/* ============================================================
   OmniSIS Design System — sis.css
   Include once in _Layout.cshtml via:
     <link rel="stylesheet" href="~/css/sis.css" asp-append-version="true" />
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=DM+Sans:opsz,wght@9..40,400;9..40,500;9..40,600;9..40,700&family=JetBrains+Mono:wght@400;500&display=swap');

/* ── Tokens ──────────────────────────────────────────────── */
:root {
    --s-bg: #f5f6fa;
    --s-surface: #ffffff;
    --s-border: #e2e5ee;
    --s-border-focus: #a5b4fc;
    --s-text: #1a1d2e;
    --s-muted: #6b7280;
    --s-muted-lt: #9ca3af;
    --s-accent: #4f46e5;
    --s-accent-hover: #4338ca;
    --s-accent-lt: #eef2ff;
    --s-accent-ring: rgba(79,70,229,.12);
    --s-success: #059669;
    --s-success-lt: #ecfdf5;
    --s-success-bd: #86efac;
    --s-warning: #d97706;
    --s-warning-lt: #fffbeb;
    --s-warning-bd: #fcd34d;
    --s-danger: #dc2626;
    --s-danger-lt: #fef2f2;
    --s-danger-bd: #fca5a5;
    --s-purple-lt: #ede9fe;
    --s-purple: #5b21b6;
    --s-radius: 10px;
    --s-radius-sm: 6px;
    --s-radius-lg: 14px;
    --s-radius-full: 999px;
    --s-shadow: 0 1px 3px rgba(0,0,0,.06), 0 4px 16px rgba(0,0,0,.04);
    --s-shadow-md: 0 4px 20px rgba(79,70,229,.12);
    --s-shadow-lg: 0 20px 60px rgba(0,0,0,.18);
    --s-font: 'DM Sans', system-ui, sans-serif;
    --s-mono: 'JetBrains Mono', monospace;
    --s-transition: .15s ease;
}

/* ── Base reset for sis-page scope ───────────────────────── */
.sis-page {
    font-family: var(--s-font);
    color: var(--s-text);
    font-size: .875rem;
    line-height: 1.5;
}

/* ── Page Header ─────────────────────────────────────────── */
.sis-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 20px;
}

.sis-header__left {
    display: flex;
    align-items: center;
    gap: 14px;
}

.sis-header__icon {
    width: 44px;
    height: 44px;
    background: var(--s-accent);
    border-radius: var(--s-radius-sm);
    display: grid;
    place-items: center;
    color: #fff;
    font-size: 20px;
    box-shadow: var(--s-shadow-md);
    flex-shrink: 0;
}

.sis-header__title {
    font-size: 1.35rem;
    font-weight: 700;
    margin: 0;
    line-height: 1.2;
}

.sis-header__sub {
    font-size: .78rem;
    color: var(--s-muted);
    margin: 2px 0 0;
}

.sis-header__actions {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    align-items: center;
}

/* ── Buttons ─────────────────────────────────────────────── */
.sis-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 7px 14px;
    border-radius: var(--s-radius-sm);
    font-size: .82rem;
    font-weight: 600;
    font-family: var(--s-font);
    border: 1.5px solid transparent;
    cursor: pointer;
    transition: all var(--s-transition);
    white-space: nowrap;
    text-decoration: none;
    line-height: 1;
    user-select: none;
}

.sis-btn--sm {
    padding: 5px 10px;
    font-size: .76rem;
}

.sis-btn--lg {
    padding: 10px 20px;
    font-size: .9rem;
}

.sis-btn--primary {
    background: var(--s-accent);
    color: #fff;
    border-color: var(--s-accent);
}

    .sis-btn--primary:hover {
        background: var(--s-accent-hover);
        border-color: var(--s-accent-hover);
        color: #fff;
        transform: translateY(-1px);
        box-shadow: var(--s-shadow-md);
    }

.sis-btn--ghost {
    background: transparent;
    color: var(--s-text);
    border-color: var(--s-border);
}

