/* ==========================================================================
   Notebook Interface — Google Colab-style
   Prefix: nb-   |   Design tokens: var(--tc-*)
   ========================================================================== */

/* 1. Full-bleed page override
   ========================================================================== */
.nb-fullbleed {
    padding: 0 !important;
    overflow: hidden;
    flex: 1;
    min-height: 0;
    display: flex;
    flex-direction: column;
    width: 100%;
}

/* 2. Page grid: sidebar + main
   ========================================================================== */
.nb-page {
    display: grid;
    grid-template-columns: 250px 1fr;
    flex: 1;
    min-height: 0;
    height: 100%;
    background: var(--tc-bg-base);
    font-family: var(--tc-font-sans);
    color: var(--tc-text-primary);
}

/* 3. Sidebar — glass panel
   ========================================================================== */
.nb-sidebar {
    display: flex;
    flex-direction: column;
    background: var(--tc-glass-bg-sidebar);
    backdrop-filter: blur(var(--tc-glass-blur));
    -webkit-backdrop-filter: blur(var(--tc-glass-blur));
    border-right: var(--tc-glass-border);
    overflow: hidden;
}

.nb-sidebar-header {
    padding: 16px;
    border-bottom: var(--tc-glass-border);
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.nb-sidebar-title {
    font-size: var(--tc-font-size-sm);
    font-weight: var(--tc-font-weight-semi);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--tc-text-secondary);
}

.nb-create-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    width: 100%;
    padding: 8px 12px;
    border: none;
    border-radius: var(--tc-radius-sm);
    background: var(--tc-primary);
    color: #fff;
    font-size: var(--tc-font-size-sm);
    font-weight: var(--tc-font-weight-medium);
    cursor: pointer;
    transition: background 0.15s;
}

.nb-create-btn:hover {
    background: var(--tc-primary-hover);
}

.nb-sidebar-open-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    width: 100%;
    padding: 8px 12px;
    border: 1px solid var(--tc-primary);
    border-radius: var(--tc-radius-sm);
    background: transparent;
    color: var(--tc-primary);
    font-size: var(--tc-font-size-sm);
    font-weight: var(--tc-font-weight-medium);
    cursor: pointer;
    transition: background 0.15s, color 0.15s;
}

.nb-sidebar-open-btn:hover {
    background: var(--tc-primary);
    color: #fff;
}

.nb-search {
    width: 100%;
    padding: 8px 12px;
    border: var(--tc-glass-border);
    border-radius: var(--tc-radius-sm);
    background: var(--tc-glass-bg-input);
    color: var(--tc-text-primary);
    font-size: var(--tc-font-size-sm);
    font-family: var(--tc-font-sans);
    outline: none;
    transition: border 0.15s;
}

.nb-search::placeholder {
    color: var(--tc-text-muted);
}

.nb-search:focus {
    border: var(--tc-glass-border-focus);
}

/* 4. Notebook list
   ========================================================================== */
.nb-list {
    flex: 1;
    overflow-y: auto;
    padding: 8px 0;
}

.nb-list-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
    cursor: pointer;
    font-size: var(--tc-font-size-sm);
    color: var(--tc-text-secondary);
    border-left: 3px solid transparent;
    transition: background 0.15s, color 0.15s, border-color 0.15s;
}

.nb-list-item:hover {
    background: var(--tc-glass-bg-hover);
    color: var(--tc-text-primary);
}

.nb-list-item.active {
    background: var(--tc-glass-bg-active);
    color: var(--tc-text-primary);
    border-left-color: var(--tc-primary);
}

.nb-list-item-icon {
    flex-shrink: 0;
    width: 16px;
    height: 16px;
    opacity: 0.6;
}

.nb-list-item-name {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.nb-list-item-date {
    font-size: var(--tc-font-size-xs);
    color: var(--tc-text-muted);
    flex-shrink: 0;
}

/* 5. Main area
   ========================================================================== */
.nb-main {
    display: flex;
    flex-direction: column;
    min-width: 0;
    overflow: hidden;
}

.nb-cells-area {
    flex: 1;
    overflow-y: auto;
    padding: 24px 32px 64px;
}

/* 6. Toolbar
   ========================================================================== */
.nb-toolbar {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 8px 16px;
    border-bottom: var(--tc-glass-border);
    background: var(--tc-glass-bg-topbar);
    backdrop-filter: blur(var(--tc-glass-blur-light));
    -webkit-backdrop-filter: blur(var(--tc-glass-blur-light));
    flex-shrink: 0;
}

