* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
    --bg-primary: #0f1923;
    --bg-secondary: #162333;
    --bg-card: #1a2d42;
    --bg-hover: #213a52;
    --text-primary: #e8edf3;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --accent: #38bdf8;
    --accent-dim: rgba(56, 189, 248, 0.15);
    --success: #22c55e;
    --success-dim: rgba(34, 197, 94, 0.15);
    --warning: #f59e0b;
    --warning-dim: rgba(245, 158, 11, 0.15);
    --error: #ef4444;
    --error-dim: rgba(239, 68, 68, 0.15);
    --purple: #a78bfa;
    --purple-dim: rgba(167, 139, 250, 0.15);
    --border: rgba(255,255,255,0.08);
    --radius: 12px;
    --radius-sm: 8px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    overflow: hidden;
    height: 100vh;
}

.sql-lab-container {
    height: 100vh;
    display: flex;
    flex-direction: column;
}

.studio-header {
    background: var(--bg-secondary);
    padding: 0.6rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border);
    min-height: 52px;
}

.studio-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo-mark {
    width: 32px; height: 32px;
    background: linear-gradient(135deg, var(--accent), #818cf8);
    border-radius: 8px;
    display: flex; align-items: center; justify-content: center;
}

.logo-mark::after { content: 'G'; color: white; font-weight: 700; font-size: 16px; }

.logo-text { font-size: 1.2rem; font-weight: 700; color: var(--text-primary); line-height: 1.1; }
.logo-subtitle { font-size: 0.65rem; color: var(--accent); text-transform: uppercase; letter-spacing: 2px; }

.studio-controls { display: flex; gap: 0.5rem; align-items: center; }

.sql-badge {
    background: var(--accent-dim);
    color: var(--accent);
    padding: 0.3rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

.btn-nav {
    background: transparent;
    color: var(--text-secondary);
    padding: 0.4rem 0.75rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    text-decoration: none;
    font-size: 0.8rem;
    display: flex; align-items: center; gap: 0.3rem;
    transition: all 0.2s;
}

.btn-nav:hover { background: var(--bg-hover); color: var(--text-primary); }

.btn-icon {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.4rem;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    transition: all 0.2s;
}

.btn-icon:hover { background: var(--bg-hover); }

.btn-icon-small {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.25rem 0.5rem;
    border-radius: 6px;
    font-size: 0.85rem;
    transition: all 0.2s;
}

.btn-icon-small:hover { background: var(--bg-hover); }

.studio-panels {
    flex: 1;
    display: flex;
    overflow: hidden;
}

.panel {
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.tutor-panel {
    width: 360px;
    min-width: 280px;
    border-right: 1px solid var(--border);
    background: var(--bg-secondary);
}

.editor-panel {
    flex: 1;
    min-width: 300px;
}

.output-panel {
    width: 380px;
    min-width: 280px;
    border-left: 1px solid var(--border);
    background: var(--bg-secondary);
    display: flex;
    flex-direction: column;
}

.panel-header {
    padding: 0.6rem 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border);
    background: rgba(0,0,0,0.15);
    min-height: 40px;
}

.panel-header h3 { font-size: 0.85rem; font-weight: 600; color: var(--text-secondary); }

.panel-content {
    flex: 1;
    overflow-y: auto;
    padding: 1rem;
}

.output-content {
    flex: 1;
    overflow-y: auto;
    padding: 0.75rem;
}

.resize-handle {
    width: 4px;
    cursor: col-resize;
    background: transparent;
    transition: background 0.2s;
}

.resize-handle:hover { background: var(--accent); }

.curriculum-view { padding-bottom: 2rem; }

.curriculum-level {
    margin-bottom: 1.5rem;
}

.level-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 0.75rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border);
}

.level-icon { font-size: 1.5rem; }

.level-info h4 { font-size: 0.95rem; font-weight: 600; color: var(--text-primary); }
.level-info p { font-size: 0.75rem; color: var(--text-secondary); margin-top: 0.15rem; }

.topic-list { display: flex; flex-direction: column; gap: 0.4rem; }

.topic-card {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.65rem 0.75rem;
    background: var(--bg-card);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.2s;
    border: 1px solid transparent;
}

