/* ===== 全局样式 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg-primary: #0d1117;
    --bg-secondary: #161b22;
    --bg-tertiary: #21262d;
    --bg-hover: #30363d;
    --text-primary: #e6edf3;
    --text-secondary: #8b949e;
    --accent: #238636;
    --accent-hover: #2ea043;
    --accent-light: #3fb950;
    --border: #30363d;
    -- shadow: rgba(0, 0, 0, 0.3);
    --danger: #da3633;
    --warning: #d29922;
    --info: #58a6ff;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
}

.hidden {
    display: none !important;
}

/* ===== 导航栏 ===== */
.navbar {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    padding: 0 20px;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
}

.nav-left {
    display: flex;
    align-items: center;
    gap: 15px;
}

.menu-btn {
    background: none;
    border: 1px solid var(--border);
    color: var(--text-primary);
    font-size: 18px;
    cursor: pointer;
    padding: 8px 10px;
    border-radius: 6px;
    transition: all 0.2s;
}

.menu-btn:hover {
    background: var(--bg-tertiary);
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 700;
    color: var(--accent-light);
}

.logo i {
    font-size: 24px;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 15px;
}

.lang-selector {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    border: 1px solid var(--border);
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 14px;
}

.lang-selector:hover {
    background: var(--bg-tertiary);
}

/* ===== 侧边栏 ===== */
.sidebar {
    position: fixed;
    top: 0;
    left: -280px;
    width: 280px;
    height: 100vh;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border);
    z-index: 200;
    transition: left 0.3s ease;
    overflow-y: auto;
}

.sidebar.open {
    left: 0;
}

.sidebar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    border-bottom: 1px solid var(--border);
    font-size: 18px;
    font-weight: 600;
}

.close-btn {
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 20px;
    cursor: pointer;
}

.sidebar-content {
    padding: 10px;
}

.sidebar-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 15px;
    color: var(--text-primary);
    text-decoration: none;
    border-radius: 6px;
    transition: all 0.2s;
    margin-bottom: 5px;
}

.sidebar-item:hover, .sidebar-item.active {
    background: var(--bg-tertiary);
}

.sidebar-item i {
    width: 20px;
    text-align: center;
}

.sidebar-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.5);
    z-index: 150;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s;
}

.sidebar-overlay.open {
    opacity: 1;
    visibility: visible;
}

/* ===== 主内容区 ===== */
.main-content {
    padding: 40px 20px 60px;
}

.page-title {
    text-align: center;
    font-size: 28px;
    margin-bottom: 10px;
    font-weight: 700;
}

.highlight {
    color: var(--accent-light);
}

.page-subtitle {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 40px;
    font-size: 16px;
}

/* ===== 输入方式标签 ===== */
.input-method-tabs {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 30px;
}

.tab-btn {
    padding: 12px 30px;
    border: 2px solid var(--border);
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 15px;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    gap: 8px;
}

.tab-btn:hover {
    border-color: var(--accent);
}

.tab-btn.active {
    background: var(--accent);
    border-color: var(--accent);
    color: white;
}

/* ===== 输入区域 ===== */
.input-section {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 20px;
    margin-bottom: 30px;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
    font-weight: 600;
}

.section-header span {
    display: flex;
    align-items: center;
    gap: 8px;
}

.clear-btn {
    background: none;
    border: 1px solid var(--danger);
    color: var(--danger);
    padding: 6px 12px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 13px;
    display: flex;
    align-items: center;
    gap: 5px;
    transition: all 0.2s;
}

.clear-btn:hover {
    background: var(--danger);
    color: white;
}

textarea {
    width: 100%;
    min-height: 200px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 15px;
    color: var(--text-primary);
    font-size: 14px;
    font-family: 'Consolas', 'Monaco', monospace;
    resize: vertical;
    outline: none;
    transition: border-color 0.2s;
}

textarea:focus {
    border-color: var(--accent);
}

.char-count {
    text-align: right;
    margin-top: 8px;
    font-size: 13px;
    color: var(--text-secondary);
}

