:root {
    --bg: #f4f6f8;
    --surface: #ffffff;
    --border: #e0e4e8;
    --text: #1f2937;
    --text-muted: #6b7280;
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --danger: #dc2626;
    --success: #16a34a;
    --radius: 8px;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
}

.topnav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 12px 24px;
    flex-wrap: wrap;
    gap: 8px;
}

.topnav-brand { font-weight: 700; font-size: 1.1rem; }

.topnav-links a {
    color: var(--text-muted);
    text-decoration: none;
    margin-left: 18px;
    font-size: 0.95rem;
}
.topnav-links a:first-child { margin-left: 0; }
.topnav-links a:hover { color: var(--primary); }

.content {
    max-width: 1100px;
    margin: 0 auto;
    padding: 24px;
}

.card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
    margin-bottom: 20px;
}

h1 { font-size: 1.5rem; margin-top: 0; }
h2 { font-size: 1.15rem; margin-top: 0; }

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.92rem;
}
th, td {
    text-align: left;
    padding: 8px 10px;
    border-bottom: 1px solid var(--border);
}
code {
    overflow-wrap: break-word;
    word-break: break-word;
}
th { color: var(--text-muted); font-weight: 600; }
tr:hover td { background: #fafbfc; }
.num { text-align: right; font-variant-numeric: tabular-nums; }

form label {
    display: block;
    margin-bottom: 14px;
    font-size: 0.9rem;
    color: var(--text-muted);
    overflow-wrap: break-word;
}
form input[type=text], form input[type=password], form input[type=date],
form input[type=number], form select, form input[type=file] {
    display: block;
    width: 100%;
    max-width: 100%;
    margin-top: 4px;
    padding: 8px 10px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 1rem;
    color: var(--text);
}
form input[type=file] {
    /* Widget "Choose File" gốc trình duyệt không co nhỏ theo width như input thường - overflow:hidden
       ngăn nó đẩy rộng cả form trên màn hình hẹp (mobile). */
    overflow: hidden;
    padding: 6px;
}

button, .btn {
    background: var(--primary);
    color: #fff;
    border: none;
    padding: 9px 18px;
    border-radius: 6px;
    font-size: 0.95rem;
    cursor: pointer;
    text-decoration: none;
    display: inline-block;
}
button:hover, .btn:hover { background: var(--primary-hover); }
button.secondary, .btn.secondary { background: var(--text-muted); }
button.danger, .btn.danger { background: var(--danger); }

.msg-error {
    background: #fef2f2;
    border: 1px solid #fecaca;
    color: var(--danger);
    padding: 10px 14px;
    border-radius: 6px;
}
.msg-ok {
    background: #f0fdf4;
    border: 1px solid #bbf7d0;
    color: var(--success);
    padding: 10px 14px;
    border-radius: 6px;
}

.auth-page {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
}
.auth-box {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px;
    width: 340px;
}

.badge {
    display: inline-block;
    padding: 2px 8px;
    border-radius: 999px;
    font-size: 0.8rem;
    color: #fff;
}

.filters {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    align-items: end;
    margin-bottom: 16px;
}
.filters label { margin-bottom: 0; min-width: 140px; }

.stat-row {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
    margin-bottom: 20px;
}
.stat-tile {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px 20px;
    flex: 1;
    min-width: 160px;
}
.stat-tile .label { color: var(--text-muted); font-size: 0.85rem; }
.stat-tile .value { font-size: 1.4rem; font-weight: 700; margin-top: 4px; }

.charts-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}
@media (max-width: 800px) {
    .charts-grid { grid-template-columns: 1fr; }
}

/* Bảng giao dịch trên mobile: chuyển mỗi dòng thành 1 "card" thay vì bảng nằm ngang phải cuộn. */
@media (max-width: 700px) {
    .responsive-table thead { display: none; }
    .responsive-table, .responsive-table tbody, .responsive-table tr, .responsive-table td {
        display: block;
        width: 100%;
    }
    .responsive-table tr {
        border: 1px solid var(--border);
        border-radius: var(--radius);
        margin-bottom: 10px;
        padding: 4px 12px;
    }
    .responsive-table tr:hover td { background: none; }
    .responsive-table td {
        display: flex;
        justify-content: space-between;
        align-items: center;
        gap: 12px;
        padding: 6px 0;
        border-bottom: 1px solid var(--border);
        text-align: right;
    }
    .responsive-table td:last-child { border-bottom: none; }
    .responsive-table td::before {
        content: attr(data-label);
        font-weight: 600;
        color: var(--text-muted);
        text-align: left;
        flex-shrink: 0;
    }
    /* Ô chứa form nhiều control (select/input/nút) thay vì 1 giá trị đơn - xếp dọc, chiếm hết chiều
       rộng thay vì ép vào bố cục "nhãn: giá trị" nằm ngang. */
    .responsive-table td.form-cell {
        flex-direction: column;
        align-items: stretch;
        text-align: left;
    }
    .responsive-table td.form-cell::before {
        margin-bottom: 4px;
    }
    .responsive-table td.form-cell form {
        width: 100%;
    }
}