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

/* Accessibility: Skip link for keyboard navigation */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: #000;
    color: white;
    padding: 8px;
    text-decoration: none;
    z-index: 100;
}

.skip-link:focus {
    top: 0;
}

/* Accessibility: Screen reader only content */
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #d0d0d0 0%, #a8a8a8 100%);
    color: #333;
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
header {
    text-align: center;
    padding: 20px 0;
    color: white;
}

header h1 {
    font-size: 2.5em;
    font-weight: 700;
    margin-bottom: 5px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.2);
}

.subtitle {
    font-size: 1.1em;
    opacity: 0.9;
    font-weight: 300;
}

/* Chat Wrapper */
.chat-wrapper {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: white;
    border-radius: 16px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
    overflow: hidden;
    margin-bottom: 20px;
}

/* Progress Section */
.progress-section {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 60px 40px;
    text-align: center;
}

.progress-content {
    max-width: 500px;
    width: 100%;
    background: white;
    border-radius: 16px;
    padding: 40px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

.andrew-image {
    width: 200px;
    height: auto;
    margin: 0 auto 30px;
    display: block;
    border-radius: 8px;
}

.loading-title {
    font-size: 1.4em;
    margin-bottom: 25px;
    color: #333;
    font-weight: 500;
    text-align: center;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: #e9ecef;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 12px;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #0078d4, #50a0e8);
    border-radius: 4px;
    width: 0%;
    transition: width 0.3s ease;
}

.progress-text {
    font-size: 0.95em;
    color: #666;
    margin-bottom: 8px;
    font-weight: 400;
    text-align: center;
}

.progress-info {
    font-size: 0.85em;
    color: #999;
    font-style: italic;
    text-align: center;
}

/* Chat Container */
.chat-container {
    display: flex;
    flex-direction: column;
    height: 70vh;
    min-height: 500px;
}

/* Chat Header */
.chat-header {
    background: linear-gradient(135deg, #787878 0%, #5a5a5a 100%);
    color: white;
    padding: 12px 25px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0;
}

.chat-header h2 {
    font-size: 1.4em;
    font-weight: 600;
}

.header-buttons {
    display: flex;
    gap: 10px;
}

.restart-btn, .mode-toggle-btn, .about-btn {
    background: rgba(255,255,255,0.2);
    color: white;
    border: 1px solid rgba(255,255,255,0.3);
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 0.9em;
    cursor: pointer;
    transition: all 0.2s;
    font-weight: 500;
}

.restart-btn:hover, .mode-toggle-btn:hover, .about-btn:hover {
    background: rgba(255,255,255,0.3);
    transform: translateY(-1px);
}

.restart-btn:focus, .mode-toggle-btn:focus, .about-btn:focus {
    outline: 3px solid #fff;
    outline-offset: 2px;
    background: rgba(255,255,255,0.3);
}

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

.mode-toggle-btn:disabled:hover {
    transform: none;
    background: rgba(255,255,255,0.2);
}

.chat-description {
    font-size: 0.9em;
    opacity: 0.9;
    font-weight: 300;
}

/* Chat Messages */
.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 25px;
    background: #f8f9fa;
}

.message {
    display: flex;
    margin-bottom: 20px;
    gap: 12px;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.user-message {
    justify-content: flex-end;
}

.assistant-message {
    justify-content: flex-start;
}

.avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5em;
    flex-shrink: 0;
}

.andrew-avatar {
    background: white;
    box-shadow: 0 2px 8px rgba(0, 120, 212, 0.3);
    padding: 0;
    overflow: hidden;
}

.avatar-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.user-avatar {
    background: linear-gradient(135deg, #f093fb, #f5576c);
    box-shadow: 0 2px 8px rgba(245, 87, 108, 0.3);
}

.message-content {
    max-width: 70%;
}

.user-message .message-content {
    background: linear-gradient(135deg, #0078d4, #50a0e8);
    color: white;
    border-radius: 18px 18px 4px 18px;
    padding: 12px 18px;
    box-shadow: 0 2px 8px rgba(0, 120, 212, 0.2);
}