.nb-toolbar-sep {
    width: 1px;
    height: 20px;
    margin: 0 6px;
    background: rgba(148, 163, 184, 0.12);
}

.nb-runtime-badge {
    margin-left: auto;
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 4px 10px;
    border-radius: var(--tc-radius-pill);
    font-size: var(--tc-font-size-xs);
    font-weight: var(--tc-font-weight-medium);
    border: var(--tc-glass-border);
    background: var(--tc-glass-bg);
}

.nb-runtime-badge::before {
    content: "";
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--tc-text-muted);
}

.nb-runtime-badge.connected::before {
    background: var(--tc-success);
    box-shadow: 0 0 6px var(--tc-success-glow);
}

.nb-runtime-badge.disconnected::before {
    background: var(--tc-error);
}

/* 7. Toolbar buttons
   ========================================================================== */
.nb-toolbar-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 4px;
    padding: 6px 10px;
    border: var(--tc-glass-border);
    border-radius: var(--tc-radius-sm);
    background: var(--tc-glass-bg);
    color: var(--tc-text-secondary);
    font-size: var(--tc-font-size-xs);
    font-family: var(--tc-font-sans);
    cursor: pointer;
    transition: background 0.15s, color 0.15s, border 0.15s;
}

.nb-toolbar-btn:hover {
    background: var(--tc-glass-bg-hover);
    color: var(--tc-text-primary);
    border: var(--tc-glass-border-hover);
}

.nb-toolbar-btn.nb-run-all {
    background: var(--tc-primary);
    border-color: transparent;
    color: #fff;
}

.nb-toolbar-btn.nb-run-all:hover {
    background: var(--tc-primary-hover);
}

/* 8. Cell — grid layout
   ========================================================================== */
.nb-cell {
    display: grid;
    grid-template-columns: 52px 1fr;
    grid-template-rows: auto auto;
    border: var(--tc-glass-border);
    border-radius: var(--tc-radius-md);
    background: var(--tc-glass-bg);
    margin-bottom: 8px;
    position: relative;
    transition: border 0.15s, box-shadow 0.2s;
}

.nb-cell:hover {
    border: var(--tc-glass-border-hover);
}

.nb-cell:focus-within {
    border: var(--tc-glass-border-focus);
    box-shadow: 0 0 0 3px var(--tc-primary-glow);
}

/* 9. Gutter — run button + execution count
   ========================================================================== */
.nb-gutter {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 10px 0 8px;
    gap: 6px;
    grid-row: 1 / -1;
}

.nb-run-btn {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    border: var(--tc-glass-border);
    background: var(--tc-glass-bg);
    color: var(--tc-text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: background 0.15s, color 0.15s, border 0.15s;
    position: relative;
    flex-shrink: 0;
}

.nb-run-btn:hover {
    background: var(--tc-primary);
    border-color: var(--tc-primary);
    color: #fff;
}

.nb-exec-count {
    font-family: var(--tc-font-mono);
    font-size: 10px;
    color: var(--tc-text-muted);
    line-height: 1;
}

/* 10. Cell toolbar — hover-reveal
   ========================================================================== */
.nb-cell-toolbar {
    position: absolute;
    top: 4px;
    right: 8px;
    display: flex;
    gap: 2px;
    opacity: 0;
    transition: opacity 0.15s;
    z-index: 2;
}

.nb-cell:hover .nb-cell-toolbar {
    opacity: 1;
}

.nb-cell-toolbar button {
    padding: 4px 6px;
    border: none;
    border-radius: 4px;
    background: transparent;
    color: var(--tc-text-muted);
    font-size: var(--tc-font-size-xs);
    cursor: pointer;
    transition: background 0.12s, color 0.12s;
}

.nb-cell-toolbar button:hover {
    background: var(--tc-glass-bg-hover);
    color: var(--tc-text-primary);
}

.nb-cell-toolbar button.nb-delete-btn:hover {
    background: var(--tc-error-surface);
    color: var(--tc-error);
}

/* 11. Code input — Monaco container
   ========================================================================== */
.nb-code-input {
    min-height: 60px;
    padding: 8px 12px 8px 0;
    font-family: var(--tc-font-mono);
    font-size: var(--tc-font-size-sm);
    line-height: 1.6;
    overflow: hidden;
    border-radius: 0 var(--tc-radius-md) 0 0;
}

