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

:root {
    --primary-color: #4A90D9;
    --primary-dark: #3A7BC8;
    --secondary-color: #6C757D;
    --success-color: #28A745;
    --danger-color: #DC3545;
    --warning-color: #FFC107;
    --bg-color: #F5F7FA;
    --card-bg: #FFFFFF;
    --text-primary: #2C3E50;
    --text-secondary: #6C757D;
    --border-color: #DEE2E6;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --radius: 8px;
}

html, body {
    width: 100%;
    height: 100%;
    height: 100dvh;
    overflow: hidden;
    overscroll-behavior: none;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg-color);
    color: var(--text-primary);
    font-size: 14px;
    line-height: 1.5;
}

/* 表单视图：尽量去掉外圈“白边框/留白” */
body.is-form-view .main-content {
    padding: 0;
    gap: 0;
}

body.is-form-view .tab-content {
    flex: 1;
    overflow: hidden;
}

body.is-form-view .form-section {
    border-radius: 0;
    box-shadow: none;
    /* 贴边显示，但给横屏刘海机型留安全区 */
    padding-left: calc(12px + env(safe-area-inset-left));
    padding-right: calc(12px + env(safe-area-inset-right));
    padding-top: calc(12px + env(safe-area-inset-top));
    padding-bottom: 0;
    touch-action: pan-y;
    -webkit-overflow-scrolling: touch;
}

.app-container {
    display: flex;
    flex-direction: column;
    width: 100%;
    height: 100vh;
    height: 100dvh;
    max-width: 100%;
    overflow: hidden;
}

.header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 12px 20px;
    flex-shrink: 0;
    box-shadow: var(--shadow);
}

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

.header h1 {
    font-size: 18px;
    font-weight: 600;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 8px;
}

.close-btn {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.3);
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 13px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.close-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    border-color: rgba(255, 255, 255, 0.5);
}

.close-btn:active {
    background: rgba(255, 255, 255, 0.4);
}

.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    padding: 12px;
    gap: 12px;
}

.content-wrapper {
    display: flex;
    gap: 12px;
    flex: 1;
    overflow: hidden;
}

.left-panel {
    width: 200px;
    flex-shrink: 0;
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 16px;
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    min-height: 0;
}

.panel-title {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--primary-color);
}

.feedback-buttons {
    display: flex;
    flex-direction: column;
    gap: 10px;
    flex: 1;
    min-height: 0;
    overflow-y: auto;
    overflow-x: hidden;
    touch-action: pan-y;
    -webkit-overflow-scrolling: touch;
    overscroll-behavior: contain;
}

.feedback-btn {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 14px 16px;
    background: linear-gradient(135deg, #E8F4FD 0%, #D4E9FC 100%);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: left;
}

.feedback-btn:hover {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    border-color: var(--primary-color);
    transform: translateX(4px);
}

.feedback-btn:hover .btn-icon,
.feedback-btn:hover .btn-text {
    color: white;
}

.btn-icon {
    font-size: 20px;
}

.btn-text {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-primary);
}

.right-panel {
    flex: 1;
    min-width: 0;
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 16px;
    box-shadow: var(--shadow);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    touch-action: pan-y;
    -webkit-overflow-scrolling: touch;
    overscroll-behavior: contain;
}

.faq-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
    flex-shrink: 0;
}

.faq-header .panel-title {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

.search-box {
    position: relative;
    width: 200px;
}

.search-box input {
    width: 100%;
    padding: 10px 14px;
    padding-right: 36px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 13px;
    transition: border-color 0.3s ease;
}

.search-box input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.search-icon {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 14px;
}

.faq-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    position: relative;
    min-height: 0;
}

.faq-categories {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    grid-auto-rows: minmax(140px, auto);
    gap: 12px;
    overflow-y: auto;
    overflow-x: hidden;
    scrollbar-width: thin;
    -webkit-overflow-scrolling: touch;
    flex: 1 1 0;
    min-height: 0;
    height: auto;
    touch-action: pan-y;
    align-content: stretch;
    align-items: stretch;
    overscroll-behavior: contain;
}

