/* 全局样式 */
:root {
    --primary-color: #3498db;
    --secondary-color: #2ecc71;
    --accent-color: #9b59b6;
    --background-color: #ffffff;
    --card-background: #f8f9fa;
    --text-color: #333333;
    --text-secondary: #666666;
    --border-color: #e0e0e0;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --header-height: 70px;
    --transition-speed: 0.3s;
}

/* 暗黑模式变量 */
[data-theme="dark"] {
    --primary-color: #3498db;
    --secondary-color: #2ecc71;
    --accent-color: #9b59b6;
    --background-color: #121212;
    --card-background: #1e1e1e;
    --text-color: #f0f0f0;
    --text-secondary: #aaaaaa;
    --border-color: #333333;
    --shadow-color: rgba(0, 0, 0, 0.3);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
    transition: background-color var(--transition-speed), color var(--transition-speed);
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
}

/* 头部样式 */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background-color: var(--background-color);
    box-shadow: 0 2px 10px var(--shadow-color);
    z-index: 1000;
    transition: background-color var(--transition-speed), box-shadow var(--transition-speed);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

.logo h1 {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--text-color);
}

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

nav ul {
    display: flex;
}

nav ul li {
    margin-left: 25px;
}

nav ul li a {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-color);
    transition: color 0.2s;
    position: relative;
}

nav ul li a:hover {
    color: var(--primary-color);
}

nav ul li a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: width 0.3s;
}

nav ul li a:hover::after {
    width: 100%;
}

.theme-toggle {
    cursor: pointer;
    font-size: 1.2rem;
    color: var(--text-color);
    transition: color 0.2s;
}

.theme-toggle:hover {
    color: var(--primary-color);
}

/* 英雄区域样式 */
.hero {
    padding: 150px 0 80px;
    text-align: center;
    position: relative;
    background: radial-gradient(ellipse at center, rgba(52, 152, 219, 0.15) 0%, rgba(46, 204, 113, 0.1) 50%, rgba(155, 89, 182, 0.05) 100%);
    overflow: hidden;
}

/* 添加高级背景效果 */
.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='100' height='100' viewBox='0 0 100 100' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M11 18c3.866 0 7-3.134 7-7s-3.134-7-7-7-7 3.134-7 7 3.134 7 7 7zm48 25c3.866 0 7-3.134 7-7s-3.134-7-7-7-7 3.134-7 7 3.134 7 7 7zm-43-7c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zm63 31c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zM34 90c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zm56-76c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zM12 86c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm28-65c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm23-11c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm-6 60c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm29 22c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zM32 63c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm57-13c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm-9-21c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM60 91c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM35 41c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM12 60c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2z' fill='%233498db' fill-opacity='0.05' fill-rule='evenodd'/%3E%3C/svg%3E");
    opacity: 0.8;
    z-index: 0;
}

.hero .container {
    position: relative;
    z-index: 1;
}

.hero h2 {
    font-size: 2.5rem;
    margin-bottom: 15px;
    color: var(--text-color);
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

.hero p {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 30px;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.search-box {
    max-width: 600px;
    margin: 0 auto;
    overflow: hidden;
    border-radius: 20px;
    box-shadow: 0 10px 25px rgba(52, 152, 219, 0.2), 0 2px 5px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s, box-shadow 0.3s;
    backdrop-filter: blur(5px);
    background-color: rgba(255, 255, 255, 0.9);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.search-box form {
    display: flex;
    flex-direction: column;
    width: 100%;
}

.search-box .search-options {
    display: flex;
    justify-content: center;
    padding: 8px 0;
    background-color: rgba(240, 240, 240, 0.5);
    border-top: 1px solid rgba(200, 200, 200, 0.3);
}

[data-theme="dark"] .search-box .search-options {
    background-color: rgba(50, 50, 50, 0.5);
    border-top: 1px solid rgba(70, 70, 70, 0.3);
}

.search-box .search-options label {
    margin: 0 10px;
    font-size: 0.85rem;
    display: flex;
    align-items: center;
    cursor: pointer;
}

.search-box .search-options input[type="radio"] {
    margin-right: 5px;
}

/* 移动设备适配 */
@media (max-width: 768px) {
    .search-box {
        max-width: 90%;
    }
    