.topic-card:hover { background: var(--bg-hover); border-color: var(--accent); transform: translateX(2px); }
.topic-card.completed { border-left: 3px solid var(--success); }
.topic-card.completed .topic-info strong { color: var(--text-secondary); }

.capstone-card { background: var(--purple-dim); border: 1px solid rgba(167,139,250,0.2); }
.capstone-card:hover { border-color: var(--purple); }

.topic-status { font-size: 1.1rem; flex-shrink: 0; width: 24px; text-align: center; }
.topic-info { flex: 1; min-width: 0; }
.topic-info strong { font-size: 0.8rem; display: block; color: var(--text-primary); }
.topic-info small { font-size: 0.7rem; color: var(--text-muted); }
.topic-steps { font-size: 0.7rem; color: var(--text-muted); white-space: nowrap; }

.topic-progress-mini {
    height: 3px;
    background: rgba(255,255,255,0.06);
    border-radius: 2px;
    margin-top: 0.3rem;
    overflow: hidden;
}

.topic-progress-bar {
    height: 100%;
    background: var(--accent);
    border-radius: 2px;
    transition: width 0.3s;
}

.progress-bar-container {
    padding: 0.5rem 1rem;
    border-top: 1px solid var(--border);
    background: rgba(0,0,0,0.1);
}

.progress-info { display: flex; justify-content: space-between; font-size: 0.7rem; color: var(--text-muted); margin-bottom: 0.3rem; }

.progress-track {
    height: 4px;
    background: rgba(255,255,255,0.06);
    border-radius: 2px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent), #818cf8);
    border-radius: 2px;
    transition: width 0.4s ease;
}

.tutor-bubble {
    display: flex;
    gap: 0.75rem;
    margin-bottom: 1rem;
    align-items: flex-start;
}

.tutor-avatar {
    width: 36px;
    height: 36px;
    background: var(--accent-dim);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    flex-shrink: 0;
}

.debug-bubble .tutor-avatar { background: var(--warning-dim); }
.teachback-bubble .tutor-avatar { background: var(--purple-dim); }
.exercise-bubble .tutor-avatar { background: var(--success-dim); }

.tutor-message {
    flex: 1;
    background: var(--bg-card);
    border-radius: 0 var(--radius) var(--radius) var(--radius);
    padding: 0.85rem 1rem;
    border: 1px solid var(--border);
    line-height: 1.6;
}

.lesson-text {
    font-size: 0.85rem;
    color: var(--text-primary);
    line-height: 1.7;
}

.lesson-text code {
    background: rgba(56, 189, 248, 0.12);
    color: var(--accent);
    padding: 0.15rem 0.4rem;
    border-radius: 4px;
    font-family: 'JetBrains Mono', 'Fira Code', monospace;
    font-size: 0.8rem;
}

.lesson-text strong { color: var(--accent); font-weight: 600; }

.teaching-note {
    margin-top: 0.65rem;
    padding: 0.6rem 0.75rem;
    background: var(--accent-dim);
    border-radius: var(--radius-sm);
    font-size: 0.8rem;
    color: var(--accent);
    border-left: 3px solid var(--accent);
}

.note-icon { margin-right: 0.3rem; }

.code-example {
    background: var(--bg-card);
    border-radius: var(--radius-sm);
    overflow: hidden;
    margin-bottom: 0.75rem;
    border: 1px solid var(--border);
}

.code-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.4rem 0.75rem;
    background: rgba(0,0,0,0.2);
    font-size: 0.75rem;
    color: var(--text-muted);
}

.btn-try {
    background: var(--success);
    color: white;
    border: none;
    padding: 0.25rem 0.6rem;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.72rem;
    font-weight: 600;
    transition: all 0.2s;
}

.btn-try:hover { background: #16a34a; transform: translateY(-1px); }

.code-block {
    padding: 0.75rem;
    margin: 0;
    font-family: 'JetBrains Mono', 'Fira Code', monospace;
    font-size: 0.8rem;
    line-height: 1.6;
    color: #e2e8f0;
    overflow-x: auto;
    white-space: pre-wrap;
    word-break: break-word;
}

