* { box-sizing: border-box; }
body {
  font-family: 'Poppins', sans-serif;
  margin: 0;
  padding: 0;
  background: linear-gradient(to bottom right, #09090a, #1e293b);
  color: white;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}
.screen {
  display: none;
  justify-content: center;
  align-items: center;
  flex-direction: column;
  min-height: 100vh;
  padding: 20px;
  animation: fadeIn 1s ease-in-out;
  width: 100%;
}
.active { display: flex; }
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}
.tutor-image {
  max-width: 200px;
  animation: fadeIn 1s ease-in;
}
h1, h2, p { text-align: center; }
button {
  padding: 12px 24px;
  border-radius: 12px;
  border: none;
  margin: 10px;
  font-weight: bold;
  cursor: pointer;
  font-size: 1rem;
  transition: background-color 0.2s ease, transform 0.2s ease;
  flex-shrink: 0;
}
button:hover:not(:disabled) {
  transform: translateY(-2px);
}
button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}
.continue-btn { background: #38bdf8; color: #0f172a; }
.continue-btn:hover { background: #0ea5e9; }
.exit-btn { background: #ef4444; color: white; }
.exit-btn:hover { background: #dc2626; }
input, select, textarea {
  padding: 12px;
  margin-top: 10px;
  border-radius: 10px;
  border: none;
  font-size: 1em;
  width: 100%;
  background-color: rgba(255, 255, 255, 0.1);
  color: white;
}
input::placeholder, textarea::placeholder {
    color: rgba(255, 255, 255, 0.6);
}
input:focus, select:focus, textarea:focus {
    outline: none;
    border: 2px solid #38bdf8;
}
.invalid {
  border: 2px solid #ef4444 !important;
}
textarea {
    resize: vertical;
    min-height: 100px;
}
textarea::-webkit-scrollbar {
    width: 8px;
}
textarea::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 10px;
}
textarea::-webkit-scrollbar-thumb {
    background-color: #38bdf8;
    border-radius: 10px;
    border: 2px solid rgba(255, 255, 255, 0.05);
}
textarea::-webkit-scrollbar-thumb:hover {
    background-color: #0ea5e9;
}
.container {
  max-width: 500px;
  width: 100%;
  margin: 20px auto;
  padding: 20px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 15px;
  box-shadow: 0 0 25px rgba(56, 189, 248, 0.2);
  position: relative;
}
.response-box, .flashcards, .quiz-section, .history-box, .notes-section, .past-question-solver-box, .limit-message-box {
  background-color: #1e293b;
  padding: 15px;
  border-radius: 12px;
  margin-top: 10px;
  line-height: 1.6;
  white-space: pre-wrap;
  word-wrap: break-word;
}
.limit-message-box {
    background-color: #b91c1c;
    border: 1px solid #ef4444;
    color: white;
    font-weight: bold;
    text-align: center;
}
.toggle-box {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 10px;
  margin-top: 10px;
}
.toggle-box label {
  font-weight: bold;
  color: #38bdf8;
}
.switch {
  position: relative;
  display: inline-block;
  width: 60px;
  height: 34px;
}
.switch input {
  opacity: 0;
  width: 0;
  height: 0;
}
.slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: #ccc;
  -webkit-transition: .4s;
  transition: .4s;
  border-radius: 34px;
}
.slider:before {
  position: absolute;
  content: "";
  height: 26px;
  width: 26px;
  left: 4px;
  bottom: 4px;
  background-color: white;
  -webkit-transition: .4s;
  transition: .4s;
  border-radius: 50%;
}
input:checked + .slider {
  background-color: #38bdf8;
}
input:focus + .slider {
  box-shadow: 0 0 1px #38bdf8;
}
input:checked + .slider:before {
  -webkit-transform: translateX(26px);
  -ms-transform: translateX(26px);
  transform: translateX(26px);
}
.microphone-button {
  background-color: #facc15;
  color: black;
  margin-bottom: 10px;
}
.microphone-button:hover { background-color: #eab308; }
.google-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  background: white;
  color: #0f172a;
  font-weight: bold;
}
.google-btn:hover { background-color: #e5e7eb; }
.google-btn img {
  width: 20px;
  height: 20px;
  margin-right: 8px;
}
.quiz-question {
    margin-bottom: 15px;
    padding-bottom: 10px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}
.quiz-question label {
    display: block;
    margin-top: 5px;
    cursor: pointer;
}
.quiz-results {
    margin-top: 20px;
    font-weight: bold;
    color: #38bdf8;
    font-size: 1.2em;
}
.quiz-answer-correct {
    color: #6ee7b7;
    font-weight: bold;
}
.quiz-answer-incorrect {
    color: #fca5a5;
    font-weight: bold;
}
.quiz-feedback-text {
    font-size: 0.9em;
    margin-left: 20px;
    color: #ccc;
}
.history-nav-buttons, .flashcard-nav-buttons {
    display: flex;
    justify-content: center;
    margin-top: 10px;
}
.history-nav-buttons button, .flashcard-nav-buttons button {
    background: #a78bfa;
    color: white;
    padding: 8px 15px;
    margin: 0 5px;
    border-radius: 8px;
}
.history-nav-buttons button:hover:not(:disabled), .flashcard-nav-buttons button:hover:not(:disabled) {
    background: #8b5cf6;
}
.speech-controls {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-top: 10px;
}
.speech-controls button {
    margin: 0;
}
.speak-button {
  background-color: #10b981;
  color: white;
}
.speak-button:hover { background-color: #059669; }
.pause-button {
    background-color: #fbbf24;
    color: black;
}
.pause-button:hover { background-color: #f59e0b; }
.resume-button {
    background-color: #22c55e;
    color: white;
}
.resume-button:hover { background-color: #16a34a; }
.stop-button {
    background-color: #facc15;
    color: black;
    margin: 10px auto;
    display: none;
    width: fit-content;
}
.stop-button:hover {
    background-color: #eab308;
}
select {
    color: #38bdf8;
    font-weight: 600;
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    background-image: url('data:image/svg+xml;charset=US-ASCII,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20width%3D%22292.4%22%20height%3D%22292.4%22%3E%3Cpath%20fill%3D%22%2338bdf8%22%20d%3D%22M287%2C197.9c-3.2%2C3.2-8.3%2C3.2-11.6%2C0L146.2%2C68.9L16.9%2C197.9c-3.2%2C3.2-8.3%2C3.2-11.6%2C0c-3.2-3.2-3.2-8.3%2C0-11.6l135-135c3.2-3.2%2C8.3-3.2%2C11.6%2C0l135%2C135C290.3%2C189.6%2C290.3%2C194.7%2C287%2C197.9z%22%2F%3E%3C%2Fsvg%3E');
    background-repeat: no-repeat;