/* ===== 上传区域 ===== */
.upload-area {
    border: 2px dashed var(--border);
    border-radius: 10px;
    padding: 50px 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
    background: var(--bg-tertiary);
}

.upload-area:hover, .upload-area.dragover {
    border-color: var(--accent);
    background: rgba(35, 134, 54, 0.1);
}

.upload-area i {
    font-size: 48px;
    color: var(--accent);
    margin-bottom: 15px;
}

.upload-area p {
    margin: 5px 0;
    color: var(--text-secondary);
}

.browse-link {
    color: var(--accent-light);
    text-decoration: underline;
    cursor: pointer;
}

.upload-hint {
    font-size: 13px;
}

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

#fileInput {
    display: none;
}

.file-list {
    margin-top: 20px;
}

.file-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 15px;
    background: var(--bg-tertiary);
    border-radius: 8px;
    margin-bottom: 10px;
}

.file-item-info {
    display: flex;
    align-items: center;
    gap: 10px;
}

.file-item-info i {
    font-size: 20px;
    color: var(--accent-light);
}

.file-item-name {
    font-weight: 500;
}

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

.file-item-remove {
    background: none;
    border: none;
    color: var(--danger);
    cursor: pointer;
    font-size: 16px;
    padding: 5px;
}

/* ===== 选项区域 ===== */
.options-section {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 20px;
    margin-bottom: 30px;
}

.option-group label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
    margin-bottom: 15px;
    font-size: 16px;
}

.option-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 0;
    border-bottom: 1px solid var(--border);
}

.option-row:last-child {
    border-bottom: none;
}

.option-row span {
    color: var(--text-secondary);
}

select, input[type="text"] {
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    color: var(--text-primary);
    padding: 8px 12px;
    border-radius: 6px;
    font-size: 14px;
    outline: none;
    min-width: 200px;
}

select:focus, input[type="text"]:focus {
    border-color: var(--accent);
}

/* ===== 格式选择区域 ===== */
.format-section {
    margin-bottom: 30px;
}

.format-section > label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
    margin-bottom: 15px;
    font-size: 16px;
}

.format-selector {
    position: relative;
}

.format-display {
    background: var(--bg-secondary);
    border: 2px solid var(--accent);
    border-radius: 8px;
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    font-size: 18px;
    font-weight: 700;
    color: var(--accent-light);
    transition: all 0.2s;
}

.format-display:hover {
    background: var(--bg-tertiary);
}

.format-dropdown {
    position: absolute;
    top: calc(100% + 5px);
    left: 0;
    right: 0;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 10px;
    max-height: 400px;
    overflow-y: auto;
    z-index: 50;
    box-shadow: 0 10px 40px var(--shadow);
    display: none;
}

.format-dropdown.open {
    display: block;
}

.format-search {
    padding: 15px;
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    background: var(--bg-secondary);
    z-index: 1;
}

.format-search input {
    width: 100%;
    padding: 10px 15px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-primary);
    font-size: 14px;
    outline: none;
}

.format-search input:focus {
    border-color: var(--accent);
}

.format-categories {
    padding: 15px;
}

.format-category {
    margin-bottom: 20px;
}

.format-category h4 {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 10px;
    padding-bottom: 5px;
    border-bottom: 1px solid var(--border);
}

.format-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 8px;
}

.format-item {
    padding: 10px 12px;
    background: var(--bg-tertiary);
    border-radius: 6px;
    cursor: pointer;
    font-size: 13px;
    transition: all 0.2s;
    border: 1px solid transparent;
}

.format-item:hover {
    background: var(--bg-hover);
    border-color: var(--accent);
}

.format-item.selected {
    background: rgba(35, 134, 54, 0.2);
    border-color: var(--accent);
    color: var(--accent-light);
}

/* ===== 转换按钮 ===== */
.convert-section {
    text-align: center;
    margin-bottom: 50px;
}

