/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Professional Color Palette - Inspired by Stripe/Vercel */
    --primary: #0070f3;
    --primary-dark: #0051cc;
    --primary-light: #3291ff;
    --secondary: #00d9ff;
    --accent: #7928ca;
    --success: #00c896;
    --warning: #f5a623;
    --error: #ff6b6b;
    
    /* Neutral Colors */
    --white: #ffffff;
    --gray-50: #fafbfc;
    --gray-100: #f4f6f8;
    --gray-200: #e6eaee;
    --gray-300: #d1d9e0;
    --gray-400: #b3c1cc;
    --gray-500: #8b9bb0;
    --gray-600: #647082;
    --gray-700: #485967;
    --gray-800: #2d3748;
    --gray-900: #1a202c;
    
    /* Typography */
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-12: 3rem;
    --space-16: 4rem;
    
    /* Transitions */
    --transition-base: all 0.2s ease-in-out;
    --transition-colors: color 0.15s ease-in-out, background-color 0.15s ease-in-out, border-color 0.15s ease-in-out;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', sans-serif;
    line-height: 1.6;
    color: var(--gray-800);
    background: linear-gradient(135deg, var(--gray-50) 0%, var(--gray-100) 100%);
    min-height: 100vh;
    font-size: var(--font-size-base);
}

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

/* Header Styles */
.header {
    background: var(--white);
    backdrop-filter: blur(20px);
    padding: var(--space-12) 0;
    text-align: center;
    border-bottom: 1px solid var(--gray-200);
    box-shadow: var(--shadow-sm);
}

.title {
    font-size: var(--font-size-4xl);
    font-weight: 800;
    margin-bottom: var(--space-2);
    color: var(--gray-900);
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.025em;
}

.subtitle {
    font-size: var(--font-size-lg);
    color: var(--gray-600);
    font-weight: 500;
}

/* Navigation Styles */
.nav {
    background: var(--white);
    backdrop-filter: blur(20px);
    padding: var(--space-4) 0;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid var(--gray-200);
}

.nav-buttons {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: var(--space-2);
}

.nav-btn {
    padding: var(--space-3) var(--space-6);
    border: 1px solid var(--gray-300);
    background: var(--white);
    color: var(--gray-700);
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition-base);
    font-weight: 500;
    font-size: var(--font-size-sm);
    letter-spacing: -0.01em;
    position: relative;
    overflow: hidden;
}

.nav-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.6), transparent);
    transition: left 0.5s;
}

.nav-btn:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary);
    color: var(--primary);
}

.nav-btn:hover::before {
    left: 100%;
}

.nav-btn.active {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
    border-color: var(--primary);
    box-shadow: var(--shadow-md);
}

/* Main Content */
.main-content {
    background: var(--white);
    min-height: calc(100vh - 200px);
    margin: var(--space-8) auto;
    border-radius: 16px;
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    border: 1px solid var(--gray-200);
}

.section {
    display: none;
    padding: var(--space-8);
    animation: fadeInUp 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.section.active {
    display: block;
}

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

.section-header {
    text-align: center;
    margin-bottom: var(--space-12);
    padding-bottom: var(--space-6);
    border-bottom: 1px solid var(--gray-200);
}

.section-header h2 {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: var(--space-3);
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.025em;
}

.section-header p {
    font-size: var(--font-size-lg);
    color: var(--gray-600);
    line-height: 1.6;
    font-weight: 500;
}

/* SVG Diagram Styles */
.diagram-container {
    display: flex;
    justify-content: center;
    margin: 2rem 0;
    overflow: hidden; /* keep box size while scaling inner svg */
}

.pv-diagram {
    max-width: 100%;
    width: 100%;
    height: auto;
    border: 2px solid #e0e0e0;
    border-radius: 15px;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    padding: 0.5rem; /* increase usable drawing area inside box */
    transform: scale(1.06); /* visually enlarge contents without changing box size */
    transform-origin: center top;
}

.component {
    cursor: pointer;
    transition: all 0.3s ease;
}

.component:hover {
    filter: brightness(1.1);
    transform-origin: center center;
    transform: none;
}

