/* --- Global --- */
:root {
  --color-bg-dark: #252525;
  --color-bg-light: #333333;
  --color-primary-dark: #4d0005;
  --color-primary: #870005;
  --color-accent: #c85050;
  --color-text: #ffffff;
  --color-text-dim: #b0b0b0;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

body {
  background-color: var(--color-bg-dark);
  color: var(--color-text);
  display: flex;
  height: 100vh;
  overflow: hidden;
}

a {
  color: var(--color-accent);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

/* --- Auth Pages (Login/Register) --- */
.auth-container {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
  height: 100vh;
  background-color: var(--color-bg-dark);
}

.auth-box {
  width: 100%;
  max-width: 400px;
  padding: 30px;
  margin: 50px;
  background-image: linear-gradient(
    to bottom right,
    var(--color-primary),
    var(--color-primary-dark)
  );
  border-radius: 30px;
  box-shadow: 0 10px 50px rgba(0, 0, 0, 0.7);
  color: var(--color-text);
  text-align: center;
}
.auth-box h2 {
  font-size: 26px;
  font-weight: bold;
  letter-spacing: 1.2px;
  margin-bottom: 20px;
}
.auth-box .icon {
  font-size: 24px;
  margin-bottom: 10px;
}

.form-group {
  margin-bottom: 20px;
  position: relative;
}
.form-group input {
  width: 100%;
  padding: 12px 15px 12px 45px;
  border-radius: 15px;
  border: none;
  background-color: var(--color-text);
  color: #000;
  font-size: 16px;
}
.form-group .icon {
  position: absolute;
  left: 15px;
  top: 50%;
  transform: translateY(-50%);
  color: #555;
  font-size: 20px; /* Material Icons size */
}

.btn {
  padding: 10px 20px;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  font-weight: bold;
  cursor: pointer;
  background-color: var(--color-accent);
  color: var(--color-text);
  transition: background-color 0.2s;
}
.btn:hover {
  background-color: #e06a6a;
}
.auth-box .btn {
  width: 100%;
  padding: 12px;
}

.auth-box .links {
  margin-top: 20px;
}
.auth-box .links a {
  color: var(--color-text);
  font-size: 14px;
  display: block;
  margin-top: 10px;
}

/* --- Main App Layout (Base) --- */
.drawer {
  width: 280px;
  height: 100vh;
  background-color: var(--color-bg-dark);
  border-right: 1px solid #444;
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
}
.drawer-header {
  height: 60px;
  background-color: var(--color-primary-dark);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: bold;
  color: var(--color-text);
  border-bottom: 1px solid #444;
}
.drawer-content {
  flex-grow: 1;
  overflow-y: auto;
}
.drawer-content .list-header {
  padding: 16px 16px 5px;
  color: var(--color-text-dim);
  font-weight: bold;
  font-size: 14px;
  text-transform: uppercase;
}
.drawer-list {
  list-style: none;
}
.drawer-list li a {
  display: flex;
  align-items: center;
  padding: 12px 16px;
  color: var(--color-text);
  text-decoration: none;
  transition: background-color 0.2s;
  border-radius: 8px;
  margin: 4px 8px;
}
.drawer-list li a:hover {
  background-color: var(--color-bg-light);
}
.drawer-list li a .icon {
  /* CHANGE: Reduced spacing for sidebar icon/text gap */
  margin-right: 8px;
  font-size: 20px;
}
/* ADDED: Style for the currently active lesson link */
.drawer-list li a.active {
    background-color: var(--color-primary);
    font-weight: bold;
}

.drawer-footer {
  padding: 16px;
  border-top: 1px solid #444;
}
.drawer-footer a {
  display: flex;
  align-items: center;
  text-decoration: none;
  padding: 8px;
  border-radius: 8px;
  transition: background-color 0.2s;
}
.drawer-footer a:hover {
  background-color: var(--color-bg-light);
}
.drawer-footer .avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background-color: var(--color-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  margin-right: 10px;
}
.drawer-footer .username {
  color: var(--color-text);
  font-weight: bold;
  flex-grow: 1;
}
.drawer-footer .icon {
  color: var(--color-text-dim);
  font-size: 16px;
}

.main-content {
  flex-grow: 1;
  height: 100vh;
  display: flex;
  flex-direction: column;
  /* ADDED: Required for positioning background title/Ensuring correct base color */
  position: relative;
  background-color: var(--color-bg-dark);
}

.app-bar {
  height: 60px;
  background-color: var(--color-primary-dark);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  font-size: 20px;
  font-weight: bold;
  color: var(--color-text);
  flex-shrink: 0;
  border-bottom: 1px solid #444;
}
.app-bar .back-button {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--color-text);
    text-decoration: none;
}

.page-body {
  flex-grow: 1;
  overflow-y: auto;
  padding: 20px;
  display: flex;
  flex-direction: column;
}