.faq-categories::-webkit-scrollbar {
    width: 6px;
}

.faq-categories::-webkit-scrollbar-track {
    background: transparent;
}

.faq-categories::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 3px;
}

.category-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    padding: 24px 16px;
    background: linear-gradient(135deg, #E8F4FD 0%, #D4E9FC 100%);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    cursor: pointer;
    transition: all 0.3s ease;
    -webkit-tap-highlight-color: transparent;
    touch-action: pan-y;
    pointer-events: auto;
    height: auto;
}

.category-card:hover {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(74, 144, 217, 0.3);
}

.category-card:hover .category-icon,
.category-card:hover .category-name,
.category-card:hover .category-subtitle {
    color: white;
}

.category-icon {
    font-size: 32px;
}

.category-name {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-primary);
}

.category-subtitle {
    font-size: 12px;
    color: var(--text-secondary);
}

.faq-list-container,
.faq-search-results {
    display: none;
    flex-direction: column;
    flex: 1;
    min-width: 0;
    min-height: 0;
    overflow: hidden;
}

.faq-list-container.active,
.faq-search-results.active {
    display: flex;
}

.back-to-categories {
    align-self: flex-start;
    padding: 8px 16px;
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 13px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.3s ease;
    margin-bottom: 16px;
    flex-shrink: 0;
}

.back-to-categories:hover {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
}

.faq-list-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--primary-color);
    flex-shrink: 0;
}

.faq-list {
    flex: 1;
    min-width: 0;
    min-height: 0;
    overflow-y: auto;
    overflow-x: hidden;
    display: flex;
    flex-direction: column;
    gap: 10px;
    padding-right: 8px;
    scrollbar-width: thin;
    -webkit-overflow-scrolling: touch;
    touch-action: pan-y;
    overscroll-behavior: contain;
}

.faq-list::-webkit-scrollbar {
    width: 6px;
}

.faq-list::-webkit-scrollbar-track {
    background: transparent;
}

.faq-list::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 3px;
}

.faq-item {
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    overflow: hidden;
    transition: all 0.3s ease;
    background: white;
}

.faq-item:hover {
    border-color: var(--primary-color);
}

.faq-question {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 12px;
    padding: 14px 16px;
    background: var(--bg-color);
    cursor: pointer;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
    pointer-events: auto;
}

.faq-question span:first-child {
    flex: 1;
    min-width: 0;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-primary);
    line-height: 1.5;
    word-break: break-word;
}

.faq-arrow {
    font-size: 10px;
    color: var(--text-secondary);
    transition: transform 0.3s ease;
    flex-shrink: 0;
}

.faq-item.open .faq-arrow {
    transform: rotate(180deg);
}

.faq-answer {
    display: none;
    padding: 16px;
    background: white;
    border-top: 1px solid var(--border-color);
    word-break: break-word;
}

.faq-item.open .faq-answer {
    display: block;
}

.faq-answer p {
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 10px;
    line-height: 1.6;
}

.faq-answer p:last-child {
    margin-bottom: 0;
}

.faq-answer strong {
    color: var(--text-primary);
    font-weight: 600;
}

.no-results {
    display: none;
    align-items: center;
    justify-content: center;
    padding: 40px;
    color: var(--text-secondary);
    font-size: 14px;
    flex: 1;
}

.no-results.show {
    display: flex;
}

.tab-content {
    display: none;
    flex: 1;
    overflow: hidden;
    min-height: 0;
}

.tab-content.active {
    display: flex;
}

.form-section {
    display: none;
    flex-direction: column;
    width: 100%;
    flex: 1;
    min-height: 0;
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 20px;
    padding-bottom: 0;
    box-shadow: var(--shadow);
    overflow-y: auto;
    overscroll-behavior: contain;
}

.form-section.active {
    display: flex;
}

.form-section::-webkit-scrollbar {
    width: 6px;
}

.form-section::-webkit-scrollbar-track {
    background: transparent;
}

.form-section::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 3px;
}

.back-btn {
    align-self: flex-start;
    padding: 8px 16px;
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 13px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.3s ease;
    margin-bottom: 16px;
}