.component-label {
    font-family: 'Segoe UI', sans-serif;
    font-size: 14px;
    font-weight: 600;
    fill: #333;
}

.connection {
    stroke-dasharray: 5,5;
    animation: dash 2s linear infinite;
}

@keyframes dash {
    to { stroke-dashoffset: -10; }
}

.connection-label {
    font-size: 12px;
    fill: #666;
    font-weight: 500;
}

/
}

/* Layout: Place System Overview to the right of the diagram */
#diagram-section {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 270px;
    grid-template-areas:
        "header header"
        "diagram stats";
    gap: 1.5rem;
    align-items: start;
}

#diagram-section .section-header {
    grid-area: header;
    margin-bottom: 0; /* handled by grid gap */
    padding-bottom: 0;
    border-bottom: none;
}

#diagram-section .diagram-container {
    grid-area: diagram;
    margin: 0; /* remove extra vertical spacing within grid */
    justify-content: flex-start;
}

#diagram-section .diagram-stats {
    grid-area: stats;
    display: block;
    margin-top: 0;
}

/* Ensure the System Overview uses available sidebar width only */
#diagram-section .diagram-stats .stat-card {
    width: 100%;
}

.stat-card {
    background: #f4f6f8;
    color: var(--gray-800);
    padding: 1.5rem;
    border-radius: 15px;
    border: 1px solid var(--gray-200);
    box-shadow: var(--shadow);
}

.stat-card h4 {
    margin-bottom: 1rem;
    font-size: 1.2rem;
    color: var(--gray-900);
}

.stat-card p {
    margin-bottom: 0.5rem;
}

/* Panel Selection Styles */
.panel-selection {
    background: white;
    padding: 1.5rem;
    border-radius: 15px;
    border: 1px solid #e5e7eb;
    margin-bottom: 2rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.panel-selection h3 {
    color: #2563eb;
    margin-bottom: 1rem;
    font-size: 1.3rem;
    font-weight: 600;
}

.panel-selector {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.panel-selector label {
    font-weight: 600;
    color: #374151;
    min-width: 150px;
}

.panel-dropdown {
    flex: 1;
    padding: 0.75rem 1rem;
    border: 2px solid #d1d5db;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s ease;
    background: white;
    font-weight: 500;
}

.panel-dropdown:focus {
    outline: none;
    border-color: #2563eb;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

/* Array Configuration Styles */
.config-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

.module-specs, .configuration-panel {
    background: white;
    padding: 1.5rem;
    border-radius: 15px;
    border: 1px solid #e5e7eb;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.module-specs h3, .configuration-panel h3 {
    color: #2563eb;
    margin-bottom: 1rem;
    font-size: 1.3rem;
    font-weight: 600;
}

.spec-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.5rem;
}

.spec-item {
    display: flex;
    justify-content: space-between;
    padding: 0.75rem 0;
    border-bottom: 1px solid #f3f4f6;
    transition: background-color 0.2s ease;
}

.spec-item:hover {
    background-color: #f8fafc;
    border-radius: 6px;
    margin: 0 -0.5rem;
    padding: 0.75rem 0.5rem;
}

.spec-item label {
    font-weight: 600;
    color: #374151;
}

.spec-item span {
    color: #1f2937;
    font-weight: 500;
}

.config-inputs {
    margin-bottom: 1.5rem;
}

.input-group {
    display: flex;
    align-items: center;
    margin-bottom: 1rem;
    gap: 1rem;
}

.input-group label {
    flex: 1;
    font-weight: 600;
    color: #374151;
}

.input-group input {
    flex: 1;
    padding: 0.75rem;
    border: 2px solid #d1d5db;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s ease;
    font-weight: 500;
}

.input-group input:focus {
    outline: none;
    border-color: #2563eb;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.help-btn {
    width: 30px;
    height: 30px;
    border-radius: 50%;
    border: 2px solid #2563eb;
    background: white;
    color: #2563eb;
    cursor: pointer;
    font-weight: bold;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.875rem;
}

