body {
    margin: 0;
    background: #f4f6fb;
    font-family: Arial, sans-serif;
    color: #1f2937;
}

.app-wrapper {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: 250px;
    background: linear-gradient(180deg, #1f2937, #111827);
    color: white;
    padding: 24px 18px;
    box-shadow: 4px 0 20px rgba(0,0,0,0.08);
}

.brand {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 30px;
}

.sidebar .nav-link {
    color: #d1d5db;
    padding: 12px 14px;
    border-radius: 12px;
    margin-bottom: 8px;
    transition: 0.2s;
}

.sidebar .nav-link:hover {
    background: rgba(255,255,255,0.08);
    color: #fff;
}

.main-content {
    flex: 1;
    padding: 28px;
}

.topbar {
    margin-bottom: 24px;
}

.card-modern {
    border: 0;
    border-radius: 20px;
    background: #fff;
    box-shadow: 0 10px 30px rgba(15, 23, 42, 0.08);
}

.stat-box {
    padding: 24px;
    border-radius: 20px;
    background: white;
    box-shadow: 0 10px 30px rgba(15, 23, 42, 0.08);
}

.stat-title {
    font-size: 14px;
    color: #6b7280;
}

.stat-number {
    font-size: 34px;
    font-weight: 700;
    margin-top: 8px;
}

.btn-main {
    background: #111827;
    color: white;
    border-radius: 12px;
    padding: 10px 18px;
    border: 0;
}

.btn-main:hover {
    background: #000;
    color: white;
}

.table thead th {
    background: #f9fafb;
}

.preview-box {
    background: #fff;
    border-radius: 20px;
    min-height: 500px;
    box-shadow: inset 0 0 0 1px #e5e7eb;
    overflow: hidden;
}

.preview-frame {
    width: 100%;
    min-height: 500px;
    border: 0;
    background: white;
}

.form-control, .form-select, .btn {
    border-radius: 12px !important;
}