/* ============================================================
   Tree & Graph Visualizer — Styles
   ============================================================ */

/* ===========================
   Page Header
   =========================== */
.page-header {
    text-align: center;
    padding: 60px 20px 40px;
}

.page-header h1 {
    font-size: 2.2rem;
    font-weight: 700;
    background: linear-gradient(135deg, #007AFF, #5AC8FA, #34d399);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 10px;
}

.page-header p {
    font-size: 1.05rem;
    opacity: 0.7;
    max-width: 480px;
    margin: 0 auto;
}

/* ===========================
   Controls
   =========================== */
.controls-section {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.control-row {
    display: flex;
    flex-wrap: wrap;
    align-items: flex-end;
    gap: 16px;
    padding: 20px;
    background: var(--card-background);
    border-radius: var(--border-radius);
    box-shadow: 0 4px 20px var(--shadow-color);
    border: 1px solid rgba(0, 122, 255, 0.1);
    margin-bottom: 16px;
    transition: all var(--transition-speed) ease;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
    min-width: 140px;
    flex: 1;
}

.control-label {
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    opacity: 0.6;
    display: flex;
    align-items: center;
    gap: 8px;
}

.value-badge {
    background: rgba(0, 122, 255, 0.12);
    padding: 1px 8px;
    border-radius: 6px;
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--primary-color);
    font-variant-numeric: tabular-nums;
}

.control-select {
    padding: 10px 14px;
    border-radius: 8px;
    border: 1px solid rgba(0, 122, 255, 0.2);
    background: var(--card-background);
    color: var(--text-color);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-speed) ease;
    outline: none;
}

.control-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.15);
}

.control-slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: rgba(0, 122, 255, 0.2);
    outline: none;
    cursor: pointer;
    transition: background 0.2s;
}

.control-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    box-shadow: 0 2px 6px rgba(0, 122, 255, 0.3);
    transition: transform 0.2s;
}

.control-slider::-webkit-slider-thumb:hover {
    transform: scale(1.15);
}

.control-slider::-moz-range-thumb {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    border: none;
    box-shadow: 0 2px 6px rgba(0, 122, 255, 0.3);
}

/* Mode Tabs */
.mode-tabs {
    display: flex;
    gap: 4px;
    background: rgba(128, 128, 128, 0.08);
    border-radius: 10px;
    padding: 3px;
}

.mode-tab {
    flex: 1;
    padding: 8px 16px;
    border: none;
    border-radius: 8px;
    background: transparent;
    color: var(--text-color);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.25s ease;
    opacity: 0.6;
}

.mode-tab.active {
    background: var(--card-background);
    color: var(--primary-color);
    opacity: 1;
    box-shadow: 0 2px 8px var(--shadow-color);
}

.mode-tab:hover:not(.active) {
    opacity: 0.85;
}

/* Input group */
.input-group {
    flex: 2;
    min-width: 280px;
}

.input-row {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.control-input {
    flex: 1;
    min-width: 160px;
    padding: 10px 14px;
    border-radius: 8px;
    border: 1px solid rgba(0, 122, 255, 0.2);
    background: var(--card-background);
    color: var(--text-color);
    font-size: 0.9rem;
    outline: none;
    transition: border-color var(--transition-speed) ease;
}

.control-input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.12);
}

/* Tree insert controls */
.tree-insert-row {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
    margin-top: 8px;
    padding-top: 8px;
    border-top: 1px solid rgba(128,128,128,0.15);
}

.tree-insert-row.hidden {
    display: none;
}

.insert-input {
    flex: 1;
    min-width: 80px;
    max-width: 130px;
    padding: 8px 12px;
    border-radius: 8px;
    border: 1px solid rgba(0, 122, 255, 0.2);
    background: var(--card-background);
    color: var(--text-color);
    font-size: 0.85rem;
    outline: none;
    transition: border-color var(--transition-speed) ease;
}

.insert-input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.12);
}

.btn-insert {
    padding: 8px 12px;
    font-size: 0.8rem;
}

.btn-insert i {
    font-size: 0.8rem;
}

/* Graph start controls */
.graph-start-row {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
    align-items: center;
    margin-top: 8px;
    padding-top: 8px;
    border-top: 1px solid rgba(128,128,128,0.15);
}

.graph-start-row.hidden {
    display: none;
}

.insert-label {
    font-size: 0.8rem;
    font-weight: 600;
    opacity: 0.7;
    white-space: nowrap;
}

.start-select {
    min-width: 60px;
    max-width: 80px;
    padding: 6px 10px;
    border-radius: 6px;
    border: 1px solid rgba(0, 122, 255, 0.2);
    background: var(--card-background);
    color: var(--text-color);
    font-size: 0.85rem;
    font-weight: 500;
    outline: none;
    cursor: pointer;
}

.start-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.12);
}

/* Action Buttons */
.control-actions {
    flex: none;
    flex-direction: row;
    align-items: flex-end;
    gap: 8px;
    min-width: auto;
    margin-left: auto;
}