.help-btn:hover {
    background: #2563eb;
    color: white;
    transform: scale(1.05);
}

.visual-array {
    text-align: center;
}

.array-visual {
    display: grid;
    gap: 5px;
    justify-content: center;
    margin-top: 1rem;
    min-height: 150px;
    padding: 1rem;
    background: #ffffff;
    border-radius: 10px;
    border: 2px dashed #d1d5db;
}

.module-visual {
    width: 40px;
    height: 60px;
    background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
    border-radius: 4px;
    border: 1px solid #1e40af;
    position: relative;
    transition: all 0.3s ease;
}

.module-visual:hover {
    transform: scale(1.05);
}

.array-results {
    grid-column: 1 / -1;
    background: white;
    padding: 1.5rem;
    border-radius: 15px;
    border: 1px solid #e5e7eb;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.array-results h3 {
    color: #2563eb;
    margin-bottom: 1rem;
    font-size: 1.3rem;
    font-weight: 600;
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.result-item {
    display: flex;
    justify-content: space-between;
    padding: 0.75rem;
    background: #f8fafc;
    border-radius: 8px;
    border: 1px solid #e5e7eb;
    transition: all 0.2s ease;
}

.result-item:hover {
    background: white;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    transform: translateY(-1px);
}

.result-item label {
    font-weight: 600;
    color: #374151;
}

.result-item span {
    color: #2563eb;
    font-weight: 700;
}

.result-item.derated {
    border-color: #fbbf24;
    background: #fefbf1;
}

.result-item.derated label {
    color: #92400e;
}

.result-item.derated span {
    color: #d97706;
}

.proceed-btn {
    width: 100%;
    padding: 1rem;
    background: linear-gradient(135deg, #059669 0%, #047857 100%);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 6px rgba(5, 150, 105, 0.2);
}

.proceed-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(5, 150, 105, 0.3);
    background: linear-gradient(135deg, #047857 0%, #065f46 100%);
}

/* MPPT Selection Styles */
.mppt-container {
    display: grid;
    gap: 2rem;
}

.array-summary {
    background: white;
    padding: 1.5rem;
    border-radius: 15px;
    border: 1px solid #e5e7eb;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.array-summary h3 {
    color: #2563eb;
    margin-bottom: 1rem;
    font-size: 1.3rem;
    font-weight: 600;
}

.summary-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.summary-item {
    display: flex;
    justify-content: space-between;
    padding: 0.75rem;
    background: white;
    border-radius: 8px;
    border: 1px solid #bae6fd;
}

.summary-item label {
    font-weight: 600;
    color: #374151;
}

.summary-item span {
    color: #0c4a6e;
    font-weight: 700;
}

.controller-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-top: 1rem;
}

.controller-card {
    background: var(--white);
    border: 1px solid var(--gray-300);
    border-radius: 12px;
    padding: var(--space-6);
    transition: var(--transition-base);
    position: relative;
    box-shadow: var(--shadow);
}

.controller-card:hover {
    border-color: var(--primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.controller-card h4 {
    color: var(--gray-900);
    margin-bottom: var(--space-4);
    font-size: var(--font-size-xl);
    font-weight: 600;
    line-height: 1.3;
}

.controller-specs p {
    margin-bottom: var(--space-2);
    color: var(--gray-600);
    font-size: var(--font-size-sm);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.controller-specs strong {
    color: var(--gray-800);
    font-weight: 600;
}

.select-controller, .select-inverter {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
    border: none;
    border-radius: 8px;
    font-weight: 600;
    font-size: var(--font-size-sm);
    cursor: pointer;
    transition: var(--transition-base);
    margin-top: var(--space-4);
    position: relative;
    overflow: hidden;
}

.select-controller::before, .select-inverter::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.6s;
}

.select-controller:hover::before, .select-inverter:hover::before {
    left: 100%;
}

.select-controller:hover, .select-inverter:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--accent) 100%);
}

.controller-card.selected {
    border-color: var(--success);
    background: linear-gradient(135deg, rgba(0, 200, 150, 0.03) 0%, rgba(0, 200, 150, 0.08) 100%);
    box-shadow: 0 0 0 3px rgba(0, 200, 150, 0.1), var(--shadow);
}