    .search-box .search-input-group {
        flex-direction: row;
    }
    
    .search-box input[type="text"] {
        padding: 15px 20px;
        font-size: 1rem;
    }
    
    .search-box button {
        padding: 0 20px;
        font-size: 1rem;
    }
    
    .search-box .search-options {
        padding: 6px 0;
    }
    
    .search-box .search-options label {
        font-size: 0.8rem;
        margin: 0 5px;
    }
}

[data-theme="dark"] .search-box {
    background-color: rgba(30, 30, 30, 0.9);
    border: 1px solid rgba(60, 60, 60, 0.2);
}

.search-box:hover {
    transform: translateY(-2px);
    box-shadow: 0 15px 30px rgba(52, 152, 219, 0.25), 0 5px 10px rgba(0, 0, 0, 0.1);
}

.search-box .search-input-group {
    display: flex;
    width: 100%;
}

.search-box input[type="text"] {
    flex: 1;
    padding: 18px 25px;
    border: none;
    outline: none;
    font-size: 1.05rem;
    color: var(--text-color);
    background-color: transparent;
}

.search-box button {
    padding: 0 30px;
    border: none;
    background: linear-gradient(135deg, var(--primary-color) 0%, #2980b9 100%);
    color: white;
    cursor: pointer;
    transition: all 0.3s;
    font-size: 1.1rem;
    border-top-right-radius: 20px;
}

.search-box button:hover {
    background: linear-gradient(135deg, #2980b9 0%, var(--primary-color) 100%);
    box-shadow: 0 0 10px rgba(52, 152, 219, 0.5);
}

/* 主要内容区域 */
main {
    padding: 40px 0;
}

/* 分类样式 */
.category {
    margin-bottom: 60px;
}

.category-header {
    margin-bottom: 30px;
    position: relative;
}

.category-header h3 {
    font-size: 1.8rem;
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    color: var(--text-color);
}

.category-header h3 i {
    margin-right: 10px;
    color: var(--primary-color);
}

.category-header p {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* 工具卡片样式 */
.tool-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 30px;
}

.tool-result {
    margin-top: 25px;
    min-height: 30px;
    padding: 20px;
    border-radius: 12px;
    border: 2px solid var(--border-color);
    background-color: var(--background-color);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.tool-result:empty {
    padding: 0;
    border: none;
    box-shadow: none;
}

.tool-result::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 5px;
    height: 100%;
    background: linear-gradient(to bottom, var(--primary-color), #2980b9);
}

.tool-card {
    background-color: var(--card-background);
    border-radius: 20px;
    padding: 35px;
    box-shadow: 0 15px 35px var(--shadow-color);
    transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
    border: 1px solid rgba(255, 255, 255, 0.1);
    position: relative;
    overflow: hidden;
    z-index: 1;
    margin-bottom: 20px;
}

/* 工具输入框样式 */
.tool-input {
    margin-bottom: 20px;
    display: flex;
    flex-direction: column;
}

.tool-select {
    width: 100%;
    padding: 16px 20px;
    border-radius: 12px;
    border: 2px solid var(--border-color);
    background-color: var(--background-color);
    color: var(--text-color);
    font-size: 1.1rem;
    transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    height: auto;
    min-height: 55px;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%233498db' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 20px center;
    cursor: pointer;
}

.tool-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.25);
    transform: translateY(-2px);
}

.tool-text-input {
    width: 100%;
    padding: 16px 20px;
    border-radius: 12px;
    border: 2px solid var(--border-color);
    background-color: var(--background-color);
    color: var(--text-color);
    font-size: 1.1rem;
    transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    height: auto;
    min-height: 55px;
}

.tool-text-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.25);
    transform: translateY(-2px);
}

.tool-button {
    background: linear-gradient(135deg, var(--primary-color) 0%, #2980b9 100%);
    color: white;
    border: none;
    padding: 16px 24px;
    border-radius: 12px;
    cursor: pointer;
    font-size: 1.1rem;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-block;
    text-align: center;
    box-shadow: 0 4px 10px rgba(52, 152, 219, 0.25);
    position: relative;
    overflow: hidden;
    z-index: 1;
    min-height: 55px;
}

.tool-button::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #2980b9 0%, var(--primary-color) 100%);
    opacity: 0;
    z-index: -1;
    transition: opacity 0.3s ease;
}

.tool-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 18px rgba(52, 152, 219, 0.4);
}