.expected-output {
    font-size: 0.75rem;
    color: var(--text-muted);
    padding: 0.4rem 0.6rem;
    background: rgba(0,0,0,0.15);
    border-radius: 6px;
    margin-bottom: 0.75rem;
}

.output-label { color: var(--text-secondary); font-weight: 500; }

.exercise-label {
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--success);
    margin-bottom: 0.4rem;
}

.debug-bubble .exercise-label { color: var(--warning); }
.teachback-bubble .exercise-label { color: var(--purple); }

.exercise-instruction {
    font-size: 0.85rem;
    line-height: 1.6;
    color: var(--text-primary);
}

.exercise-instruction code {
    background: rgba(56, 189, 248, 0.12);
    color: var(--accent);
    padding: 0.1rem 0.35rem;
    border-radius: 4px;
    font-family: monospace;
    font-size: 0.8rem;
}

.exercise-instruction strong { color: var(--accent); }

.hint-section {
    margin: 0.75rem 0;
    background: var(--bg-card);
    border-radius: var(--radius-sm);
    padding: 0.65rem;
    border: 1px solid var(--border);
}

.hint-header {
    font-size: 0.72rem;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.hint-buttons {
    display: flex;
    gap: 0.3rem;
    flex-wrap: wrap;
}

.hint-btn {
    background: rgba(255,255,255,0.05);
    border: 1px solid var(--border);
    color: var(--text-secondary);
    padding: 0.3rem 0.55rem;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.7rem;
    transition: all 0.2s;
    white-space: nowrap;
}

.hint-btn:hover { background: var(--accent-dim); border-color: var(--accent); color: var(--accent); }
.hint-btn.used { background: var(--accent-dim); border-color: var(--accent); color: var(--accent); opacity: 0.7; }

.hint-display {
    margin-top: 0.5rem;
}

.hint-content {
    background: var(--accent-dim);
    border-radius: var(--radius-sm);
    padding: 0.65rem 0.75rem;
    border-left: 3px solid var(--accent);
}

.hint-label {
    font-size: 0.65rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--accent);
    margin-bottom: 0.3rem;
}

.hint-text {
    font-size: 0.8rem;
    color: var(--text-primary);
    line-height: 1.5;
}

.hint-text code {
    background: rgba(0,0,0,0.3);
    padding: 0.1rem 0.3rem;
    border-radius: 3px;
    font-family: monospace;
    font-size: 0.75rem;
    color: var(--accent);
}

.step-nav {
    display: flex;
    justify-content: space-between;
    margin-top: 1rem;
    padding-top: 0.75rem;
    border-top: 1px solid var(--border);
}

.btn-nav-step {
    padding: 0.45rem 1rem;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 0.8rem;
    font-weight: 500;
    transition: all 0.2s;
}

.btn-prev { background: rgba(255,255,255,0.08); color: var(--text-secondary); }
.btn-prev:hover { background: rgba(255,255,255,0.12); }
.btn-next { background: var(--accent); color: white; }
.btn-next:hover { background: #0ea5e9; }
.btn-complete { background: var(--success); color: white; }
.btn-complete:hover { background: #16a34a; }

.key-concepts {
    margin: 0.75rem 0;
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.concept-tags { display: flex; flex-wrap: wrap; gap: 0.3rem; margin-top: 0.4rem; }

.concept-tag {
    background: var(--purple-dim);
    color: var(--purple);
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    font-size: 0.7rem;
    font-weight: 500;
}

.teachback-input { margin-top: 0.75rem; }

.teachback-textarea {
    width: 100%;
    min-height: 100px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    padding: 0.75rem;
    font-family: inherit;
    font-size: 0.82rem;
    resize: vertical;
    line-height: 1.5;
}

.teachback-textarea:focus { outline: none; border-color: var(--purple); }
.teachback-textarea::placeholder { color: var(--text-muted); }

.btn-submit-teachback {
    margin-top: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--purple);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 0.8rem;
    font-weight: 600;
    width: 100%;
    transition: all 0.2s;
}