    .sis-btn--ghost:hover {
        background: var(--s-accent-lt);
        border-color: var(--s-accent);
        color: var(--s-accent);
    }

.sis-btn--success {
    background: var(--s-success-lt);
    color: var(--s-success);
    border-color: var(--s-success-bd);
}

    .sis-btn--success:hover {
        background: var(--s-success);
        color: #fff;
        border-color: var(--s-success);
    }

.sis-btn--danger {
    background: var(--s-danger-lt);
    color: var(--s-danger);
    border-color: var(--s-danger-bd);
}

    .sis-btn--danger:hover {
        background: var(--s-danger);
        color: #fff;
        border-color: var(--s-danger);
    }

.sis-btn--warning {
    background: var(--s-warning-lt);
    color: var(--s-warning);
    border-color: var(--s-warning-bd);
}

    .sis-btn--warning:hover {
        background: var(--s-warning);
        color: #fff;
        border-color: var(--s-warning);
    }

.sis-btn:disabled,
.sis-btn[disabled] {
    opacity: .45;
    pointer-events: none;
}

/* ── Dropdown ────────────────────────────────────────────── */
.sis-dropdown {
    position: relative;
    display: inline-block;
}

.sis-dropdown__menu {
    display: none;
    position: absolute;
    right: 0;
    top: calc(100% + 6px);
    background: var(--s-surface);
    border: 1px solid var(--s-border);
    border-radius: var(--s-radius-sm);
    box-shadow: var(--s-shadow);
    min-width: 160px;
    z-index: 200;
    overflow: hidden;
}

    .sis-dropdown__menu.is-open {
        display: block;
    }

.sis-dropdown__item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 9px 14px;
    font-size: .82rem;
    text-decoration: none;
    color: var(--s-text);
    transition: background var(--s-transition);
    cursor: pointer;
    border: none;
    background: none;
    width: 100%;
    font-family: var(--s-font);
    font-weight: 500;
}

    .sis-dropdown__item + .sis-dropdown__item {
        border-top: 1px solid var(--s-border);
    }

    .sis-dropdown__item:hover {
        background: var(--s-bg);
    }

/* ── Controls bar (search + filters) ────────────────────── */
.sis-controls {
    background: var(--s-surface);
    border: 1px solid var(--s-border);
    border-radius: var(--s-radius);
    padding: 14px 16px;
    margin-bottom: 16px;
    box-shadow: var(--s-shadow);
}

.sis-controls__row {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    align-items: flex-end;
}

.sis-controls__search {
    position: relative;
    flex: 1 1 260px;
    min-width: 200px;
}

    .sis-controls__search .sis-icon {
        position: absolute;
        left: 11px;
        top: 50%;
        transform: translateY(-50%);
        color: var(--s-muted);
        font-size: .9rem;
        pointer-events: none;
    }

/* shared input/select base */
.sis-input,
.sis-search-input,
.sis-filter-select,
.sis-textarea {
    font-family: var(--s-font);
    font-size: .85rem;
    color: var(--s-text);
    border: 1.5px solid var(--s-border);
    border-radius: var(--s-radius-sm);
    background: var(--s-bg);
    transition: border-color var(--s-transition), box-shadow var(--s-transition), background var(--s-transition);
}

    .sis-input:focus,
    .sis-search-input:focus,
    .sis-filter-select:focus,
    .sis-textarea:focus {
        outline: none;
        border-color: var(--s-accent);
        box-shadow: 0 0 0 3px var(--s-accent-ring);
        background: #fff;
    }

.sis-search-input {
    width: 100%;
    padding: 8px 12px 8px 34px;
}

.sis-input {
    padding: 8px 12px;
    width: 100%;
}

.sis-textarea {
    padding: 9px 12px;
    width: 100%;
    resize: vertical;
    min-height: 80px;
}

