

.sparkle-particle {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent-gold);
  box-shadow: 0 0 10px var(--accent-gold);
  animation: particleFly 0.6s ease-out forwards;
}

@keyframes particleFly {
  0% {
    transform: translate(-50%, -50%) scale(1);
    opacity: 1;
  }
  100% {
    transform: translate(calc(-50% + var(--dx)), calc(-50% + var(--dy))) scale(0);
    opacity: 0;
  }
}

/* ==========================================================================
   Discovery Notification Toast & Share System
   ========================================================================== */
#toast-container {
  position: fixed;
  bottom: 20px;
  right: 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  z-index: 1000;
  pointer-events: none;
  max-width: calc(100vw - 40px);
}

.toast {
  background: linear-gradient(135deg, #1c2128 0%, #2d333b 100%);
  border: 1px solid var(--accent-purple);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.6), 0 0 14px rgba(137, 87, 229, 0.35);
  padding: 12px 16px;
  border-radius: var(--radius-md);
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 12px;
  pointer-events: auto;
  animation: slideInToast 0.35s cubic-bezier(0.16, 1, 0.3, 1) forwards;
  min-width: 270px;
}

.toast.toast-hint {
  border-color: var(--accent-gold);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.6), 0 0 14px rgba(241, 224, 90, 0.35);
}

.toast.toast-milestone {
  border-color: #3fb950;
  background: linear-gradient(135deg, #16241a 0%, #1e3825 100%);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.7), 0 0 18px rgba(63, 185, 80, 0.4);
}

.toast.removing {
  animation: slideOutToast 0.3s ease forwards;
}

.toast-emoji {
  font-size: 2rem;
  flex-shrink: 0;
}

.toast-content {
  display: flex;
  flex-direction: column;
  gap: 2px;
  flex: 1;
}

.toast-tag {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--accent-gold);
  letter-spacing: 0.05em;
}

.toast-title {
  font-size: 0.95rem;
  font-weight: 600;
}

.toast-formula {
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.toast-actions {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: auto;
}

.toast-share-btn {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: all 0.15s ease;
  white-space: nowrap;
}

.toast-share-btn:hover {
  background: #2b313a;
  border-color: var(--accent-purple);
  color: #fff;
}

.toast-share-btn.copied {
  background: rgba(63, 185, 80, 0.2);
  border-color: var(--accent-green);
  color: #7ee787;
}

@keyframes slideInToast {
  from { transform: translateY(30px) scale(0.9); opacity: 0; }
  to { transform: translateY(0) scale(1); opacity: 1; }
}

@keyframes slideOutToast {
  from { transform: translateY(0) scale(1); opacity: 1; }
  to { transform: translateY(20px) scale(0.9); opacity: 0; }
}

/* ==========================================================================
   Modals (Grimoire, Milestones, Feedback)
   ========================================================================== */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(5px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 500;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease;
  padding: 16px;
}

.modal-backdrop.open {
  opacity: 1;
  pointer-events: auto;
}

.modal-window {
  width: 100%;
  max-width: 620px;
  max-height: 85vh;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.8);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transform: scale(0.95);
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.modal-backdrop.open .modal-window {
  transform: scale(1);
}

.modal-header {
  padding: 14px 18px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-title {
  font-size: 1.05rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 8px;
}

.modal-body {
  padding: 16px;
  overflow-y: auto;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 12px;
  touch-action: pan-y;
  min-height: 0;
}

.grimoire-desc {
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

/* Grimoire Recipe List */
.recipe-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 8px;
}

.recipe-card {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 9px 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.88rem;
}

.recipe-card.undiscovered {
  opacity: 0.45;
  filter: grayscale(0.8);
}

.recipe-formula {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 1.05rem;
}

.recipe-arrow {
  color: var(--text-muted);
  font-size: 0.78rem;
}

.recipe-result-tag {
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.82rem;
}

/* Mastery Tiers List */
.tiers-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.tier-card {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 12px 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  transition: all 0.2s ease;
}

.tier-card.unlocked {
  border-color: rgba(63, 185, 80, 0.5);
  background: linear-gradient(90deg, rgba(63, 185, 80, 0.1) 0%, #21262d 100%);
}

.tier-card.current {
  border-color: var(--accent-gold);
  box-shadow: 0 0 14px rgba(241, 224, 90, 0.25);
}

.tier-info {
  display: flex;
  align-items: center;
  gap: 12px;
}

.tier-icon {
  font-size: 1.8rem;
}

.tier-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-primary);
}

.tier-requirement {
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.tier-status-pill {
  font-size: 0.72rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 9999px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
}

.tier-card.unlocked .tier-status-pill {
  background: rgba(63, 185, 80, 0.2);
  border-color: var(--accent-green);
  color: #7ee787;
}

.tier-card.current .tier-status-pill {
  background: rgba(241, 224, 90, 0.2);
  border-color: var(--accent-gold);
  color: #fff48f;
}

/* Feedback Modal Styling */
.feedback-window {
  max-width: 520px;
}

.feedback-form {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.category-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.category-pill-label {
  cursor: pointer;
}