.back-btn:hover {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
}

.form-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--primary-color);
}

.feedback-form {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.form-group {
    margin-bottom: 20px;
}

.form-group:last-of-type {
    margin-bottom: 24px;
}

.label-required::after {
    content: ' *';
    color: var(--danger-color);
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-primary);
    font-size: 14px;
}

.input-hint {
    display: block;
    margin-top: 4px;
    font-size: 12px;
    color: var(--text-secondary);
}

.input-field {
    width: 100%;
    padding: 12px 14px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 14px;
    transition: border-color 0.3s ease;
    background: white;
}

.input-field:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(74, 144, 217, 0.1);
}

.input-field::placeholder {
    color: #ADB5BD;
}

.textarea-field {
    width: 100%;
    padding: 12px 14px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 14px;
    resize: vertical;
    min-height: 100px;
    font-family: inherit;
    transition: border-color 0.3s ease;
}

.textarea-field:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(74, 144, 217, 0.1);
}

.textarea-field::placeholder {
    color: #ADB5BD;
}

.checkbox-group {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}

.checkbox-item {
    display: flex;
    align-items: center;
    cursor: pointer;
    padding: 10px 12px;
    background: var(--bg-color);
    border-radius: var(--radius);
    transition: background 0.2s ease;
}

.checkbox-item:hover {
    background: #E8F4FD;
}

.checkbox-item input[type="checkbox"] {
    width: 18px;
    height: 18px;
    margin-right: 10px;
    accent-color: var(--primary-color);
    cursor: pointer;
}

.checkbox-label {
    font-size: 13px;
    color: var(--text-primary);
}

.upload-area {
    position: relative;
    border: 2px dashed var(--border-color);
    border-radius: var(--radius);
    padding: 24px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: var(--bg-color);
}

.upload-area:hover {
    border-color: var(--primary-color);
    background: #E8F4FD;
}

.upload-area.dragover {
    border-color: var(--primary-color);
    background: #E8F4FD;
}

.upload-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.upload-icon {
    font-size: 32px;
}

.upload-text {
    color: var(--text-secondary);
    font-size: 13px;
}

.file-input {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    cursor: pointer;
}

.preview-container {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 16px;
}

.preview-item {
    position: relative;
    width: 80px;
    height: 80px;
    border-radius: var(--radius);
    overflow: hidden;
    border: 1px solid var(--border-color);
}

.preview-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.preview-item .remove-btn {
    position: absolute;
    top: 4px;
    right: 4px;
    width: 20px;
    height: 20px;
    background: rgba(220, 53, 69, 0.9);
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 12px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    line-height: 1;
}

.submit-btn {
    width: 100%;
    padding: 14px 24px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    border: none;
    border-radius: var(--radius);
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(74, 144, 217, 0.3);
}

.submit-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(74, 144, 217, 0.4);
}

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

.submit-btn:disabled {
    background: var(--secondary-color);
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.toast {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0.8);
    background: rgba(0, 0, 0, 0.8);
    color: white;
    padding: 16px 32px;
    border-radius: var(--radius);
    font-size: 14px;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 1000;
    max-width: 80%;
    text-align: center;
}

.toast.show {
    opacity: 1;
    visibility: visible;
    transform: translate(-50%, -50%) scale(1);
}

.toast.success {
    background: rgba(40, 167, 69, 0.95);
}

.toast.error {
    background: rgba(220, 53, 69, 0.95);
}

.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 16px;
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.loading-overlay.show {
    opacity: 1;
    visibility: visible;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.loading-overlay span {
    color: white;
    font-size: 14px;
}

.landscape-warning {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-color);
    z-index: 9999;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 16px;
}

.landscape-warning .rotate-icon {
    font-size: 48px;
    animation: rotate 2s ease-in-out infinite;
}

@keyframes rotate {
    0%, 100% {
        transform: rotate(0deg);
    }
    50% {
        transform: rotate(90deg);
    }
}

.landscape-warning p {
    font-size: 16px;
    color: var(--text-secondary);
    text-align: center;
    padding: 0 20px;
}