/* 12. Markdown input + rendered
   ========================================================================== */
.nb-md-input {
    width: 100%;
    min-height: 60px;
    padding: 12px 16px 12px 0;
    border: none;
    background: transparent;
    color: var(--tc-text-primary);
    font-family: var(--tc-font-mono);
    font-size: var(--tc-font-size-sm);
    line-height: 1.6;
    resize: vertical;
    outline: none;
}

.nb-md-rendered {
    padding: 12px 16px 12px 0;
    font-size: var(--tc-font-size-base);
    line-height: 1.7;
    color: var(--tc-text-primary);
}

.nb-md-rendered h1 { font-size: var(--tc-font-size-2xl); font-weight: var(--tc-font-weight-bold); margin: 0 0 12px; }
.nb-md-rendered h2 { font-size: var(--tc-font-size-xl); font-weight: var(--tc-font-weight-semi); margin: 0 0 10px; }
.nb-md-rendered h3 { font-size: var(--tc-font-size-lg); font-weight: var(--tc-font-weight-semi); margin: 0 0 8px; }
.nb-md-rendered p  { margin: 0 0 8px; }
.nb-md-rendered ul,
.nb-md-rendered ol { padding-left: 24px; margin: 0 0 8px; }
.nb-md-rendered code {
    font-family: var(--tc-font-mono);
    font-size: 0.85em;
    padding: 2px 6px;
    border-radius: 4px;
    background: var(--tc-glass-bg-active);
}
.nb-md-rendered pre code { display: block; padding: 12px; border-radius: var(--tc-radius-sm); overflow-x: auto; }
.nb-md-rendered blockquote {
    margin: 0 0 8px;
    padding: 8px 16px;
    border-left: 3px solid var(--tc-primary);
    color: var(--tc-text-secondary);
    background: var(--tc-glass-bg);
    border-radius: 0 var(--tc-radius-sm) var(--tc-radius-sm) 0;
}
.nb-md-rendered a { color: var(--tc-primary); text-decoration: none; }
.nb-md-rendered a:hover { text-decoration: underline; }

/* 13. Output area
   ========================================================================== */
.nb-output {
    grid-column: 2;
    border-top: var(--tc-glass-border-subtle);
    padding: 10px 12px 10px 0;
    min-height: 0;
}

.nb-output:empty { display: none; }

.nb-output-text {
    font-family: var(--tc-font-mono);
    font-size: var(--tc-font-size-sm);
    line-height: 1.55;
    white-space: pre-wrap;
    word-break: break-word;
    color: var(--tc-text-primary);
}

.nb-output-html { font-size: var(--tc-font-size-sm); line-height: 1.55; }

.nb-output-image {
    display: flex;
    justify-content: center;
    padding: 8px 0;
}

.nb-output-image img {
    max-width: 100%;
    border-radius: var(--tc-radius-sm);
}

.nb-output-error {
    font-family: var(--tc-font-mono);
    font-size: var(--tc-font-size-sm);
    line-height: 1.55;
    white-space: pre-wrap;
    word-break: break-word;
    background: var(--tc-error-surface);
    border-left: 3px solid var(--tc-error);
    border-radius: 0 var(--tc-radius-sm) var(--tc-radius-sm) 0;
    padding: 10px 14px;
    color: #fca5a5;
}

.nb-output-dataframe {
    overflow-x: auto;
    max-height: 400px;
    overflow-y: auto;
}

.nb-output-dataframe table {
    width: 100%;
    border-collapse: collapse;
    font-family: var(--tc-font-mono);
    font-size: var(--tc-font-size-xs);
}

.nb-output-dataframe thead {
    position: sticky;
    top: 0;
    z-index: 1;
}

.nb-output-dataframe th {
    background: var(--tc-glass-bg-active);
    color: var(--tc-text-secondary);
    font-weight: var(--tc-font-weight-semi);
    padding: 6px 10px;
    text-align: left;
    border-bottom: var(--tc-glass-border);
    white-space: nowrap;
}

.nb-output-dataframe td {
    padding: 5px 10px;
    border-bottom: var(--tc-glass-border-subtle);
    color: var(--tc-text-primary);
    white-space: nowrap;
}

.nb-output-dataframe tr:hover td {
    background: var(--tc-glass-bg);
}

/* 14. Running / complete / error states
   ========================================================================== */
.nb-cell-running {
    border-left: 3px solid var(--tc-primary);
    box-shadow: -4px 0 12px -2px var(--tc-primary-glow);
}

