:root {
  /* Apple HIG Colors */
  --system-blue: #007AFF;
  --system-blue-hover: #005bb5;
  --system-red: #FF3B30;
  --system-red-hover: #d63127;
  --system-orange: #FF9500;
  
  /* Theme Variables (Light) */
  --bg-color: #F2F2F7;
  --card-bg: #FFFFFF;
  --msg-bubble-bg: #FFFFFF;
  --msg-bubble-border: rgba(0,0,0,0.05);
  
  --text-main: #1D1D1F;
  --text-light: #6E6E73;
  --text-code: #D93874;
  --border-color: #D2D2D7;
  
  --app-header-bg: rgba(255, 255, 255, 0.75);
  --app-panel-bg: rgba(242, 242, 247, 0.95);
  --app-modal-bg: rgba(255, 255, 255, 0.9);
  --pre-bg: #F5F5F7;
  
  --safe-area-inset-bottom: env(safe-area-inset-bottom, 20px);
}

/* Theme Variables (Dark) */
:root[data-theme="dark"] {
  --bg-color: #000000;
  --card-bg: #1C1C1E;
  --msg-bubble-bg: #2C2C2E;
  --msg-bubble-border: rgba(255,255,255,0.05);
  
  --text-main: #FFFFFF;
  --text-light: #98989D;
  --text-code: #FF6482;
  --border-color: #38383A;
  
  --app-header-bg: rgba(28, 28, 30, 0.75);
  --app-panel-bg: rgba(0, 0, 0, 0.85);
  --app-modal-bg: rgba(28, 28, 30, 0.9);
  --pre-bg: #2C2C2E;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", "Pretendard", sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.4;
  height: 100vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
}

/* Header (Glassmorphism) */
.app-header {
  background: var(--app-header-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 0.5px solid rgba(0, 0, 0, 0.15);
  padding: 14px 20px;
  z-index: 10;
  flex-shrink: 0;
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.header-inner h1 {
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: -0.4px;
}

.header-inner h1 span {
  font-weight: 400;
  color: var(--text-light);
}

.header-left, .header-right {
  display: flex;
  align-items: center;
}

.header-right {
  gap: 8px;
}

.admin-header-info {
  display: flex;
  align-items: center;
  background: rgba(0, 122, 255, 0.1);
  padding: 4px 8px;
  border-radius: 6px;
  margin-left: 10px;
}

.url-badge {
  font-size: 0.65rem;
  font-weight: 700;
  color: white;
  background: var(--system-blue);
  padding: 3px 6px;
  border-radius: 4px;
  margin-right: 6px;
  letter-spacing: 0.5px;
}

.url-txt {
  font-size: 0.8rem;
  color: var(--system-blue);
  font-weight: 500;
}

.admin-tools {
  display: flex;
  align-items: center;
  gap: 4px;
}

.icon-btn {
  background: none;
  border: none;
  color: var(--system-blue);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  padding: 6px;
  border-radius: 50%;
  transition: background 0.2s;
}
.icon-btn:hover {
  background: rgba(0, 122, 255, 0.1);
}

.text-danger { color: var(--system-red) !important; }
.text-warning { color: var(--system-orange) !important; }

/* Main Layout */
.container {
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  position: relative;
}

/* Alerts & status */
.alert {
  background-color: rgba(255, 59, 48, 0.1);
  color: var(--system-red);
  padding: 10px 16px;
  border-radius: 12px;
  margin: 16px;
  font-size: 0.9rem;
  font-weight: 500;
  text-align: center;
  flex-shrink: 0;
}

.hidden { display: none !important; }

/* Scrollable message viewer */
.viewer-container {
  flex-grow: 1;
  overflow-y: auto;
  padding: 20px;
  display: flex;
  flex-direction: column;
  -webkit-overflow-scrolling: touch;
}

.empty-state {
  text-align: center;
  color: var(--text-light);
  padding: 40px 20px;
  font-size: 0.95rem;
}

.message-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
  padding-bottom: 20px;
}

/* Chat Bubbles (HIG Minimal) */
.message-wrapper {
  display: flex;
  flex-direction: column;
  animation: popDown 0.4s cubic-bezier(0.16, 1, 0.3, 1) forwards;
  opacity: 0;
  transform: translateY(-10px) scale(0.98);
  width: 100%;
}

