/* CSS Variables for Dark/Light Themes */
:root {
    /* Dark theme (default) */
    --bg-primary: #0a0b0d;
    --bg-secondary: #1a1d23;
    --bg-tertiary: #252832;
    --bg-accent: #2d3140;
    
    --text-primary: #e4e6ea;
    --text-secondary: #b0b3b8;
    --text-muted: #8a8d93;
    
    --border-primary: #3a3d4a;
    --border-secondary: #252832;
    
    --accent-primary: #00d4ff;
    --accent-secondary: #0099cc;
    --accent-gradient: linear-gradient(135deg, #00d4ff 0%, #0099cc 100%);
    
    --success-color: #00c851;
    --success-bg: rgba(0, 200, 81, 0.1);
    
    --warning-color: #ffbb33;
    --warning-bg: rgba(255, 187, 51, 0.1);
    
    --error-color: #ff4444;
    --error-bg: rgba(255, 68, 68, 0.1);
    
    --shadow-light: rgba(0, 0, 0, 0.2);
    --shadow-medium: rgba(0, 0, 0, 0.4);
    --shadow-heavy: rgba(0, 0, 0, 0.6);
    
    --blur-light: blur(10px);
    --blur-medium: blur(20px);
    
    --transition-fast: all 0.2s ease;
    --transition-medium: all 0.3s ease;
    --transition-slow: all 0.5s ease;
    
    --border-radius: 12px;
    --border-radius-large: 20px;
}

/* Light theme */
[data-theme="light"] {
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #ffffff;
    --bg-accent: #f1f3f4;
    
    --text-primary: #1a1a1a;
    --text-secondary: #4a5568;
    --text-muted: #718096;
    
    --border-primary: #e2e8f0;
    --border-secondary: #edf2f7;
    
    --accent-primary: #0066cc;
    --accent-secondary: #0052a3;
    --accent-gradient: linear-gradient(135deg, #0066cc 0%, #0052a3 100%);
    
    --success-color: #00a041;
    --success-bg: rgba(0, 160, 65, 0.1);
    
    --shadow-light: rgba(0, 0, 0, 0.05);
    --shadow-medium: rgba(0, 0, 0, 0.1);
    --shadow-heavy: rgba(0, 0, 0, 0.15);
}

/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-primary);
    transition: var(--transition-medium);
    overflow-x: hidden;
}

/* Custom scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--accent-primary);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-secondary);
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 24px;
    position: relative;
}

/* Theme Toggle */
.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    background: var(--bg-secondary);
    border: 2px solid var(--border-primary);
    border-radius: 50px;
    padding: 8px;
    cursor: pointer;
    transition: var(--transition-medium);
    backdrop-filter: var(--blur-light);
    box-shadow: 0 8px 32px var(--shadow-medium);
}

.theme-toggle:hover {
    transform: scale(1.05);
    box-shadow: 0 12px 40px var(--shadow-heavy);
}

.theme-toggle-icon {
    width: 24px;
    height: 24px;
    color: var(--accent-primary);
    transition: var(--transition-fast);
}

/* Header styles */
header {
    text-align: center;
    margin-bottom: 48px;
    padding: 48px 32px;
    background: var(--accent-gradient);
    color: white;
    border-radius: var(--border-radius-large);
    box-shadow: 0 20px 60px var(--shadow-heavy);
    position: relative;
    overflow: hidden;
}

header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E") repeat;
    opacity: 0.1;
}

header h1 {
    font-size: 3.5rem;
    margin-bottom: 16px;
    font-weight: 700;
    letter-spacing: -0.02em;
    position: relative;
    text-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

header p {
    font-size: 1.25rem;
    opacity: 0.95;
    position: relative;
    max-width: 600px;
    margin: 0 auto;
}

/* Form styles */
#manual-j-form {
    background: var(--bg-secondary);
    padding: 40px;
    border-radius: var(--border-radius-large);
    box-shadow: 0 20px 60px var(--shadow-medium);
    margin-bottom: 32px;
    border: 1px solid var(--border-primary);
    backdrop-filter: var(--blur-medium);
}

.form-section {
    margin-bottom: 48px;
    padding-bottom: 32px;
    border-bottom: 1px solid var(--border-primary);
    position: relative;
}

.form-section:last-child {
    border-bottom: none;
    margin-bottom: 0;
}

.form-section h2 {
    color: var(--accent-primary);
    font-size: 1.75rem;
    margin-bottom: 24px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--accent-primary);
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 12px;
}

.form-section h3 {
    color: var(--text-secondary);
    font-size: 1.25rem;
    margin: 32px 0 16px 0;
    font-weight: 600;
}