.sis-filter-select {
    padding: 8px 28px 8px 10px;
    appearance: none;
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3e%3cpath fill='none' stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M2 5l6 6 6-6'/%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 8px center;
    background-size: 12px;
    cursor: pointer;
    min-width: 140px;
}

    .sis-filter-select.is-active {
        border-color: var(--s-accent);
        background-color: var(--s-accent-lt);
        color: var(--s-accent);
        font-weight: 600;
    }

/* Form layout helpers */
.sis-form-group {
    margin-bottom: 16px;
}

.sis-form-label {
    display: block;
    font-size: .8rem;
    font-weight: 600;
    color: var(--s-text);
    margin-bottom: 5px;
}

.sis-form-hint {
    font-size: .75rem;
    color: var(--s-muted);
    margin-top: 4px;
}

.sis-form-error {
    font-size: .75rem;
    color: var(--s-danger);
    margin-top: 4px;
}

.sis-input.is-invalid,
.sis-filter-select.is-invalid {
    border-color: var(--s-danger);
}

/* ── Active-filter chips ─────────────────────────────────── */
.sis-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-top: 10px;
}

.sis-chip {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    background: var(--s-accent-lt);
    color: var(--s-accent);
    border: 1px solid #c7d2fe;
    border-radius: var(--s-radius-full);
    padding: 3px 10px;
    font-size: .75rem;
    font-weight: 600;
}

    .sis-chip button {
        background: none;
        border: none;
        cursor: pointer;
        padding: 0;
        color: var(--s-accent);
        font-size: .8rem;
        line-height: 1;
        margin-left: 2px;
        opacity: .7;
        transition: opacity var(--s-transition);
    }

        .sis-chip button:hover {
            opacity: 1;
        }

/* ── Prereq warning bar ──────────────────────────────────── */
.sis-prereq {
    display: flex;
    align-items: center;
    gap: 12px;
    background: var(--s-warning-lt);
    border: 1.5px solid var(--s-warning-bd);
    border-radius: var(--s-radius);
    padding: 12px 16px;
    font-size: .84rem;
    color: #92400e;
    margin-bottom: 16px;
}

/* ── Bulk-action bar ─────────────────────────────────────── */
.sis-bulk {
    display: none;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
    background: var(--s-accent-lt);
    border: 1.5px solid #c7d2fe;
    border-radius: var(--s-radius);
    padding: 10px 14px;
    margin-bottom: 14px;
}

    .sis-bulk.is-visible {
        display: flex;
    }

.sis-bulk__count {
    font-size: .83rem;
    font-weight: 700;
    color: var(--s-accent);
}

.sis-bulk__sep {
    color: #c7d2fe;
}

.sis-bulk__status-select {
    padding: 6px 28px 6px 10px;
    appearance: none;
    border: 1.5px solid #c7d2fe;
    border-radius: var(--s-radius-sm);
    font-size: .8rem;
    font-family: var(--s-font);
    background: #fff url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3e%3cpath fill='none' stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M2 5l6 6 6-6'/%3e%3c/svg%3e") right 8px center / 12px no-repeat;
    cursor: pointer;
    min-width: 130px;
}

/* ── Card ────────────────────────────────────────────────── */
.sis-card {
    background: var(--s-surface);
    border: 1px solid var(--s-border);
    border-radius: var(--s-radius);
    box-shadow: var(--s-shadow);
    overflow: hidden;
}

.sis-card__header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 18px;
    border-bottom: 1px solid var(--s-border);
    font-weight: 600;
}

.sis-card__body {
    padding: 18px;
}

.sis-card__footer {
    padding: 12px 18px;
    border-top: 1px solid var(--s-border);
    background: #f8f9fc;
    font-size: .8rem;
    color: var(--s-muted);
}

/* Stat widget card */
.sis-stat {
    background: var(--s-surface);
    border: 1px solid var(--s-border);
    border-radius: var(--s-radius);
    box-shadow: var(--s-shadow);
    padding: 18px 20px;
    display: flex;
    align-items: center;
    gap: 14px;
}

