/* ========== CSS Variables ========== */
:root {
    --primary: #4F46E5;
    --primary-light: #6366F1;
    --primary-dark: #4338CA;
    --primary-glow: rgba(79, 70, 229, 0.2);
    --accent: #F97316;
    --accent-light: #FB923C;
    --success: #10B981;
    --success-glow: rgba(16, 185, 129, 0.2);
    --warning: #F59E0B;
    --warning-glow: rgba(245, 158, 11, 0.2);
    --danger: #EF4444;
    --danger-glow: rgba(239, 68, 68, 0.2);

    --bg-root: #F5F7FA;
    --bg-surface: #FFFFFF;
    --bg-card: #FFFFFF;
    --bg-elevated: #F9FAFB;
    --bg-input: #F3F4F6;
    --bg-hover: #F0F1F3;

    --text-primary: #111827;
    --text-secondary: #4B5563;
    --text-muted: #9CA3AF;
    --text-inverse: #FFFFFF;

    --border-default: #E5E7EB;
    --border-light: #F3F4F6;
    --border-accent: rgba(79, 70, 229, 0.3);

    --radius-xs: 6px;
    --radius-sm: 8px;
    --radius: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.06);
    --shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.1);
    --shadow-glow: 0 0 24px var(--primary-glow);

    --font-mono: 'JetBrains Mono', 'Cascadia Code', 'Fira Code', 'Monaco', 'Menlo', monospace;
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;

    --transition-fast: 150ms ease;
    --transition: 250ms ease;
    --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ========== Reset ========== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 15px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-root);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ========== Scrollbar ========== */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}
::-webkit-scrollbar-track {
    background: var(--bg-surface);
    border-radius: 3px;
}
::-webkit-scrollbar-thumb {
    background: var(--border-default);
    border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* ========== Top Bar ========== */
.top-bar {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.88);
    backdrop-filter: blur(16px) saturate(180%);
    border-bottom: 1px solid var(--border-default);
}

.top-bar-inner {
    max-width: 1280px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    padding: 0 24px;
    height: 56px;
    gap: 32px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 700;
    font-size: 1.15rem;
    letter-spacing: -0.02em;
}

.logo svg {
    color: var(--accent);
}

.top-nav {
    display: flex;
    gap: 4px;
}

.nav-link {
    padding: 6px 16px;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all var(--transition-fast);
}

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

.nav-link.active {
    color: var(--primary-light);
    background: rgba(79, 70, 229, 0.1);
}

.header-actions {
    margin-left: auto;
    display: flex;
    align-items: center;
    gap: 12px;
}

.check-dot {
    width: 9px;
    height: 9px;
    border-radius: 50%;
    display: inline-block;
    background: var(--text-muted);
    transition: background var(--transition);
}

.check-dot.supported { background: var(--success); box-shadow: 0 0 6px var(--success-glow); }
.check-dot.unsupported { background: var(--danger); box-shadow: 0 0 6px var(--danger-glow); }

/* ========== App Container ========== */
.app-container {
    max-width: 1280px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 24px;
    padding: 24px;
    min-height: calc(100vh - 56px);
}

/* ========== Sidebar ========== */
.sidebar {
    display: flex;
    flex-direction: column;
    gap: 16px;
    position: sticky;
    top: 80px;
    align-self: start;
}

.product-panel, .device-panel {
    background: var(--bg-card);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.panel-header {
    padding: 16px 20px;
    border-bottom: 1px solid var(--border-light);
}

.panel-header h3 {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.panel-header h3 svg {
    color: var(--text-muted);
}

.product-list {
    padding: 8px;
    max-height: 360px;
    overflow-y: auto;
}

.product-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
    border: 1px solid transparent;
    position: relative;
}

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

.product-item.selected {
    background: rgba(79, 70, 229, 0.08);
    border-color: var(--border-accent);
}

