:root {
    --primary: #3b82f6;
    --bg: #f8fafc;
    --card-bg: #ffffff;
    --text: #1e293b;
    --text-light: #64748b;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg);
    color: var(--text);
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 100vh;
}

/* 头部样式 */
header {
    text-align: center;
    padding: 40px 20px 20px;
    width: 100%;
    max-width: 800px;
}

h1 { margin: 0 0 10px 0; font-size: 2rem; }

/* 搜索框容器 */
.search-box {
    position: relative;
    width: 100%;
    max-width: 500px;
    margin: 0 auto 20px;
}

/* 搜索图标样式 */
.search-icon {
    position: absolute;
    left: 18px;
    top: 50%;
    transform: translateY(-50%);
    width: 20px;
    height: 20px;
    color: #94a3b8;
    pointer-events: none;
}

/* 输入框样式 */
input {
    width: 100%;
    padding: 15px 20px 15px 50px; /* 左边距加大给图标留位 */
    border-radius: 50px;
    border: 1px solid #e2e8f0;
    font-size: 16px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    outline: none;
    transition: all 0.3s;
    box-sizing: border-box;
}

input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

/* 筛选按钮组 */
.filter-group {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 8px;
    margin-bottom: 10px;
}

.filter-btn {
    background: #fff;
    border: 1px solid #e2e8f0;
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.2s;
    color: var(--text-light);
}

.filter-btn:hover { background: #eff6ff; color: var(--primary); }

.filter-btn.active {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
    box-shadow: 0 2px 4px rgba(59, 130, 246, 0.3);
}

/* --- 核心修复：主容器与分块网格样式 --- */

/* 主容器：负责居中和宽度限制 */
#flagContainer {
    width: 90%;
    max-width: 1000px;
    padding-bottom: 50px;
    display: flex; 
    flex-direction: column;
    align-items: center; /* 让里面的板块居中 */
}

/* 每个大洲的板块 */
.region-section {
    width: 100%;
    margin-bottom: 40px;
}

/* 大洲标题 */
.region-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 15px;
    padding-left: 15px;
    border-left: 5px solid var(--primary);
    text-align: left;
}

/* ✅ 关键修复：这里的类名必须是 region-grid */
.region-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 15px;
    width: 100%;
}

/* 卡片样式 */
.card {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 20px 10px;
    text-align: center;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    border: 1px solid #e2e8f0;
    user-select: none;
    position: relative;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    border-color: var(--primary);
}

.card:active { transform: scale(0.98); }

.flag { font-size: 3rem; display: block; margin-bottom: 8px; }
.name { font-size: 0.9rem; font-weight: 600; }
.code { font-size: 0.75rem; color: var(--text-light); margin-top: 4px; }

/* 提示框 */
#toast {
    visibility: hidden;
    min-width: 250px;
    background-color: rgba(30, 41, 59, 0.9);
    color: #fff;
    text-align: center;
    border-radius: 8px;
    padding: 12px;
    position: fixed;
    z-index: 100;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 16px;
    opacity: 0;
    transition: all 0.3s;
    backdrop-filter: blur(4px);
}

#toast.show { visibility: visible; opacity: 1; bottom: 50px; }

/* 无结果提示 */
.no-result {
    text-align: center;
    color: var(--text-light);
    width: 100%;
    padding: 40px;
    display: none;
}

footer { margin-top: auto; padding: 20px; font-size: 0.8rem; color: var(--text-light); }