.sis-stat__icon {
    width: 42px;
    height: 42px;
    border-radius: var(--s-radius-sm);
    display: grid;
    place-items: center;
    font-size: 18px;
    flex-shrink: 0;
}

.sis-stat__icon--accent {
    background: var(--s-accent-lt);
    color: var(--s-accent);
}

.sis-stat__icon--success {
    background: var(--s-success-lt);
    color: var(--s-success);
}

.sis-stat__icon--warning {
    background: var(--s-warning-lt);
    color: var(--s-warning);
}

.sis-stat__icon--danger {
    background: var(--s-danger-lt);
    color: var(--s-danger);
}

.sis-stat__value {
    font-size: 1.5rem;
    font-weight: 700;
    line-height: 1;
}

.sis-stat__label {
    font-size: .78rem;
    color: var(--s-muted);
    margin-top: 3px;
}

/* ── Table ───────────────────────────────────────────────── */
.sis-table {
    width: 100%;
    border-collapse: collapse;
    font-size: .84rem;
}

    .sis-table thead tr {
        background: #f8f9fc;
        border-bottom: 2px solid var(--s-border);
    }

    .sis-table th {
        padding: 10px 14px;
        text-align: left;
        font-size: .72rem;
        font-weight: 700;
        letter-spacing: .05em;
        text-transform: uppercase;
        color: var(--s-muted);
        white-space: nowrap;
    }

    .sis-table tbody tr {
        border-bottom: 1px solid var(--s-border);
        transition: background var(--s-transition);
    }

        .sis-table tbody tr:last-child {
            border-bottom: none;
        }

        .sis-table tbody tr:hover {
            background: #f9fafb;
        }

        .sis-table tbody tr.is-selected {
            background: var(--s-accent-lt);
        }

    .sis-table td {
        padding: 10px 14px;
        vertical-align: middle;
    }

/* Table loading state */
.sis-table-wrap {
    position: relative;
}

    .sis-table-wrap.is-loading::after {
        content: '';
        position: absolute;
        inset: 0;
        background: rgba(255,255,255,.6);
        backdrop-filter: blur(1px);
        border-radius: 0 0 var(--s-radius) var(--s-radius);
        z-index: 10;
    }

/* ── Student cell ────────────────────────────────────────── */
.sis-student {
    display: flex;
    align-items: center;
    gap: 10px;
}

.sis-avatar {
    width: 34px;
    height: 34px;
    flex-shrink: 0;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--s-border);
    background: #e5e7eb;
}

.sis-student__name {
    font-weight: 600;
}

.sis-student__id {
    font-size: .73rem;
    color: var(--s-muted);
    font-family: var(--s-mono);
}

/* ── Badges ──────────────────────────────────────────────── */
.sis-badge {
    display: inline-flex;
    align-items: center;
    padding: 2px 8px;
    border-radius: var(--s-radius-full);
    font-size: .72rem;
    font-weight: 600;
    white-space: nowrap;
    gap: 4px;
}

.sis-badge--grade {
    background: var(--s-purple-lt);
    color: var(--s-purple);
}

.sis-badge--active {
    background: #d1fae5;
    color: #065f46;
}

.sis-badge--inactive {
    background: #f3f4f6;
    color: #4b5563;
}

.sis-badge--warn {
    background: #fef3c7;
    color: #92400e;
}

.sis-badge--danger {
    background: #fee2e2;
    color: #991b1b;
}

.sis-badge--default {
    background: #f3f4f6;
    color: #6b7280;
}

.sis-badge--accent {
    background: var(--s-accent-lt);
    color: var(--s-accent);
}

.sis-badge--success {
    background: var(--s-success-lt);
    color: var(--s-success);
}

/* ── Row action buttons ──────────────────────────────────── */
.sis-actions {
    display: flex;
    gap: 4px;
    justify-content: flex-end;
}