.controller-card.selected .select-controller {
    background: linear-gradient(135deg, var(--success) 0%, #00b894 100%);
    box-shadow: var(--shadow-md);
}

.controller-card.incorrect {
    border-color: var(--error);
    background: linear-gradient(135deg, rgba(255, 107, 107, 0.03) 0%, rgba(255, 107, 107, 0.08) 100%);
    box-shadow: 0 0 0 3px rgba(255, 107, 107, 0.1), var(--shadow);
}

.controller-card.incorrect .select-controller {
    background: linear-gradient(135deg, var(--error) 0%, #e74c3c 100%);
    box-shadow: var(--shadow-md);
}

.selection-feedback, .inverter-feedback {
    background: white;
    border-radius: 15px;
    padding: 1.5rem;
    margin-top: 2rem;
    border-left: 5px solid #2563eb;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.selection-feedback.correct {
    border-left-color: #059669;
    background: linear-gradient(135deg, #f0fdf4 0%, #ecfdf5 100%);
}

.selection-feedback.incorrect {
    border-left-color: #dc2626;
    background: linear-gradient(135deg, #fef2f2 0%, #fee2e2 100%);
}

.feedback-title {
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.feedback-title.correct {
    color: #059669;
}

.feedback-title.correct::before {
    content: '✓ ';
    font-weight: bold;
    margin-right: 0.5rem;
}

.feedback-title.incorrect {
    color: #dc2626;
}

.feedback-title.incorrect::before {
    content: '✗ ';
    font-weight: bold;
    margin-right: 0.5rem;
}

.feedback-content {
    color: #374151;
    line-height: 1.8;
}

.feedback-formula {
    background: #f8fafc;
    border: 1px solid #e5e7eb;
    border-radius: 8px;
    padding: 1rem;
    margin: 1rem 0;
    font-family: 'Inter', monospace;
    font-size: 0.9rem;
    line-height: 1.6;
    color: #374151;
}

.hints-panel {
    margin-top: 2rem;
    text-align: center;
}

.hint-btn {
    padding: 0.75rem 1.5rem;
    background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
    color: white;
    border: none;
    border-radius: 25px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.hint-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(245, 158, 11, 0.4);
}

.hints-content {
    background: #fffbeb;
    border: 2px solid #f59e0b;
    border-radius: 15px;
    padding: 1.5rem;
    margin-top: 1rem;
    text-align: left;
    box-shadow: 0 4px 6px rgba(245, 158, 11, 0.1);
}

.hints-content h4 {
    color: #92400e;
    margin-bottom: 1rem;
}

.hints-content ul {
    list-style-type: none;
    padding-left: 0;
}

.hints-content li {
    margin-bottom: 0.75rem;
    padding: 0.75rem;
    background: white;
    border-radius: 8px;
    border-left: 4px solid #f59e0b;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    transition: all 0.2s ease;
}

.hints-content li:hover {
    transform: translateX(4px);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.hints-content strong {
    color: #92400e;
}

/* Site Analysis Styles */
.site-container {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

.location-panel, .angle-panel, .performance-impact {
    background: white;
    padding: 1.5rem;
    border-radius: 15px;
    border: 1px solid #e5e7eb;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.location-panel h3, .angle-panel h3, .performance-impact h3 {
    color: #2563eb;
    margin-bottom: 1rem;
    font-size: 1.3rem;
    font-weight: 600;
}

.location-selector {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.location-dropdown {
    padding: 0.75rem;
    border: 2px solid #d1d5db;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s ease;
    background: white;
    font-weight: 500;
}

.location-dropdown:focus {
    outline: none;
    border-color: #2563eb;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.location-info h4 {
    color: #374151;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.angle-control {
    margin-bottom: 1.5rem;
}

.angle-control label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #374151;
}

.angle-slider {
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: #e5e7eb;
    outline: none;
    margin-bottom: 0.5rem;
    transition: all 0.3s ease;
}