    background-position: right 0.7em top 50%, 0 0;
    background-size: 0.65em auto, 100%;
    border: 2px solid rgba(255, 255, 255, 0.1);
    padding-right: 2.5em;
    box-shadow: none;
}
select option {
    color: #0f172a;
    background-color: #1e293b;
}
select:focus {
    border-color: #38bdf8;
    outline: none;
}
select, select#courseSelect, select#subject {
  color: #38bdf8;
  font-weight: 600;
  background-color: #1e293b;
  border: 2px solid #38bdf8;
  border-radius: 10px;
  padding: 12px 40px 12px 12px;
  font-size: 1em;
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
  background-image: url('data:image/svg+xml;utf8,<svg fill="none" stroke="%2338bdf8" stroke-width="4" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path stroke-linecap="round" stroke-linejoin="round" d="M19 9l-7 7-7-7"></path></svg>');
  background-repeat: no-repeat;
  background-position: right 1em center;
  background-size: 1.5em;
  transition: border-color 0.2s;
  box-shadow: 0 4px 24px 0 rgba(56,189,248,0.15);
}
select:focus, select#courseSelect:focus, select#subject:focus {
  border-color: #a78bfa;
  outline: none;
  box-shadow: 0 0 0 3px #a78bfa55;
}
select option {
  color: #0f172a;
  background-color: #e0e7ef;
  font-weight: 500;
  padding: 10px 0;
  border-radius: 8px;
}
.advanced-tools-section {
    display: flex;
    flex-direction: column;
    gap: 15px;
}
.advanced-tools-section > div {
    margin-top: 0;
    padding: 10px 0;
}
.advanced-tools-section label {
    margin-bottom: 5px;
    display: block;
}
.advanced-tools-section button {
    width: auto;
    margin-left: 0;
    margin-right: 10px;
}
.image-input-controls {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-top: 10px;
    flex-wrap: wrap;
}
.image-input-controls button {
    background-color: #fca5a5;
    color: black;
    padding: 10px 15px;
    border-radius: 8px;
    margin: 0;
    font-size: 1.2em;
    flex-grow: 1;
    min-width: 120px;
}
.image-input-controls button:hover {
    background-color: #ef4444;
}
#imagePreviewContainer {
    margin-top: 10px;
    padding: 10px;
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 10px;
    text-align: center;
    display: none;
    position: relative;
}
#imagePreviewContainer img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    display: block;
    margin: 0 auto;
}
#imagePreviewContainer .placeholder-text {
    color: rgba(255, 255, 255, 0.6);
    font-style: italic;
    padding: 20px;
}
#cameraStream video {
    max-width: 100%;
    border-radius: 8px;
    margin-top: 10px;
    display: none;
}
.camera-buttons {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
    margin-top: 10px;
}
.camera-buttons button {
    background-color: #60a5fa;
    color: white;
    flex-grow: 1;
    min-width: 100px;
}
.camera-buttons button:hover {
    background-color: #3b82f6;
}
.clear-image-btn {
    background-color: #ef4444;
    color: white;
    margin-top: 10px;
    padding: 8px 15px;
    font-size: 0.9rem;
}
.clear-image-btn:hover {
    background-color: #dc2626;
}
.quiz-control-buttons {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-top: 10px;
}
.quiz-control-buttons button {
    background-color: #facc15;
    color: black;
    font-size: 0.9em;
    padding: 8px 15px;
}
.quiz-control-buttons button:hover {
    background-color: #eab308;
}
#upgradeButton {
    position: absolute;
    top: 1px;
    right: 2px;
    background-color: #a78bfa;
    color: white;
    padding: 8px 15px;
    border-radius: 10px;
    font-size: 0.9em;
    font-weight: bold;
    z-index: 10;
    cursor: pointer;
    transition: background-color 0.2s ease, transform 0.2s ease;
}
#upgradeButton:hover {
    background-color: #8b5cf6;
    transform: translateY(-2px);
}
@media (max-width: 600px) {
    .container {
        margin: 10px;
        padding: 15px;
    }
    h1 { font-size: 1.8em; }
    h2 { font-size: 1.3em; }
    button {
        padding: 10px 15px;
        font-size: 0.9rem;
        margin: 8px;
    }
    .speech-controls, .image-input-controls, .camera-buttons, .quiz-control-buttons {
        flex-direction: column;
        gap: 8px;
    }
    .speech-controls button, .image-input-controls button, .camera-buttons button, .quiz-control-buttons button {
        width: 100%;
        margin: 0;
    }
    /* Hide pause and resume buttons on mobile */
    .pause-button, .resume-button {
        display: none !important;
    }
    .toggle-box {
        flex-direction: column;
        align-items: flex-start;
        gap: 5px;
    }
    #upgradeButton {
        position: static;
        width: 100%;
        margin-bottom: 10px;
    }
}
#upgradeModal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.7);
    z-index: 9999;
    justify-content: center;
    align-items: center;
}
#upgradeModal > div {
    background: #fff;
    color: #222;
    border-radius: 18px;
    max-width: 350px;
    width: 90vw;
    padding: 32px 20px 24px 20px;
    text-align: center;
    position: relative;
}
#upgradeModal h2 {
    color: #a78bfa;
}
#upgradeModal ul {
    text-align: left;
    margin: 18px 0;
    color: #222;
    font-size: 1em;
    line-height: 1.7;
}
#upgradeModal .price {
    font-size: 1.2em;
    font-weight: bold;
    margin-bottom: 18px;
    color: #10b981;
}
#upgradeModal button {
    width: 100%;
    margin-bottom: 10px;
} 
.styled-select {
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
  background-color: #0f172a;
  color: #38bdf8;
  border: 2px solid #38bdf8;
  border-radius: 20px; 
  padding: 10px 40px 10px 16px;
  font-size: 1.1em;
  font-family: 'Poppins', sans-serif;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
  box-shadow: 0 2px 8px rgba(56,189,248,0.05);
  cursor: pointer;
  margin-bottom: 16px;
  position: relative;
  background-image: url("data:image/svg+xml;utf8,<svg fill='skyblue' height='20' viewBox='0 0 20 20' width='20' xmlns='http://www.w3.org/2000/svg'><path d='M5.516 7.548a.75.75 0 0 1 1.06 0L10 10.97l3.424-3.423a.75.75 0 1 1 1.06 1.06l-3.954 3.954a.75.75 0 0 1-1.06 0L5.516 8.608a.75.75 0 0 1 0-1.06z'/></svg>");
  background-repeat: no-repeat;
  background-position: right 12px center;
  background-size: 20px 20px;
  padding-right: 48px;
}