@media (orientation: portrait) and (max-width: 768px) {
    .landscape-warning {
        display: flex;
    }
    
    .app-container {
        display: none;
    }
}

@media (max-width: 768px) {
    html,
    body {
        height: auto;
        min-height: 100%;
        overflow-y: auto;
    }

    .app-container {
        height: auto;
        min-height: 100vh;
        overflow: visible;
    }

    .main-content,
    .content-wrapper {
        min-height: 0;
        overflow-y: auto;
    }

    .right-panel {
        min-width: 0;
        padding: 12px;
        overflow-y: auto;
        -webkit-overflow-scrolling: touch;
    }

    .faq-container {
        min-height: 0;
        overflow: visible;
        overflow-y: auto;
        -webkit-overflow-scrolling: touch;
        /* 移动端高度经常是 auto，保持 flex:1 会导致子项高度被算成 0 */
        flex: none;
    }

    .faq-list-container,
    .faq-search-results {
        width: 100%;
        min-height: 0;
        overflow: visible;
    }
    
    .faq-categories {
        overflow-y: auto;
        -webkit-overflow-scrolling: touch;
        touch-action: pan-y;
        /* 同上，避免 flex-basis=0 导致网格高度为 0 */
        flex: none;
    }
    
    .faq-list {
        overflow-y: auto;
        -webkit-overflow-scrolling: touch;
        touch-action: pan-y;
    }
    
    .category-card {
        -webkit-tap-highlight-color: rgba(74, 144, 217, 0.3);
        touch-action: pan-y;
        cursor: pointer;
    }
    
    .faq-question {
        -webkit-tap-highlight-color: rgba(74, 144, 217, 0.3);
        touch-action: manipulation;
        cursor: pointer;
        padding: 12px 14px;
    }

    .faq-question span:first-child {
        font-size: 13px;
        line-height: 1.4;
    }

    .faq-arrow {
        margin-top: 2px;
    }
    
    .faq-item {
        touch-action: manipulation;
        overflow: visible;
    }

    .faq-answer {
        padding: 14px;
    }

    .faq-answer p {
        font-size: 12px;
    }

    .faq-list {
        flex: none;
        overflow-y: auto;
        overflow-x: hidden;
        padding-right: 0;
    }
}

@media (orientation: landscape) and (max-height: 500px) {
    .header {
        padding: 8px 16px;
    }
    
    .header h1 {
        font-size: 16px;
    }
    
    .main-content {
        padding: 8px;
        gap: 8px;
    }
    
    .left-panel {
        width: 180px;
        padding: 12px;
    }
    
    .panel-title {
        font-size: 14px;
        margin-bottom: 12px;
        padding-bottom: 8px;
    }
    
    .feedback-btn {
        padding: 10px 12px;
    }
    
    .btn-icon {
        font-size: 18px;
    }
    
    .btn-text {
        font-size: 13px;
    }
    
    .right-panel {
        padding: 12px;
    }
    
    .faq-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }
    
    .search-box {
        width: 100%;
    }
    
    .faq-categories {
        grid-template-columns: repeat(2, 1fr);
        gap: 8px;
    }
    
    .category-card {
        padding: 16px 12px;
    }
    
    .category-icon {
        font-size: 24px;
    }
    
    .category-name {
        font-size: 13px;
    }
    
    .category-subtitle {
        font-size: 11px;
    }
    
    .faq-question {
        padding: 12px 14px;
    }
    
    .faq-question span:first-child {
        font-size: 13px;
    }
    
    .faq-answer {
        padding: 14px;
    }
    
    .faq-answer p {
        font-size: 12px;
    }
    
    .form-section {
        padding: 16px;
        padding-bottom: 0;
    }
    
    .form-title {
        font-size: 16px;
        margin-bottom: 16px;
    }
    
    .form-group {
        margin-bottom: 16px;
    }
    
    .input-field,
    .textarea-field {
        padding: 10px 12px;
    }
    
    .textarea-field {
        min-height: 80px;
    }
    
    .checkbox-group {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .upload-area {
        padding: 16px;
    }
    