.assistant-message .message-content {
    background: white;
    color: #333;
    border-radius: 18px 18px 18px 4px;
    padding: 12px 18px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

.message-author {
    font-size: 0.85em;
    font-weight: 600;
    margin-bottom: 4px;
    opacity: 0.8;
}

.user-message .message-author {
    color: rgba(255,255,255,0.9);
}

.message-text {
    font-size: 0.95em;
    line-height: 1.5;
}

.message-text p {
    margin-bottom: 10px;
}

.message-text p:last-child {
    margin-bottom: 0;
}

.message-text strong {
    font-weight: 600;
}

.message-text em {
    font-style: italic;
}

.message-text a {
    color: #0078d4;
    text-decoration: none;
    font-weight: 500;
}

.message-text a:hover {
    text-decoration: underline;
}

.assistant-message .message-text a {
    color: #0078d4;
}

.user-message .message-text a {
    color: white;
    text-decoration: underline;
}

/* Welcome Message */
.welcome-message {
    background: white;
    border-radius: 18px;
    padding: 20px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.1);
    margin-bottom: 20px;
    display: flex;
    gap: 15px;
}

.welcome-message .avatar {
    margin-top: 5px;
}

.welcome-message .message-content {
    max-width: 100%;
    background: transparent;
    box-shadow: none;
    padding: 0;
}

.welcome-message ul {
    margin: 15px 0;
    padding-left: 20px;
}

.welcome-message li {
    margin: 8px 0;
}

/* Typing Indicator */
.typing-indicator {
    display: inline-block;
    font-size: 1.5em;
    letter-spacing: 2px;
    animation: blink 1.4s infinite;
}

@keyframes blink {
    0%, 100% { opacity: 0.3; }
    50% { opacity: 1; }
}

/* System Message */
.system-message {
    text-align: center;
    margin: 15px 0;
    padding: 8px 16px;
    background: rgba(0, 120, 212, 0.1);
    border-radius: 16px;
    font-size: 0.9em;
    color: #0078d4;
    font-style: italic;
}

/* Chat Input Area */
.chat-input-area {
    background: white;
    padding: 12px 25px 8px 25px;
    border-top: 1px solid #e9ecef;
}

/* Example Questions */
.example-questions {
    margin-top: 12px;
    margin-bottom: 0;
}

.example-label {
    font-size: 0.85em;
    color: #666;
    margin-bottom: 8px;
    font-weight: 500;
}

.example-buttons {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.example-btn {
    background: #f0f8ff;
    border: 1px solid #d0e8ff;
    color: #0078d4;
    padding: 8px 14px;
    border-radius: 16px;
    font-size: 0.85em;
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 100%;
}

.example-btn:hover {
    background: #e0f2ff;
    border-color: #a0d0ff;
    transform: translateY(-1px);
    box-shadow: 0 2px 4px rgba(0, 120, 212, 0.15);
}

.example-btn:focus {
    outline: 2px solid #0078d4;
    outline-offset: 2px;
}

.example-btn:active {
    transform: translateY(0);
}

.input-wrapper {
    display: flex;
    gap: 12px;
    align-items: flex-end;
}

#user-input {
    flex: 1;
    padding: 12px 16px;
    border: 2px solid #e9ecef;
    border-radius: 24px;
    font-size: 0.95em;
    font-family: inherit;
    resize: none;
    min-height: 48px;
    max-height: 150px;
    transition: border-color 0.2s;
}

#user-input:focus {
    outline: none;
    border-color: #0078d4;
    box-shadow: 0 0 0 3px rgba(0, 120, 212, 0.1);
}

.send-btn {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, #0078d4, #50a0e8);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
    flex-shrink: 0;
}

.send-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 120, 212, 0.4);
}

.send-btn:focus {
    outline: 3px solid #0078d4;
    outline-offset: 3px;
}

.send-btn:active {
    transform: translateY(0);
}

.send-icon {
    font-size: 1.3em;
    display: flex;
    align-items: center;
    justify-content: center;
}