.btn-action {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 10px 18px;
    border: none;
    border-radius: 8px;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.25s ease;
    white-space: nowrap;
}

.btn-action i {
    font-size: 0.95rem;
}

.btn-primary {
    background: linear-gradient(135deg, #007AFF, #0056d6);
    color: white;
    box-shadow: 0 4px 14px rgba(0, 122, 255, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 122, 255, 0.4);
}

.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.btn-secondary {
    background: var(--card-background);
    color: var(--text-color);
    border: 1px solid rgba(0, 122, 255, 0.2);
    box-shadow: 0 2px 8px var(--shadow-color);
}

.btn-secondary:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: translateY(-1px);
}

.btn-secondary:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    transform: none;
}

/* ===========================
   Visualization Canvas
   =========================== */
.viz-section {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.viz-container {
    position: relative;
    background: var(--card-background);
    border-radius: var(--border-radius);
    box-shadow: 0 4px 20px var(--shadow-color);
    border: 1px solid rgba(0, 122, 255, 0.1);
    min-height: 420px;
    overflow: hidden;
    transition: all var(--transition-speed) ease;
}

#viz-canvas {
    display: block;
    width: 100%;
    height: 460px;
    cursor: default;
}

.viz-placeholder {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 12px;
    opacity: 0.35;
    pointer-events: none;
    transition: opacity 0.4s ease;
}

.viz-placeholder i {
    font-size: 3.5rem;
    color: var(--primary-color);
}

.viz-placeholder p {
    font-size: 1rem;
    font-weight: 500;
}

.viz-placeholder.hidden {
    opacity: 0;
}

/* ===========================
   Info Bar (Stats + Legend)
   =========================== */
.info-bar {
    max-width: 1200px;
    margin: 16px auto 0;
    padding: 0 20px;
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
}

.stats-panel {
    flex: 2;
    min-width: 280px;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    background: var(--card-background);
    border-radius: var(--border-radius);
    padding: 16px 20px;
    box-shadow: 0 4px 20px var(--shadow-color);
    border: 1px solid rgba(0, 122, 255, 0.1);
}

.stat-item {
    flex: 1;
    min-width: 100px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.stat-icon {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 122, 255, 0.1);
    border-radius: 8px;
    color: var(--primary-color);
    font-size: 0.9rem;
    flex-shrink: 0;
}

.stat-label {
    font-size: 0.75rem;
    font-weight: 500;
    opacity: 0.6;
}

.stat-value {
    font-size: 1rem;
    font-weight: 700;
    font-variant-numeric: tabular-nums;
}

.status-ready     { color: var(--text-color); }
.status-running   { color: #007AFF; }
.status-paused    { color: #f59e0b; }
.status-completed { color: #10b981; }

.legend-panel {
    flex: 1;
    min-width: 200px;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 10px 14px;
    background: var(--card-background);
    border-radius: var(--border-radius);
    padding: 16px 20px;
    box-shadow: 0 4px 20px var(--shadow-color);
    border: 1px solid rgba(0, 122, 255, 0.1);
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.8rem;
    font-weight: 500;
    opacity: 0.85;
}

.legend-color {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    flex-shrink: 0;
}

/* Tree legend colors */
.legend-tree-default   { background: #94a3b8; }
.legend-tree-visiting  { background: #f59e0b; box-shadow: 0 0 6px rgba(245,158,11,0.5); }
.legend-tree-visited   { background: #10b981; }

/* Graph legend colors */
.legend-graph-unvisited   { background: #94a3b8; }
.legend-graph-discovered  { background: #f59e0b; box-shadow: 0 0 6px rgba(245,158,11,0.5); }
.legend-graph-processed   { background: #10b981; }
.legend-graph-path        { background: #007AFF; box-shadow: 0 0 6px rgba(0,122,255,0.5); }

/* ===========================
   Step Description
   =========================== */
.step-description {
    max-width: 1200px;
    margin: 16px auto 40px;
    padding: 0 20px;
}

.step-content {
    background: var(--card-background);
    border-radius: var(--border-radius);
    padding: 18px 24px;
    box-shadow: 0 4px 20px var(--shadow-color);
    border: 1px solid rgba(0, 122, 255, 0.1);
    display: flex;
    align-items: center;
    gap: 14px;
    font-size: 0.95rem;
    font-weight: 500;
    transition: all var(--transition-speed) ease;
}

.step-icon {
    color: var(--primary-color);
    opacity: 0.4;
    font-size: 1rem;
}

#step-text {
    flex: 1;
    line-height: 1.6;
}

/* ===========================
   Footer (delegate to global styles)
   =========================== */
.footer {
    margin-top: 60px;
}

/* ===========================
   Output Panel
   =========================== */
.output-section {
    max-width: 1200px;
    margin: 16px auto 40px;
    padding: 0 20px;
}

