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

:root {
    --bg-primary: #f5f5f5;
    --bg-secondary: #fff;
    --bg-tertiary: #f9f9f9;
    --bg-result: #e8f5e9;
    --border-color: #ddd;
    --text-primary: #333;
    --text-secondary: #555;
    --text-result: #2e7d32;
    --text-result-value: #1b5e20;
    --button-primary: #4CAF50;
    --button-hover: #45a049;
    --input-border: #ccc;
    --grid-color: #e0e0e0;
    --axis-color: #000000;
}

body.dark-mode {
    --bg-primary: #1e1e1e;
    --bg-secondary: #2d2d2d;
    --bg-tertiary: #252525;
    --bg-result: #1a3a1a;
    --border-color: #404040;
    --text-primary: #e0e0e0;
    --text-secondary: #b0b0b0;
    --text-result: #81c784;
    --text-result-value: #a5d6a7;
    --button-primary: #4CAF50;
    --button-hover: #66bb6a;
    --input-border: #505050;
    --grid-color: #404040;
    --axis-color: #ffffff;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    height: 100vh;
    overflow: hidden;
}

.container {
    display: flex;
    height: 100vh;
    width: 100%;
}

/* Left Panel - Formulas */
.left-panel {
    width: 40%;
    background-color: var(--bg-primary);
    display: flex;
    flex-direction: column;
    border-right: 2px solid var(--border-color);
}

.header {
    padding: 20px;
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
}

.header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.header-buttons {
    display: flex;
    gap: 8px;
    align-items: center;
}

.header h1 {
    font-size: 24px;
    color: var(--text-primary);
    margin: 0;
}

.theme-toggle {
    padding: 6px 10px;
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 5px;
    cursor: pointer;
    font-size: 18px;
    transition: background-color 0.3s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    background-color: var(--border-color);
}

.units-button {
    padding: 6px 12px;
    background-color: var(--button-primary);
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: background-color 0.3s;
}

.units-button:hover {
    background-color: var(--button-hover);
}

.clear-all-button {
    width: auto;
    padding: 6px 12px;
    margin: 0;
    background-color: #ff5252;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 12px;
    font-weight: 600;
    transition: background-color 0.3s;
}

.clear-all-button:hover {
    background-color: #ff1744;
}

.search-box {
    width: 100%;
    padding: 10px 15px;
    font-size: 14px;
    border: 1px solid var(--input-border);
    border-radius: 5px;
    outline: none;
    transition: border-color 0.3s;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
}

.search-box:focus {
    border-color: #4CAF50;
}

.formulas-container {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
}

.formula-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 15px;
    margin-bottom: 15px;
    transition: box-shadow 0.3s;
}

.formula-card:hover {
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.formula-card.hidden {
    display: none;
}

.formula-header {
    display: flex;
    align-items: center;
    margin-bottom: 10px;
    gap: 10px;
}

.formula-checkbox {
    width: 20px;
    height: 20px;
    cursor: pointer;
}

.formula-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    flex: 1;
}

.add-instance-button {
    background-color: var(--button-primary);
    color: white;
    border: none;
    padding: 5px 12px;
    border-radius: 4px;
    font-size: 13px;
    cursor: pointer;
    transition: background-color 0.2s;
}

.add-instance-button:hover {
    background-color: var(--button-hover);
}

.instances-container {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-top: 10px;
}

.instance-card {
    background-color: var(--bg-tertiary);
    border-left: 3px solid var(--button-primary);
    padding: 10px;
    border-radius: 4px;
}

.instance-header {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
}

.instance-label {
    flex: 1;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
}

.remove-instance-button {
    background-color: #f44336;
    color: white;
    border: none;
    padding: 2px 8px;
    border-radius: 3px;
    font-size: 12px;
    cursor: pointer;
    transition: background-color 0.2s;
}

.remove-instance-button:hover {
    background-color: #d32f2f;
}

.formula-expression {
    font-size: 18px;
    color: var(--text-secondary);
    margin: 10px 0;
    font-family: 'Courier New', monospace;
    background-color: var(--bg-tertiary);
    padding: 15px;
    border-radius: 5px;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 5px;
    line-height: 2;
}

.fraction {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    vertical-align: middle;
    margin: 0 3px;
}

.numerator {
    display: flex;
    align-items: center;
    gap: 5px;
    border-bottom: 2px solid var(--text-secondary);
    padding: 2px 5px;
}

.denominator {
    display: flex;
    align-items: center;
    gap: 5px;
    padding: 2px 5px;
}

.inline-input {
    width: 50px;
    padding: 4px 6px;
    border: 2px solid #4CAF50;
    border-radius: 4px;
    font-size: 16px;
    font-family: 'Courier New', monospace;
    text-align: center;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    outline: none;
    transition: border-color 0.3s, box-shadow 0.3s;
}

/* Remove number input arrows/spinners */
.inline-input::-webkit-outer-spin-button,
.inline-input::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

.inline-input[type=number] {
    -moz-appearance: textfield;
}

.inline-input:focus {
    border-color: #2196F3;
    box-shadow: 0 0 5px rgba(33, 150, 243, 0.3);
}