.input-info {
    margin-top: 8px;
    min-height: 20px;
}

.search-status {
    font-size: 0.85em;
    color: #666;
    font-style: italic;
}

.disclaimer {
    text-align: center;
    margin-top: 4px;
    padding-top: 4px;
    padding-bottom: 2px;
    border-top: 1px solid #e9ecef;
}

.disclaimer p {
    font-size: 0.7em;
    color: #999;
    margin: 0;
    line-height: 1;
}

/* Footer */
footer {
    text-align: center;
    padding: 15px;
    color: white;
    font-size: 0.9em;
    opacity: 0.8;
}

/* Modal Styles */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
}

.modal-content {
    position: relative;
    background: white;
    border-radius: 16px;
    max-width: 600px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    animation: modalSlideIn 0.3s ease;
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.modal-header {
    padding: 25px 30px 20px;
    border-bottom: 1px solid #e9ecef;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.modal-header h2 {
    margin: 0;
    color: #0078d4;
    font-size: 1.5em;
}

.modal-close {
    background: none;
    border: none;
    font-size: 2em;
    color: #666;
    cursor: pointer;
    padding: 0;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: all 0.2s;
}

.modal-close:hover {
    background: #f0f0f0;
    color: #333;
}

.modal-close:focus {
    outline: 3px solid #0078d4;
    outline-offset: 2px;
}

.modal-body {
    padding: 25px 30px;
}

.modal-body p {
    margin-bottom: 15px;
    line-height: 1.6;
}

.modal-body ul {
    margin: 15px 0 15px 20px;
    padding: 0;
}

.modal-body li {
    margin-bottom: 10px;
    line-height: 1.6;
}

.modal-body code {
    background: #f5f5f5;
    padding: 2px 8px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    color: #0078d4;
    font-size: 0.9em;
}

.modal-body .warning {
    background: #fff3cd;
    border-left: 4px solid #ffc107;
    padding: 12px 15px;
    border-radius: 4px;
    color: #856404;
}

.modal-footer {
    padding: 20px 30px 25px;
    border-top: 1px solid #e9ecef;
    display: flex;
    justify-content: flex-end;
}

.modal-btn {
    background: linear-gradient(135deg, #0078d4, #50a0e8);
    color: white;
    border: none;
    padding: 10px 24px;
    border-radius: 24px;
    font-size: 1em;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.modal-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 120, 212, 0.4);
}

.modal-btn:focus {
    outline: 3px solid #0078d4;
    outline-offset: 3px;
}

.ai-mode-link {
    color: #0078d4;
    text-decoration: underline;
    cursor: pointer;
}

.ai-mode-link:hover {
    color: #005a9e;
}

.ai-mode-link:focus {
    outline: 2px solid #0078d4;
    outline-offset: 2px;
    border-radius: 2px;
}

/* Scrollbar Styling */
.chat-messages::-webkit-scrollbar {
    width: 8px;
}

.chat-messages::-webkit-scrollbar-track {
    background: #f1f1f1;
}

.chat-messages::-webkit-scrollbar-thumb {
    background: #ccc;
    border-radius: 4px;
}

.chat-messages::-webkit-scrollbar-thumb:hover {
    background: #aaa;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 10px;
    }

    header h1 {
        font-size: 2em;
    }

    .chat-wrapper {
        border-radius: 12px;
    }

    .chat-container {
        height: 65vh;
    }

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

    .chat-messages {
        padding: 15px;
    }

    .chat-input-area {
        padding: 15px;
    }

    #user-input {
        font-size: 16px; /* Prevents zoom on iOS */
    }
}

@media (max-width: 480px) {
    header h1 {
        font-size: 1.8em;
    }

    .subtitle {
        font-size: 1em;
    }

    .header-buttons {
        flex-direction: column;
        gap: 6px;
    }

    .restart-btn, .mode-toggle-btn, .about-btn {
        padding: 6px 12px;
        font-size: 0.85em;
    }

    .avatar {
        width: 36px;
        height: 36px;
        font-size: 1.3em;
    }
    
    .example-btn {
        font-size: 0.8em;
        padding: 6px 10px;
    }
}