.nb-cell-running .nb-run-btn {
    color: transparent;
    pointer-events: none;
}

.nb-cell-running .nb-run-btn::after {
    content: "";
    position: absolute;
    width: 16px;
    height: 16px;
    border: 2px solid transparent;
    border-top-color: var(--tc-primary);
    border-right-color: var(--tc-primary);
    border-radius: 50%;
    animation: nb-spin 0.6s linear infinite;
}

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

.nb-cell-complete .nb-exec-count { color: var(--tc-success); }
.nb-cell-complete .nb-run-btn { color: var(--tc-success); border-color: rgba(20, 184, 166, 0.25); }

.nb-cell-error {
    border-left: 3px solid var(--tc-error);
}

.nb-cell-error .nb-exec-count { color: var(--tc-error); }
.nb-cell-error .nb-run-btn { color: var(--tc-error); border-color: rgba(239, 68, 68, 0.25); }

/* 15. Add cell — hover-reveal between cells
   ========================================================================== */
.nb-add-cell {
    display: flex;
    justify-content: center;
    gap: 8px;
    padding: 4px 0;
    opacity: 0;
    transition: opacity 0.2s;
}

.nb-add-cell:hover,
.nb-cells-area > :hover + .nb-add-cell {
    opacity: 1;
}

.nb-add-cell button {
    padding: 4px 14px;
    border: 1px dashed rgba(148, 163, 184, 0.2);
    border-radius: var(--tc-radius-sm);
    background: transparent;
    color: var(--tc-text-muted);
    font-size: var(--tc-font-size-xs);
    font-family: var(--tc-font-sans);
    cursor: pointer;
    transition: background 0.15s, color 0.15s, border-color 0.15s;
}

.nb-add-cell button:hover {
    background: var(--tc-glass-bg-hover);
    color: var(--tc-text-primary);
    border-color: rgba(148, 163, 184, 0.35);
}

/* 16. Empty state
   ========================================================================== */
.nb-empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    gap: 16px;
    color: var(--tc-text-muted);
    text-align: center;
    padding: 32px;
}

.nb-empty-state-icon {
    width: 64px;
    height: 64px;
    border-radius: var(--tc-radius-lg);
    background: var(--tc-glass-bg);
    border: var(--tc-glass-border);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    color: var(--tc-text-muted);
}

.nb-empty-state-title {
    font-size: var(--tc-font-size-lg);
    font-weight: var(--tc-font-weight-semi);
    color: var(--tc-text-secondary);
}

.nb-empty-state-desc {
    font-size: var(--tc-font-size-sm);
    max-width: 320px;
    line-height: 1.5;
}

/* 17. Responsive
   ========================================================================== */
@media (max-width: 900px) {
    .nb-page {
        grid-template-columns: 1fr;
    }

    .nb-sidebar {
        display: none;
    }

    .nb-sidebar.nb-sidebar-open {
        display: flex;
        position: fixed;
        top: 56px;
        left: 0;
        bottom: 0;
        width: 280px;
        z-index: 100;
        box-shadow: 4px 0 24px rgba(0, 0, 0, 0.4);
    }

    .nb-cells-area {
        padding: 16px 20px 48px;
    }
}

@media (max-width: 480px) {
    .nb-cell {
        grid-template-columns: 36px 1fr;
    }

    .nb-gutter {
        padding: 8px 0 6px;
    }

    .nb-run-btn {
        width: 24px;
        height: 24px;
    }

    .nb-toolbar {
        padding: 6px 8px;
        gap: 2px;
    }

    .nb-toolbar-btn {
        padding: 5px 8px;
        font-size: 10px;
    }

    .nb-cells-area {
        padding: 12px 8px 40px;
    }

    .nb-md-rendered h1 { font-size: var(--tc-font-size-lg); }
    .nb-md-rendered h2 { font-size: var(--tc-font-size-md); }
}

/* 18. Print
   ========================================================================== */
@media print {
    .nb-sidebar,
    .nb-toolbar,
    .nb-gutter,
    .nb-cell-toolbar,
    .nb-add-cell {
        display: none !important;
    }

    .nb-page {
        display: block;
        height: auto;
    }

    .nb-cell {
        grid-template-columns: 1fr;
        border: 1px solid #ccc;
        break-inside: avoid;
        margin-bottom: 12px;
    }

    .nb-output {
        grid-column: 1;
    }

    .nb-cells-area {
        overflow: visible;
        padding: 0;
    }
}