:root {
  --primary-color: #00a884;
  --secondary-color: #0b141a;
  --background-color: #f0f2f5;
  --text-color: #3b4a54;
  --text-color-light: #8696a0;
  --panel-header-background: #f0f2f5;
  --chat-background: #e5ddd5;
  --message-sent-background: #d9fdd3;
  --message-received-background: #ffffff;
  --icon-color: #54656f;
  --border-color: #d1d7db;
}

[data-theme="dark"] {
  --primary-color: #4a90e2; /* Brighter Blue */
  --secondary-color: #f0f2f5;
  --background-color: #1a2339; /* Dark Navy Blue */
  --text-color: #e9edef;
  --text-color-light: #8696a0;
  --panel-header-background: #2a3950; /* Lighter Navy */
  --chat-background: #1a2339; /* Dark Navy Blue */
  --message-sent-background: #357ABD; /* Darker Blue for sent messages */
  --message-received-background: #2a3950; /* Lighter Navy */
  --icon-color: #aebac1;
  --border-color: #3a4a60; /* Lighter border */
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Segoe UI', Helvetica, Arial, sans-serif;
}

body {
  background-color: var(--background-color);
  color: var(--text-color);
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  transition: background-color 0.3s, color 0.3s;
}

.app-container {
  display: flex;
  width: 95vw;
  height: 95vh;
  max-width: 1600px;
  background-color: var(--panel-header-background);
  box-shadow: 0 1px 1px 0 rgba(0, 0, 0, 0.06), 0 2px 5px 0 rgba(0, 0, 0, 0.2);
}

/* --- Sidebar --- */
.sidebar {
  width: 30%;
  max-width: 415px;
  display: flex;
  flex-direction: column;
  background-color: var(--message-received-background);
  border-right: 1px solid var(--border-color);
}

.sidebar-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 16px;
  background-color: var(--panel-header-background);
}

.avatar img {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  cursor: pointer;
}

.actions i {
  color: var(--icon-color);
  margin-left: 20px;
  font-size: 20px;
  cursor: pointer;
}

.notifications {
  display: flex;
  align-items: center;
  padding: 12px;
  background-color: #8edafc;
}

.notifications i {
  color: #00a884;
  margin-right: 10px;
}

.search-container {
  display: flex;
  align-items: center;
  padding: 8px 12px;
  background-color: var(--panel-header-background);
}

.search-container input {
  flex: 1;
  border: none;
  outline: none;
  padding: 9px 12px;
  border-radius: 8px;
  background-color: var(--message-received-background);
  color: var(--text-color);
}

.search-container i {
  color: var(--icon-color);
  margin-right: 10px;
}

.chat-list {
  flex: 1;
  overflow-y: auto;
}

.chat-item {
  display: flex;
  align-items: center;
  padding: 12px 16px;
  cursor: pointer;
  border-bottom: 1px solid var(--border-color);
  transition: background-color 0.2s;
}

.chat-item:hover {
  background-color: var(--panel-header-background);
}

.chat-item.active {
    background-color: var(--border-color);
}

.chat-details {
  flex: 1;
  margin-left: 15px;
}

.chat-details h3 {
  font-size: 16px;
  font-weight: 400;
}

.chat-details p {
  font-size: 14px;
  color: var(--text-color-light);
}

.chat-meta {
  text-align: right;
}

.chat-meta .time {
  font-size: 12px;
  color: var(--text-color-light);
}

.chat-meta .unread {
  background-color: var(--primary-color);
  color: white;
  font-size: 12px;
  font-weight: bold;
  border-radius: 50%;
  width: 20px;
  height: 20px;
  display: flex;
  justify-content: center;
  align-items: center;
  margin-top: 5px;
}

.chat-meta .delete-icon {
  color: var(--icon-color);
  font-size: 16px;
  visibility: hidden;
  opacity: 0;
  transition: opacity 0.2s;
}

.chat-item:hover .delete-icon {
  visibility: visible;
  opacity: 1;
}

/* --- Modal Styles --- */
.modal {
  display: none; 
  position: fixed; 
  z-index: 20;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  overflow: auto;
  background-color: rgba(0,0,0,0.6);
}

.modal-content {
  background-color: var(--panel-header-background);
  color: var(--text-color);
  margin: 15% auto;
  padding: 20px;
  border: 1px solid var(--border-color);
  width: 80%;
  max-width: 400px;
  border-radius: 10px;
  text-align: center;
  position: relative;
}

.close-btn {
  position: absolute;
  top: 10px;
  right: 20px;
  color: var(--icon-color);
  font-size: 28px;
  font-weight: bold;
  cursor: pointer;
}

.profile-info img {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  margin-bottom: 10px;
}

.profile-info button {
  background-color: var(--primary-color);
  color: white;
  border: none;
  padding: 10px 20px;
  border-radius: 5px;
  cursor: pointer;
  margin-top: 15px;
}

.profile-details-edit {
    display: none;
    flex-direction: column;
    gap: 10px;
    margin-top: 10px;
}

.profile-details-edit input {
    padding: 8px;
    border-radius: 5px;
    border: 1px solid var(--border-color);
    background-color: var(--message-received-background);
    color: var(--text-color);
}