.output-panel {
    background: var(--card-background);
    border-radius: var(--border-radius);
    box-shadow: 0 4px 20px var(--shadow-color);
    border: 1px solid rgba(0, 122, 255, 0.1);
    overflow: hidden;
    transition: all var(--transition-speed) ease;
}

.output-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 20px;
    border-bottom: 1px solid rgba(128,128,128,0.12);
    background: rgba(0,0,0,0.02);
}

.dark-mode .output-header {
    background: rgba(255,255,255,0.03);
}

.output-title {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.9rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.03em;
    opacity: 0.7;
}

.output-title i {
    color: var(--primary-color);
    font-size: 1rem;
}

.btn-output-clear {
    padding: 6px 10px;
    font-size: 0.75rem;
    background: transparent;
    border: none;
    opacity: 0.4;
    cursor: pointer;
    color: var(--text-color);
    transition: opacity 0.2s;
}

.btn-output-clear:hover {
    opacity: 0.9;
}

.output-body {
    padding: 16px 20px;
    max-height: 200px;
    overflow-y: auto;
    font-size: 0.85rem;
    font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Fira Code', monospace;
    line-height: 1.7;
    background: rgba(0,0,0,0.015);
}

.dark-mode .output-body {
    background: rgba(0,0,0,0.2);
}

.output-body::-webkit-scrollbar {
    width: 6px;
}
.output-body::-webkit-scrollbar-track {
    background: transparent;
}
.output-body::-webkit-scrollbar-thumb {
    background: rgba(0,122,255,0.2);
    border-radius: 3px;
}

.output-line {
    padding: 2px 0;
    border-bottom: 1px solid rgba(128,128,128,0.05);
    display: flex;
    align-items: baseline;
    gap: 8px;
}

.output-line .output-step {
    color: var(--primary-color);
    font-weight: 600;
    font-size: 0.75rem;
    min-width: 28px;
    opacity: 0.6;
}

.output-line .output-msg {
    flex: 1;
    word-break: break-word;
}

.output-placeholder {
    opacity: 0.35;
    font-style: italic;
    font-family: inherit;
    text-align: center;
    padding: 12px 0;
}

.output-highlight {
    background: rgba(245,158,11,0.1);
    border-left: 3px solid #f59e0b;
    padding-left: 10px;
}

/* ===========================
   Dark mode adjustments
   =========================== */
.dark-mode .control-row,
.dark-mode .viz-container,
.dark-mode .stats-panel,
.dark-mode .legend-panel,
.dark-mode .step-content {
    border-color: rgba(255, 255, 255, 0.08);
}

.dark-mode .control-select {
    background-color: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.15);
}

.dark-mode .control-select option {
    background-color: #1a1a2e;
    color: #e0e0e0;
}

.dark-mode .control-input {
    background-color: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.15);
    color: var(--text-color);
}

.dark-mode .control-slider {
    background: rgba(255, 255, 255, 0.15);
}

.dark-mode .btn-secondary {
    background: rgba(0, 122, 255, 0.15);
    border-color: rgba(0, 122, 255, 0.25);
}

.dark-mode .btn-secondary:hover {
    background: rgba(0, 122, 255, 0.25);
}

.dark-mode .stat-icon {
    background: rgba(0, 122, 255, 0.2);
}

.dark-mode .mode-tabs {
    background: rgba(255, 255, 255, 0.06);
}

.dark-mode .mode-tab.active {
    background: rgba(0, 122, 255, 0.2);
    color: #60a5fa;
}

/* ===========================
   Responsive
   =========================== */
@media (max-width: 768px) {
    .page-header { padding: 40px 16px 24px; }
    .page-header h1 { font-size: 1.6rem; }

    .control-row {
        flex-direction: column;
        align-items: stretch;
        gap: 12px;
        padding: 16px;
    }

    .control-group {
        min-width: unset;
    }

    .control-actions {
        flex-direction: row;
        flex-wrap: wrap;
        margin-left: unset;
        justify-content: center;
    }

    .btn-action {
        flex: 1;
        justify-content: center;
        min-width: 60px;
        padding: 10px 12px;
        font-size: 0.8rem;
    }

    .viz-container { min-height: 300px; }
    #viz-canvas { height: 320px; }

    .stats-panel { padding: 12px 16px; }
    .stat-item { min-width: 80px; }

    .legend-panel { padding: 12px 16px; gap: 8px 12px; }

    .step-content { padding: 14px 18px; font-size: 0.9rem; }

    .mode-tabs { flex-direction: row; }
    .mode-tab { padding: 6px 12px; font-size: 0.8rem; }
}

@media (max-width: 480px) {
    #viz-canvas { height: 260px; }

    .control-actions .btn-action span {
        display: none;
    }

    .btn-action {
        min-width: 44px;
        padding: 10px;
    }

    .btn-action i {
        font-size: 1rem;
        margin: 0;
    }

    .stat-value { font-size: 0.9rem; }
    .legend-item { font-size: 0.7rem; }
    .input-row .control-input { min-width: 120px; }
}