.form-group {
    margin-bottom: 24px;
    position: relative;
}

.form-group label {
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-secondary);
    font-size: 0.95rem;
    display: block;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 16px 20px;
    border: 2px solid var(--border-primary);
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: var(--transition-medium);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    font-family: inherit;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 4px rgba(0, 212, 255, 0.1);
    transform: translateY(-2px);
}

.form-group input:hover,
.form-group select:hover {
    border-color: var(--accent-secondary);
}

.form-group input[readonly] {
    background: var(--bg-accent);
    color: var(--text-muted);
    cursor: not-allowed;
}

.form-group input:invalid {
    border-color: var(--error-color);
    box-shadow: 0 0 0 4px var(--error-bg);
}

.form-group input:valid {
    border-color: var(--success-color);
}

.calculate-btn {
    background: var(--accent-gradient);
    color: white;
    border: none;
    padding: 20px 48px;
    font-size: 1.2rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition-medium);
    font-weight: 600;
    display: block;
    margin: 40px auto 0;
    min-width: 240px;
    position: relative;
    overflow: hidden;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    box-shadow: 0 8px 32px rgba(0, 212, 255, 0.3);
}

.calculate-btn::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 0.5s;
}

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

.calculate-btn:hover {
    transform: translateY(-4px);
    box-shadow: 0 16px 48px rgba(0, 212, 255, 0.4);
}

.calculate-btn:active {
    transform: translateY(-2px);
}

/* Results styles */
.results-section {
    background: var(--bg-secondary);
    padding: 40px;
    border-radius: var(--border-radius-large);
    box-shadow: 0 20px 60px var(--shadow-medium);
    margin-top: 32px;
    border: 1px solid var(--border-primary);
    backdrop-filter: var(--blur-medium);
}

.results-section h2 {
    color: var(--accent-primary);
    font-size: 2rem;
    margin-bottom: 32px;
    text-align: center;
    border-bottom: 2px solid var(--accent-primary);
    padding-bottom: 16px;
    font-weight: 700;
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
    margin-bottom: 48px;
}

.result-item {
    background: var(--bg-tertiary);
    padding: 32px 24px;
    border-radius: var(--border-radius);
    text-align: center;
    border: 1px solid var(--border-primary);
    transition: var(--transition-medium);
    position: relative;
    overflow: hidden;
}

.result-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: var(--accent-gradient);
}

.result-item:hover {
    transform: translateY(-6px);
    box-shadow: 0 16px 48px var(--shadow-medium);
    border-color: var(--accent-primary);
}

.result-item h3 {
    color: var(--text-secondary);
    font-size: 1rem;
    margin-bottom: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.result-value {
    font-size: 2.25rem;
    font-weight: 800;
    color: var(--accent-primary);
    text-shadow: 0 2px 8px rgba(0, 212, 255, 0.2);
}

.breakdown-section {
    margin-top: 48px;
    padding-top: 32px;
    border-top: 1px solid var(--border-primary);
}

.breakdown-section h3 {
    color: var(--text-secondary);
    font-size: 1.5rem;
    margin-bottom: 24px;
    font-weight: 600;
}

#load-breakdown {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 20px;
}

.breakdown-item {
    background: var(--bg-tertiary);
    padding: 24px;
    border-radius: var(--border-radius);
    border: 1px solid var(--border-primary);
    transition: var(--transition-medium);
    position: relative;
}

.breakdown-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 32px var(--shadow-light);
    border-color: var(--accent-primary);
}

.breakdown-item h4 {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 8px;
    font-weight: 600;
}

.breakdown-value {
    font-weight: 600;
    color: var(--accent-primary);
    font-size: 1rem;
    line-height: 1.4;
}

/* Responsive design */
@media (max-width: 768px) {
    .container {
        padding: 15px;
    }

    header h1 {
        font-size: 2rem;
    }

    header p {
        font-size: 1rem;
    }

    #manual-j-form {
        padding: 20px;
    }

    .form-section h2 {
        font-size: 1.4rem;
    }

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

    .result-value {
        font-size: 1.5rem;
    }
}

@media (max-width: 480px) {
    header {
        padding: 20px;
    }

    header h1 {
        font-size: 1.8rem;
    }

    #manual-j-form {
        padding: 15px;
    }

    .calculate-btn {
        padding: 12px 30px;
        font-size: 1rem;
    }

    .results-section {
        padding: 20px;
    }

    #load-breakdown {
        grid-template-columns: 1fr;
    }
}

/* Animation for results appearing */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.results-section.show {
    animation: fadeIn 0.5s ease;
}

/* Loading state */
.calculate-btn.loading {
    background: #ccc;
    cursor: not-allowed;
}