.sis-action-btn {
    padding: 4px 9px;
    border-radius: var(--s-radius-sm);
    font-size: .75rem;
    font-weight: 600;
    border: 1px solid var(--s-border);
    background: var(--s-surface);
    color: var(--s-muted);
    text-decoration: none;
    cursor: pointer;
    transition: all .12s;
    white-space: nowrap;
    font-family: var(--s-font);
    line-height: 1.4;
}

    .sis-action-btn:hover {
        border-color: var(--s-accent);
        color: var(--s-accent);
        background: var(--s-accent-lt);
    }

    .sis-action-btn.edit:hover {
        border-color: #f59e0b;
        color: #b45309;
        background: #fffbeb;
    }

    .sis-action-btn.guardians:hover {
        border-color: #8b5cf6;
        color: #6d28d9;
        background: #f5f3ff;
    }

    .sis-action-btn.delete:hover {
        border-color: var(--s-danger);
        color: var(--s-danger);
        background: var(--s-danger-lt);
    }

    .sis-action-btn.success:hover {
        border-color: var(--s-success);
        color: var(--s-success);
        background: var(--s-success-lt);
    }

/* ── Empty state ─────────────────────────────────────────── */
.sis-empty {
    text-align: center;
    padding: 60px 20px;
    color: var(--s-muted);
}

.sis-empty__icon {
    font-size: 2.5rem;
    margin-bottom: 12px;
    opacity: .4;
}

.sis-empty__title {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--s-text);
}

.sis-empty__text {
    font-size: .84rem;
}

/* ── Table footer / pagination ───────────────────────────── */
.sis-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
    padding: 12px 16px;
    border-top: 1px solid var(--s-border);
    font-size: .8rem;
    color: var(--s-muted);
    background: #f8f9fc;
}

.sis-pager {
    display: flex;
    gap: 4px;
    align-items: center;
}

.sis-page-btn {
    min-width: 32px;
    height: 32px;
    padding: 0 8px;
    display: grid;
    place-items: center;
    border-radius: var(--s-radius-sm);
    border: 1.5px solid var(--s-border);
    background: var(--s-surface);
    color: var(--s-text);
    font-size: .8rem;
    font-weight: 600;
    text-decoration: none;
    transition: all .12s;
    cursor: pointer;
}

    .sis-page-btn:hover {
        border-color: var(--s-accent);
        color: var(--s-accent);
        background: var(--s-accent-lt);
    }

    .sis-page-btn.is-active {
        background: var(--s-accent);
        border-color: var(--s-accent);
        color: #fff;
    }

    .sis-page-btn.is-disabled {
        opacity: .4;
        pointer-events: none;
    }

/* ── Modal / Overlay ─────────────────────────────────────── */
.sis-overlay {
    position: fixed;
    inset: 0;
    background: rgba(10,12,26,.5);
    display: none;
    place-items: center;
    z-index: 1000;
    backdrop-filter: blur(2px);
}

    .sis-overlay.is-open {
        display: grid;
    }

.sis-modal {
    background: var(--s-surface);
    border-radius: var(--s-radius-lg);
    box-shadow: var(--s-shadow-lg);
    width: 100%;
    max-width: 520px;
    margin: 20px;
    overflow: hidden;
    animation: sisModalIn .18s ease;
}

.sis-modal--lg {
    max-width: 720px;
}

.sis-modal--sm {
    max-width: 380px;
}

@keyframes sisModalIn {
    from {
        opacity: 0;
        transform: translateY(12px) scale(.97);
    }

    to {
        opacity: 1;
        transform: none;
    }
}

.sis-modal__header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 18px 22px;
    border-bottom: 1px solid var(--s-border);
}

.sis-modal__title {
    font-weight: 700;
    font-size: 1rem;
}

.sis-modal__close {
    background: none;
    border: none;
    font-size: 1.2rem;
    cursor: pointer;
    color: var(--s-muted);
    transition: color var(--s-transition);
    padding: 2px 6px;
    border-radius: 4px;
}