.styled-select:focus {
  border-color: #a78bfa;
  box-shadow: 0 0 0 2px #a78bfa33;
}

.styled-select option {
  background: #1e293b;
  color: #38bdf8;
}

/* Custom arrow using a background SVG */
.styled-select {
  background-image: url("data:image/svg+xml;utf8,<svg fill='skyblue' height='20' viewBox='0 0 20 20' width='20' xmlns='http://www.w3.org/2000/svg'><path d='M5.516 7.548a.75.75 0 0 1 1.06 0L10 10.97l3.424-3.423a.75.75 0 1 1 1.06 1.06l-3.954 3.954a.75.75 0 0 1-1.06 0L5.516 8.608a.75.75 0 0 1 0-1.06z'/></svg>");
  background-repeat: no-repeat;
  background-position: right 12px center;
  background-size: 20px 20px;
  padding-right: 48px;
}
.styled-select::-ms-expand {
  display: none;
} 

.plus-emoji-container {
  display: flex;
  justify-content: center;
  align-items: center;
  margin-bottom: 8px;
}

.plus-emoji {
  font-size: 2.5rem; 
  display: inline-block;
  line-height: 1;
  filter: drop-shadow(0 2px 8px #a78bfa88);
  animation: plus-bounce 1.2s infinite alternate;
}

@keyframes plus-bounce {
  0% { transform: translateY(0); }
  100% { transform: translateY(-6px) scale(1.08); }
}