@keyframes popDown {
  to { opacity: 1; transform: translateY(0) scale(1); }
}

.message-item {
  display: flex;
  flex-direction: column;
  align-self: flex-start;
  background: var(--msg-bubble-bg);
  border-radius: 20px;
  border-top-left-radius: 4px;
  max-width: 85%;
  padding: 16px 20px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.03);
  border: 0.5px solid var(--msg-bubble-border);
}

.message-content {
  font-size: 0.95rem;
  word-break: break-word;
  color: var(--text-main);
}

.message-content h1, .message-content h2, .message-content h3 {
  margin-bottom: 12px;
  margin-top: 12px;
  font-size: 1.15em;
  font-weight: 600;
  letter-spacing: -0.3px;
}
.message-content h1:first-child, .message-content h2:first-child, .message-content p:first-child { margin-top: 0; }
.message-content p { margin-bottom: 12px; line-height: 1.5; }
.message-content p:last-child { margin-bottom: 0; }

.message-content pre {
  background: transparent;
  color: var(--text-main);
  padding: 0;
  border-radius: 0;
  overflow-x: hidden;
  margin: 0;
  font-size: 0.95rem;
  border: none;
  line-height: 1.5;
  white-space: pre-wrap;
  word-break: break-word;
}

.message-content code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  background: var(--pre-bg);
  color: var(--text-code);
  padding: 3px 6px;
  border-radius: 6px;
  font-size: 0.85em;
}
.message-content pre code {
  background: transparent;
  padding: 0;
  color: inherit;
}

.message-actions {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  margin-top: 10px;
  padding-top: 10px;
  border-top: 0.5px solid var(--border-color);
}

/* Fixed Bottom Admin Panel */
.admin-panel {
  flex-shrink: 0;
  background: var(--app-panel-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-top: 0.5px solid var(--border-color);
  padding: 10px 16px calc(10px + var(--safe-area-inset-bottom));
  width: 100%;
}

.chat-input-wrapper {
  display: flex;
  align-items: flex-end;
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 4px 4px 4px 14px;
}

.chat-input-wrapper textarea {
  border: none;
  background: transparent;
  flex-grow: 1;
  padding: 8px 0;
  margin: 0;
  max-height: 300px;
  min-height: 24px;
  resize: none;
  overflow-y: auto;
  line-height: 1.4;
  font-family: inherit;
  font-size: 0.95rem;
  color: var(--text-main);
}

.chat-input-wrapper textarea:focus {
  outline: none;
  box-shadow: none;
}

.send-icon-btn {
  background: var(--system-blue);
  color: white;
  border: none;
  border-radius: 50%;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  margin-bottom: 1px;
  margin-left: 8px;
  flex-shrink: 0;
  transition: opacity 0.2s;
}
.send-icon-btn:active {
  opacity: 0.7;
}
.send-icon-btn:hover {
  background: var(--system-blue-hover);
}

/* Buttons (iOS Style) */
.btn {
  padding: 8px 16px;
  border-radius: 20px;
  font-weight: 500;
  cursor: pointer;
  border: none;
  font-size: 0.9rem;
  transition: opacity 0.2s, background 0.2s;
}
.btn:active { opacity: 0.7; }

.btn-sm { 
  padding: 4px 12px; 
  font-size: 0.8rem; 
  border-radius: 12px; 
}

.btn-primary { 
  background: var(--system-blue); 
  color: white; 
}
.btn-primary:active { background: var(--system-blue-hover); }

.btn-outline { 
  background: rgba(0, 122, 255, 0.1); 
  color: var(--system-blue); 
}
.btn-outline:active { background: rgba(0, 122, 255, 0.2); }

.btn-danger { 
  background: rgba(255, 59, 48, 0.1); 
  color: var(--system-red); 
}
.btn-danger:active { background: rgba(255, 59, 48, 0.2); }

.btn-warning { 
  background: rgba(255, 149, 0, 0.1); 
  color: var(--system-orange);
}
.btn-warning:active { background: rgba(255, 149, 0, 0.2); }

.btn-text { 
  background: none; 
  color: var(--system-blue); 
}

/* Modal */
.modal {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 50;
  padding: 20px;
  animation: fadeIn 0.2s;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.modal-content {
  background: var(--app-modal-bg);
  backdrop-filter: blur(30px);
  -webkit-backdrop-filter: blur(30px);
  padding: 24px;
  border-radius: 18px;
  width: 100%;
  max-width: 320px;
  box-shadow: 0 20px 40px rgba(0,0,0,0.3);
  text-align: center;
}