.angle-slider::-webkit-slider-thumb {
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: #2563eb;
    cursor: pointer;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease;
}

.angle-slider::-webkit-slider-thumb:hover {
    background: #1d4ed8;
    transform: scale(1.1);
}

.angle-slider::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: #2563eb;
    cursor: pointer;
    border: none;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

#tilt-display, #azimuth-display {
    display: inline-block;
    font-weight: 600;
    color: #2563eb;
    font-size: 1.1rem;
}

.optimal-indicator {
    font-size: 0.875rem;
    color: #059669;
    font-weight: 500;
    margin-top: 0.25rem;
}

.angle-explanation, .lat-explanation {
    margin-top: var(--space-3);
    padding: var(--space-2) var(--space-3);
    background: var(--gray-50);
    border-radius: 6px;
    border-left: 3px solid var(--primary);
}

.angle-explanation p, .lat-explanation p {
    margin: 0;
    color: var(--gray-600);
    font-style: italic;
    line-height: 1.4;
}

.azimuth-compass {
    margin-top: 1rem;
    text-align: center;
}

.compass-directions {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.5rem;
    font-size: 0.875rem;
    color: #6b7280;
}

.hemisphere-note {
    margin-top: 0.5rem;
    padding: 0.5rem;
    background: #fef3c7;
    border: 1px solid #f59e0b;
    border-radius: 6px;
    font-size: 0.875rem;
    color: #92400e;
    text-align: center;
    display: none;
}

.impact-grid {
    display: grid;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.impact-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem;
    background: #f8fafc;
    border-radius: 8px;
    border: 1px solid #e5e7eb;
}

.impact-item label {
    font-weight: 600;
    color: #374151;
}

.impact-item span {
    color: #2563eb;
    font-weight: 600;
}

.site-recommendations h4 {
    color: #374151;
    margin-bottom: 0.75rem;
    font-weight: 600;
}

.site-recommendations ul {
    list-style: none;
    padding: 0;
}

.site-recommendations li {
    padding: 0.5rem 0;
    color: #6b7280;
    font-size: 0.9rem;
    border-bottom: 1px solid #f3f4f6;
}

.site-recommendations li:before {
    content: '✓';
    color: #059669;
    font-weight: bold;
    margin-right: 0.5rem;
}

/* DC Load Analysis Styles */
.dc-load-analysis {
    background: white;
    padding: 1.5rem;
    border-radius: 15px;
    border: 1px solid #e5e7eb;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    margin-bottom: 2rem;
}

.dc-load-analysis h3 {
    color: #dc2626;
    margin-bottom: 1rem;
    font-size: 1.3rem;
    font-weight: 600;
}

.dc-load-table {
    overflow-x: auto;
}

.dc-load-table table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: 10px;
    overflow: hidden;
    border: 1px solid #e5e7eb;
}

.dc-load-table th,
.dc-load-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid #f3f4f6;
}

.dc-load-table th {
    background: #dc2626;
    color: white;
    font-weight: 600;
}

.dc-load-table .total-row {
    background: #fef2f2;
    font-weight: 600;
    color: #dc2626;
}

/* System Simulation Styles */
.simulation-container {
    display: grid;
    gap: 2rem;
}

.simulation-controls {
    background: white;
    padding: 1.5rem;
    border-radius: 15px;
    border: 1px solid #e5e7eb;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.simulation-controls h3 {
    color: #2563eb;
    margin-bottom: 1rem;
    font-size: 1.3rem;
    font-weight: 600;
}

.control-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.control-item {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.control-item label {
    font-weight: 600;
    color: #374151;
    font-size: 0.9rem;
}

.control-item span, .control-item select {
    padding: 0.5rem;
    border: 1px solid #e5e7eb;
    border-radius: 6px;
    background: #f8fafc;
    font-weight: 500;
    color: #2563eb;
}

.control-item select {
    background: white;
    cursor: pointer;
    transition: all 0.3s ease;
}

.control-item select:focus {
    outline: none;
    border-color: #2563eb;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.simulate-button {
    width: 100%;
    padding: 1rem 2rem;
    background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 6px rgba(37, 99, 235, 0.2);
}