#saveProfileBtn {
    display: none;
}

#renameContactBtn {
    font-size: 14px;
    color: var(--icon-color);
    margin-left: 10px;
    cursor: pointer;
    display: none; /* Hidden by default */
}

.contact-details:hover #renameContactBtn {
    display: inline-block;
}

/* --- Chat Area --- */
.chat-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  background-color: var(--chat-background);
}

.chat-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 16px;
  background-color: var(--panel-header-background);
  border-left: 1px solid var(--border-color);
}

.chat-info {
  display: flex;
  align-items: center;
}

.chat-info .avatar {
  margin-right: 15px;
}

.contact-details h2 {
  font-size: 16px;
  font-weight: 400;
}

.contact-details p {
  font-size: 13px;
  color: var(--text-color-light);
}

.chat-actions i {
  color: var(--icon-color);
  margin-left: 20px;
  font-size: 20px;
  cursor: pointer;
}

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

.no-chat-selected {
    text-align: center;
    margin-top: 50px;
    color: var(--text-color-light);
}

.message-bubble {
  display: flex;
  max-width: 65%;
  padding: 8px 12px;
  border-radius: 8px;
  position: relative;
  word-wrap: break-word;
  opacity: 0;
  transform: translateY(10px);
  animation: slideIn 0.3s forwards;
}

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

.message-bubble.sent {
  background-color: var(--message-sent-background);
  align-self: flex-end;
}

.message-bubble.received {
  background-color: var(--message-received-background);
  align-self: flex-start;
}

.message-content p {
  margin: 0;
  padding-right: 50px; /* Space for timestamp */
}

.message-content .attached-file-container {
  display: flex;
  align-items: center;
  background-color: var(--background-color);
  padding: 10px;
  border-radius: 5px;
  margin-top: 5px;
  border: 1px solid var(--border-color);
  transition: background-color 0.2s;
}

.message-content .attached-file-container:hover {
  background-color: var(--panel-header-background);
}

.attached-image {
  max-width: 100%;
  border-radius: 5px;
  margin-top: 5px;
}

.attached-file {
  display: flex;
  align-items: center;
  text-decoration: none;
  color: var(--text-color);
}

.attached-file i {
  margin-right: 10px;
  font-size: 20px;
}

.message-timestamp {
  position: absolute;
  bottom: 5px;
  right: 10px;
  font-size: 11px;
  color: var(--text-color-light);
}

.message-status {
    display: inline-block;
    margin-left: 4px;
    color: #4fc3f7; /* Blue for sent/delivered */
}

.message-status.read {
    color: #4fc3f7; /* Same blue, but could be different */
}

.typing-indicator {
    font-style: italic;
    color: var(--text-color-light);
    margin: 10px 20px;
    align-self: flex-start;
}

.chat-input-area {
  display: flex;
  align-items: center;
  padding: 10px 16px;
  background-color: var(--panel-header-background);
}

.chat-input-area {
  display: flex;
  align-items: center;
  padding: 10px 16px;
  background-color: var(--panel-header-background);
  position: relative; /* For emoji picker positioning */
}

.emoji-picker {
  display: none;
  position: absolute;
  bottom: 60px; /* Position above the input area */
  left: 10px;
  background-color: var(--message-received-background);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 10px;
  width: 300px;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(30px, 1fr));
  gap: 5px;
  box-shadow: 0 -2px 10px rgba(0,0,0,0.1);
}

.emoji-picker span {
  cursor: pointer;
  font-size: 20px;
  text-align: center;
  padding: 5px;
  border-radius: 5px;
  transition: background-color 0.2s;
}

.emoji-picker span:hover {
  background-color: var(--panel-header-background);
}

.chat-input-area i {
  color: var(--icon-color);
  font-size: 24px;
  margin: 0 10px;
  cursor: pointer;
}

#messageInput {
  flex: 1;
  border: none;
  outline: none;
  padding: 12px 18px;
  border-radius: 8px;
  background-color: var(--message-received-background);
  color: var(--text-color);
  font-size: 15px;
}

#sendIcon {
    display: none;
}

/* --- Theme Switcher --- */
.theme-switcher {
  position: fixed;
  bottom: 20px;
  right: 20px;
}

#theme-toggle {
  display: none;
}

#theme-toggle + label {
  font-size: 24px;
  cursor: pointer;
  color: var(--icon-color);
}

#theme-toggle:checked ~ .app-container {
  /* This is handled by JS now */
}

.fa-sun { display: none; }
.fa-moon { display: block; }

[data-theme="dark"] .fa-sun { display: block; }
[data-theme="dark"] .fa-moon { display: none; }

/* --- Responsive --- */
@media (max-width: 768px) {
  .sidebar {
    position: absolute;
    left: -100%;
    width: 100%;
    z-index: 10;
    transition: left 0.3s ease-in-out;
  }
  .sidebar.open {
    left: 0;
  }
  .chat-area {
    width: 100%;
  }
  .chat-header .fa-bars {
    display: block; /* Show hamburger menu */
  }
}