*{margin:0;padding:0;box-sizing:border-box}
body{font-family:'Segoe UI','PingFang SC','Microsoft YaHei',sans-serif;background:#f0f2f5;min-height:100vh;color:#333}
.container{max-width:1200px;margin:0 auto;padding:0 16px}

/* ===== 首页头部 ===== */
.site-header{text-align:center;padding:48px 20px 32px}
.site-header h1{font-size:2em;color:#1a1a2e;margin-bottom:8px;font-weight:700;letter-spacing:-.5px}
.site-header p{color:#666;font-size:1.05em}

/* ===== 工具页头部 ===== */
.tool-header{display:flex;align-items:center;justify-content:space-between;padding:20px 0;border-bottom:1px solid #e8e8e8;margin-bottom:24px;flex-wrap:wrap;gap:12px}
.tool-header h1{font-size:1.4em;color:#1a1a2e;font-weight:600;display:flex;align-items:center;gap:10px}
.tool-header h1 span{opacity:.6;font-weight:400}
.hdr-icon{width:28px;height:28px;flex-shrink:0}
.btn-back{display:inline-flex;align-items:center;gap:6px;padding:8px 16px;background:#fff;border:1px solid #d9d9d9;border-radius:6px;color:#555;text-decoration:none;font-size:.9em;transition:all .2s}
.btn-back:hover{background:#f5f5f5;border-color:#bbb;color:#333}

/* ===== 分类导航 ===== */
.category-nav{display:flex;justify-content:center;gap:6px;margin-bottom:32px;flex-wrap:wrap}
.category-btn{padding:8px 20px;border:1px solid #d9d9d9;border-radius:6px;background:#fff;color:#555;font-size:.9em;cursor:pointer;transition:all .2s}
.category-btn:hover{border-color:#4a90d9;color:#4a90d9}
.category-btn.active{background:#4a90d9;color:#fff;border-color:#4a90d9;font-weight:600}

/* ===== 工具卡片网格 ===== */
.tools-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:14px;padding-bottom:40px}
.tool-card{background:#fff;border-radius:8px;padding:22px 20px;cursor:pointer;border:1px solid #e8e8e8;transition:all .2s}
.tool-card:hover{border-color:#4a90d9;box-shadow:0 2px 12px rgba(74,144,217,.12);transform:translateY(-2px)}
.card-icon{width:40px;height:40px;margin-bottom:12px;color:#4a90d9;display:flex;align-items:center;justify-content:center;background:#eef4fb;border-radius:8px;padding:8px}
.card-icon svg{width:24px;height:24px}
.tool-card h3{font-size:1.05em;color:#1a1a2e;margin-bottom:6px;font-weight:600}
.tool-card p{color:#888;font-size:.85em;line-height:1.4}

/* ===== 工具内容区 ===== */
.tool-content{background:#fff;border-radius:8px;padding:28px;max-width:780px;margin:0 auto 32px;border:1px solid #e8e8e8}
.input-group{margin-bottom:18px}
.input-group label{display:block;margin-bottom:6px;font-weight:600;color:#444;font-size:.9em}
.input-group textarea,.input-group input,.input-group select{width:100%;padding:10px 12px;border:1px solid #d9d9d9;border-radius:6px;font-size:.95em;resize:vertical;transition:border-color .2s;font-family:'Consolas','Cascadia Code',monospace}
.input-group textarea:focus,.input-group input:focus,.input-group select:focus{outline:none;border-color:#4a90d9;box-shadow:0 0 0 2px rgba(74,144,217,.15)}
.input-group input[type=file]{padding:8px;font-family:inherit}
.button-group{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:18px}
.button-group button{padding:9px 20px;border:1px solid #d9d9d9;border-radius:6px;background:#fff;color:#444;font-size:.9em;cursor:pointer;transition:all .2s}
.button-group button:hover{background:#f5f5f5;border-color:#bbb}
.button-group button:first-child{background:#4a90d9;border-color:#4a90d9;color:#fff}
.button-group button:first-child:hover{background:#357abd}
.output-group{margin-top:18px;padding-top:18px;border-top:1px solid #f0f0f0}
.output-group label{display:block;margin-bottom:6px;font-weight:600;color:#444;font-size:.9em}
.output-group textarea{width:100%;padding:10px 12px;border:1px solid #e8e8e8;border-radius:6px;font-size:.95em;background:#fafafa;resize:vertical;font-family:'Consolas','Cascadia Code',monospace;color:#333}
.output-group button{margin-top:8px;padding:7px 16px;border:1px solid #d9d9d9;border-radius:6px;background:#fff;color:#555;font-size:.85em;cursor:pointer;transition:all .2s}
.output-group button:hover{background:#f5f5f5}

/* ===== 彩票球样式 ===== */
.ball{display:inline-block;width:36px;height:36px;line-height:36px;text-align:center;border-radius:50%;color:#fff;font-size:.95em;margin:0 2px;font-weight:700}
.ball-front,.ball-red{background:linear-gradient(135deg,#e74c3c,#c0392b)}
.ball-back,.ball-blue{background:linear-gradient(135deg,#3498db,#2980b9)}

/* ===== 响应式 ===== */
@media(max-width:768px){
  .site-header{padding:32px 16px 24px}
  .site-header h1{font-size:1.5em}
  .tools-grid{grid-template-columns:1fr}
  .tool-content{padding:20px}
  .tool-header{flex-direction:column;align-items:flex-start}
}