    .submit-btn {
        padding: 12px 20px;
        font-size: 14px;
    }
}

@media (min-width: 1024px) {
    .content-wrapper {
        max-width: 1200px;
        margin: 0 auto;
    }
    
    .left-panel {
        width: 240px;
    }
    
    .checkbox-group {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .faq-categories {
        grid-template-columns: repeat(4, 1fr);
    }
}

@media (hover: none) and (pointer: coarse) {
    html,
    body {
        height: 100%;
        min-height: 100%;
        overflow-x: hidden;
        overflow-y: hidden;
    }

    body {
        position: fixed;
        inset: 0;
        width: 100%;
    }

    .app-container {
        height: 100vh;
        height: 100dvh;
        min-height: 100dvh;
        overflow: hidden;
    }

    .main-content {
        min-height: 0;
        overflow: hidden;
        padding: env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left);
        gap: 0;
    }

    .content-wrapper {
        flex: 1;
        align-items: flex-start;
        min-height: 0;
        overflow: hidden;
        gap: 0;
    }

    .left-panel {
        position: sticky;
        top: 0;
        align-self: flex-start;
        /* header 已移除，避免错误预留高度 */
        max-height: calc(100dvh - env(safe-area-inset-top) - env(safe-area-inset-bottom));
        border-radius: 0;
        box-shadow: none;
    }

    .right-panel {
        min-width: 0;
        min-height: 0;
        /* header 已移除，避免错误预留高度 */
        max-height: calc(100dvh - env(safe-area-inset-top) - env(safe-area-inset-bottom));
        overflow-y: auto;
        overflow-x: hidden;
        -webkit-overflow-scrolling: touch;
        border-radius: 0;
        box-shadow: none;
    }

    .faq-list-container,
    .faq-search-results,
    .faq-list {
        flex: 1;
        min-height: 0;
        height: 100%;
        max-height: none;
        overflow: visible;
    }

    /* 触屏设备下，faq 分类用内容高度，避免闪一下就被“100%高度链”挤没 */
    .faq-container {
        flex: none;
        height: auto;
        max-height: none;
        overflow: visible;
    }

    .faq-categories {
        flex: none;
    }

    .faq-item {
        overflow: visible;
    }

    .faq-answer {
        overflow: visible;
    }

    body.is-form-view .main-content {
        overflow: hidden;
        touch-action: none;
    }

    body.is-form-view .tab-content {
        overflow: hidden;
        touch-action: pan-y;
    }

    body.is-form-view .form-section {
        overflow-y: auto;
        overflow-x: hidden;
        -webkit-overflow-scrolling: touch;
        touch-action: pan-y;
        overscroll-behavior: contain;
    }
}

input:invalid:not(:placeholder-shown),
textarea:invalid:not(:placeholder-shown) {
    border-color: var(--danger-color);
}

input:valid:not(:placeholder-shown),
textarea:valid:not(:placeholder-shown) {
    border-color: var(--success-color);
}

.dt-modal {
    position: fixed;
    inset: 0;
    display: none;
    z-index: 1200;
}

.dt-modal.show {
    display: block;
}

.dt-modal-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
}

.dt-modal-card {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    width: min(420px, calc(100% - 32px));
    background: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.25);
    padding: 16px;
}

.dt-modal-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.dt-modal-body {
    display: grid;
    grid-template-columns: 1fr;
    gap: 12px;
}

.dt-field {
    display: grid;
    grid-template-columns: 56px 1fr;
    align-items: center;
    gap: 10px;
    font-size: 13px;
    color: var(--text-secondary);
}

.dt-field.dt-field-single {
    grid-template-columns: 72px 1fr;
}

.dt-field input {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 14px;
    background: white;
}

.dt-modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: 10px;
    margin-top: 14px;
}

.dt-btn {
    padding: 10px 14px;
    border-radius: 10px;
    border: 1px solid var(--border-color);
    background: white;
    cursor: pointer;
    font-size: 14px;
}

.dt-btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    border-color: var(--primary-color);
    color: white;
}

.dt-btn-secondary {
    color: var(--text-secondary);
}