/* ========================================
   BLDC/PMSM Servo Driver Design Calculator
   Modern Industrial UI Design
   ======================================== */

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary: #64748b;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --info: #06b6d4;
    
    --bg-dark: #0f172a;
    --bg-card: #1e293b;
    --bg-input: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    
    --border: #334155;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4);
    
    --radius: 8px;
    --radius-lg: 12px;
}

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

body {
    font-family: 'Segoe UI', 'Noto Sans KR', system-ui, -apple-system, sans-serif;
    background: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

/* ========================================
   Header
   ======================================== */
.header {
    text-align: center;
    padding: 30px 0;
    border-bottom: 1px solid var(--border);
    margin-bottom: 30px;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    margin-bottom: 10px;
}

.logo i {
    font-size: 2.5rem;
    color: var(--primary);
}

.logo h1 {
    font-size: 1.8rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary), var(--info));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* ========================================
   Main Content Grid
   ======================================== */
.main-content {
    display: grid;
    grid-template-columns: 380px 1fr;
    gap: 25px;
    margin-bottom: 30px;
}

@media (max-width: 1024px) {
    .main-content {
        grid-template-columns: 1fr;
    }
}

/* ========================================
   Panels
   ======================================== */
.panel {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 25px;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border);
}

.panel h2 {
    font-size: 1.2rem;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-primary);
}

.panel h2 i {
    color: var(--primary);
}

.section-subtitle {
    font-size: 1rem;
    margin: 20px 0 15px;
    padding-top: 15px;
    border-top: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-secondary);
}

/* ========================================
   Input Styles
   ======================================== */
.input-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.input-group label {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.input-group input,
.input-group select {
    padding: 10px 12px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text-primary);
    font-size: 0.95rem;
    transition: all 0.2s;
}

.input-group input:focus,
.input-group select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.2);
}

.input-group.full-width {
    grid-column: 1 / -1;
}

/* ========================================
   Buttons
   ======================================== */
.btn-primary,
.btn-secondary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    border: none;
    border-radius: var(--radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    width: 100%;
    margin-top: 20px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(37, 99, 235, 0.3);
}

.btn-secondary {
    background: var(--bg-input);
    color: var(--text-primary);
    border: 1px solid var(--border);
    width: auto;
    margin-bottom: 20px;
}

.btn-secondary:hover {
    background: var(--border);
}

/* ========================================
   Results Panel
   ======================================== */
.results-panel {
    max-height: 800px;
    overflow-y: auto;
}

.results-panel::-webkit-scrollbar {
    width: 8px;
}

.results-panel::-webkit-scrollbar-track {
    background: var(--bg-dark);
    border-radius: var(--radius);
}

.results-panel::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: var(--radius);
}

.result-card {
    background: var(--bg-dark);
    border-radius: var(--radius);
    margin-bottom: 15px;
    overflow: hidden;
    border: 1px solid var(--border);
}

.card-header {
    background: linear-gradient(90deg, rgba(37, 99, 235, 0.2), transparent);
    padding: 12px 15px;
    display: flex;
    align-items: center;
    gap: 10px;
    border-bottom: 1px solid var(--border);
}

.card-header i {
    color: var(--primary);
    font-size: 1.1rem;
}

.card-header h3 {
    font-size: 1rem;
    font-weight: 600;
}

.card-body {
    padding: 15px;
}

.result-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 0;
    border-bottom: 1px solid var(--border);
}

.result-item:last-child {
    border-bottom: none;
}

.result-label {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.result-value {
    font-family: 'Consolas', 'Monaco', monospace;
    font-weight: 600;
    color: var(--success);
}

.result-value.highlight {
    color: var(--warning);
    font-size: 1.1rem;
}

.result-value.critical {
    color: var(--danger);
}

.formula-box {
    background: rgba(15, 23, 42, 0.5);
    padding: 10px;
    border-radius: var(--radius);
    margin-top: 10px;
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 0.85rem;
    color: var(--text-muted);
    border-left: 3px solid var(--info);
}

/* ========================================
   Tabs Section
   ======================================== */
.tabs-section {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border);
    overflow: hidden;
}

.tabs {
    display: flex;
    flex-wrap: wrap;
    background: var(--bg-dark);
    border-bottom: 1px solid var(--border);
}

.tab-btn {
    flex: 1;
    min-width: 150px;
    padding: 15px 20px;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.tab-btn:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

.tab-btn.active {
    color: var(--primary);
    background: var(--bg-card);
    border-bottom: 2px solid var(--primary);
}

.tab-content {
    padding: 25px;
}

.tab-pane {
    display: none;
}

.tab-pane.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.tab-pane h3 {
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
}

/* ========================================
   Checklist Styles
   ======================================== */
.checklist-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
}

.checklist-category {
    background: var(--bg-dark);
    border-radius: var(--radius);
    padding: 20px;
    border: 1px solid var(--border);
}

.checklist-category h4 {
    color: var(--primary);
    margin-bottom: 15px;
    font-size: 1rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

.checklist-item {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 8px 0;
    border-bottom: 1px solid var(--border);
}

.checklist-item:last-child {
    border-bottom: none;
}

.checklist-item input[type="checkbox"] {
    margin-top: 3px;
    accent-color: var(--primary);
}