.product-item.selected::before {
    content: '';
    position: absolute;
    left: 0;
    top: 12px;
    bottom: 12px;
    width: 3px;
    background: var(--primary);
    border-radius: 0 3px 3px 0;
}

.product-icon {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-xs);
    background: var(--bg-input);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.85rem;
    color: var(--accent);
    flex-shrink: 0;
}

.product-item.selected .product-icon {
    background: rgba(249, 115, 22, 0.15);
}

.product-meta {
    flex: 1;
    min-width: 0;
}

.product-name {
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-primary);
}

.product-chip {
    font-size: 0.78rem;
    color: var(--text-muted);
    margin-top: 2px;
}

.device-info {
    padding: 16px 20px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.device-property {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.85rem;
}

.device-prop-label {
    color: var(--text-muted);
}

.device-prop-value {
    font-weight: 500;
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 0.8rem;
}

/* ========== Main Content ========== */
.main-content {
    display: flex;
    flex-direction: column;
    gap: 20px;
    min-width: 0;
}

/* ========== Info Bar ========== */
.info-bar {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 14px 24px;
    background: var(--bg-card);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-lg);
    flex-wrap: wrap;
}

.info-chip {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.info-label {
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-muted);
    font-weight: 600;
}

.info-value {
    font-weight: 600;
    font-size: 0.9rem;
}

.status-value {
    padding: 2px 10px;
    border-radius: 20px;
    font-size: 0.8rem;
    background: rgba(100, 116, 139, 0.15);
    color: var(--text-secondary);
}

.status-value.ready { background: rgba(16, 185, 129, 0.12); color: var(--success); }
.status-value.busy { background: rgba(245, 158, 11, 0.12); color: var(--warning); }
.status-value.error { background: rgba(239, 68, 68, 0.12); color: var(--danger); }
.status-value.connected { background: rgba(79, 70, 229, 0.12); color: var(--primary-light); }

.info-divider {
    width: 1px;
    height: 28px;
    background: var(--border-default);
}

/* ========== Step Indicator ========== */
.step-indicator {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0;
    padding: 8px 0;
}

.step {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-muted);
    transition: all var(--transition);
}

.step-num {
    width: 34px;
    height: 34px;
    border-radius: 50%;
    background: var(--bg-card);
    border: 2px solid var(--border-default);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.85rem;
    transition: all var(--transition);
}

.step.active { color: var(--text-primary); }
.step.active .step-num {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
    box-shadow: 0 0 16px var(--primary-glow);
}

.step.done { color: var(--success); }
.step.done .step-num {
    background: var(--success);
    border-color: var(--success);
    color: white;
    box-shadow: 0 0 12px var(--success-glow);
}

.step-line {
    width: 60px;
    height: 2px;
    background: var(--border-default);
    margin: 0 12px;
    transition: background var(--transition);
}

.step-line.done {
    background: var(--success);
}

/* ========== Step Panels ========== */
.steps-container {
    position: relative;
}

.step-panel {
    display: none;
    animation: fadeSlideIn 0.35s ease;
}

.step-panel.active {
    display: block;
}

@keyframes fadeSlideIn {
    from {
        opacity: 0;
        transform: translateY(12px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ========== Cards ========== */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-lg);
    padding: 24px;
}

.card-title {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.05rem;
    font-weight: 600;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.card-title svg {
    color: var(--primary-light);
}

/* ========== Form Elements ========== */
.field-label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 10px;
}

.label-badge {
    font-size: 0.7rem;
    padding: 2px 8px;
    border-radius: 10px;
    background: rgba(100, 116, 139, 0.15);
    color: var(--text-muted);
    font-weight: 400;
}

.select-input {
    width: 100%;
    padding: 10px 14px;
    background: var(--bg-input);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 0.9rem;
    font-family: var(--font-sans);
    transition: all var(--transition-fast);
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%2364748B' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    padding-right: 36px;
}

.select-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-glow);
}

.select-input:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* ========== Firmware Selection ========== */
.firmware-select-group {
    margin-bottom: 20px;
}

