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

:root {
  --bg-primary: #0f0f0f;
  --bg-secondary: #1a1a1a;
  --bg-tertiary: #272727;
  --bg-hover: #333333;
  --bg-card: #1e1e1e;
  --text-primary: #f1f1f1;
  --text-secondary: #aaaaaa;
  --text-muted: #717171;
  --accent: #3ea6ff;
  --accent-hover: #65b8ff;
  --accent-glow: rgba(62, 166, 255, 0.25);
  --danger: #ff4e45;
  --success: #2ecc71;
  --warning: #f39c12;
  --border: #333333;
  --border-light: #3a3a3a;
  --radius: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --shadow: 0 4px 24px rgba(0,0,0,0.4);
  --transition: 0.2s ease;
  --font: 'Roboto', -apple-system, BlinkMacSystemFont, sans-serif;
}

html, body {
  height: 100%;
  font-family: var(--font);
  background: var(--bg-primary);
  color: var(--text-primary);
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
}

input, button, select {
  font-family: var(--font);
  font-size: inherit;
}

.hidden { display: none !important; }

.view {
  display: none;
  height: 100vh;
}
.view.active { display: flex; }

/* ===== LOBBY ===== */
#lobby {
  align-items: center;
  justify-content: center;
  background:
    radial-gradient(ellipse at 20% 50%, rgba(62,166,255,0.06) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 50%, rgba(62,166,255,0.04) 0%, transparent 50%),
    var(--bg-primary);
  animation: lobbyBg 20s ease-in-out infinite alternate;
}

@keyframes lobbyBg {
  0% { background-position: 0% 50%; }
  100% { background-position: 100% 50%; }
}

.lobby-container {
  width: 100%;
  max-width: 640px;
  padding: 24px;
  position: relative;
}

.lobby-brand {
  text-align: center;
  margin-bottom: 32px;
}

.logo-icon {
  margin-bottom: 12px;
  animation: logoPulse 3s ease-in-out infinite;
}

@keyframes logoPulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

.lobby-brand h1 {
  font-size: 2.5rem;
  font-weight: 700;
  letter-spacing: -1px;
  background: linear-gradient(135deg, #ffffff 30%, var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.tagline {
  color: var(--text-secondary);
  font-size: 1rem;
  margin-top: 4px;
  font-weight: 300;
}

.lobby-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 28px;
  box-shadow: var(--shadow);
}

.input-group {
  margin-bottom: 4px;
}

.input-group label {
  display: block;
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-bottom: 6px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.input-group input,
#room-code-input {
  width: 100%;
  padding: 12px 16px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-size: 1rem;
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.input-group input:focus,
#room-code-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

.lobby-divider {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 20px 0;
  color: var(--text-muted);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.lobby-divider::before,
.lobby-divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

.lobby-actions {
  display: flex;
  gap: 20px;
}

.action-panel {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 12px;
}

.action-panel h3 {
  font-size: 1rem;
  font-weight: 600;
}

.action-desc {
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.4;
}

.lobby-or {
  display: flex;
  align-items: center;
  color: var(--text-muted);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.lobby-or::before,
.lobby-or::after {
  content: '';
  width: 1px;
  height: 40px;
  background: var(--border);
  margin: 0 0;
}

.lobby-or span {
  writing-mode: vertical-rl;
  padding: 8px 0;
}

/* File select button */
.file-select-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  background: var(--bg-tertiary);
  border: 1px dashed var(--border-light);
  border-radius: var(--radius);
  color: var(--text-secondary);
  font-size: 0.85rem;
  cursor: pointer;
  transition: all var(--transition);
}

.file-select-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(62, 166, 255, 0.08);
}

/* File info display */
.file-info {
  width: 100%;
  padding: 10px 14px;
  background: rgba(62, 166, 255, 0.08);
  border: 1px solid rgba(62, 166, 255, 0.2);
  border-radius: var(--radius);
  font-size: 0.8rem;
  color: var(--text-secondary);
  text-align: left;
}

.file-info .file-name {
  color: var(--text-primary);
  font-weight: 500;
  word-break: break-all;
}

.file-info .file-meta {
  margin-top: 4px;
  color: var(--text-muted);
  font-size: 0.75rem;
}

/* Buttons */
.btn-primary {
  width: 100%;
  padding: 12px 24px;
  background: var(--accent);
  color: #000;
  border: none;
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
}

.btn-primary:hover:not(:disabled) {
  background: var(--accent-hover);
  box-shadow: 0 0 16px var(--accent-glow);
}

.btn-primary:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.btn-secondary {
  width: 100%;
  padding: 12px 24px;
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--bg-hover);
  border-color: var(--text-muted);
}

.btn-secondary:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

/* Error toast */
.error-toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  padding: 12px 24px;
  background: var(--danger);
  color: white;
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 500;
  box-shadow: 0 4px 20px rgba(255,78,69,0.3);
  z-index: 1000;
  animation: toastIn 0.3s ease;
}