.checklist-item label {
    color: var(--text-secondary);
    font-size: 0.9rem;
    cursor: pointer;
    flex: 1;
}

.checklist-item input[type="checkbox"]:checked + label {
    color: var(--success);
    text-decoration: line-through;
}

/* ========================================
   Mistakes List
   ======================================== */
.mistakes-list {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.mistake-card {
    background: var(--bg-dark);
    border-radius: var(--radius);
    padding: 20px;
    border: 1px solid var(--border);
    border-left: 4px solid var(--danger);
}

.mistake-card h4 {
    color: var(--danger);
    margin-bottom: 10px;
    font-size: 1rem;
}

.mistake-card .consequence {
    color: var(--warning);
    font-size: 0.9rem;
    margin-bottom: 8px;
}

.mistake-card .solution {
    color: var(--success);
    font-size: 0.9rem;
}

.mistake-card .solution::before {
    content: '✓ 해결: ';
    font-weight: 600;
}

.mistake-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 24px;
    height: 24px;
    background: var(--danger);
    color: white;
    border-radius: 50%;
    font-size: 0.8rem;
    font-weight: 700;
    margin-right: 10px;
}

/* ========================================
   Certification Grid
   ======================================== */
.certification-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
}

.cert-card {
    background: var(--bg-dark);
    border-radius: var(--radius);
    padding: 20px;
    border: 1px solid var(--border);
}

.cert-card h4 {
    color: var(--info);
    margin-bottom: 15px;
    font-size: 1rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

.cert-item {
    padding: 8px 0;
    border-bottom: 1px solid var(--border);
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.cert-item:last-child {
    border-bottom: none;
}

/* ========================================
   Test Timeline
   ======================================== */
.test-timeline {
    display: flex;
    flex-direction: column;
    gap: 0;
}

.test-phase {
    display: flex;
    gap: 20px;
    position: relative;
    padding-bottom: 20px;
}

.test-phase::before {
    content: '';
    position: absolute;
    left: 20px;
    top: 40px;
    bottom: 0;
    width: 2px;
    background: var(--border);
}

.test-phase:last-child::before {
    display: none;
}

.phase-number {
    width: 40px;
    height: 40px;
    background: var(--primary);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    flex-shrink: 0;
    z-index: 1;
}

.phase-content {
    flex: 1;
    background: var(--bg-dark);
    border-radius: var(--radius);
    padding: 20px;
    border: 1px solid var(--border);
}

.phase-content h4 {
    color: var(--primary);
    margin-bottom: 12px;
    font-size: 1rem;
}

.phase-content ul {
    list-style: none;
}

.phase-content li {
    padding: 6px 0;
    color: var(--text-secondary);
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

.phase-content li::before {
    content: '▸';
    color: var(--primary);
}

/* ========================================
   BOM Tables
   ======================================== */
.bom-tables {
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.bom-category {
    background: var(--bg-dark);
    border-radius: var(--radius);
    overflow: hidden;
    border: 1px solid var(--border);
}

.bom-category h4 {
    background: rgba(37, 99, 235, 0.1);
    padding: 12px 15px;
    margin: 0;
    font-size: 1rem;
    color: var(--primary);
}

.bom-table {
    width: 100%;
    border-collapse: collapse;
}

.bom-table th,
.bom-table td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

.bom-table th {
    background: rgba(255, 255, 255, 0.02);
    color: var(--text-secondary);
    font-weight: 600;
    font-size: 0.85rem;
    text-transform: uppercase;
}

.bom-table td {
    color: var(--text-primary);
    font-size: 0.9rem;
}

.bom-table tr:hover td {
    background: rgba(255, 255, 255, 0.02);
}

.bom-table .qty {
    text-align: center;
    font-weight: 600;
    color: var(--info);
}

.bom-table .ref {
    font-family: 'Consolas', 'Monaco', monospace;
    color: var(--warning);
}

/* ========================================
   Utilities
   ======================================== */
.placeholder {
    color: var(--text-muted);
    text-align: center;
    padding: 30px;
    font-style: italic;
}

.loading {
    text-align: center;
    padding: 40px;
    color: var(--text-secondary);
}

.highlight-box {
    background: rgba(245, 158, 11, 0.1);
    border: 1px solid var(--warning);
    border-radius: var(--radius);
    padding: 15px;
    margin-top: 15px;
}

.highlight-box.warning {
    background: rgba(239, 68, 68, 0.1);
    border-color: var(--danger);
}

.highlight-box.success {
    background: rgba(16, 185, 129, 0.1);
    border-color: var(--success);
}

/* ========================================
   Footer
   ======================================== */
.footer {
    text-align: center;
    padding: 30px;
    margin-top: 30px;
    border-top: 1px solid var(--border);
    color: var(--text-muted);
    font-size: 0.9rem;
}

.footer p {
    margin: 5px 0;
}

/* ========================================
   Responsive
   ======================================== */
@media (max-width: 768px) {
    .input-grid {
        grid-template-columns: 1fr;
    }
    
    .tabs {
        flex-direction: column;
    }
    
    .tab-btn {
        width: 100%;
        justify-content: flex-start;
    }
    
    .logo h1 {
        font-size: 1.4rem;
    }
    
    .test-phase {
        flex-direction: column;
        gap: 10px;
    }
    
    .test-phase::before {
        display: none;
    }
}