/* ===== CSS Variables ===== */
:root {
  --bg-primary: #0a0a0a;
  --bg-secondary: #1a1a1a;
  --bg-card: #1e1e1e;
  --bg-card-hover: #252525;
  --bg-input: #2a2a2a;
  
  --accent-primary: #c8ff00;
  --accent-secondary: #a3cc00;
  --accent-glow: rgba(200, 255, 0, 0.15);
  
  --text-primary: #ffffff;
  --text-secondary: #a0a0a0;
  --text-muted: #666666;
  
  --border-color: #333333;
  --border-radius-sm: 8px;
  --border-radius-md: 12px;
  --border-radius-lg: 20px;
  --border-radius-xl: 28px;
  
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.4);
  --shadow-glow: 0 0 30px var(--accent-glow);
  
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
  --transition-slow: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  
  --safe-area-bottom: env(safe-area-inset-bottom, 0px);
}

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  /* Prevent scroll on html element on mobile */
  overflow: hidden;
  height: 100%;
  height: -webkit-fill-available;
}

body {
  font-family: 'Outfit', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  min-height: 100dvh;
  min-height: -webkit-fill-available;
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  /* Prevent iOS bounce scroll */
  overscroll-behavior: none;
  position: fixed;
  width: 100%;
  top: 0;
  left: 0;
}

button {
  font-family: inherit;
  border: none;
  background: none;
  cursor: pointer;
  color: inherit;
}

input {
  font-family: inherit;
  border: none;
  background: none;
  outline: none;
  color: inherit;
}

/* ===== App Container ===== */
.app-container {
  display: flex;
  flex-direction: column;
  height: 100vh;
  height: 100dvh;
  max-width: 480px;
  margin: 0 auto;
  position: relative;
  background: var(--bg-primary);
}

@media (min-width: 768px) {
  .app-container {
    max-width: 600px;
    border-left: 1px solid var(--border-color);
    border-right: 1px solid var(--border-color);
  }
}

/* ===== Header ===== */
.app-header {
  padding: 16px 20px;
  background: linear-gradient(180deg, var(--bg-primary) 0%, transparent 100%);
  position: sticky;
  top: 0;
  z-index: 10;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo-icon {
  font-size: 24px;
  filter: drop-shadow(0 0 8px var(--accent-primary));
}

.logo-text {
  font-size: 24px;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent-primary) 0%, #ffffff 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.header-subtitle {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 2px;
  letter-spacing: 0.5px;
}

/* ===== Chat Container ===== */
.chat-container {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 0 16px 20px;
  scroll-behavior: smooth;
}

.chat-container::-webkit-scrollbar {
  width: 4px;
}

.chat-container::-webkit-scrollbar-track {
  background: transparent;
}

.chat-container::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 2px;
}

/* ===== Welcome Section ===== */
.welcome-section {
  text-align: center;
  padding: 40px 20px;
  animation: fadeInUp 0.6s ease;
}

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

.welcome-avatar {
  width: 80px;
  height: 80px;
  margin: 0 auto 20px;
  background: linear-gradient(135deg, var(--bg-card) 0%, var(--bg-secondary) 100%);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 40px;
  box-shadow: var(--shadow-glow);
  border: 2px solid var(--accent-primary);
}

.welcome-section h1 {
  font-size: 28px;
  font-weight: 600;
  margin-bottom: 12px;
  background: linear-gradient(135deg, #ffffff 0%, var(--text-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.welcome-section p {
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.5;
  max-width: 280px;
  margin: 0 auto;
}

.quick-topics {
  display: flex;
  gap: 12px;
  justify-content: center;
  margin-top: 32px;
  flex-wrap: wrap;
}

.quick-topic-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 14px 20px;
  background: var(--bg-card);
  border-radius: var(--border-radius-lg);
  font-size: 14px;
  font-weight: 500;
  transition: all var(--transition-normal);
  border: 1px solid var(--border-color);
}

.quick-topic-btn:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
}

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

.topic-icon {
  font-size: 20px;
}

/* ===== Messages ===== */
.messages-container {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.message {
  display: flex;
  gap: 12px;
  animation: messageIn 0.3s ease;
}

@keyframes messageIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.message.user {
  flex-direction: row-reverse;
}

.message-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--bg-card);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  flex-shrink: 0;
}

.message.user .message-avatar {
  background: var(--accent-primary);
  color: var(--bg-primary);
}

.message-content {
  max-width: 75%;
  padding: 14px 18px;
  border-radius: var(--border-radius-lg);
  font-size: 15px;
  line-height: 1.5;
}

.message.assistant .message-content {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-bottom-left-radius: var(--border-radius-sm);
}

.message.user .message-content {
  background: linear-gradient(135deg, var(--accent-primary) 0%, var(--accent-secondary) 100%);
  color: var(--bg-primary);
  border-bottom-right-radius: var(--border-radius-sm);
}