.modal-content h2 { 
  margin-bottom: 6px; 
  font-size: 1.1rem; 
  font-weight: 600; 
}

.modal-content p { 
  color: var(--text-light); 
  margin-bottom: 20px; 
  font-size: 0.85rem; 
}

.modal-content input {
  width: 100%;
  padding: 12px 14px;
  border: 0.5px solid var(--border-color);
  border-radius: 10px;
  margin-bottom: 20px;
  font-size: 1rem;
  background: var(--card-bg);
  color: var(--text-main);
  text-align: center;
}
.modal-content input:focus {
  outline: none;
  border-color: var(--system-blue);
}

.modal-actions {
  display: flex;
  border-top: 0.5px solid var(--border-color);
  margin: 0 -24px -24px -24px;
}

.modal-actions .btn {
  flex: 1;
  background: none;
  border-radius: 0;
  padding: 14px;
  font-size: 1rem;
  color: var(--system-blue);
}

.modal-actions .btn:first-child {
  border-right: 0.5px solid var(--border-color);
  color: var(--system-red);
}

/* ========================================================= */
/* Responsive Layout (Media Queries)                         */
/* ========================================================= */

/* Tablet & Smaller Desktop (Max 1024px) */
@media (max-width: 1024px) {
  .message-item {
    max-width: 90%;
  }
}

/* Mobile & Small Tablet (Max 768px) */
@media (max-width: 768px) {
  .app-header {
    padding: 10px 16px;
  }
  
  .header-inner h1 {
    font-size: 1.05rem;
  }
  
  .viewer-container {
    padding: 16px;
  }
  
  .message-item {
    max-width: 95%; /* 모바일에서는 텍스트 영역을 더 넓게 보장 */
    padding: 10px 14px;
    border-radius: 16px;
    border-top-left-radius: 4px;
  }

  .message-content h1, .message-content h2, .message-content h3 {
    font-size: 1.05em;
  }
  
  .message-content {
    font-size: 0.9rem;
  }

  .message-content pre {
    padding: 10px;
    font-size: 0.8rem;
  }

  .admin-panel {
    padding: 10px 12px calc(10px + var(--safe-area-inset-bottom));
  }
  
  .chat-input-wrapper {
    padding: 4px 4px 4px 10px;
  }
  
  .btn {
    font-size: 0.85rem;
    padding: 6px 14px;
  }
}

/* Extra Small Mobile (Max 480px) */
@media (max-width: 480px) {
  .message-item {
    max-width: 100%; /* 아주 작은 화면에서는 100%로 꽉 채움 */
  }
  
  .url-badge {
    display: none; /* 공간 절약을 위해 ROOM 배지 숨김 */
  }
  
  .admin-header-info {
    margin-left: 6px;
    padding: 4px 6px;
  }
}

/* ========================================================= */
/* Print & Native PDF Styles                                 */
/* ========================================================= */
.print-container {
  display: none;
}

@media print {
  /* Hide all normal UI */
  body.is-printing > *:not(.print-container) {
    display: none !important;
  }
  
  body.is-printing {
    background: #FFF;
    color: #000;
    height: auto;
    overflow: auto;
  }

  /* Show Print Container */
  .print-container {
    display: block !important;
    padding: 20px;
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", "Pretendard", sans-serif;
    color: #000;
  }

  .print-container h1 {
    font-size: 24px;
    margin-bottom: 5px;
  }

  .print-container p {
    font-size: 14px;
    margin-bottom: 20px;
    color: #666;
  }

  .print-container hr {
    margin-bottom: 20px;
    border: none;
    border-top: 2px solid #EEE;
  }

  .print-item {
    margin-bottom: 25px;
    padding: 15px;
    border: 1px solid #CCC;
    border-radius: 8px;
  }

  .print-page-break {
    page-break-inside: avoid;
    break-inside: avoid;
  }

  .print-item h3 {
    margin-top: 0;
    margin-bottom: 15px;
    color: #007AFF;
    font-size: 16px;
  }
  
  .print-item pre {
    white-space: pre-wrap;
    word-break: break-word;
    font-size: 12px;
    line-height: 1.6;
    margin: 0;
    color: #000;
  }
}