.btn-submit-teachback:hover { background: #8b5cf6; }

.editor-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.query-editor { flex: 1; min-height: 200px; }

.editor-toolbar { display: flex; align-items: center; gap: 0.5rem; }

.filename {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-family: monospace;
}

.run-controls { display: flex; gap: 0.3rem; }

.btn-run {
    background: var(--success);
    color: white;
    border: none;
    padding: 0.35rem 0.85rem;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.78rem;
    font-weight: 600;
    display: flex; align-items: center; gap: 0.3rem;
    transition: all 0.2s;
}

.btn-run:hover { background: #16a34a; transform: translateY(-1px); }

.btn-reset {
    background: rgba(255,255,255,0.08);
    color: var(--text-secondary);
    border: none;
    padding: 0.35rem 0.65rem;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.75rem;
    display: flex; align-items: center; gap: 0.2rem;
    transition: all 0.2s;
}

.btn-reset:hover { background: rgba(255,255,255,0.12); }

.task-banner {
    background: var(--accent-dim);
    border-top: 1px solid rgba(56,189,248,0.2);
    padding: 0.5rem 0.75rem;
    font-size: 0.78rem;
    color: var(--accent);
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.task-icon { font-size: 0.85rem; }

.submit-btn {
    background: var(--success);
    color: white;
    border: none;
    padding: 0.7rem;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    width: 100%;
}

.submit-btn:hover { background: #16a34a; }

.output-toolbar { display: flex; align-items: center; gap: 0.5rem; }

.row-count {
    font-size: 0.72rem;
    color: var(--text-muted);
    font-weight: 500;
}

.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    color: var(--text-muted);
    text-align: center;
}

.empty-icon { font-size: 2rem; margin-bottom: 0.5rem; opacity: 0.5; }
.empty-state p { font-size: 0.8rem; line-height: 1.5; }

.result-table-wrap { overflow-x: auto; }

.result-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.78rem;
}

.result-table th {
    background: rgba(0,0,0,0.3);
    color: var(--accent);
    padding: 0.45rem 0.6rem;
    text-align: left;
    font-weight: 600;
    white-space: nowrap;
    border-bottom: 2px solid var(--accent-dim);
}

.result-table td {
    padding: 0.4rem 0.6rem;
    border-bottom: 1px solid var(--border);
    color: var(--text-primary);
    white-space: nowrap;
}

.result-table tr:hover td { background: rgba(255,255,255,0.03); }
.null-val { color: var(--text-muted); font-style: italic; }

.output-error {
    padding: 0.75rem;
    background: var(--error-dim);
    border-radius: var(--radius-sm);
    border-left: 3px solid var(--error);
}

.error-title { font-weight: 600; color: var(--error); margin-bottom: 0.3rem; font-size: 0.82rem; }
.error-msg { font-size: 0.8rem; color: var(--text-primary); line-height: 1.5; }
.error-hint { margin-top: 0.5rem; font-size: 0.78rem; color: var(--accent); }

.output-success {
    padding: 0.75rem;
    background: var(--success-dim);
    border-radius: var(--radius-sm);
    border-left: 3px solid var(--success);
    font-size: 0.82rem;
    color: var(--success);
}

.output-message {
    padding: 0.75rem;
    font-size: 0.82rem;
    color: var(--text-muted);
    text-align: center;
}

.output-loading {
    padding: 1rem;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.82rem;
}

.validation-result {
    padding: 0.75rem;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: flex-start;
    gap: 0.6rem;
    margin-bottom: 0.5rem;
}

.validation-result.success { background: var(--success-dim); border-left: 3px solid var(--success); }
.validation-result.fail { background: var(--error-dim); border-left: 3px solid var(--error); }
.validation-result.partial { background: var(--warning-dim); border-left: 3px solid var(--warning); }

.validation-icon { font-size: 1.2rem; flex-shrink: 0; }
.validation-msg { font-size: 0.82rem; line-height: 1.5; }
.validation-msg strong { display: block; margin-bottom: 0.2rem; }

.db-explorer {
    border-top: 1px solid var(--border);
    background: rgba(0,0,0,0.1);
    max-height: 200px;
    overflow-y: auto;
    transition: max-height 0.3s;
}

