:root {
    --rstudio-blue: #4d8dc9;
    --rstudio-blue-hover: #3b7bb7;
    --bg-color: #f0f2f5;
    --card-bg: #ffffff;
    --text-main: #333333;
    --text-muted: #666666;
    --border-color: #e1e4e8;
    --warning-bg: #fff3cd;
    --warning-text: #856404;
    --warning-border: #ffeeba;
    --success-bg: #d4edda;
    --success-text: #155724;
    --error-bg: #f8d7da;
    --error-text: #721c24;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    width: 100%;
    max-width: 900px;
    margin: 40px auto;
    padding: 0 20px;
    flex-grow: 1;
}

header {
    text-align: center;
    margin-bottom: 40px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border-color);
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-bottom: 10px;
}

.logo i {
    font-size: 2.5rem;
    color: var(--rstudio-blue);
}

.logo h1 {
    font-size: 2.2rem;
    font-weight: 700;
    color: #444;
}

.logo span {
    color: var(--rstudio-blue);
}

.subtitle {
    color: var(--text-muted);
    font-size: 1rem;
}

/* Landing Options */
#landing-view {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.options-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

@media (max-width: 600px) {
    .options-grid {
        grid-template-columns: 1fr;
    }
}

.option-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 40px 30px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

.option-card:hover {
    border-color: var(--rstudio-blue);
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    transform: translateY(-2px);
}

.option-card i {
    font-size: 3rem;
    color: var(--rstudio-blue);
}

.option-card h2 {
    font-size: 1.4rem;
    color: #444;
}

.option-card p {
    font-size: 0.95rem;
    color: var(--text-muted);
}

.no-decoration {
    text-decoration: none;
    color: inherit;
}

/* Warning Box */
.alert-warning {
    background-color: var(--warning-bg);
    border: 1px solid var(--warning-border);
    color: var(--warning-text);
    padding: 20px;
    border-radius: 8px;
    display: flex;
    gap: 15px;
    align-items: flex-start;
}

.alert-warning i {
    font-size: 1.4rem;
    margin-top: 3px;
}

.alert-warning div h4 {
    margin-bottom: 5px;
    font-weight: 600;
}

.alert-warning div p {
    font-size: 0.9rem;
}

/* Tabs & Navigation */
.nav-back {
    margin-bottom: 20px;
}

.btn-link {
    background: none;
    border: none;
    color: var(--rstudio-blue);
    cursor: pointer;
    font-size: 1rem;
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 5px 0;
}

.btn-link:hover {
    text-decoration: underline;
}

/* Sections */
.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.3s ease-in;
}

.card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 30px;
}

.card h2 {
    margin-bottom: 25px;
    font-size: 1.5rem;
    color: #444;
    border-bottom: 1px solid #f0f0f0;
    padding-bottom: 15px;
}

/* Forms */
.input-group {
    margin-bottom: 20px;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    font-size: 0.9rem;
    color: #555;
}

.input-group input {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 1rem;
}

.input-group input:focus {
    outline: none;
    border-color: var(--rstudio-blue);
    box-shadow: 0 0 0 3px rgba(77, 141, 201, 0.2);
}

.btn-primary {
    background-color: var(--rstudio-blue);
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 4px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    transition: background-color 0.2s;
}

.btn-primary:hover {
    background-color: var(--rstudio-blue-hover);
}

.btn-primary:disabled {
    background-color: #ccc;
    cursor: not-allowed;
}

/* Upload Area */
.upload-area {
    border: 2px dashed #ccc;
    border-radius: 8px;
    padding: 40px;
    text-align: center;
    margin-bottom: 20px;
    background: #fafafa;
    cursor: pointer;
    transition: all 0.2s;
}

.upload-area:hover {
    border-color: var(--rstudio-blue);
    background: #f0f7ff;
}

.upload-area i {
    font-size: 2.5rem;
    color: #aaa;
    margin-bottom: 15px;
}

.btn-secondary {
    background: #fff;
    border: 1px solid #ccc;
    padding: 8px 16px;
    border-radius: 4px;
    cursor: pointer;
    font-weight: 500;
}

.file-list {
    margin: 20px 0;
    max-height: 200px;
    overflow-y: auto;
    border: 1px solid #eee;
    border-radius: 4px;
}

.file-item {
    display: flex;
    justify-content: space-between;
    padding: 10px 15px;
    border-bottom: 1px solid #eee;
    font-size: 0.9rem;
}

.file-item:last-child {
    border-bottom: none;
}

/* Messages */
.message {
    margin-top: 20px;
    padding: 15px;
    border-radius: 4px;
    font-size: 0.95rem;
    display: none;
}

.message.success {
    display: block;
    background-color: var(--success-bg);
    color: var(--success-text);
    border: 1px solid #c3e6cb;
}

.message.error {
    display: block;
    background-color: var(--error-bg);
    color: var(--error-text);
    border: 1px solid #f5c6cb;
}

.message-actions {
    margin-top: 15px;
    display: flex;
    gap: 10px;
}

footer {
    padding: 30px;
    text-align: center;
    font-size: 0.85rem;
    color: var(--text-muted);
    border-top: 1px solid var(--border-color);
    background: #fff;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(5px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Robot Test Widget */
.robot-widget {
    margin: 20px 0;
    padding: 10px;
    background: #f9f9f9;
    border: 1px solid #d3d3d3;
    border-radius: 3px;
    width: fit-content;
}

.robot-checkbox-wrapper {
    display: flex;
    align-items: center;
    gap: 12px;
    cursor: pointer;
    user-select: none;
    min-width: 280px;
}

.robot-checkbox {
    width: 24px;
    height: 24px;
    border: 2px solid #c1c1c1;
    border-radius: 2px;
    background: white;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}

.robot-checkbox i {
    color: #009900;
    font-size: 14px;
    display: none;
}

.robot-checkbox.checked {
    border-color: #009900;
}

.robot-checkbox.checked i {
    display: block;
}

.robot-logo {
    margin-left: auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    font-size: 0.7rem;
    color: #666;
}

.robot-logo i {
    font-size: 1.5rem;
    margin-bottom: 2px;
}

/* Robot Overlay */
.robot-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.robot-overlay.active {
    display: flex;
}

.robot-modal {
    background: white;
    padding: 20px;
    border-radius: 8px;
    max-width: 90%;
    width: 600px;
    box-shadow: 0 5px 30px rgba(0,0,0,0.3);
}

.robot-modal h3 {
    margin-bottom: 10px;
    font-size: 1.2rem;
}

.robot-modal p {
    margin-bottom: 15px;
    font-size: 0.9rem;
    color: #666;
}

.canvas-container {
    position: relative;
    width: 100%;
    overflow: hidden;
    border: 1px solid #ddd;
    margin-bottom: 20px;
}

.canvas-container img {
    width: 100%;
    display: block;
}

.canvas-container canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    cursor: crosshair;
}

.modal-status-msg {
    margin-top: -10px;
    margin-bottom: 15px;
    font-size: 0.9rem;
    min-height: 1.2rem;
    color: #e74c3c;
    font-weight: 500;
}

.modal-status-msg.success {
    color: #27ae60;
}

.modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: 10px;
}