/* --- Chat Interface --- */
.chat-container {
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
}
.chat-messages {
  flex-grow: 1;
  overflow-y: auto;
  padding: 10px;
  display: flex;
  flex-direction: column;
}
.chat-placeholder {
  flex-grow: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  font-size: 20px;
  font-weight: bold;
  color: var(--color-text);
}
.message-bubble {
  max-width: 70%;
  padding: 10px 15px;
  border-radius: 18px;
  margin-bottom: 10px;
  word-wrap: break-word;
  white-space: pre-wrap; /* Preserve newlines */
}
.message-bubble.user {
  background-color: var(--color-accent);
  color: var(--color-text);
  align-self: flex-end;
  border-bottom-right-radius: 4px;
}
.message-bubble.assistant {
  background-color: var(--color-bg-light);
  color: var(--color-text);
  align-self: flex-start;
  border-bottom-left-radius: 4px;
}
.message-bubble strong {
    color: var(--color-accent);
}

.input-bar {
  padding: 10px;
  background-color: var(--color-primary-dark);
  flex-shrink: 0;
}
.input-bar form {
  display: flex;
  align-items: center;
}
.input-bar input {
  flex-grow: 1;
  padding: 12px 16px;
  border: none;
  border-radius: 20px;
  background-color: var(--color-text);
  color: #000;
  font-size: 16px;
}
.input-bar button {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: none;
  background-color: var(--color-text);
  color: var(--color-primary);
  font-size: 22px;
  margin-left: 8px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  /* ADDED: Transition for disabled/hover effects */
  transition: background-color 0.2s;
}
/* ADDED: Hover and Disabled states for send button */
.input-bar button:hover:not(:disabled) {
    background-color: var(--color-text-dim);
}
.input-bar button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* --- Lessons "Start" Button --- */
.start-button-container {
    /* CHANGE: Overrides the user's properties to center content and take up full height/space */
    flex-grow: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--color-bg-dark);
}
.start-button {
    background-color: var(--color-accent);
    color: var(--color-text);
    font-size: 18px;
    font-weight: bold;
    padding: 14px 40px;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    /* ADDED: Transition for hover/disabled effects */
    transition: background-color 0.2s;
}
/* ADDED: Hover and Disabled states for start button */
.start-button:hover:not(:disabled) {
    background-color: #e06a6a;
}
.start-button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* --- Courses Page --- */
.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 16px;
}
.course-card {
    background-color: var(--color-bg-light);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
    transition: transform 0.2s;
}
.course-card:hover {
    transform: translateY(-5px);
}
.course-card a {
    text-decoration: none;
}
.course-card img {
    width: 100%;
    height: 120px;
    object-fit: cover;
    display: block;
}
.course-card-title {
    padding: 12px;
    text-align: center;
    color: var(--color-text);
    font-weight: bold;
}

.fab {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 56px;
    height: 56px;
    background-color: var(--color-primary);
    color: var(--color-text);
    border-radius: 50%;
    border: none;
    font-size: 24px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.4);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
}

/* Generate Course Dialog */
.dialog-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.7);
    display: none; /* Hidden by default */
    align-items: center;
    justify-content: center;
    /* ADDED: Needed to ensure dialog is on top of everything else */
    z-index: 1000;
}
.dialog-box {
    background: var(--color-bg-dark);
    padding: 24px;
    border-radius: 12px;
    width: 90%;
    max-width: 400px;
}
.dialog-box h3 {
    color: var(--color-text);
    font-weight: bold;
    margin-bottom: 20px;
}
.dialog-box .form-group input {
    background: var(--color-bg-light);
    color: var(--color-text);
    border: 1px solid #555;
    padding: 12px 15px;
    border-radius: 10px;
}
.dialog-actions {
    margin-top: 20px;
    display: flex;
    justify-content: flex-end;
    gap: 10px;
}
.dialog-actions .btn-secondary {
    background: none;
    color: var(--color-text-dim);
}
.dialog-actions .btn-primary {
    background: var(--color-accent);
    color: var(--color-text);
}

/* --- User Settings --- */
.settings-container {
    max-width: 600px;
    margin: 40px auto;
    padding: 24px;
    display: flex;
    flex-direction: column;
    align-items: center;
}
.settings-container .avatar {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    background-color: var(--color-accent);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 40px;
    font-weight: bold;
    margin-bottom: 20px;
}
.settings-container .username {
    font-size: 22px;
    font-weight: bold;
    color: var(--color-text);
}
.settings-container .email {
    font-size: 16px;
    color: var(--color-text-dim);
    margin-top: 8px;
}
.settings-container hr {
    width: 100%;
    border-color: #444;
    margin: 40px 0 20px;
}
.settings-container .btn-logout {
    width: 100%;
    padding: 14px;
    font-size: 16px;
    background-color: var(--color-accent);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}
/* --- Flash Messages (in App Bar) --- */
.flash-message {
    position: absolute;
    left: 20px;
    top: 50%;
    transform: translateY(-50%);
    padding: 8px 12px;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 500;
}
.flash-message.error {
    background-color: var(--color-accent);
    color: var(--color-text);
}
.flash-message.success {
    background-color: #4CAF50;
    color: var(--color-text);
}


/* --- Loading Spinner --- */
@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}
.icon-spin {
    animation: spin 1s linear infinite;
}

/* --- System Message (for errors in chat) --- */
.message-bubble.system {
    background-color: transparent;
    color: var(--color-text-dim);
    align-self: center;
    font-style: italic;
    font-size: 14px;
}