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

:root {
  --primary: #FFA31A;
  --primary-dark: #CC8215;
  --bg-dark: #1B1B1B;
  --surface: #292929;
  --surface-light: #363636;
  --text-white: #FFFFFF;
  --text-gray: #B3B3B3;
  --text-dark: #8C8C8C;
  --success: #4CAF50;
  --error: #F44336;
  --sent: #2196F3;
  --received: #4CAF50;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  background-color: var(--bg-dark);
  color: var(--text-white);
  min-height: 100vh;
}

#app {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Login Screen */
.login-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 20px;
}

.login-box {
  background: var(--surface);
  border-radius: 16px;
  padding: 40px;
  width: 100%;
  max-width: 400px;
  text-align: center;
}

.login-logo {
  font-size: 48px;
  margin-bottom: 16px;
}

.login-title {
  font-size: 24px;
  font-weight: 600;
  margin-bottom: 8px;
}

.login-subtitle {
  color: var(--text-gray);
  margin-bottom: 32px;
}

.input-group {
  margin-bottom: 20px;
}

.input-group input {
  width: 100%;
  padding: 16px;
  border: 2px solid var(--surface-light);
  border-radius: 12px;
  background: var(--bg-dark);
  color: var(--text-white);
  font-size: 16px;
  outline: none;
  transition: border-color 0.2s;
}

.input-group input:focus {
  border-color: var(--primary);
}

.input-group input::placeholder {
  color: var(--text-dark);
}

.btn {
  width: 100%;
  padding: 16px;
  border: none;
  border-radius: 12px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}

.btn-primary {
  background: var(--primary);
  color: var(--bg-dark);
}

.btn-primary:hover {
  background: var(--primary-dark);
}

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

.error-message {
  color: var(--error);
  margin-top: 16px;
  font-size: 14px;
}

/* Main App Layout */
.app-container {
  display: flex;
  flex-direction: column;
  height: 100vh;
}

/* Header */
.header {
  background: var(--surface);
  padding: 16px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--surface-light);
}

.header-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

.header-title {
  font-size: 20px;
  font-weight: 600;
}

.header-status {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--text-gray);
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--success);
}

.btn-logout {
  background: transparent;
  border: 1px solid var(--surface-light);
  color: var(--text-gray);
  padding: 8px 16px;
  border-radius: 8px;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.2s;
}

.btn-logout:hover {
  border-color: var(--error);
  color: var(--error);
}

/* Conversation List */
.conversation-list {
  flex: 1;
  overflow-y: auto;
  padding: 8px;
}

.conversation-item {
  display: flex;
  align-items: center;
  padding: 16px;
  border-radius: 12px;
  cursor: pointer;
  transition: background 0.2s;
  margin-bottom: 4px;
}

.conversation-item:hover {
  background: var(--surface);
}

.conversation-item.active {
  background: var(--surface-light);
}

.conversation-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: 600;
  color: var(--bg-dark);
  margin-right: 12px;
  flex-shrink: 0;
}

.conversation-info {
  flex: 1;
  min-width: 0;
}

.conversation-name {
  font-weight: 500;
  margin-bottom: 4px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.conversation-preview {
  color: var(--text-gray);
  font-size: 14px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.conversation-meta {
  text-align: right;
  flex-shrink: 0;
}

.conversation-time {
  font-size: 12px;
  color: var(--text-dark);
  margin-bottom: 4px;
}

.conversation-badge {
  background: var(--primary);
  color: var(--bg-dark);
  font-size: 12px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 10px;
  display: inline-block;
}

/* Message Thread */
.message-thread {
  display: flex;
  flex-direction: column;
  height: 100%;
}

.thread-header {
  background: var(--surface);
  padding: 16px 20px;
  display: flex;
  align-items: center;
  gap: 12px;
  border-bottom: 1px solid var(--surface-light);
}

