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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}
.back-to-classroom{display:inline-flex;align-items:center;margin:0 0 14px;padding:9px 14px;border-radius:999px;background:rgba(255,255,255,.92);color:#4f46a5;font-weight:700;text-decoration:none;box-shadow:0 6px 20px rgba(43,38,120,.16)}
.back-to-classroom:hover{background:#fff;transform:translateY(-1px)}

.container {
    max-width: 1600px;
    margin: 0 auto;
    background: white;
    border-radius: 12px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    overflow: hidden;
}

header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 30px;
    text-align: center;
}

header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
}

header p {
    font-size: 1.2em;
    opacity: 0.9;
}

.main-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    padding: 20px;
}

.config-panel {
    background: #f8f9fa;
    padding: 25px;
    border-radius: 8px;
    max-height: calc(100vh - 200px);
    overflow-y: auto;
}

.config-panel h2 {
    color: #333;
    margin-bottom: 20px;
    font-size: 1.8em;
    border-bottom: 3px solid #667eea;
    padding-bottom: 10px;
}

.config-section {
    background: white;
    padding: 20px;
    margin-bottom: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.config-section h3 {
    color: #667eea;
    margin-bottom: 15px;
    font-size: 1.3em;
}

.form-group {
    margin-bottom: 15px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    color: #555;
    font-weight: 500;
}

input[type="text"],
input[type="number"],
input[type="color"],
select,
textarea {
    width: 100%;
    padding: 10px;
    border: 2px solid #e0e0e0;
    border-radius: 6px;
    font-size: 14px;
    transition: border-color 0.3s;
}

input[type="text"]:focus,
input[type="number"]:focus,
select:focus,
textarea:focus {
    outline: none;
    border-color: #667eea;
}

textarea {
    resize: vertical;
    font-family: 'Courier New', monospace;
}

.import-options {
    margin-bottom: 15px;
}

.import-options label {
    display: block;
    margin-bottom: 10px;
    padding: 10px;
    background: #f0f0f0;
    border-radius: 6px;
    cursor: pointer;
    transition: background 0.3s;
}

.import-options label:hover {
    background: #e0e0e0;
}

.import-options input[type="radio"] {
    margin-right: 8px;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 6px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    margin-right: 10px;
    margin-top: 10px;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
    transform: translateY(-2px);
}

.btn-success {
    background: linear-gradient(135deg, #28a745 0%, #20c997 100%);
    color: white;
}

.btn-success:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(40, 167, 69, 0.4);
}

.btn-success:disabled {
    background: #6c757d;
    cursor: not-allowed;
    transform: none;
}

.btn-wordbank{background:linear-gradient(135deg,#f59e0b,#f97316);color:#fff}.btn-wordbank span{display:inline-block;margin-left:7px;padding:2px 7px;border-radius:999px;background:rgba(255,255,255,.22);font-size:12px}.wordbank-panel{margin-top:16px;padding:18px;border:2px solid #f3c16d;border-radius:12px;background:#fffaf0}.wordbank-panel[hidden]{display:none}.wordbank-heading{display:flex;align-items:flex-start;justify-content:space-between;gap:12px;margin-bottom:14px}.wordbank-heading strong{display:block;color:#7c3e08;font-size:18px}.wordbank-heading small{display:block;margin-top:5px;color:#8a6a45;line-height:1.5}.wordbank-heading button{border:0;background:transparent;color:#8a6a45;font-size:26px;cursor:pointer}.wordbank-login-notice{display:flex;align-items:center;justify-content:space-between;gap:12px;margin:12px 0;padding:12px 14px;border-radius:9px;background:#fff0d6;color:#7c3e08}.wordbank-login-notice.is-logged-in{justify-content:flex-start;background:#e7f8ee;color:#176b3a;border:1px solid #9bd8b5}.wordbank-login-notice a{padding:8px 12px;border-radius:8px;background:#7c3e08;color:#fff;text-decoration:none;font-weight:700;white-space:nowrap}.wordbank-selectors{display:grid;grid-template-columns:1fr 1fr;gap:12px}.wordbank-selectors label{font-weight:700;color:#554536}.wordbank-selectors select{margin-top:7px;background:#fff}.field-title{display:block;margin:16px 0 8px;color:#554536}.wordbank-units{display:flex;flex-wrap:wrap;gap:8px;max-height:170px;overflow:auto;padding:10px;border:1px solid #eadbc5;border-radius:9px;background:#fff}.wordbank-units label,.wordbank-ai-options label{display:inline-flex;align-items:center;gap:6px;padding:8px 10px;border-radius:8px;background:#f5efe6;cursor:pointer}.wordbank-ai-options{display:flex;align-items:center;flex-wrap:wrap;gap:8px;margin-top:14px}.wordbank-ai-options b{margin-right:5px;color:#554536}.wordbank-footer{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-top:14px}.wordbank-footer #wordbank-summary{color:#7c5b34;font-weight:700}@media(max-width:720px){.wordbank-selectors{grid-template-columns:1fr}.wordbank-footer{align-items:stretch;flex-direction:column}.wordbank-login-notice{align-items:flex-start;flex-direction:column}}

#payment-status {
    margin-top: 15px;
    padding: 15px;
    background: #f8f9fa;
    border-radius: 8px;
    border: 2px solid #28a745;
}

#qr-code-container img {
    margin: 10px 0;
}

#payment-waiting {
    padding: 20px;
}

.info-text {
    color: #666;
    font-size: 14px;
    margin-top: 10px;
}

.action-buttons {
    margin-top: 30px;
    text-align: center;
}

#progress-container {
    margin-top: 20px;
}

.progress-bar {
    width: 100%;
    height: 30px;
    background: #e0e0e0;
    border-radius: 15px;
    overflow: hidden;
    margin-bottom: 10px;
}

#progress-fill {
    height: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    width: 0%;
    transition: width 0.3s;
    border-radius: 15px;
}

#progress-text {
    text-align: center;
    color: #666;
    font-weight: 500;
}

.preview-panel {
    background: #f8f9fa;
    padding: 25px;
    border-radius: 8px;
    max-height: calc(100vh - 200px);
    overflow-y: auto;
}

.preview-panel h2 {
    color: #333;
    margin-bottom: 20px;
    font-size: 1.8em;
    border-bottom: 3px solid #667eea;
    padding-bottom: 10px;
}

#preview-container {
    background: white;
    border-radius: 8px;
    padding: 20px;
    min-height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    overflow-x: auto;
    overflow-y: auto;
    width: 100%;
}

.preview-placeholder {
    text-align: center;
    color: #999;
    font-size: 18px;
}

#preview-container img {
    max-width: 100%;
    width: auto;
    height: auto;
    min-width: 1000px;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

input[type="range"] {
    width: 70%;
    vertical-align: middle;
}

#opacity-value {
    margin-left: 10px;
    color: #667eea;
    font-weight: 600;
}

/* 滚动条样式 */
.config-panel::-webkit-scrollbar,
.preview-panel::-webkit-scrollbar {
    width: 8px;
}

.config-panel::-webkit-scrollbar-track,
.preview-panel::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 4px;
}

.config-panel::-webkit-scrollbar-thumb,
.preview-panel::-webkit-scrollbar-thumb {
    background: #667eea;
    border-radius: 4px;
}

.config-panel::-webkit-scrollbar-thumb:hover,
.preview-panel::-webkit-scrollbar-thumb:hover {
    background: #764ba2;
}

/* 响应式设计 */
@media (max-width: 1200px) {
    .main-content {
        grid-template-columns: 1fr;
    }
}