.simulate-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(37, 99, 235, 0.3);
    background: linear-gradient(135deg, #1d4ed8 0%, #1e40af 100%);
}

.simulation-results {
    background: white;
    padding: 1.5rem;
    border-radius: 15px;
    border: 1px solid #e5e7eb;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.simulation-results h3 {
    color: #2563eb;
    margin-bottom: 1rem;
    font-size: 1.3rem;
    font-weight: 600;
}

.chart-container {
    margin: 2rem 0;
    text-align: center;
}

.summary-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-box {
    text-align: center;
    padding: 1rem;
    background: #f8fafc;
    border-radius: 10px;
    border: 1px solid #e5e7eb;
}

.stat-value {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: #2563eb;
    margin-bottom: 0.25rem;
}

.stat-label {
    font-size: 0.875rem;
    color: #6b7280;
    font-weight: 500;
}

.performance-insights h4 {
    color: #374151;
    margin-bottom: 1rem;
    font-weight: 600;
}

.performance-insights ul {
    list-style: none;
    padding: 0;
}

.performance-insights li {
    padding: 0.75rem;
    margin-bottom: 0.5rem;
    background: #f0f9ff;
    border-left: 4px solid #2563eb;
    border-radius: 0 6px 6px 0;
    color: #1e40af;
    font-weight: 500;
}

/* Power Flow Animation */
.power-flow {
    stroke-dasharray: 10,5;
    animation: powerFlowAnimation 2s linear infinite;
}

@keyframes powerFlowAnimation {
    0% { stroke-dashoffset: 0; }
    100% { stroke-dashoffset: -15; }
}

.power-label {
    font-weight: 600;
    font-size: 14px;
    fill: #059669;
}

/* Inverter Selection Styles */
.inverter-container {
    display: grid;
    gap: 2rem;
}

.load-analysis {
    background: white;
    padding: 1.5rem;
    border-radius: 15px;
    border: 1px solid #e5e7eb;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.load-analysis h3 {
    color: #a855f7;
    margin-bottom: 1rem;
    font-size: 1.3rem;
    font-weight: 600;
}

.load-table {
    overflow-x: auto;
}

.load-table table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: 10px;
    overflow: hidden;
    border: 1px solid #e5e7eb;
}

.load-table th,
.load-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid #f3f4f6;
}

.load-table th {
    background: #a855f7;
    color: white;
    font-weight: 600;
}

.load-table .total-row {
    background: #faf5ff;
    font-weight: 600;
    color: #a855f7;
}

.inverter-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-top: 1rem;
}

.inverter-card {
    background: white;
    border: 2px solid #e5e7eb;
    border-radius: 15px;
    padding: 1.5rem;
    transition: all 0.3s ease;
    position: relative;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.inverter-card:hover {
    border-color: #a855f7;
    transform: translateY(-5px);
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

.inverter-card h4 {
    color: #1f2937;
    margin-bottom: 1rem;
    font-size: 1.2rem;
}

.inverter-specs p {
    margin-bottom: 0.5rem;
    color: #4b5563;
}

.inverter-specs strong {
    color: #1f2937;
}

.inverter-card.selected {
    border-color: #059669;
    background: linear-gradient(135deg, #f0fdf4 0%, #ecfdf5 100%);
    box-shadow: 0 0 0 3px rgba(5, 150, 105, 0.1);
}

.inverter-card.selected .select-inverter {
    background: linear-gradient(135deg, #059669 0%, #047857 100%);
    box-shadow: 0 4px 6px rgba(5, 150, 105, 0.2);
}

.inverter-card.incorrect {
    border-color: #dc2626;
    background: linear-gradient(135deg, #fef2f2 0%, #fee2e2 100%);
    box-shadow: 0 0 0 3px rgba(220, 38, 38, 0.1);
}

.inverter-card.incorrect .select-inverter {
    background: linear-gradient(135deg, #dc2626 0%, #b91c1c 100%);
    box-shadow: 0 4px 6px rgba(220, 38, 38, 0.2);
}

