:root {
    --primary: #00205B;
    --accent: #FFB400;
    --bg: #f5f5f5;
    --card: #ffffff;
    --text: #212121;
    --radius: 12px;
    --shadow: 0 4px 12px rgba(0,0,0,0.08);
}

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

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

header {
    background: var(--primary);
    color: #fff;
    padding: 60px 20px;
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 15px;
    font-weight: 800;
}

header p {
    font-size: 1.2rem;
    opacity: 0.9;
    max-width: 700px;
    margin: 0 auto;
}

main {
    flex: 1;
    max-width: 1100px;
    margin: 0 auto;
    padding: 40px 20px;
    width: 100%;
}

/* 快速工具箱样式 */
.quick-box {
    background: var(--card);
    border: 2px solid var(--accent);
    border-radius: var(--radius);
    padding: 30px;
    margin-bottom: 50px;
    text-align: center;
    box-shadow: var(--shadow);
}

.quick-result {
    font-family: monospace;
    font-size: 1.8rem;
    display: block;
    margin: 15px 0;
    color: var(--primary);
    font-weight: bold;
}

/* 工具网格样式 */
.tool-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
}

.tool-card {
    background: var(--card);
    padding: 30px;
    border-radius: var(--radius);
    text-decoration: none;
    color: inherit;
    box-shadow: var(--shadow);
    transition: transform 0.3s, box-shadow 0.3s;
    display: flex;
    flex-direction: column;
    border: 1px solid rgba(0,0,0,0.05);
}

.tool-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.12);
}

.tool-card h2 {
    color: var(--primary);
    margin-bottom: 12px;
    font-size: 1.4rem;
}

.tool-card p {
    font-size: 0.95rem;
    color: #555;
    margin-bottom: 20px;
    flex: 1;
}

.btn {
    display: inline-block;
    background: var(--accent);
    color: var(--primary);
    padding: 12px 24px;
    border-radius: 8px;
    font-weight: bold;
    border: none;
    cursor: pointer;
    text-align: center;
    transition: background 0.2s;
}

.btn:hover {
    background: #e6a200;
}

footer {
    background: var(--primary);
    color: #fff;
    text-align: center;
    padding: 40px 20px;
    margin-top: 60px;
}

footer a {
    color: var(--accent);
    text-decoration: none;
    margin: 0 10px;
}

article.card {
    background: var(--card);
    padding: 40px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-top: -20px;
    margin-bottom: 40px;
}


article h2 {
    color: var(--primary);
    margin: 1.5rem 0 1rem;
    font-size: 1.5rem;
    border-left: 4px solid var(--accent);
    padding-left: 15px;
}

article h3 {
    color: var(--primary);
    margin: 1.2rem 0 0.8rem;
    font-size: 1.2rem;
}

article p {
    margin-bottom: 1.2rem;
    color: #444;
}


article ul, article ol {
    margin-bottom: 1.5rem;
    padding-left: 25px;
}

article li {
    margin-bottom: 0.8rem;
    color: #444;
}

article a {
    color: var(--primary);
    text-decoration: none;
    border-bottom: 1px solid var(--accent);
    transition: background 0.2s;
}

article a:hover {
    background: rgba(255, 180, 0, 0.1);
}

.center-box {
    text-align: center;
    padding: 60px 20px;
}

.center-box h2 {
    font-size: 4rem;
    color: var(--accent);
    margin-bottom: 10px;
}

footer a {
    color: var(--accent);
    text-decoration: none;
    font-weight: 500;
}

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

@media (max-width: 600px) {
    header h1 { font-size: 1.8rem; }
    .quick-result { font-size: 1.4rem; }

    article.card {
        padding: 25px 15px;
        margin-top: 0;
    }
    
    article h2 {
        font-size: 1.3rem;
    }
}