.db-explorer:not(.open) { max-height: 36px; overflow: hidden; }

.db-explorer-header {
    padding: 0.5rem 0.75rem;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.db-explorer.open .chevron { transform: rotate(90deg); }
.chevron { transition: transform 0.2s; font-size: 0.7rem; }

.db-explorer-content { padding: 0 0.5rem 0.5rem; }

.table-item {
    padding: 0.4rem 0.5rem;
    border-radius: 6px;
    cursor: pointer;
    margin-bottom: 0.25rem;
    transition: all 0.15s;
}

.table-item:hover { background: var(--bg-hover); }

.table-name { font-size: 0.75rem; font-weight: 600; color: var(--text-primary); margin-bottom: 0.2rem; }

.table-cols { display: flex; flex-wrap: wrap; gap: 0.2rem; }

.col-tag {
    font-size: 0.62rem;
    color: var(--text-muted);
    background: rgba(255,255,255,0.04);
    padding: 0.1rem 0.35rem;
    border-radius: 3px;
}

.capstone-header { margin-bottom: 1rem; }

.capstone-desc {
    font-size: 0.82rem;
    line-height: 1.6;
    white-space: pre-line;
}

.capstone-tasks { display: flex; flex-direction: column; gap: 0.4rem; }

.capstone-task {
    background: var(--bg-card);
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    overflow: hidden;
}

.task-header {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.6rem 0.75rem;
    cursor: pointer;
    transition: background 0.15s;
}

.task-header:hover { background: rgba(255,255,255,0.03); }

.task-num {
    width: 22px; height: 22px;
    background: var(--accent-dim);
    color: var(--accent);
    border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    font-size: 0.7rem;
    font-weight: 700;
    flex-shrink: 0;
}

.task-desc { flex: 1; font-size: 0.78rem; color: var(--text-primary); }
.task-status { font-size: 0.85rem; }

.task-body {
    display: none;
    padding: 0.5rem 0.75rem 0.75rem;
    gap: 0.4rem;
}

.capstone-task.open .task-body { display: flex; }

.btn-load-task, .btn-submit-task {
    flex: 1;
    padding: 0.4rem;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.75rem;
    font-weight: 500;
    transition: all 0.2s;
}

.btn-load-task { background: var(--accent-dim); color: var(--accent); }
.btn-load-task:hover { background: rgba(56,189,248,0.25); }
.btn-submit-task { background: var(--success); color: white; }
.btn-submit-task:hover { background: #16a34a; }

.capstone-nav { margin-top: 1rem; }

.teachback-prompt {
    font-size: 0.85rem;
    line-height: 1.7;
    white-space: pre-line;
    color: var(--text-primary);
}

.mobile-tab-bar { display: none; }

@media (max-width: 768px) {
    .studio-header { padding: 0.4rem 0.75rem; }
    .studio-controls .btn-nav,
    .studio-controls .sql-badge { display: none; }

    .mobile-tab-bar {
        display: flex;
        background: var(--bg-secondary);
        border-bottom: 1px solid var(--border);
    }

    .mobile-tab {
        flex: 1;
        background: none;
        border: none;
        color: var(--text-muted);
        padding: 0.5rem;
        cursor: pointer;
        display: flex;
        flex-direction: column;
        align-items: center;
        gap: 0.15rem;
        font-size: 0.65rem;
        border-bottom: 2px solid transparent;
        transition: all 0.2s;
    }

    .mobile-tab.active { color: var(--accent); border-bottom-color: var(--accent); }
    .mobile-tab-icon { font-size: 1rem; }
    .mobile-tab-label { font-size: 0.6rem; }

    .studio-panels {
        flex-direction: column;
    }

    .tutor-panel, .editor-panel, .output-panel {
        display: none;
        width: 100% !important;
        min-width: 0;
        border: none;
    }

    .panel.mobile-active {
        display: flex !important;
        flex: 1;
    }

    .resize-handle { display: none; }
}

@media (max-width: 400px) {
    .studio-header { padding: 0.3rem 0.5rem; }
    .logo-text { font-size: 1rem; }
}