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

body {
    background: #0f172a;
    color: #e2e8f0;
    font-family: Arial, Helvetica, sans-serif;
    min-height: 100vh;
}

.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 30px;
    background: #111827;
    border-bottom: 1px solid #334155;
}

.app-header h1 {
    font-size: 28px;
    margin-bottom: 6px;
}

.app-header p {
    color: #94a3b8;
}

.header-link {
    text-decoration: none;
    color: white;
    background: #2563eb;
    padding: 10px 18px;
    border-radius: 8px;
}

.page-shell {
    max-width: 1800px;
    margin: 0 auto;
    padding: 20px;
}

.panel {
    background: #1e293b;
    border: 1px solid #334155;
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 20px;
}

.panel h2 {
    margin-bottom: 20px;
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 15px;
}

.slider-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 20px;
}

label {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.checkbox-label input[type="checkbox"] {
    width: 22px;
    height: 22px;
}

select,
input[type="range"] {
    width: 100%;
}

select {
    background: #0f172a;
    color: white;
    border: 1px solid #475569;
    border-radius: 8px;
    padding: 10px;
}

.primary-button {
    margin-top: 20px;
    padding: 12px 20px;
    background: #16a34a;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
}

.primary-button:hover {
    background: #15803d;
}

.result-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 15px;
}

.result-card {
    background: #0f172a;
    border: 1px solid #334155;
    border-radius: 10px;
    padding: 15px;
}

.result-card span {
    display: block;
    color: #94a3b8;
    margin-bottom: 8px;
}

.result-card strong {
    display: block;
    font-size: 28px;
    margin-bottom: 4px;
}

.result-card small {
    color: #64748b;
}

.result-notes {
    margin-top: 20px;
    padding: 15px;
    background: #0f172a;
    border-radius: 10px;
    border: 1px solid #334155;
}

.balance-card {
    border-width: 2px;
}

.balance-good {
    color: #22c55e;
}

.balance-warning {
    color: #f59e0b;
}

.balance-bad {
    color: #ef4444;
}

.balance-helper {
    margin-top: 10px;
    color: #cbd5e1;
    font-size: 14px;
    line-height: 1.4;
}

.balance-explainer {
    margin-top: 20px;
    padding: 15px;
    background: #0f172a;
    border: 1px solid #334155;
    border-radius: 10px;
}

.balance-explainer strong {
    display: block;
    margin-bottom: 8px;
}

.balance-explainer p {
    color: #cbd5e1;
    line-height: 1.5;
}

.refrig-diagram {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

.component {
    width: 420px;
    background: #0f172a;
    border: 1px solid #334155;
    border-radius: 12px;
    padding: 15px;
    text-align: center;
}

.component h3 {
    margin-bottom: 15px;
}

.vertical-line {
    width: 4px;
    height: 40px;
    background: #2563eb;
}

.data {
    margin-bottom: 10px;
}

.data strong {
    display: block;
    font-size: 22px;
}

.diagram-header-row {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 20px;
    margin-bottom: 20px;
}

.diagram-subtitle {
    color: #94a3b8;
    line-height: 1.5;
}

.diagram-view-control {
    min-width: 260px;
}

.refrigeration-circuit {
    position: relative;
    min-height: 760px;
    background:
        linear-gradient(rgba(148, 163, 184, 0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(148, 163, 184, 0.05) 1px, transparent 1px),
        #0f172a;
    background-size: 32px 32px;
    border: 1px solid #334155;
    border-radius: 16px;
    padding: 30px;
    overflow: hidden;
}

.circuit-component,
.circuit-summary-card {
    position: absolute;
    background: #1e293b;
    border: 2px solid #475569;
    border-radius: 14px;
    padding: 16px;
    z-index: 3;
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.25);
}

.circuit-component h3,
.circuit-summary-card h3 {
    margin-bottom: 14px;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-size: 14px;
    color: #e2e8f0;
}

.circuit-data-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(120px, 1fr));
    gap: 12px;
}

.circuit-data-grid .data {
    background: #0f172a;
    border: 1px solid #334155;
    border-radius: 10px;
    padding: 10px;
    margin-bottom: 0;
}

