body {
    font-family: 'Inter', sans-serif;
    background-color: #f8fafc; /* slate-50 */
    color: #334155; /* slate-700 */
}
.nav-link {
    transition: color 0.3s ease;
}
.nav-link:hover {
    color: #0284c7; /* sky-600 */
}
.btn-primary {
    background-color: #0ea5e9; /* sky-500 */
    color: white;
    transition: background-color 0.3s ease;
}
.btn-primary:hover {
    background-color: #0284c7; /* sky-600 */
}
.btn-secondary {
    background-color: #e2e8f0; /* slate-200 */
    color: #475569; /* slate-600 */
    transition: background-color 0.3s ease;
}
.btn-secondary:hover {
    background-color: #cbd5e1; /* slate-300 */
}
.section-title {
    color: #1e293b; /* slate-800 */
}
.card {
    background-color: white;
    border-radius: 0.75rem;
    box-shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -2px rgb(0 0 0 / 0.1);
}
.interactive-stepper .step-content {
    display: none;
}
.interactive-stepper .step-content.active {
    display: block;
}
.accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.5s ease-in-out;
}
.critical-path-row {
    background-color: #fecaca; /* red-200 */
}
/* Game Styles */
.game-task {
    cursor: pointer;
    transition: all 0.2s ease-in-out;
}
.game-task-circle {
    transition: all 0.2s ease-in-out;
}
.game-task.selected .game-task-circle {
    stroke: #10B981; /* Green-500 */
    stroke-width: 4px;
    transform: scale(1.1);
}
.game-task.correct .game-task-circle {
    fill: #D1FAE5; /* Green-100 */
    stroke: #059669; /* Green-600 */
    stroke-width: 4px;
}
.game-task.incorrect .game-task-circle {
    fill: #FEE2E2; /* Red-100 */
    stroke: #DC2626; /* Red-600 */
    stroke-width: 4px;
}
.game-dependency-line {
    stroke: #6B7280; /* Gray-500 */
    stroke-width: 2;
}
.game-no-select {
    -webkit-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

/* AI Tutor Chatbot Styles */
#chatbot-toggle-btn {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background-color: #0ea5e9; /* sky-500 */
    color: white;
    width: 4rem;
    height: 4rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -2px rgb(0 0 0 / 0.1);
    cursor: pointer;
    transition: transform 0.3s ease, background-color 0.3s ease;
    z-index: 1000;
}
#chatbot-toggle-btn:hover {
    background-color: #0284c7; /* sky-600 */
    transform: scale(1.1);
}

#chatbot-window {
    position: fixed;
    bottom: 7rem;
    right: 2rem;
    width: 90%;
    max-width: 400px;
    height: 70vh;
    max-height: 600px;
    background-color: white;
    border-radius: 1rem;
    box-shadow: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    transform-origin: bottom right;
    transition: transform 0.3s ease-out, opacity 0.3s ease-out;
    transform: scale(0.95);
    opacity: 0;
    z-index: 999;
}

#chatbot-window.hidden {
    transform: scale(0.95);
    opacity: 0;
    pointer-events: none;
}

#chatbot-window:not(.hidden) {
    transform: scale(1);
    opacity: 1;
}

#chatbot-header {
    background-color: #0ea5e9; /* sky-500 */
    color: white;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-shrink: 0;
}

#chatbot-close-btn {
    background: none;
    border: none;
    color: white;
    cursor: pointer;
    opacity: 0.8;
    transition: opacity 0.2s;
}

#chatbot-close-btn:hover {
    opacity: 1;
}

#chatbot-messages {
    flex-grow: 1;
    overflow-y: auto;
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.chat-message {
    padding: 0.75rem 1rem;
    border-radius: 1.25rem;
    max-width: 80%;
    line-height: 1.5;
}

.ai-message {
    background-color: #f1f5f9; /* slate-100 */
    color: #334155; /* slate-700 */
    align-self: flex-start;
    border-bottom-left-radius: 0.25rem;
}

.user-message {
    background-color: #0ea5e9; /* sky-500 */
    color: white;
    align-self: flex-end;
    border-bottom-right-radius: 0.25rem;
}

#chatbot-input-container {
    padding: 1rem;
    border-top: 1px solid #e2e8f0; /* slate-200 */
    background-color: #f8fafc; /* slate-50 */
    flex-shrink: 0;
}

#chatbot-form {
    display: flex;
    gap: 0.5rem;
}

#chatbot-input {
    flex-grow: 1;
    border: 1px solid #cbd5e1; /* slate-300 */
    border-radius: 9999px;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    outline: none;
    transition: border-color 0.2s;
}

#chatbot-input:focus {
    border-color: #0ea5e9; /* sky-500 */
}

#chatbot-send-btn {
    background-color: #0ea5e9; /* sky-500 */
    color: white;
    border: none;
    border-radius: 50%;
    width: 3rem;
    height: 3rem;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: background-color 0.2s;
}

#chatbot-send-btn:hover {
    background-color: #0284c7; /* sky-600 */
}

.typing-indicator {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}
.typing-indicator span {
    width: 8px;
    height: 8px;
    background-color: #94a3b8; /* slate-400 */
    border-radius: 50%;
    animation: bounce 1.4s infinite ease-in-out both;
}
.typing-indicator span:nth-child(1) { animation-delay: -0.32s; }
.typing-indicator span:nth-child(2) { animation-delay: -0.16s; }

@keyframes bounce {
  0%, 80%, 100% { transform: scale(0); }
  40% { transform: scale(1.0); }
}