:root {
    --bg: #f9fafb;
    --container-bg: #ffffff;
    --text: #1f2937;
    --border: #e2e8f0;
    --card-bg: #f8fafc;
    --primary: #2563eb;
    --success: #10b981;
    --danger: #ef4444;
    --muted: #64748b;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 30px rgba(0,0,0,0.1);
}

[data-theme="dark"] {
    --bg: #0f172a;
    --container-bg: #1e293b;
    --text: #f1f5f9;
    --border: #334155;
    --card-bg: #1e293b;
    --muted: #94a3b8;
    --shadow-lg: 0 10px 30px rgba(0,0,0,0.3);
}

body {
    margin: 0;
    padding: 20px;
    background: var(--bg);
    color: var(--text);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    line-height: 1.6;
    min-height: 100vh;
    transition: background 0.3s, color 0.3s;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    background: var(--container-bg);
    border-radius: 16px;
    padding: 30px;
    box-shadow: var(--shadow-lg);
    transition: all 0.3s;
}

/* Header */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    flex-wrap: wrap;
    gap: 15px;
}

h1 {
    margin: 0;
    font-size: 1.9rem;
    color: var(--primary);
    font-weight: 700;
}

.subtitle {
    text-align: center;
    color: var(--muted);
    font-size: 1.1rem;
    margin-bottom: 30px;
}

/* Controls */
.controls {
    display: flex;
    gap: 10px;
}

button.toggle {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 8px 16px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.2s;
    color: var(--text);
    font-weight: 500;
}

button.toggle:hover {
    border-color: var(--primary);
    color: var(--primary);
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
}

/* Upload Zone */
#drop-zone {
    border: 2px dashed var(--border);
    border-radius: 16px;
    padding: 60px 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
    background: var(--card-bg);
    position: relative;
}

#drop-zone:hover, #drop-zone.dragover {
    border-color: var(--primary);
    background: rgba(37, 99, 235, 0.05);
    transform: scale(1.005);
}

.upload-icon {
    font-size: 48px;
    color: var(--muted);
    margin-bottom: 16px;
}

.hint {
    font-size: 0.9rem;
    color: var(--muted);
}

.hidden { display: none !important; }

/* Alerts */
.alert {
    padding: 16px;
    border-radius: 12px;
    margin: 20px 0;
    border: 1px solid transparent;
    font-weight: 500;
    word-break: break-all;
}

.error {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger);
    border-color: rgba(239, 68, 68, 0.2);
}

.success {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success);
    border-color: rgba(16, 185, 129, 0.2);
}

/* Results Area */
.results-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin: 40px 0 20px 0;
    flex-wrap: wrap;
    gap: 10px;
}

.results-header h2 { margin: 0; }

/* Rate Cards (Charts) */
.rate-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
    margin-bottom: 40px;
}

.rate-card {
    background: #fff;
    color: white;
    border-radius: 20px;
    padding: 24px;
    text-align: center;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1);
    position: relative;
    overflow: hidden;
    transition: transform 0.3s ease;
}

.rate-card:hover { transform: translateY(-5px); }
.rate-card.spf { background: linear-gradient(135deg, #10b981 0%, #059669 100%); box-shadow: 0 10px 25px -5px rgba(16, 185, 129, 0.4); }
.rate-card.dkim { background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%); box-shadow: 0 10px 25px -5px rgba(245, 158, 11, 0.4); }
.rate-card.dmarc { background: linear-gradient(135deg, #6366f1 0%, #4f46e5 100%); box-shadow: 0 10px 25px -5px rgba(99, 102, 241, 0.4); }

.rate-card h3 {
    margin: 0 0 15px 0;
    font-size: 1.1rem;
    opacity: 0.9;
    font-weight: 600;
}

.chart-container {
    height: 120px;
    width: 100%;
    position: relative;
    margin-bottom: 10px;
}