    .sis-modal__close:hover {
        color: var(--s-text);
        background: var(--s-bg);
    }

.sis-modal__body {
    padding: 22px;
}

.sis-modal__footer {
    padding: 14px 22px;
    border-top: 1px solid var(--s-border);
    display: flex;
    gap: 10px;
    justify-content: flex-end;
}

/* ── File dropzone ───────────────────────────────────────── */
.sis-dropzone {
    border: 2px dashed #c7d2fe;
    border-radius: var(--s-radius);
    background: var(--s-accent-lt);
    padding: 36px 20px;
    text-align: center;
    cursor: pointer;
    transition: all var(--s-transition);
    position: relative;
}

    .sis-dropzone:hover,
    .sis-dropzone.is-over {
        border-color: var(--s-accent);
        background: #e0e7ff;
    }

    .sis-dropzone i {
        font-size: 2rem;
        color: var(--s-accent);
        margin-bottom: 10px;
        display: block;
    }

.sis-dropzone__label {
    font-size: .85rem;
    font-weight: 600;
    color: var(--s-accent);
}

.sis-dropzone__sub {
    font-size: .76rem;
    color: var(--s-muted);
    margin-top: 4px;
}

.sis-dropzone input {
    position: absolute;
    inset: 0;
    opacity: 0;
    cursor: pointer;
}

.sis-file-chosen {
    display: none;
    align-items: center;
    gap: 10px;
    background: #f0fdf4;
    border: 1.5px solid var(--s-success-bd);
    border-radius: var(--s-radius-sm);
    padding: 10px 14px;
    margin-top: 12px;
    font-size: .83rem;
}

    .sis-file-chosen.is-visible {
        display: flex;
    }

/* ── Toast notifications ─────────────────────────────────── */
.sis-toast {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 2000;
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 18px;
    border-radius: var(--s-radius);
    font-size: .85rem;
    font-weight: 600;
    font-family: var(--s-font);
    box-shadow: 0 4px 20px rgba(0,0,0,.12);
    max-width: 380px;
    animation: sisToastIn .25s ease;
    transition: opacity .4s ease;
}

@keyframes sisToastIn {
    from {
        opacity: 0;
        transform: translateX(20px);
    }

    to {
        opacity: 1;
        transform: none;
    }
}

.sis-toast--success {
    background: var(--s-success-lt);
    color: #065f46;
    border: 1.5px solid var(--s-success-bd);
}

.sis-toast--error {
    background: var(--s-danger-lt);
    color: #991b1b;
    border: 1.5px solid var(--s-danger-bd);
}

.sis-toast--warning {
    background: var(--s-warning-lt);
    color: #92400e;
    border: 1.5px solid var(--s-warning-bd);
}

.sis-toast--info {
    background: var(--s-accent-lt);
    color: var(--s-accent);
    border: 1.5px solid #c7d2fe;
}

.sis-toast__close {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.1rem;
    margin-left: auto;
    opacity: .6;
    transition: opacity var(--s-transition);
}

    .sis-toast__close:hover {
        opacity: 1;
    }

/* ── Section divider ─────────────────────────────────────── */
.sis-divider {
    border: none;
    border-top: 1px solid var(--s-border);
    margin: 20px 0;
}

/* ── Spinner ─────────────────────────────────────────────── */
.sis-spinner {
    width: 18px;
    height: 18px;
    border: 2.5px solid var(--s-border);
    border-top-color: var(--s-accent);
    border-radius: 50%;
    animation: sisSpin .65s linear infinite;
    display: inline-block;
    flex-shrink: 0;
}

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

/* ── Search highlight ────────────────────────────────────── */
.sis-highlight {
    background: #fef9c3;
    border-radius: 2px;
    padding: 0 1px;
}

/* ── Responsive: hide low-priority columns on mobile ─────── */
@media (max-width: 640px) {
    .sis-col-hide-sm {
        display: none;
    }

    .sis-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .sis-header__actions {
        width: 100%;
    }
}