.btn-back {
  background: none;
  border: none;
  color: var(--text-white);
  font-size: 24px;
  cursor: pointer;
  padding: 4px;
}

.thread-info {
  flex: 1;
}

.thread-name {
  font-weight: 600;
  font-size: 18px;
}

.thread-number {
  color: var(--text-gray);
  font-size: 14px;
}

/* Messages */
.messages-container {
  flex: 1;
  overflow-y: auto;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.message {
  max-width: 75%;
  padding: 12px 16px;
  border-radius: 18px;
  font-size: 15px;
  line-height: 1.4;
  position: relative;
}

.message-sent {
  background: var(--sent);
  color: white;
  align-self: flex-end;
  border-bottom-right-radius: 4px;
}

.message-received {
  background: var(--surface-light);
  color: var(--text-white);
  align-self: flex-start;
  border-bottom-left-radius: 4px;
}

.message-time {
  font-size: 11px;
  color: rgba(255, 255, 255, 0.7);
  margin-top: 4px;
  text-align: right;
}

.message-status {
  font-size: 11px;
  margin-top: 2px;
  text-align: right;
}

.message-status.pending {
  color: var(--text-dark);
}

.message-status.sent {
  color: var(--text-gray);
}

.message-status.delivered {
  color: var(--success);
}

.message-status.failed {
  color: var(--error);
}

/* Compose */
.compose-container {
  background: var(--surface);
  padding: 16px 20px;
  display: flex;
  align-items: flex-end;
  gap: 12px;
  border-top: 1px solid var(--surface-light);
}

.compose-input {
  flex: 1;
  background: var(--bg-dark);
  border: none;
  border-radius: 24px;
  padding: 12px 20px;
  color: var(--text-white);
  font-size: 16px;
  resize: none;
  outline: none;
  max-height: 120px;
  font-family: inherit;
}

.compose-input::placeholder {
  color: var(--text-dark);
}

.btn-send {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--primary);
  border: none;
  color: var(--bg-dark);
  font-size: 20px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
  flex-shrink: 0;
}

.btn-send:hover {
  background: var(--primary-dark);
}

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

/* New Message FAB */
.fab {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--primary);
  border: none;
  color: var(--bg-dark);
  font-size: 28px;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
  transition: transform 0.2s, background 0.2s;
}

.fab:hover {
  background: var(--primary-dark);
  transform: scale(1.05);
}

/* New Message Modal */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  z-index: 100;
}

.modal {
  background: var(--surface);
  border-radius: 16px;
  width: 100%;
  max-width: 500px;
  max-height: 90vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.modal-header {
  padding: 20px;
  border-bottom: 1px solid var(--surface-light);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-title {
  font-size: 20px;
  font-weight: 600;
}

.btn-close {
  background: none;
  border: none;
  color: var(--text-gray);
  font-size: 24px;
  cursor: pointer;
}

.modal-body {
  padding: 20px;
  flex: 1;
  overflow-y: auto;
}

.modal-footer {
  padding: 20px;
  border-top: 1px solid var(--surface-light);
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  margin-bottom: 8px;
  color: var(--text-gray);
  font-size: 14px;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 14px 16px;
  border: 2px solid var(--surface-light);
  border-radius: 12px;
  background: var(--bg-dark);
  color: var(--text-white);
  font-size: 16px;
  outline: none;
  transition: border-color 0.2s;
  font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--primary);
}

.form-group textarea {
  resize: vertical;
  min-height: 100px;
}

/* Empty State */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  padding: 40px;
  text-align: center;
}

.empty-state-icon {
  font-size: 64px;
  margin-bottom: 16px;
}

.empty-state-title {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 8px;
}

.empty-state-text {
  color: var(--text-gray);
}

/* Loading */
.loading {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 40px;
}

.spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--surface-light);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

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

/* Responsive */
@media (max-width: 600px) {
  .login-box {
    padding: 30px 20px;
  }

  .message {
    max-width: 85%;
  }
}