.version-select-row {
    display: flex;
    gap: 8px;
}

.version-select-row .select-input {
    flex: 1;
}

.custom-upload-section {
    margin-bottom: 20px;
}

.upload-area {
    position: relative;
    border: 2px dashed var(--border-default);
    border-radius: var(--radius);
    padding: 36px 20px;
    text-align: center;
    cursor: pointer;
    transition: all var(--transition);
    background: #F9FAFB;
}

.upload-area:hover, .upload-area.dragover {
    border-color: var(--primary);
    background: rgba(79, 70, 229, 0.04);
}

.upload-area.dragover {
    border-style: solid;
    background: rgba(79, 70, 229, 0.08);
    box-shadow: inset 0 0 32px rgba(79, 70, 229, 0.06);
}

.upload-area input {
    position: absolute;
    inset: 0;
    opacity: 0;
    cursor: pointer;
}

.upload-icon {
    width: 44px;
    height: 44px;
    color: var(--text-muted);
    margin-bottom: 12px;
    transition: color var(--transition);
}

.upload-area:hover .upload-icon {
    color: var(--primary-light);
}

.upload-content p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.upload-hint {
    font-size: 0.78rem !important;
    color: var(--text-muted) !important;
    margin-top: 6px;
}

/* File List */
.file-list {
    margin-top: 12px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.file-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    background: var(--bg-input);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.file-item:hover {
    border-color: var(--border-default);
}

.file-icon {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-xs);
    background: rgba(249, 115, 22, 0.12);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.file-info {
    flex: 1;
    min-width: 0;
}

.file-name {
    font-weight: 500;
    font-size: 0.88rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.file-meta {
    display: flex;
    gap: 12px;
    font-size: 0.78rem;
    color: var(--text-muted);
    margin-top: 2px;
}

.file-address-row {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-shrink: 0;
}

.file-address-row label {
    font-size: 0.8rem;
    color: var(--text-muted);
    white-space: nowrap;
}

.file-address-row input {
    width: 90px;
    padding: 6px 10px;
    background: var(--bg-surface);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-xs);
    color: var(--text-primary);
    font-size: 0.82rem;
    font-family: var(--font-mono);
}

.file-address-row input:focus {
    outline: none;
    border-color: var(--primary);
}

.file-remove {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 6px;
    border-radius: var(--radius-xs);
    font-size: 1.3rem;
    line-height: 1;
    transition: all var(--transition-fast);
    flex-shrink: 0;
}

.file-remove:hover {
    color: var(--danger);
    background: rgba(239, 68, 68, 0.1);
}

/* ========== Config Section ========== */
.config-section {
    margin-bottom: 20px;
}

.config-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 14px;
}

.config-item {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.config-item label {
    font-size: 0.78rem;
    color: var(--text-muted);
    font-weight: 500;
}

.options-row {
    display: flex;
    gap: 24px;
    align-items: center;
}

/* Custom Checkbox */
.checkbox-label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    font-size: 0.88rem;
    user-select: none;
    position: relative;
}

.checkbox-label input {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
}

.checkmark {
    width: 18px;
    height: 18px;
    border: 2px solid var(--border-default);
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    flex-shrink: 0;
}

.checkbox-label input:checked + .checkmark {
    background: var(--primary);
    border-color: var(--primary);
}

.checkbox-label input:checked + .checkmark::after {
    content: '';
    width: 5px;
    height: 9px;
    border: solid white;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg) translateY(-1px);
}

.checkbox-label:hover .checkmark {
    border-color: var(--primary-light);
}

/* ========== Step Actions ========== */
.step-actions {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 24px;
    padding-top: 20px;
    border-top: 1px solid var(--border-light);
    gap: 12px;
}

.flash-actions {
    display: flex;
    gap: 10px;
}

/* ========== Connect Instructions ========== */
.connect-instructions {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-bottom: 24px;
    padding: 20px;
    background: var(--bg-input);
    border-radius: var(--radius);
}