.convert-btn {
    background: linear-gradient(135deg, var(--accent), var(--accent-hover));
    color: white;
    border: none;
    padding: 18px 60px;
    font-size: 18px;
    font-weight: 700;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
    gap: 10px;
    box-shadow: 0 4px 15px rgba(35, 134, 54, 0.4);
}

.convert-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(35, 134, 54, 0.6);
}

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

.convert-hint {
    margin-top: 15px;
    color: var(--text-secondary);
    font-size: 14px;
}

/* ===== 结果区域 ===== */
.result-section {
    background: var(--bg-secondary);
    border: 1px solid var(--accent);
    border-radius: 10px;
    padding: 20px;
    margin-bottom: 50px;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.result-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    font-size: 18px;
    font-weight: 600;
    color: var(--accent-light);
}

.result-header span {
    display: flex;
    align-items: center;
    gap: 8px;
}

.close-result {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 18px;
    padding: 5px;
}

.result-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
}

.result-info p {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 5px;
    font-size: 14px;
    color: var(--text-secondary);
}

.result-actions {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.action-btn {
    padding: 10px 20px;
    border: 1px solid var(--border);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all 0.2s;
}

.action-btn:hover {
    background: var(--bg-hover);
}

.download-btn {
    background: var(--accent);
    border-color: var(--accent);
    color: white;
}

.download-btn:hover {
    background: var(--accent-hover);
}

.preview-area {
    margin-top: 20px;
    background: var(--bg-tertiary);
    border-radius: 8px;
    padding: 15px;
    max-height: 300px;
    overflow-y: auto;
}

.preview-area pre {
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 13px;
    white-space: pre-wrap;
    word-wrap: break-word;
    color: var(--text-primary);
}

/* ===== 功能特点 ===== */
.features-section {
    margin-bottom: 50px;
}

.features-section h2 {
    text-align: center;
    font-size: 24px;
    margin-bottom: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.feature-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 30px 20px;
    text-align: center;
    transition: all 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
    border-color: var(--accent);
    box-shadow: 0 10px 30px var(--shadow);
}

.feature-card i {
    font-size: 36px;
    color: var(--accent-light);
    margin-bottom: 15px;
}

.feature-card h3 {
    margin-bottom: 10px;
    font-size: 18px;
}

.feature-card p {
    font-size: 14px;
    color: var(--text-secondary);
}

/* ===== 支持格式 ===== */
.formats-info-section {
    margin-bottom: 50px;
}

.formats-info-section h2 {
    text-align: center;
    font-size: 24px;
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.formats-intro {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 25px;
}

.formats-tags {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
}

.format-tag {
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.2s;
    cursor: default;
}

.format-tag:hover {
    background: var(--accent);
    border-color: var(--accent);
    color: white;
}

/* ===== 底部 ===== */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    padding: 30px 20px;
    text-align: center;
}

.footer p {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 10px;
}

.footer-links a {
    color: var(--accent-light);
    text-decoration: none;
    margin: 0 5px;
}

.footer-links a:hover {
    text-decoration: underline;
}

/* ===== 加载动画 ===== */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.loading-spinner {
    text-align: center;
    color: var(--text-primary);
}

.loading-spinner i {
    font-size: 60px;
    color: var(--accent-light);
    margin-bottom: 20px;
}

.loading-spinner p {
    font-size: 18px;
}

/* ===== 响应式设计 ===== */
@media (max-width: 768px) {
    .page-title {
        font-size: 22px;
    }
    
    .input-method-tabs {
        flex-direction: column;
        align-items: center;
    }
    
    .tab-btn {
        width: 100%;
        justify-content: center;
    }
    
    .format-grid {
        grid-template-columns: 1fr;
    }
    
    .result-content {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .result-actions {
        width: 100%;
        justify-content: stretch;
    }
    
    .action-btn {
        flex: 1;
        justify-content: center;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    select, input[type="text"] {
        min-width: 150px;
    }
}

@media (max-width: 480px) {
    .nav-container {
        height: 50px;
    }
    
    .logo span {
        display: none;
    }
    
    .main-content {
        padding: 20px 15px 40px;
    }
    
    .page-title {
        font-size: 18px;
    }
}