.message-content p {
  margin-bottom: 8px;
}

.message-content p:last-child {
  margin-bottom: 0;
}

.message-content ul, .message-content ol {
  margin: 8px 0;
  padding-left: 20px;
}

.message-content li {
  margin-bottom: 4px;
}

.message-content strong {
  color: var(--accent-primary);
}

.message.user .message-content strong {
  color: var(--bg-primary);
}

/* Food Analysis Result */
.food-analysis {
  margin-top: 12px;
}

.food-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 14px;
  background: var(--bg-secondary);
  border-radius: var(--border-radius-md);
  margin-bottom: 8px;
}

.food-item:last-child {
  margin-bottom: 0;
}

.food-name {
  font-weight: 500;
}

.food-calories {
  color: var(--accent-primary);
  font-weight: 600;
}

.food-total {
  display: flex;
  justify-content: space-between;
  padding: 12px 14px;
  background: linear-gradient(135deg, var(--accent-glow) 0%, transparent 100%);
  border-radius: var(--border-radius-md);
  border: 1px solid var(--accent-primary);
  margin-top: 12px;
  font-weight: 600;
}

/* Typing Indicator */
.typing-indicator {
  display: flex;
  gap: 4px;
  padding: 8px 0;
}

.typing-indicator span {
  width: 8px;
  height: 8px;
  background: var(--text-muted);
  border-radius: 50%;
  animation: typing 1.4s infinite;
}

.typing-indicator span:nth-child(2) {
  animation-delay: 0.2s;
}

.typing-indicator span:nth-child(3) {
  animation-delay: 0.4s;
}

@keyframes typing {
  0%, 60%, 100% {
    transform: translateY(0);
    opacity: 0.4;
  }
  30% {
    transform: translateY(-8px);
    opacity: 1;
  }
}

/* Upload Button in Chat */
.upload-chat-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  background: linear-gradient(135deg, var(--accent-primary) 0%, var(--accent-secondary) 100%);
  color: var(--bg-primary);
  border-radius: var(--border-radius-md);
  font-weight: 600;
  font-size: 14px;
  margin-top: 12px;
  transition: all var(--transition-normal);
}

.upload-chat-btn:hover {
  transform: scale(1.02);
  box-shadow: var(--shadow-glow);
}

/* ===== Topics Overlay ===== */
.topics-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 90;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
}

.topics-overlay.active {
  opacity: 1;
  visibility: visible;
}

/* ===== Topics Floating Menu ===== */
.topics-floating-menu {
  position: absolute;
  bottom: calc(80px + var(--safe-area-bottom));
  right: 20px;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 12px;
  z-index: 100;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all var(--transition-normal);
  pointer-events: none;
}

.topics-floating-menu.active {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  pointer-events: auto;
}

/* Stagger animation for pills */
.topics-floating-menu.active .topic-pill {
  animation: pillSlideIn 0.3s ease forwards;
}

.topics-floating-menu.active .topic-pill:nth-child(1) {
  animation-delay: 0.05s;
}

.topics-floating-menu.active .topic-pill:nth-child(2) {
  animation-delay: 0s;
}

@keyframes pillSlideIn {
  from {
    opacity: 0;
    transform: translateX(20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.topic-pill {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 22px;
  background: #ffffff;
  color: #1a1a1a;
  border-radius: 50px;
  font-size: 15px;
  font-weight: 600;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  transition: all var(--transition-normal);
  opacity: 0;
  white-space: nowrap;
}

.topic-pill:hover {
  transform: scale(1.03);
  box-shadow: 0 6px 25px rgba(0, 0, 0, 0.4);
}

.topic-pill:active {
  transform: scale(0.98);
}

.topic-pill-icon {
  font-size: 20px;
}

/* Disabled state for topic pills */
.topic-pill:disabled,
.topic-pill.disabled {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

/* ===== Input Area ===== */
.input-area {
  display: flex;
  gap: 12px;
  padding: 16px 20px;
  padding-bottom: calc(16px + var(--safe-area-bottom));
  padding-right: 140px; /* Leave space for Topics button (button width ~120px + 20px margin) */
  background: linear-gradient(180deg, transparent 0%, var(--bg-primary) 20%);
  position: sticky;
  bottom: 0;
}

.input-wrapper {
  flex: 1;
  display: flex;
  align-items: center;
  background: var(--bg-input);
  border-radius: var(--border-radius-xl);
  padding: 4px 6px 4px 20px;
  border: 1px solid var(--border-color);
  transition: border-color var(--transition-fast);
}

.input-wrapper:focus-within {
  border-color: var(--accent-primary);
}

.input-wrapper input {
  flex: 1;
  padding: 12px 0;
  font-size: 15px;
  background: transparent;
}