.circuit-data-grid .data div {
    color: #94a3b8;
    font-size: 13px;
    margin-bottom: 6px;
}

.circuit-data-grid .data strong {
    font-size: 22px;
}

.circuit-data-grid .data small {
    color: #64748b;
}

.circuit-line {
    position: absolute;
    z-index: 1;
}

.circuit-line::after {
    content: "";
    position: absolute;
    width: 0;
    height: 0;
}

.circuit-line span {
    position: absolute;
    display: inline-block;
    background: #111827;
    border: 1px solid #334155;
    border-radius: 999px;
    padding: 5px 10px;
    color: #cbd5e1;
    font-size: 12px;
    white-space: nowrap;
}

.circuit-line-discharge,
.circuit-line-liquid {
    background: #ef4444;
}

.circuit-line-expansion {
    background: #f59e0b;
}

.circuit-line-suction {
    background: #2563eb;
}

.schematic-loop-svg {
    display: none;
}

/* Schematic closed-loop refrigeration view */
.circuit-schematic {
    min-height: 760px;
}

.circuit-schematic .schematic-loop-svg {
    display: block;
    position: absolute;
    inset: 55px 50px 135px 50px;
    z-index: 1;
    overflow: visible;
}

.schematic-pipe {
    fill: none;
    stroke-width: 18;
    stroke-linecap: round;
    stroke-linejoin: round;
    opacity: 0.92;
}

.suction-pipe {
    stroke: #22d3ee;
}

.discharge-pipe {
    stroke: #ef4444;
}

.liquid-pipe {
    stroke: #f97316;
}

.expansion-pipe {
    stroke: #f59e0b;
}

.schematic-line-label {
    fill: #cbd5e1;
    font-size: 28px;
    font-weight: 700;
    letter-spacing: 0.02em;
}

.circuit-schematic .circuit-line {
    display: none;
}

.circuit-schematic .circuit-compressor {
    top: 50px;
    left: 50%;
    width: 380px;
    transform: translateX(-50%);
}

.circuit-schematic .circuit-evaporator {
    top: 245px;
    left: 85px;
    width: 370px;
}

.circuit-schematic .circuit-condenser {
    top: 245px;
    right: 85px;
    width: 370px;
}

.circuit-schematic .circuit-txv {
    top: 505px;
    left: 50%;
    width: 280px;
    transform: translateX(-50%);
}

.circuit-schematic .circuit-summary-card {
    left: 50%;
    bottom: 30px;
    width: 760px;
    transform: translateX(-50%);
}

.circuit-schematic .circuit-summary-card .circuit-data-grid {
    grid-template-columns: repeat(4, minmax(120px, 1fr));
}

/* Industrial / P&ID style */
.circuit-industrial {
    min-height: 720px;
}

.circuit-industrial .schematic-loop-svg {
    display: none;
}

.circuit-industrial .circuit-component,
.circuit-industrial .circuit-summary-card {
    border-radius: 4px;
    box-shadow: none;
}

.circuit-industrial .circuit-condenser {
    top: 60px;
    left: 80px;
    width: 380px;
}

.circuit-industrial .circuit-txv {
    top: 60px;
    left: 560px;
    width: 280px;
}

.circuit-industrial .circuit-evaporator {
    top: 60px;
    right: 80px;
    width: 380px;
}

.circuit-industrial .circuit-compressor {
    bottom: 80px;
    left: 80px;
    width: 420px;
}

.circuit-industrial .circuit-summary-card {
    bottom: 80px;
    right: 80px;
    width: 420px;
}

.circuit-industrial .circuit-line-condenser-to-txv {
    top: 145px;
    left: 460px;
    width: 100px;
    height: 4px;
}

.circuit-industrial .circuit-line-condenser-to-txv::after {
    right: -10px;
    top: -6px;
    border-top: 8px solid transparent;
    border-bottom: 8px solid transparent;
    border-left: 12px solid #ef4444;
}

.circuit-industrial .circuit-line-condenser-to-txv span {
    top: -34px;
    left: 10px;
}