@keyframes toastIn {
  from { opacity: 0; transform: translateX(-50%) translateY(20px); }
  to { opacity: 1; transform: translateX(-50%) translateY(0); }
}

/* ===== FILE CHECK MODAL ===== */
.modal {
  position: fixed;
  inset: 0;
  z-index: 500;
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0.7);
  backdrop-filter: blur(4px);
}

.modal-content {
  position: relative;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 28px;
  max-width: 480px;
  width: 90%;
  box-shadow: var(--shadow);
  animation: modalIn 0.25s ease;
}

@keyframes modalIn {
  from { opacity: 0; transform: scale(0.95); }
  to { opacity: 1; transform: scale(1); }
}

.modal-content h2 {
  font-size: 1.2rem;
  margin-bottom: 8px;
}

.modal-content p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 16px;
}

.modal-instruction {
  margin-top: 16px !important;
}

.file-info-card {
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 16px;
}

.file-info-card .label {
  font-size: 0.7rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 2px;
}

.file-info-card .value {
  color: var(--text-primary);
  font-size: 0.9rem;
  font-weight: 500;
  word-break: break-all;
}

.file-info-card .row {
  display: flex;
  gap: 16px;
  margin-top: 10px;
}

.file-info-card .row > div {
  flex: 1;
}

.file-match-status {
  margin-top: 12px;
  padding: 10px 14px;
  border-radius: var(--radius);
  font-size: 0.85rem;
  font-weight: 500;
}

.file-match-status.match {
  background: rgba(46,204,113,0.1);
  border: 1px solid rgba(46,204,113,0.3);
  color: var(--success);
}

.file-match-status.mismatch {
  background: rgba(255,78,69,0.1);
  border: 1px solid rgba(255,78,69,0.3);
  color: var(--danger);
}

.modal-actions {
  display: flex;
  gap: 12px;
  margin-top: 20px;
}

.modal-actions .btn-secondary,
.modal-actions .btn-primary {
  flex: 1;
}

/* ===== ROOM VIEW ===== */
.room-layout {
  display: flex;
  width: 100%;
  height: 100vh;
  overflow: hidden;
}

/* Video Area */
.video-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  background: #000;
}

.video-topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 16px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  min-height: 48px;
}

.topbar-left,
.topbar-right {
  display: flex;
  align-items: center;
  gap: 8px;
}

.room-badge {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.room-badge strong {
  color: var(--accent);
  letter-spacing: 1px;
}

.icon-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 4px;
  border-radius: 4px;
  transition: all var(--transition);
  display: flex;
  align-items: center;
}

.icon-btn:hover {
  color: var(--text-primary);
  background: var(--bg-tertiary);
}

.file-badge {
  font-size: 0.75rem;
  color: var(--text-muted);
  background: var(--bg-tertiary);
  padding: 4px 10px;
  border-radius: 20px;
  max-width: 300px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.btn-leave {
  padding: 6px 16px;
  background: transparent;
  border: 1px solid var(--danger);
  color: var(--danger);
  border-radius: var(--radius);
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
}

.btn-leave:hover {
  background: var(--danger);
  color: white;
}

/* Video wrapper */
.video-wrapper {
  flex: 1;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: #000;
  cursor: pointer;
}

#video-player {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.video-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity var(--transition);
  pointer-events: none;
}

.big-play-btn {
  opacity: 0;
  transition: opacity 0.2s ease;
  pointer-events: auto;
  cursor: pointer;
}

.video-wrapper:not(.playing) .big-play-btn,
.video-wrapper.show-play .big-play-btn {
  opacity: 1;
}

.big-play-btn:hover svg circle {
  fill: rgba(0,0,0,0.75);
}

/* Controls bar */
.controls-bar {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background: linear-gradient(transparent, rgba(0,0,0,0.85));
  padding: 20px 12px 10px;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.video-wrapper:hover .controls-bar,
.video-wrapper:not(.playing) .controls-bar {
  opacity: 1;
}

.seek-bar-container {
  padding: 0 4px;
  margin-bottom: 4px;
}

.seek-bar {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 4px;
  background: rgba(255,255,255,0.2);
  border-radius: 2px;
  outline: none;
  cursor: pointer;
  transition: height 0.15s ease;
}

.seek-bar:hover {
  height: 6px;
}

.seek-bar::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 14px;
  height: 14px;
  background: var(--accent);
  border-radius: 50%;
  cursor: pointer;
  box-shadow: 0 0 4px rgba(0,0,0,0.3);
  transition: transform 0.15s ease;
}

.seek-bar:hover::-webkit-slider-thumb {
  transform: scale(1.3);
}

.seek-bar::-moz-range-thumb {
  width: 14px;
  height: 14px;
  background: var(--accent);
  border-radius: 50%;
  border: none;
  cursor: pointer;
}