.instruction-item {
    display: flex;
    gap: 14px;
}

.instruction-num {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: rgba(79, 70, 229, 0.15);
    color: var(--primary-light);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.82rem;
    flex-shrink: 0;
}

.instruction-item strong {
    display: block;
    font-size: 0.9rem;
    margin-bottom: 2px;
}

.instruction-item p {
    font-size: 0.82rem;
    color: var(--text-muted);
}

/* ========== Serial Section ========== */
.serial-controls {
    display: flex;
    gap: 12px;
    margin-bottom: 14px;
}

.serial-controls .select-input {
    flex: 1;
}

.connection-status {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 14px;
    background: var(--bg-input);
    border-radius: var(--radius-sm);
}

.status-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--text-muted);
    flex-shrink: 0;
    transition: all var(--transition);
}

.status-dot.connected {
    background: var(--success);
    box-shadow: 0 0 8px var(--success-glow);
    animation: pulse 2s ease-in-out infinite;
}

.status-dot.disconnected { background: var(--text-muted); }
.status-dot.error { background: var(--danger); box-shadow: 0 0 8px var(--danger-glow); }

@keyframes pulse {
    0%, 100% { box-shadow: 0 0 4px var(--success-glow); }
    50% { box-shadow: 0 0 12px var(--success-glow); }
}

.status-text {
    font-weight: 500;
    font-size: 0.9rem;
}

.status-detail {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-left: auto;
}

/* ========== Flash Summary ========== */
.flash-summary {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
    margin-bottom: 24px;
    padding: 16px;
    background: var(--bg-input);
    border-radius: var(--radius);
}

.summary-item {
    text-align: center;
}

.summary-label {
    display: block;
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin-bottom: 4px;
}

.summary-value {
    font-weight: 600;
    font-size: 0.9rem;
}

/* ========== Progress ========== */
.progress-section {
    margin-bottom: 24px;
}

.progress-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.progress-title {
    font-weight: 600;
    font-size: 0.9rem;
}

.progress-percent {
    font-weight: 700;
    font-size: 1.2rem;
    font-family: var(--font-mono);
    color: var(--primary-light);
}

.progress-track {
    position: relative;
    height: 10px;
    background: var(--bg-input);
    border-radius: 5px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    width: 0%;
    border-radius: 5px;
    transition: width 0.4s ease;
    position: relative;
    z-index: 1;
}

.progress-glow {
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.1), transparent);
    border-radius: 5px;
    transition: width 0.4s ease;
    z-index: 2;
}

.progress-stage-text {
    text-align: center;
    margin-top: 8px;
    font-size: 0.82rem;
    color: var(--text-muted);
}

/* Flash file list in step 3 */
.flash-file-list {
    display: flex;
    flex-direction: column;
    gap: 6px;
    margin-bottom: 20px;
}

.flash-file-entry {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 12px;
    background: var(--bg-input);
    border-radius: var(--radius-xs);
    font-size: 0.82rem;
}

.flash-file-status {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    flex-shrink: 0;
}

.flash-file-status.pending { background: var(--text-muted); }
.flash-file-status.flashing { background: var(--warning); box-shadow: 0 0 6px var(--warning-glow); animation: pulse 1s infinite; }
.flash-file-status.done { background: var(--success); box-shadow: 0 0 6px var(--success-glow); }
.flash-file-status.failed { background: var(--danger); }

.flash-file-name {
    flex: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.flash-file-addr {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    color: var(--text-muted);
}

/* ========== Buttons ========== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 20px;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    font-family: var(--font-sans);
    white-space: nowrap;
}

.btn:disabled {
    opacity: 0.45;
    cursor: not-allowed;
    pointer-events: none;
}

.btn-primary {
    background: var(--primary);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    background: var(--primary-dark);
    box-shadow: var(--shadow-glow);
    transform: translateY(-1px);
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--border-default);
    color: var(--text-secondary);
}