@media (max-width: 900px) {
    .sis-col-hide-md {
        display: none;
    }
}

/* ── Page header (rendered by _BreadCrumb) ───────────────────── */
.sis-page-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
    padding: 14px 0 16px;
    margin-bottom: 4px;
}

.sis-page-header__left {
    display: flex;
    align-items: center;
    gap: 14px;
}

.sis-page-header__actions {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    align-items: center;
}

/* ── Breadcrumb ──────────────────────────────────────────────── */
.sis-breadcrumb {
    display: flex;
    align-items: center;
    list-style: none;
    padding: 0;
    margin: 0;
    font-size: .75rem;
    color: var(--s-muted);
}

.sis-breadcrumb__item + .sis-breadcrumb__item::before {
    content: "›";
    padding: 0 6px;
    color: var(--s-muted-lt);
}

.sis-breadcrumb__item a {
    text-decoration: none;
    color: var(--s-muted);
    transition: color var(--s-transition);
}

    .sis-breadcrumb__item a:hover {
        color: var(--s-accent);
    }

.sis-breadcrumb__item--active {
    color: var(--s-text);
    font-weight: 500;
}

.sis-breadcrumb-bar {
    margin-bottom: 16px;
    margin-top: -10px;
}

/* ── Tabs ─────────────────────────────────────────────────── */
.sis-tab-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 10px 16px;
    font-size: .83rem;
    font-weight: 600;
    font-family: var(--s-font);
    color: var(--s-muted);
    background: none;
    border: none;
    border-bottom: 2px solid transparent;
    cursor: pointer;
    transition: color var(--s-transition), border-color var(--s-transition);
    white-space: nowrap;
    margin-bottom: -2px;
}

    .sis-tab-btn:hover {
        color: var(--s-text);
    }

    .sis-tab-btn.is-active {
        color: var(--s-accent);
        border-bottom-color: var(--s-accent);
    }

/* ── Dashboard row links ─────────────────────────────────── */
.sis-dash-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 11px 18px;
    font-size: .84rem;
    color: var(--s-text);
    text-decoration: none;
    border-bottom: 1px solid var(--s-border);
    transition: background var(--s-transition);
    font-family: var(--s-font);
}

    .sis-dash-row:hover {
        background: var(--s-bg);
        color: var(--s-text);
    }

/* ── Error page ──────────────────────────────────────────── */
.sis-error-page {
    min-height: 80vh;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--s-font);
}

.sis-error-card {
    background: var(--s-surface);
    border: 1px solid var(--s-border);
    border-radius: var(--s-radius-lg);
    box-shadow: var(--s-shadow);
    padding: 48px 52px;
    text-align: center;
    max-width: 480px;
    width: 100%;
    position: relative;
    overflow: hidden;
}

.sis-error-code {
    font-size: 7rem;
    font-weight: 900;
    line-height: 1;
    color: var(--s-accent);
    opacity: .08;
    position: absolute;
    top: 12px;
    left: 50%;
    transform: translateX(-50%);
    letter-spacing: -.02em;
    pointer-events: none;
    user-select: none;
}

.sis-error-icon {
    width: 56px;
    height: 56px;
    background: var(--s-accent-lt);
    border-radius: var(--s-radius);
    display: grid;
    place-items: center;
    font-size: 24px;
    color: var(--s-accent);
    margin: 0 auto 20px;
    position: relative;
}

.sis-error-title {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--s-text);
    margin: 0 0 8px;
}

.sis-error-sub {
    font-size: .85rem;
    color: var(--s-muted);
    margin: 0 0 28px;
    line-height: 1.6;
}

.sis-error-actions {
    display: flex;
    gap: 8px;
    justify-content: center;
    flex-wrap: wrap;
}

.sis-error-trace {
    margin-top: 28px;
    font-size: .72rem;
    color: var(--s-muted-lt);
}

    .sis-error-trace code {
        font-family: var(--s-mono);
        font-size: .72rem;
    }