:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #1e293b;
    --border-color: #e2e8f0;
}

* { box-sizing: border-box; font-family: 'Malgun Gothic', sans-serif; }

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    margin: 0; padding: 20px;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
}

header { text-align: center; margin-bottom: 30px; }
header h1 { color: var(--primary-color); }

.upload-section {
    display: flex; gap: 20px; margin-bottom: 20px;
}

.card {
    flex: 1;
    background: var(--card-bg);
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    border: 1px solid var(--border-color);
}

.action-section { text-align: center; margin-bottom: 30px; }

button {
    cursor: pointer; border: none; border-radius: 6px;
    padding: 12px 24px; font-size: 16px; font-weight: bold;
    transition: background 0.2s;
}

.btn-primary { background: var(--primary-color); color: white; }
.btn-primary:hover { background: var(--primary-hover); }
.btn-secondary { background: #10b981; color: white; margin-top: 20px;}

.status-message { margin-top: 10px; font-weight: bold; color: #64748b; }

.hidden { display: none !important; }

/* Tabs */
.tabs { display: flex; gap: 10px; margin-bottom: 10px; border-bottom: 2px solid var(--border-color); }
.tab-btn {
    background: transparent; color: var(--text-main);
    border-radius: 6px 6px 0 0; padding: 10px 20px;
    opacity: 0.6;
}
.tab-btn.active { opacity: 1; border-bottom: 3px solid var(--primary-color); font-weight: bold; }

.tab-content { display: none; background: var(--card-bg); padding: 20px; border: 1px solid var(--border-color); }
.tab-content.active { display: block; }

/* Tables */
.table-wrapper { overflow-x: auto; max-height: 400px; overflow-y: auto; }
table { width: 100%; border-collapse: collapse; font-size: 14px; }
th, td { border: 1px solid var(--border-color); padding: 8px; text-align: left; }
th { background: #f1f5f9; position: sticky; top: 0; }