.circuit-industrial .circuit-line-txv-to-evaporator {
    top: 145px;
    left: 840px;
    width: calc(100% - 1300px);
    min-width: 130px;
    height: 4px;
}

.circuit-industrial .circuit-line-txv-to-evaporator::after {
    right: -10px;
    top: -6px;
    border-top: 8px solid transparent;
    border-bottom: 8px solid transparent;
    border-left: 12px solid #f59e0b;
}

.circuit-industrial .circuit-line-txv-to-evaporator span {
    top: -34px;
    left: 12px;
}

.circuit-industrial .circuit-line-evaporator-to-compressor {
    bottom: 195px;
    left: 500px;
    width: calc(100% - 1000px);
    min-width: 260px;
    height: 4px;
}

.circuit-industrial .circuit-line-evaporator-to-compressor::after {
    left: -10px;
    top: -6px;
    border-top: 8px solid transparent;
    border-bottom: 8px solid transparent;
    border-right: 12px solid #2563eb;
}

.circuit-industrial .circuit-line-evaporator-to-compressor span {
    top: -34px;
    left: 40px;
}

.circuit-industrial .circuit-line-compressor-to-condenser {
    top: 220px;
    left: 260px;
    width: 4px;
    height: 290px;
}

.circuit-industrial .circuit-line-compressor-to-condenser::after {
    top: -10px;
    left: -6px;
    border-left: 8px solid transparent;
    border-right: 8px solid transparent;
    border-bottom: 12px solid #ef4444;
}

.circuit-industrial .circuit-line-compressor-to-condenser span {
    top: 130px;
    left: 12px;
}

.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.75);
    display: none;
    justify-content: center;
    align-items: center;
    z-index: 9999;
}

.modal-visible {
    display: flex;
}

.modal-card {
    width: min(500px, 90vw);
    background: #1e293b;
    border: 1px solid #334155;
    border-radius: 12px;
    padding: 24px;
    text-align: center;
}

.modal-card h3 {
    margin-bottom: 16px;
}

.modal-card p {
    margin-bottom: 20px;
    line-height: 1.5;
    color: #cbd5e1;
}

@media (max-width: 1100px) {
    .refrigeration-circuit {
        min-height: auto;
        display: flex;
        flex-direction: column;
        gap: 14px;
    }

    .schematic-loop-svg {
        display: none !important;
    }

    .circuit-component,
    .circuit-summary-card,
    .circuit-schematic .circuit-component,
    .circuit-schematic .circuit-summary-card,
    .circuit-industrial .circuit-component,
    .circuit-industrial .circuit-summary-card {
        position: static;
        width: 100%;
        transform: none;
    }

    .circuit-schematic .circuit-summary-card .circuit-data-grid {
        grid-template-columns: repeat(2, minmax(120px, 1fr));
    }

    .circuit-schematic .circuit-line {
        display: block;
    }

    .circuit-line,
    .circuit-schematic .circuit-line-compressor-to-condenser,
    .circuit-schematic .circuit-line-condenser-to-txv,
    .circuit-schematic .circuit-line-txv-to-evaporator,
    .circuit-schematic .circuit-line-evaporator-to-compressor,
    .circuit-industrial .circuit-line-compressor-to-condenser,
    .circuit-industrial .circuit-line-condenser-to-txv,
    .circuit-industrial .circuit-line-txv-to-evaporator,
    .circuit-industrial .circuit-line-evaporator-to-compressor {
        position: relative;
        top: auto;
        right: auto;
        bottom: auto;
        left: auto;
        width: 4px;
        height: 36px;
        margin: 0 auto;
        transform: none;
    }

    .circuit-line span {
        left: 16px;
        top: 8px;
    }

    .diagram-header-row {
        flex-direction: column;
    }

    .diagram-view-control {
        width: 100%;
    }
}

@media (max-width: 768px) {
    .app-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 15px;
    }

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

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

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

    .circuit-data-grid {
        grid-template-columns: 1fr;
    }

    .circuit-schematic .circuit-summary-card .circuit-data-grid {
        grid-template-columns: 1fr;
    }
}