.input-wrapper input::placeholder {
  color: var(--text-muted);
}

.send-btn {
  width: 44px;
  height: 44px;
  background: var(--bg-card);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  transition: all var(--transition-normal);
}

.send-btn:not(:disabled):hover {
  background: var(--accent-primary);
  color: var(--bg-primary);
  transform: scale(1.05);
}

.send-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.topics-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  height: 52px; /* Match input-wrapper height (44px send button + 4px top + 4px bottom padding) */
  padding: 0 20px;
  background: var(--accent-primary);
  color: var(--bg-primary);
  border-radius: var(--border-radius-xl);
  font-size: 14px;
  font-weight: 600;
  transition: all var(--transition-normal);
  white-space: nowrap;
  /* Absolute position within app-container, above overlay */
  position: absolute;
  bottom: calc(16px + var(--safe-area-bottom));
  right: 20px;
  z-index: 95; /* Above overlay (z-index: 90) */
}

.topics-btn:hover:not(:disabled) {
  background: var(--accent-secondary);
  transform: scale(1.02);
}

.topics-btn.active {
  background: var(--accent-secondary);
  box-shadow: var(--shadow-glow);
}

.topics-btn:disabled,
.topics-btn.disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

.topics-btn-icon {
  font-size: 16px;
}

/* Disabled state for input */
.input-wrapper input:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/* Disabled state for topic buttons */
.quick-topic-btn:disabled,
.quick-topic-btn.disabled,
.topic-item:disabled,
.topic-item.disabled {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

/* ===== Upload Modal ===== */
.upload-modal {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 200;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
  padding: 20px;
}

.upload-modal.active {
  opacity: 1;
  visibility: visible;
}

.upload-modal-content {
  width: 100%;
  max-width: 400px;
  background: var(--bg-secondary);
  border-radius: var(--border-radius-xl);
  padding: 24px;
  transform: scale(0.9) translateY(20px);
  transition: transform var(--transition-slow);
}

.upload-modal.active .upload-modal-content {
  transform: scale(1) translateY(0);
}

.upload-modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

.upload-modal-header h3 {
  font-size: 18px;
  font-weight: 600;
}

.close-modal-btn {
  width: 32px;
  height: 32px;
  background: var(--bg-input);
  border-radius: 50%;
  font-size: 20px;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.close-modal-btn:hover {
  background: var(--bg-card-hover);
  color: var(--text-primary);
}

.upload-area {
  border: 2px dashed var(--border-color);
  border-radius: var(--border-radius-lg);
  padding: 40px 20px;
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-normal);
}

.upload-area:hover {
  border-color: var(--accent-primary);
  background: var(--accent-glow);
}

.upload-area.drag-over {
  border-color: var(--accent-primary);
  background: var(--accent-glow);
}

.upload-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.upload-icon {
  font-size: 40px;
  margin-bottom: 8px;
}

.upload-placeholder p {
  font-size: 14px;
  color: var(--text-secondary);
}

.upload-hint {
  font-size: 12px;
  color: var(--text-muted);
}

.image-preview {
  position: relative;
  border-radius: var(--border-radius-lg);
  overflow: hidden;
  margin-bottom: 16px;
}

.image-preview img {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

.remove-image-btn {
  position: absolute;
  top: 10px;
  right: 10px;
  padding: 8px 16px;
  background: rgba(0, 0, 0, 0.7);
  color: #ff4444;
  border-radius: var(--border-radius-md);
  font-size: 13px;
  font-weight: 500;
}

.analyze-btn {
  width: 100%;
  padding: 16px;
  background: linear-gradient(135deg, var(--accent-primary) 0%, var(--accent-secondary) 100%);
  color: var(--bg-primary);
  border-radius: var(--border-radius-lg);
  font-size: 16px;
  font-weight: 600;
  margin-top: 16px;
  transition: all var(--transition-normal);
}

.analyze-btn:not(:disabled):hover {
  transform: scale(1.02);
  box-shadow: var(--shadow-glow);
}

.analyze-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ===== Loading Overlay ===== */
.loading-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.85);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 20px;
  z-index: 300;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
}

.loading-overlay.active {
  opacity: 1;
  visibility: visible;
}

.loading-spinner {
  width: 48px;
  height: 48px;
  border: 3px solid var(--bg-card);
  border-top-color: var(--accent-primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

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

.loading-overlay p {
  font-size: 16px;
  color: var(--text-secondary);
}

/* ===== Utilities ===== */
.hidden {
  display: none !important;
}

/* ===== Desktop Enhancements ===== */
@media (min-width: 1024px) {
  body {
    background: linear-gradient(135deg, #0a0a0a 0%, #1a1a1a 50%, #0a0a0a 100%);
  }
  
  .app-container {
    margin-top: 40px;
    margin-bottom: 40px;
    height: calc(100vh - 80px);
    border-radius: var(--border-radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-md);
  }
}