.controls-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 4px;
}

.controls-left,
.controls-right {
  display: flex;
  align-items: center;
  gap: 8px;
}

.ctrl-btn {
  background: none;
  border: none;
  color: white;
  cursor: pointer;
  padding: 6px;
  border-radius: 4px;
  display: flex;
  align-items: center;
  transition: all var(--transition);
}

.ctrl-btn:hover {
  background: rgba(255,255,255,0.1);
}

.volume-control {
  display: flex;
  align-items: center;
  gap: 4px;
}

.volume-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 70px;
  height: 3px;
  background: rgba(255,255,255,0.3);
  border-radius: 2px;
  outline: none;
  cursor: pointer;
  opacity: 0;
  width: 0;
  transition: opacity 0.2s, width 0.2s;
}

.volume-control:hover .volume-slider {
  opacity: 1;
  width: 70px;
}

.volume-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 12px;
  height: 12px;
  background: white;
  border-radius: 50%;
  cursor: pointer;
}

.volume-slider::-moz-range-thumb {
  width: 12px;
  height: 12px;
  background: white;
  border-radius: 50%;
  border: none;
  cursor: pointer;
}

.time-display {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.8);
  font-variant-numeric: tabular-nums;
  margin-left: 4px;
}

.speed-select {
  background: none;
  border: 1px solid rgba(255,255,255,0.2);
  color: white;
  padding: 4px 8px;
  border-radius: 4px;
  font-size: 0.8rem;
  cursor: pointer;
  outline: none;
}

.speed-select option {
  background: var(--bg-secondary);
  color: var(--text-primary);
}

/* ===== CHAT SIDEBAR ===== */
.chat-area {
  width: 340px;
  min-width: 340px;
  display: flex;
  flex-direction: column;
  background: var(--bg-secondary);
  border-left: 1px solid var(--border);
}

.chat-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
}

.chat-header h3 {
  font-size: 0.95rem;
  font-weight: 600;
}

.users-indicator {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.online-dot {
  width: 8px;
  height: 8px;
  background: var(--success);
  border-radius: 50%;
  animation: dotPulse 2s ease-in-out infinite;
}

@keyframes dotPulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.users-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 8px 16px;
  border-bottom: 1px solid var(--border);
}

.user-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  background: var(--bg-tertiary);
  border-radius: 20px;
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.user-chip .user-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
}

/* Chat Messages */
.chat-messages {
  flex: 1;
  overflow-y: auto;
  padding: 12px 16px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  scroll-behavior: smooth;
}

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

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

.chat-messages::-webkit-scrollbar-thumb {
  background: var(--bg-tertiary);
  border-radius: 2px;
}

.chat-messages::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

.chat-welcome {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  padding: 20px 0;
}

.chat-msg {
  padding: 6px 0;
  font-size: 0.85rem;
  line-height: 1.4;
  animation: msgIn 0.2s ease;
}

@keyframes msgIn {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

.chat-msg .msg-author {
  font-weight: 600;
  margin-right: 6px;
}

.chat-msg .msg-text {
  color: var(--text-secondary);
  word-break: break-word;
}

.chat-msg.system-msg {
  color: var(--text-muted);
  font-size: 0.8rem;
  font-style: italic;
  padding: 4px 0;
}

.chat-msg .msg-time {
  font-size: 0.7rem;
  color: var(--text-muted);
  margin-left: 6px;
}

/* Chat Input */
.chat-input-area {
  display: flex;
  gap: 8px;
  padding: 12px 16px;
  border-top: 1px solid var(--border);
  background: var(--bg-secondary);
}

#chat-input {
  flex: 1;
  padding: 10px 14px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 20px;
  color: var(--text-primary);
  font-size: 0.85rem;
  outline: none;
  transition: border-color var(--transition);
}

#chat-input:focus {
  border-color: var(--accent);
}

.chat-send-btn {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: none;
  background: var(--accent);
  color: #000;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
  flex-shrink: 0;
}

.chat-send-btn:hover {
  background: var(--accent-hover);
  box-shadow: 0 0 12px var(--accent-glow);
}

/* ===== Responsive ===== */
@media (max-width: 800px) {
  .lobby-actions {
    flex-direction: column;
  }

  .lobby-or {
    flex-direction: row;
  }

  .lobby-or::before,
  .lobby-or::after {
    width: 40px;
    height: 1px;
    writing-mode: horizontal-tb;
  }

  .lobby-or span {
    writing-mode: horizontal-tb;
  }

  .room-layout {
    flex-direction: column;
  }

  .chat-area {
    width: 100%;
    min-width: 100%;
    height: 40vh;
  }

  .video-area {
    height: 60vh;
  }

  .file-badge {
    display: none;
  }
}