.btn-outline:hover:not(:disabled) {
    border-color: var(--primary-light);
    color: var(--text-primary);
}

.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
}

.btn-ghost:hover:not(:disabled) {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.btn-danger {
    background: var(--danger);
    color: white;
}

.btn-danger:hover:not(:disabled) {
    box-shadow: 0 0 20px var(--danger-glow);
}

.btn-flash {
    background: linear-gradient(135deg, var(--accent), #EA580C);
    color: white;
    font-size: 1rem;
    padding: 12px 32px;
    position: relative;
    overflow: hidden;
}

.btn-flash:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 6px 28px rgba(249, 115, 22, 0.4);
}

.btn-flash::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.15), transparent);
    transition: left 0.5s;
}

.btn-flash:hover:not(:disabled)::after {
    left: 100%;
}

.btn-lg {
    padding: 12px 28px;
    font-size: 0.95rem;
}

.btn-sm {
    padding: 6px 12px;
    font-size: 0.8rem;
}

/* ========== Log Panel ========== */
.log-panel {
    padding: 0;
    overflow: hidden;
}

.log-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 24px;
    border-bottom: 1px solid var(--border-light);
}

.log-actions {
    display: flex;
    align-items: center;
    gap: 4px;
}

.log-area {
    padding: 16px 24px;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    max-height: 280px;
    overflow-y: auto;
    background: var(--bg-input);
}

.log-line {
    padding: 3px 0;
    display: flex;
    gap: 10px;
    line-height: 1.5;
}

.log-line .timestamp {
    color: var(--text-muted);
    flex-shrink: 0;
    font-size: 0.75rem;
}

.log-line.success { color: var(--success); }
.log-line.error { color: var(--danger); }
.log-line.warning { color: var(--warning); }
.log-line.info { color: var(--primary-light); }
.log-line.system { color: var(--text-muted); }

/* ========== Toast ========== */
.toast-container {
    position: fixed;
    bottom: 24px;
    right: 24px;
    display: flex;
    flex-direction: column-reverse;
    gap: 8px;
    z-index: 1000;
}

.toast {
    padding: 12px 20px;
    border-radius: var(--radius-sm);
    font-size: 0.88rem;
    font-weight: 500;
    color: white;
    box-shadow: var(--shadow-lg);
    animation: toastIn 0.3s ease, toastOut 0.3s ease 3s forwards;
    max-width: 380px;
}

.toast.success { background: var(--success); }
.toast.error { background: var(--danger); }
.toast.warning { background: var(--warning); color: #1a1a1a; }

@keyframes toastIn {
    from { opacity: 0; transform: translateY(16px) scale(0.95); }
    to { opacity: 1; transform: translateY(0) scale(1); }
}

@keyframes toastOut {
    from { opacity: 1; transform: translateY(0) scale(1); }
    to { opacity: 0; transform: translateY(8px) scale(0.95); }
}

/* ========== Responsive ========== */
@media (max-width: 1024px) {
    .app-container {
        grid-template-columns: 1fr;
    }

    .sidebar {
        position: static;
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 12px;
    }

    .config-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .flash-summary {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 640px) {
    .sidebar {
        grid-template-columns: 1fr;
    }

    .top-bar-inner {
        padding: 0 12px;
        gap: 16px;
    }

    .top-nav {
        display: none;
    }

    .app-container {
        padding: 12px;
    }

    .config-grid {
        grid-template-columns: 1fr;
    }

    .flash-summary {
        grid-template-columns: 1fr 1fr;
    }

    .info-bar {
        gap: 10px;
        padding: 12px;
    }

    .info-divider {
        display: none;
    }

    .serial-controls {
        flex-direction: column;
    }

    .step-actions {
        flex-direction: column;
    }

    .options-row {
        flex-direction: column;
        align-items: flex-start;
    }
}