/* Modal Styles */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
    animation: modalFadeIn 0.3s ease;
}

@keyframes modalFadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.modal-content {
    background-color: white;
    margin: 5% auto;
    padding: 2rem;
    border-radius: 20px;
    width: 90%;
    max-width: 600px;
    max-height: 80vh;
    overflow-y: auto;
    position: relative;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    animation: modalSlideIn 0.3s ease;
}

@keyframes modalSlideIn {
    from { transform: translateY(-50px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.close {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    transition: color 0.3s ease;
}

.close:hover {
    color: #667eea;
}

#modal-title, #help-title {
    color: #333;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid #667eea;
}

#modal-body, #help-body {
    line-height: 1.8;
    color: #4b5563;
}

.modal-section {
    margin-bottom: 1.5rem;
}

.modal-section h4 {
    color: #667eea;
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.modal-formula {
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    border: 1px solid #cbd5e1;
    border-radius: 8px;
    padding: 1rem;
    margin: 1rem 0;
    font-family: 'Courier New', monospace;
    font-size: 0.95rem;
    color: #334155;
}

.parameter-list {
    list-style-type: none;
    padding-left: 0;
}

.parameter-list li {
    margin-bottom: 0.5rem;
    padding: 0.5rem;
    background: #f1f5f9;
    border-radius: 6px;
    border-left: 3px solid #667eea;
}

.parameter-list strong {
    color: #334155;
}

/* Responsive Design */
@media (max-width: 768px) {
    .title {
        font-size: 2rem;
    }
    
    .nav-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .nav-btn {
        width: 80%;
        max-width: 300px;
    }
    
    .config-container,
    .site-container {
        grid-template-columns: 1fr;
    }
    
    .controller-grid,
    .inverter-grid {
        grid-template-columns: 1fr;
    }
    
    .spec-grid,
    .results-grid,
    .summary-grid,
    .control-grid,
    .summary-stats {
        grid-template-columns: 1fr;
    }
    
    .panel-selector {
        flex-direction: column;
        align-items: stretch;
    }
    
    .panel-selector label {
        min-width: auto;
        margin-bottom: 0.5rem;
    }
    
    .site-container {
        grid-template-columns: 1fr;
    }
    
    .compass-directions {
        grid-template-columns: 1fr;
    }
    
    .modal-content {
        width: 95%;
        margin: 10% auto;
        padding: 1.5rem;
    }
    
    .section {
        padding: 1rem;
    }
    
    .section-header {
        margin: -1rem -1rem 2rem -1rem;
        padding: 1.5rem 1rem 1rem 1rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 10px;
    }
    
    .title {
        font-size: 1.8rem;
    }
    
    .subtitle {
        font-size: 1rem;
    }
    
    .section-header h2 {
        font-size: 1.5rem;
    }
    
    .input-group {
        flex-direction: column;
        align-items: stretch;
        gap: 0.5rem;
    }
    
    .load-table,
    .dc-load-table {
        font-size: 0.9rem;
    }
    
    .load-table th,
    .load-table td,
    .dc-load-table th,
    .dc-load-table td {
        padding: 0.5rem;
    }
    
    .angle-control {
        margin-bottom: 1rem;
    }
    
    .stat-value {
        font-size: 1.5rem;
    }
    
    .nav-btn {
        width: 90%;
        padding: 0.6rem 1rem;
        font-size: 0.8rem;
    }
}

/* Print Styles */
@media print {
    body {
        background: white;
        color: black;
    }
    
    .header,
    .nav {
        display: none;
    }
    
    .main-content {
        box-shadow: none;
        margin: 0;
    }
    
    .section {
        display: block !important;
        page-break-after: always;
    }
    
    .modal {
        display: none !important;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* High contrast mode */
@media (prefers-contrast: high) {
    .component {
        stroke-width: 4;
    }
    
    .nav-btn,
    .select-controller,
    .select-inverter,
    .proceed-btn {
        border: 2px solid currentColor;
    }
}