.category-pill-label input[type="radio"] {
  display: none;
}

.category-pill-label span {
  display: inline-block;
  padding: 6px 12px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: all 0.15s ease;
}

.category-pill-label input[type="radio"]:checked + span {
  background: rgba(88, 166, 255, 0.2);
  border-color: var(--border-focus);
  color: #fff;
  box-shadow: 0 0 8px rgba(88, 166, 255, 0.3);
}

.form-textarea, .form-input {
  width: 100%;
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.82rem;
  outline: none;
  transition: border-color 0.2s ease;
}

.form-textarea:focus, .form-input:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 2px rgba(88, 166, 255, 0.2);
}

.feedback-stats-preview {
  font-size: 0.75rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 6px;
}

.feedback-stats-preview .stat-tag {
  background: var(--bg-tertiary);
  padding: 2px 8px;
  border-radius: 9999px;
  border: 1px solid var(--border-color);
  color: #58a6ff;
  font-weight: 600;
}

.form-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
  padding-top: 6px;
  border-top: 1px solid var(--border-color);
}

.feedback-history-section {
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px dashed var(--border-color);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.history-title {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
}

.feedback-history-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
  max-height: 120px;
  overflow-y: auto;
}

.history-card {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 6px 10px;
  font-size: 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.history-card-header {
  display: flex;
  justify-content: space-between;
  color: var(--text-muted);
  font-size: 0.68rem;
}

/* ==========================================================================
   Mobile Stacked Layout & Zero-Scroll Strict Sizing (@media max-width: 768px)
   ========================================================================== */
@media (max-width: 768px) {
  :root {
    --header-height: 50px;
  }

  .engagement-banner {
    padding: 4px 10px;
    font-size: 0.72rem;
  }

  .banner-text {
    font-size: 0.72rem;
  }

  #app-header {
    padding: 0 10px;
  }

  .brand-titles h1 {
    font-size: 0.95rem;
  }

  .brand-subtitle {
    display: none;
  }

  .stats-badge {
    padding: 4px 8px;
    font-size: 0.75rem;
  }

  .btn {
    padding: 5px 8px;
    font-size: 0.78rem;
  }

  .btn-text {
    display: none;
  }

  .btn-hint {
    display: none; /* Accessible inside canvas toolbar on mobile */
  }

  .btn-hint-mobile {
    display: inline-flex;
  }

  /* 5. Strict Viewport Scaling & Zero-Scroll Mobile Fit */
  #app-layout {
    flex-direction: column-reverse;
    flex: 1;
    height: 100%;
    min-height: 0;
    overflow: hidden;
  }

  /* Pinned Mobile Inventory Dock at Bottom - No page scroll */
  #sidebar {
    width: 100%;
    height: 135px;
    min-height: 135px;
    max-height: 135px;
    border-right: none;
    border-top: 1px solid var(--border-color);
    box-shadow: 0 -4px 16px rgba(0, 0, 0, 0.5);
    background: #13171f;
    flex-shrink: 0;
  }

  .sidebar-header {
    padding: 6px 10px;
    gap: 6px;
    border-bottom: 1px solid rgba(48, 54, 61, 0.6);
  }

  .sidebar-title-row {
    display: none;
  }

  .search-box {
    width: 100%;
  }

  .search-input {
    padding: 4px 10px 4px 26px;
    font-size: 0.75rem;
    height: 26px;
  }

  .search-icon {
    left: 8px;
    font-size: 0.72rem;
  }

  /* Horizontal smooth scroll row for inventory */
  .inventory-scroll {
    display: flex;
    flex-direction: row;
    flex-wrap: nowrap;
    overflow-x: auto;
    overflow-y: hidden;
    padding: 6px 10px;
    gap: 8px;
    touch-action: pan-x;
    -webkit-overflow-scrolling: touch;
    align-items: center;
    min-height: 0;
    flex: 1;
  }

  .inventory-scroll::-webkit-scrollbar {
    height: 4px;
  }

  .inventory-item {
    flex: 0 0 64px;
    height: 64px;
    min-height: 64px;
    padding: 4px 2px;
    border-radius: var(--radius-sm);
  }

  .inventory-item .item-emoji {
    font-size: 1.45rem;
  }

  .inventory-item .item-name {
    font-size: 0.62rem;
    max-width: 58px;
  }

  /* Canvas scales perfectly into remaining vertical space */
  #canvas-container {
    flex: 1;
    min-height: 0;
    height: auto;
  }

  .canvas-element {
    width: 68px;
    height: 68px;
  }

  .canvas-element .elem-emoji {
    font-size: 1.8rem;
  }

  .canvas-element .elem-name {
    font-size: 0.62rem;
  }

  .canvas-toolbar {
    top: 8px;
    right: 8px;
    padding: 4px;
  }

  .canvas-hint-pill {
    bottom: 8px;
    font-size: 0.68rem;
    padding: 3px 10px;
  }

  #toast-container {
    bottom: 145px; /* Floats directly above pinned mobile inventory dock */
    right: 10px;
    left: 10px;
    max-width: none;
  }

  .toast {
    min-width: unset;
    width: 100%;
  }
}