.calculate-btn.loading::after {
    content: "Calculating...";
}

/* Utility classes */
.text-center {
    text-align: center;
}

.mt-20 {
    margin-top: 20px;
}

.mb-20 {
    margin-bottom: 20px;
}

/* Quick Setup Styles */
.quick-setup {
    background: var(--bg-secondary);
    padding: 32px;
    border-radius: var(--border-radius-large);
    box-shadow: 0 20px 60px var(--shadow-medium);
    margin-bottom: 32px;
    border: 1px solid var(--border-primary);
    backdrop-filter: var(--blur-medium);
}

.quick-setup h2 {
    color: var(--accent-primary);
    font-size: 1.5rem;
    margin-bottom: 24px;
    text-align: center;
    font-weight: 600;
}

.preset-buttons {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 16px;
    margin-bottom: 32px;
}

.preset-btn {
    padding: 20px 24px;
    border: 2px solid var(--border-primary);
    border-radius: var(--border-radius);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition-medium);
    font-weight: 600;
    position: relative;
    overflow: hidden;
}

.preset-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--accent-gradient);
    opacity: 0;
    transition: var(--transition-medium);
}

.preset-btn:hover {
    border-color: var(--accent-primary);
    transform: translateY(-4px);
    box-shadow: 0 12px 32px var(--shadow-light);
}

.preset-btn.active {
    border-color: var(--accent-primary);
    background: var(--accent-gradient);
    color: white;
    box-shadow: 0 8px 32px rgba(0, 212, 255, 0.3);
}

.preset-btn.active::before {
    opacity: 1;
}

.climate-selector {
    display: flex;
    align-items: center;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.climate-selector label {
    font-weight: 600;
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.climate-selector select {
    padding: 12px 16px;
    border: 2px solid var(--border-primary);
    border-radius: var(--border-radius);
    font-size: 1rem;
    background: var(--bg-tertiary);
    color: var(--text-primary);
    min-width: 280px;
    transition: var(--transition-medium);
}

.climate-selector select:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 4px rgba(0, 212, 255, 0.1);
}

/* Form Row Layout */
.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
    margin-bottom: 24px;
}

/* Small helper text */
.form-group small {
    display: block;
    margin-top: 8px;
    color: var(--text-muted);
    font-size: 0.85rem;
    font-style: italic;
}

/* Advanced Settings Toggle */
.advanced-toggle {
    text-align: center;
    margin: 32px 0;
}

.advanced-toggle button {
    background: var(--bg-tertiary);
    border: 2px solid var(--border-primary);
    color: var(--text-secondary);
    padding: 12px 24px;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 1rem;
    transition: var(--transition-medium);
    font-weight: 600;
}

.advanced-toggle button:hover {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(0, 212, 255, 0.2);
}

/* Loading Animation */
@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.calculate-btn.loading {
    background: var(--bg-accent);
    cursor: not-allowed;
    color: var(--text-muted);
    position: relative;
    overflow: hidden;
}

.calculate-btn.loading::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, var(--accent-primary), transparent);
    animation: shimmer 2s infinite;
    opacity: 0.3;
}

.calculate-btn.loading::after {
    content: "Calculating...";
    position: relative;
    z-index: 1;
}

/* Error and success states */
.error {
    background: var(--error-bg);
    border-color: var(--error-color) !important;
    color: var(--error-color);
}

.success {
    background: var(--success-bg);
    border-color: var(--success-color) !important;
    color: var(--success-color);
}

/* Enhanced Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 16px;
    }

    header h1 {
        font-size: 2.5rem;
    }

    header p {
        font-size: 1.1rem;
    }

    #manual-j-form {
        padding: 24px;
    }

    .quick-setup {
        padding: 24px;
    }

    .form-section h2 {
        font-size: 1.5rem;
    }

    .form-row {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .preset-buttons {
        grid-template-columns: 1fr;
    }

    .climate-selector {
        flex-direction: column;
        gap: 12px;
    }

    .climate-selector select {
        min-width: 100%;
    }

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

    .result-value {
        font-size: 1.8rem;
    }

    .theme-toggle {
        top: 16px;
        right: 16px;
    }
}

@media (max-width: 480px) {
    header {
        padding: 32px 20px;
    }

    header h1 {
        font-size: 2rem;
    }

    #manual-j-form {
        padding: 20px;
    }

    .quick-setup {
        padding: 20px;
    }

    .calculate-btn {
        padding: 16px 32px;
        font-size: 1.1rem;
        min-width: 200px;
    }

    .results-section {
        padding: 24px;
    }

    #load-breakdown {
        grid-template-columns: 1fr;
    }
}