/* Dynamic System Info Styles */
.detailed-system-info {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    font-size: 0.9rem;
}

/* Hints Images */
.hints-visual {
    text-align: center;
    margin-bottom: 1rem;
    padding: 1rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 8px;
}

.hints-image {
    max-width: 100%;
    height: auto;
    border-radius: 6px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

/* Category Badges - MPPT and Inverter */
.controller-category-badge,
.inverter-category-badge {
    position: absolute;
    top: -8px;
    right: -8px;
    padding: 0.25rem 0.5rem;
    font-size: 0.7rem;
    font-weight: 600;
    border-radius: 12px;
    color: white;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    z-index: 10;
}

.controller-category-badge.small,
.inverter-category-badge.small {
    background: #10b981;
}

.controller-category-badge.medium,
.inverter-category-badge.medium {
    background: #3b82f6;
}

.controller-category-badge.large,
.inverter-category-badge.large {
    background: #8b5cf6;
}

.controller-category-badge.commercial,
.inverter-category-badge.commercial {
    background: #f59e0b;
}

.controller-category-badge.utility,
.inverter-category-badge.utility {
    background: #ef4444;
}

.inverter-features {
    margin-top: 0.5rem;
    padding-top: 0.5rem;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
}

.inverter-features p {
    font-size: 0.85rem;
    color: #6b7280;
    margin-bottom: 0;
}

.detailed-system-info p {
    margin-bottom: 0.4rem;
    opacity: 0.9;
    line-height: 1.4;
}

/* System Review Section Styles */
.review-diagram-container {
    display: flex;
    gap: 2rem;
    padding: 2rem;
    max-width: 1400px;
    margin: 0 auto;
}

.diagram-container {
    flex: 2;
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    padding: 1rem;
}

.component-info-sidebar {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.component-info-card {
    background: linear-gradient(135deg, #1e40af 0%, #1e3a8a 100%);
    border-radius: 12px;
    padding: 1.5rem;
    color: white;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.component-info-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.25);
}

.component-info-card h4 {
    margin-bottom: 1rem;
    font-size: 1.1rem;
    font-weight: 600;
    color: #ffffff;
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
    padding-bottom: 0.5rem;
}

.info-details {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.info-details p {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin: 0;
    padding: 0.25rem 0;
    font-size: 0.9rem;
}

.info-details strong {
    font-weight: 500;
    opacity: 0.9;
}

.info-details span {
    font-weight: 600;
    color: #fbbf24;
}

/* Special styling for compatibility check */
#compatibility-info {
    background: linear-gradient(135deg, #059669 0%, #047857 100%);
}

.compatibility-results {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.compatibility-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.25rem 0;
    font-size: 0.9rem;
}

.status-icon {
    font-size: 1.1rem;
    width: 1.5rem;
    text-align: center;
}

.status-icon.success {
    color: #10b981;
}

.status-icon.warning {
    color: #f59e0b;
}

.status-icon.error {
    color: #ef4444;
}

.status-icon.pending {
    color: #6b7280;
    animation: pulse 2s infinite;
}

/* Action buttons */
.review-actions {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-top: 2rem;
    padding: 0 2rem;
}

.review-actions .btn {
    padding: 1rem 2rem;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 8px;
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    min-width: 200px;
}

.btn-secondary {
    background: #6b7280;
    color: white;
}

.btn-secondary:hover {
    background: #4b5563;
    transform: translateY(-1px);
}

.btn-primary {
    background: linear-gradient(135deg, #059669 0%, #047857 100%);
    color: white;
}

.btn-primary:hover {
    background: linear-gradient(135deg, #047857 0%, #065f46 100%);
    transform: translateY(-1px);
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

/* Responsive design for review section */
@media (max-width: 768px) {
    .review-diagram-container {
        flex-direction: column;
        padding: 1rem;
        gap: 1rem;
    }
    
    .component-info-sidebar {
        order: -1;
    }
    
    .review-actions {
        flex-direction: column;
        align-items: center;
        padding: 0 1rem;
    }
    
    .review-actions .btn {
        width: 100%;
        max-width: 300px;
    }
}