:root {
    --bg-dark: #0a0c10;
    --sidebar-bg: rgba(18, 20, 26, 0.7);
    --panel-bg: rgba(22, 25, 33, 0.6);
    --text-primary: #e2e8f0;
    --text-secondary: #94a3b8;
    --accent-blue: #3b82f6;
    --accent-purple: #8b5cf6;
    --accent-green: #10b981;
    --accent-red: #ef4444;
    --accent-orange: #f59e0b;
    --border-color: rgba(255, 255, 255, 0.08);
}

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

body,
html {
    height: 100%;
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-primary);
    background-image:
        radial-gradient(circle at 15% 50%, rgba(59, 130, 246, 0.15) 0%, transparent 25%),
        radial-gradient(circle at 85% 30%, rgba(139, 92, 246, 0.15) 0%, transparent 25%);
    overflow: hidden;
}

/* Authentication Overlay */
#auth-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(10, 12, 16, 0.85);
    z-index: 9999;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(15px);
}

.auth-box {
    background: var(--panel-bg);
    border: 1px solid var(--border-color);
    padding: 3rem;
    border-radius: 16px;
    text-align: center;
    max-width: 400px;
    width: 90%;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    animation: fadeIn 0.5s ease-out;
}

.auth-icon {
    font-size: 3rem;
    margin-bottom: 20px;
    color: var(--accent-blue);
}

.auth-box h2 {
    font-size: 1.8rem;
    margin-bottom: 10px;
}

.auth-box p {
    color: var(--text-secondary);
    margin-bottom: 30px;
    font-size: 0.95rem;
}

#auth-pass {
    width: 100%;
    padding: 14px;
    margin-bottom: 20px;
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: #fff;
    font-size: 1.1rem;
    text-align: center;
    outline: none;
    transition: border 0.3s;
}

#auth-pass:focus {
    border-color: var(--accent-blue);
}

#auth-btn,
.action-btn {
    width: 100%;
    padding: 14px;
    background: var(--accent-blue);
    border: none;
    border-radius: 8px;
    color: #fff;
    font-size: 1.1rem;
    cursor: pointer;
    font-weight: 600;
    transition: background 0.3s, transform 0.2s;
}

#auth-btn:hover,
.action-btn:hover {
    background: #2563eb;
    transform: translateY(-2px);
}

/* Layout Grid */
.auth-overlay.hidden {
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.5s ease;
}

/* Mode Toggle */
.mode-toggle {
    display: flex;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 6px;
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.mode-btn {
    background: transparent;
    border: none;
    padding: 6px 12px;
    color: var(--text-muted);
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.mode-btn.active {
    background: var(--accent-blue);
    color: white;
}

.mode-btn:not(.active):hover {
    background: rgba(255, 255, 255, 0.1);
}

.app-container {
    display: flex;
    height: 100vh;
    transition: filter 0.8s ease;
}

.sidebar {
    width: 320px;
    background: var(--sidebar-bg);
    backdrop-filter: blur(12px);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    padding: 24px 0;
    overflow-y: auto;
}

.sidebar-header {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 0 24px 32px;
    border-bottom: 1px solid var(--border-color);
    font-size: 1.2rem;
}

.sidebar-header i {
    color: var(--accent-orange);
    font-size: 1.5rem;
}

.highlight {
    color: var(--accent-blue);
    font-weight: 300;
}

.control-panel {
    padding: 30px 24px;
    flex-grow: 1;
}

.control-panel h3 {
    font-size: 0.9rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 24px;
}

.input-group {
    margin-bottom: 24px;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 0.9rem;
    color: var(--text-primary);
}

.input-group input {
    width: 100%;
    padding: 12px;
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: #fff;
    font-size: 1rem;
    outline: none;
    transition: border 0.3s;
}

.input-group input:focus {
    border-color: var(--accent-blue);
}

.action-btn {
    margin-top: 20px;
}

/* Main Content Area */
.main-content {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    overflow-x: hidden;
    width: calc(100% - 320px);
}

.top-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 30px 40px;
}

.top-nav h2 {
    font-size: 1.5rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 15px;
}

.tag {
    font-size: 0.75rem;
    background: rgba(16, 185, 129, 0.2);
    color: var(--accent-green);
    padding: 4px 10px;
    border-radius: 20px;
    text-transform: uppercase;
    font-weight: 600;
    border: 1px solid rgba(16, 185, 129, 0.4);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 20px;
}

.btn-icon {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 1.2rem;
    cursor: pointer;
    transition: color 0.3s ease;
}

.btn-icon:hover {
    color: var(--text-primary);
}

.outputs-grid {
    padding: 0 40px 40px;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.kpi-card {
    background: var(--panel-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 24px;
    display: flex;
    align-items: center;
    gap: 20px;
    transition: transform 0.3s, box-shadow 0.3s;
}

.kpi-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

.kpi-icon {
    width: 54px;
    height: 54px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.kpi-icon.flow {
    background: rgba(139, 92, 246, 0.1);
    color: var(--accent-purple);
}

.kpi-icon.temp {
    background: rgba(245, 158, 11, 0.1);
    color: var(--accent-orange);
}

.kpi-icon.conv {
    background: rgba(16, 185, 129, 0.1);
    color: var(--accent-green);
}

.kpi-info h3 {
    font-size: 0.95rem;
    color: var(--text-secondary);
    font-weight: 500;
    margin-bottom: 6px;
}

.kpi-value {
    font-size: 2rem;
    font-weight: 700;
}

.kpi-value .unit {
    font-size: 1.1rem;
    font-weight: 400;
    color: var(--text-secondary);
}

.panel {
    background: var(--panel-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 24px;
    display: flex;
    flex-direction: column;
}

.comp-fraction-panel {
    grid-column: span 2;
}

.comp-chart-panel {
    grid-column: span 1;
}

.panel h3 {
    font-size: 1.1rem;
    font-weight: 500;
    margin-bottom: 24px;
    color: var(--text-primary);
}

.chart-container {
    flex-grow: 1;
    position: relative;
    width: 100%;
    height: 100%;
    min-height: 250px;
}

/* Fractions Grid */
.fractions-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.fraction-item {
    background: rgba(0, 0, 0, 0.2);
    border-radius: 10px;
    padding: 16px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border: 1px solid rgba(255, 255, 255, 0.03);
}

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

.fraction-item .value {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--text-primary);
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: scale(0.95);
    }

    to {
        opacity: 1;
        transform: scale(1);
    }
}

@media (max-width: 1200px) {
    .outputs-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .comp-fraction-panel,
    .comp-chart-panel {
        grid-column: span 2;
    }
}