.tool-button:hover::before {
    opacity: 1;
}

.tool-button:active {
    transform: translateY(-1px);
    box-shadow: 0 3px 10px rgba(52, 152, 219, 0.3);
}

.tool-textarea {
    width: 100%;
    padding: 16px 20px;
    border-radius: 12px;
    border: 2px solid var(--border-color);
    background-color: var(--background-color);
    color: var(--text-color);
    font-size: 1.1rem;
    transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    min-height: 120px;
    resize: vertical;
}

.tool-textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.25);
    transform: translateY(-2px);
}

.tool-card::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: linear-gradient(90deg, var(--primary-color), #2980b9);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.4s ease;
}

.tool-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 35px var(--shadow-color);
}

.tool-card:hover::after {
    transform: scaleX(1);
}

.tool-card h4 {
    font-size: 1.3rem;
    margin-bottom: 18px;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    font-weight: 700;
    letter-spacing: 0.5px;
}

.tool-card h4 i {
    margin-right: 12px;
    font-size: 1.4rem;
    background: linear-gradient(135deg, var(--primary-color), #2980b9);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.tool-card p {
    color: var(--text-secondary);
    font-size: 1rem;
    margin-bottom: 25px;
    line-height: 1.6;
}

.tool-form {
    display: flex;
    flex-direction: column;
}

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

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 1rem;
    color: var(--text-color);
    font-weight: 600;
    letter-spacing: 0.5px;
    position: relative;
    padding-left: 12px;
}

.form-group label::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 4px;
    height: 14px;
    background: linear-gradient(to bottom, var(--primary-color), #2980b9);
    border-radius: 2px;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 16px 20px;
    border-radius: 12px;
    border: 2px solid var(--border-color);
    background-color: var(--background-color);
    color: var(--text-color);
    font-size: 1.1rem;
    transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    height: auto;
    min-height: 55px;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.25);
    transform: translateY(-1px);
}

.form-row {
    display: flex;
    gap: 15px;
}

.form-row .form-group {
    flex: 1;
}

.tool-btn {
    background: linear-gradient(135deg, var(--primary-color) 0%, #2980b9 100%);
    color: white;
    border: none;
    padding: 14px 24px;
    border-radius: 12px;
    cursor: pointer;
    font-size: 1.05rem;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-block;
    text-align: center;
    box-shadow: 0 4px 10px rgba(52, 152, 219, 0.25);
    position: relative;
    overflow: hidden;
    z-index: 1;
}

.tool-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #2980b9 0%, var(--primary-color) 100%);
    opacity: 0;
    z-index: -1;
    transition: opacity 0.3s ease;
}

.tool-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 18px rgba(52, 152, 219, 0.4);
}

.tool-btn:hover::before {
    opacity: 1;
}

.tool-btn:active {
    transform: translateY(-1px);
    box-shadow: 0 3px 10px rgba(52, 152, 219, 0.3);
}

.result-container {
    margin-top: 25px;
    padding: 20px;
    border-radius: 12px;
    background-color: var(--background-color);
    border: 2px solid var(--border-color);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.result-container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 5px;
    height: 100%;
    background: linear-gradient(to bottom, var(--primary-color), #2980b9);
}

.result-item {
    margin: 12px 0;
    padding: 8px 0;
    word-break: break-all;
    border-bottom: 1px dashed var(--border-color);
    font-size: 1.05rem;
}

.result-item:last-child {
    border-bottom: none;
    margin-bottom: 0;
}

.success {
    color: #2ecc71;
    font-weight: 600;
    margin-bottom: 15px;
    padding: 10px 15px;
    background-color: rgba(46, 204, 113, 0.1);
    border-radius: 8px;
    display: flex;
    align-items: center;
}

.success::before {
    content: '✓';
    display: inline-block;
    margin-right: 10px;
    font-size: 1.2rem;
    font-weight: bold;
}

.error {
    color: #e74c3c;
    font-weight: 600;
    margin-bottom: 15px;
    padding: 10px 15px;
    background-color: rgba(231, 76, 60, 0.1);
    border-radius: 8px;
    display: flex;
    align-items: center;
}

.error::before {
    content: '✗';
    display: inline-block;
    margin-right: 10px;
    font-size: 1.2rem;
    font-weight: bold;
}