.inline-input::placeholder {
    color: #aaa;
    font-style: italic;
}

.formula-result {
    margin-top: 10px;
    padding: 12px;
    background-color: var(--bg-result);
    border-radius: 5px;
    font-size: 14px;
}

.result-row {
    display: flex;
    justify-content: space-between;
    padding: 4px 0;
    border-bottom: 1px solid rgba(128,128,128,0.1);
}

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

.result-label {
    font-weight: 600;
    color: var(--text-result);
    min-width: 140px;
}

.result-value {
    font-weight: 600;
    color: var(--text-result-value);
    text-align: right;
    font-family: 'Courier New', monospace;
}
    font-size: 14px;
}

.result-row {
    display: flex;
    justify-content: space-between;
    padding: 4px 0;
    border-bottom: 1px solid rgba(0,0,0,0.05);
}

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

.result-label {
    font-weight: 600;
    color: #2e7d32;
    min-width: 140px;
}

.result-value {
    font-weight: 600;
    color: #1b5e20;
    text-align: right;
    font-family: 'Courier New', monospace;
}

/* Right Panel - Graph */
.right-panel {
    width: 60%;
    background-color: var(--bg-secondary);
    display: flex;
    flex-direction: column;
}

.graph-header {
    padding: 20px;
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.graph-header h2 {
    font-size: 24px;
    color: var(--text-primary);
}

.graph-controls {
    display: flex;
    gap: 10px;
}

.graph-controls button {
    padding: 8px 16px;
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 14px;
    transition: background-color 0.3s;
}

.graph-controls button:hover {
    background-color: #45a049;
}

#graphCanvas {
    flex: 1;
    width: 100%;
    cursor: move;
}

.definitions-section {
    margin-top: 10px;
    padding: 12px;
    background-color: var(--bg-tertiary);
    border-radius: 5px;
    border-left: 3px solid var(--button-primary);
    display: flex;
    flex-direction: column;
    gap: 8px;
}

/* 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);
    align-items: center;
    justify-content: center;
}

.modal-content {
    background-color: var(--bg-secondary);
    padding: 30px;
    border-radius: 8px;
    max-width: 500px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    position: relative;
}

.units-modal-content {
    max-width: 600px;
}

.close-modal {
    position: absolute;
    top: 10px;
    right: 15px;
    font-size: 28px;
    font-weight: bold;
    color: var(--text-secondary);
    cursor: pointer;
    transition: color 0.2s;
}

.close-modal:hover {
    color: var(--text-primary);
}

.modal-content h2 {
    color: var(--text-primary);
    margin-bottom: 20px;
    font-size: 22px;
}

.units-container {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin-bottom: 20px;
}

.unit-category {
    display: flex;
    align-items: center;
    gap: 15px;
}

.unit-label {
    color: var(--text-primary);
    font-weight: 500;
    min-width: 150px;
}

.unit-select {
    flex: 1;
    padding: 8px 12px;
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 5px;
    font-size: 14px;
    cursor: pointer;
}

.unit-select:focus {
    outline: none;
    border-color: var(--button-primary);
}

.save-units-button {
    width: 100%;
    padding: 10px;
    background-color: var(--button-primary);
    color: white;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.3s;
}

.save-units-button:hover {
    background-color: var(--button-hover);
}

.definition-item {
    display: flex;
    gap: 10px;
    padding: 6px;
    font-size: 13px;
}

.variable-label {
    font-weight: bold;
    color: var(--button-primary);
    min-width: 60px;
    font-family: 'Courier New', monospace;
}

.definition-text {
    color: var(--text-primary);
    flex: 1;
}

/* Scrollbar styling */
.formulas-container::-webkit-scrollbar {
    width: 8px;
}

.formulas-container::-webkit-scrollbar-track {
    background: #f1f1f1;
}

.formulas-container::-webkit-scrollbar-thumb {
    background: #888;
    border-radius: 4px;
}

.formulas-container::-webkit-scrollbar-thumb:hover {
    background: #555;
}

/* Graph hover tooltip */
.graph-tooltip {
    position: absolute;
    background-color: rgba(0, 0, 0, 0.85);
    color: white;
    padding: 8px 12px;
    border-radius: 6px;
    font-size: 13px;
    pointer-events: none;
    z-index: 1000;
    white-space: nowrap;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

body.dark-mode .graph-tooltip {
    background-color: rgba(255, 255, 255, 0.9);
    color: #000;
    box-shadow: 0 2px 8px rgba(255, 255, 255, 0.2);
}

.graph-tooltip .tooltip-header {
    font-weight: bold;
    margin-bottom: 4px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);
    padding-bottom: 4px;
}

body.dark-mode .graph-tooltip .tooltip-header {
    border-bottom: 1px solid rgba(0, 0, 0, 0.3);
}

.graph-tooltip .tooltip-item {
    margin: 3px 0;
}

.graph-tooltip .tooltip-coords {
    font-family: 'Courier New', monospace;
}

.graph-tooltip .intercept-label {
    color: #ffeb3b;
    font-weight: bold;
}

body.dark-mode .graph-tooltip .intercept-label {
    color: #f57c00;
}

#graphCanvas {
    cursor: crosshair;
}