.rate-value {
    font-size: 3rem;
    font-weight: 800;
    line-height: 1;
    text-shadow: 0 2px 5px rgba(0,0,0,0.2);
}

/* Summary Grid */
.summary-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 16px;
    margin: 30px 0;
}

.card {
    background: var(--card-bg);
    padding: 16px;
    border-radius: 12px;
    border-left: 4px solid var(--primary);
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    word-break: break-all;
}

.card strong {
    display: block;
    margin-bottom: 4px;
    color: var(--primary);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Detail List */
.detail-list {
    background: var(--card-bg);
    padding: 20px;
    border-radius: 12px;
    font-family: 'SF Mono', 'Monaco', 'Inconsolata', monospace;
    font-size: 13px;
    max-height: 500px;
    overflow-y: auto;
    border: 1px solid var(--border);
}

.detail-list li {
    margin-bottom: 12px;
    padding: 14px;
    background: var(--container-bg);
    border-radius: 10px;
    border-left: 4px solid var(--primary);
    list-style: none;
    display: grid;
    gap: 8px 12px;
    grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
    align-items: center;
    font-size: 14px;
}

/* 手机上强制单列 + 标签独占一行 */
@media (max-width: 768px) {
    .detail-list li {
        grid-template-columns: 1fr;
        gap: 10px;
    }
    .detail-list .tag {
        align-self: flex-start;
    }
}

.detail-list .tag {
    padding: 2px 6px;
    border-radius: 4px;
    font-weight: bold;
    font-size: 11px;
}
.tag.pass { background: #dcfce7; color: #166534; }
.tag.fail { background: #fee2e2; color: #991b1b; }
.tag.none { background: #e2e8f0; color: #475569; }

/* Loading */
.loading { text-align: center; padding: 40px; }
.loading-spinner {
    border: 4px solid rgba(0,0,0,0.1);
    border-radius: 50%;
    border-top: 4px solid var(--primary);
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 0 auto 15px;
}

@keyframes spin { to { transform: rotate(360deg); } }

footer {
    text-align: center;
    margin-top: 60px;
    color: var(--muted);
    font-size: 13px;
    padding: 20px 0;
    border-top: 1px solid var(--border);
}

@media (max-width: 768px) {
    .container { padding: 15px; }
    .rate-value { font-size: 2.5rem; }
    header { flex-direction: column; align-items: flex-start; }
    .controls { width: 100%; justify-content: flex-end; }
}

/* ========== 移动端极简优化补丁（2025最新最佳实践）========== */
@media (max-width: 768px) {
    .container { padding: 16px; border-radius: 12px; }
    
    h1 { font-size: 1.6rem; }
    .subtitle { font-size: 1rem; }

    /* 上传区高度别太高 */
    #drop-zone { padding: 40px 16px; }

    /* 三个圆环卡片垂直堆叠 + 更大更易读 */
    .rate-cards {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    .rate-card {
        padding: 20px 16px;
    }
    .chart-container { height: 140px; }        /* 手机上图表更大 */
    .rate-value { font-size: 3.2rem !important; }

    /* 摘要卡片从 2 列强制改 1 列 */
    .summary-grid {
        grid-template-columns: 1fr;
    }

    /* Top IP 和 Disposition 并排太挤 → 改为垂直 */
    .summary-grid + div {
        flex-direction: column;
    }
    .summary-grid + div > div {
        min-width: 0;
    }

    /* 详细记录每行信息换行更清晰 */
    .detail-list li {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }
    .detail-list .tag {
        align-self: flex-start;
    }

    /* 让详细记录区域在手机上能舒服地滚动 */
    .detail-list {
        max-height: 60vh;
        font-size: 14px;
    }

    footer { margin-top: 40px; font-size: 12px; }
}

/* 超小屏（<400px）额外保险 */
@media (max-width: 400px) {
    .rate-value { font-size: 2.8rem !important; }
    .chart-container { height: 120px; }
}