.loading {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 15px;
    padding: 10px 15px;
    background-color: rgba(52, 152, 219, 0.1);
    border-radius: 8px;
    display: flex;
    align-items: center;
}

.loading::after {
    content: '';
    display: inline-block;
    width: 18px;
    height: 18px;
    margin-left: 12px;
    border: 3px solid var(--primary-color);
    border-radius: 50%;
    border-top-color: transparent;
    animation: spin 0.8s cubic-bezier(0.5, 0.1, 0.5, 0.9) infinite;
    box-shadow: 0 0 5px rgba(52, 152, 219, 0.3);
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

@keyframes pulse {
    0% { opacity: 0.6; transform: scale(0.98); }
    50% { opacity: 1; transform: scale(1); }
    100% { opacity: 0.6; transform: scale(0.98); }
}

/* 网站卡片网格 */
.site-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}

.site-card {
    display: flex;
    align-items: center;
    padding: 20px;
    border-radius: 10px;
    background-color: var(--card-background);
    box-shadow: 0 3px 10px var(--shadow-color);
    transition: transform 0.3s, box-shadow 0.3s;
}

.site-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px var(--shadow-color);
}

.site-icon {
    width: 50px;
    height: 50px;
    margin-right: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.site-icon img {
    max-width: 100%;
    max-height: 100%;
    border-radius: 8px;
}

.site-info h4 {
    font-size: 1.1rem;
    margin-bottom: 5px;
    color: var(--text-color);
}

.site-info p {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* 广告容器 */
.ad-container {
    margin: 30px 0;
    text-align: center;
}

.ad-banner {
    background-color: var(--card-background);
    border-radius: 10px;
    padding: 15px;
    box-shadow: 0 3px 10px var(--shadow-color);
}

/* 页脚样式 */
footer {
    background-color: var(--card-background);
    padding: 60px 0 20px;
    margin-top: 40px;
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    margin-bottom: 40px;
}

.footer-logo {
    flex: 0 0 100%;
    max-width: 300px;
    margin-bottom: 30px;
}

.footer-logo h2 {
    font-size: 1.8rem;
    margin-bottom: 10px;
    color: var(--text-color);
}

.footer-logo span {
    color: var(--primary-color);
}

.footer-logo p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    flex: 1;
    justify-content: flex-end;
}

.footer-column {
    margin-left: 60px;
    margin-bottom: 20px;
}

.footer-column h4 {
    font-size: 1.1rem;
    margin-bottom: 15px;
    color: var(--text-color);
}

.footer-column ul li {
    margin-bottom: 10px;
}

.footer-column ul li a {
    color: var(--text-secondary);
    font-size: 0.9rem;
    transition: color 0.2s;
}

.footer-column ul li a:hover {
    color: var(--primary-color);
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
}

.footer-bottom p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* 响应式设计 */
@media (max-width: 992px) {
    .hero h2 {
        font-size: 2.2rem;
    }
    
    .hero p {
        font-size: 1.1rem;
    }
    
    .site-grid {
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    }
    
    .tool-grid {
        grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    }
}

@media (max-width: 768px) {
    header {
        height: auto;
        padding: 15px 0;
    }
    
    header .container {
        flex-direction: column;
    }
    
    .logo {
        margin-bottom: 15px;
    }
    
    nav ul {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    nav ul li {
        margin: 5px 10px;
    }
    
    .theme-toggle {
        position: absolute;
        top: 20px;
        right: 20px;
    }
    
    .hero {
        padding: 120px 0 60px;
    }
    
    .hero h2 {
        font-size: 1.8rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .tool-grid {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    }
    
    .form-row {
        flex-direction: column;
        gap: 10px;
    }
    
    .footer-content {
        flex-direction: column;
    }
    
    .footer-links {
        justify-content: flex-start;
    }
    
    .footer-column {
        margin-left: 0;
        margin-right: 40px;
    }
}

@media (max-width: 576px) {
    .hero h2 {
        font-size: 1.5rem;
    }
    
    .site-grid {
        grid-template-columns: 1fr;
    }
    
    .tool-grid {
        grid-template-columns: 1fr;
    }
    
    .category-header h3 {
        font-size: 1.5rem;
    }
    
    .tool-card {
        padding: 20px;
    }
    
    .tool-btn {
        width: 100%;
    }
}