:root {
    --bg-primary: #1e1e1e;
    --bg-secondary: #2a2a2a;
    --bg-tertiary: #3c3c3c;
    --bg-input: #252525;
    --bg-readonly: #333;

    --text-primary: #e0e0e0;
    --text-secondary: #a0a0a0;
    --text-on-accent: #ffffff;
    --text-on-accent-secondary: #f0f0f0;
    
    --border-primary: #444444;
    --border-secondary: #555555;
    
    --accent-primary: #4CAF50;
    --accent-primary-hover: #5cb85c;
    
    --accent-secondary: #007bff;
    --accent-secondary-hover: #0069d9;

    --info-text: #2c9be2;

    --error-excellent: #28a745;
    --error-good: #17a2b8;
    --error-acceptable: #ffc107;
    --error-poor: #dc3545;
}

/* Base styles */
body {
    margin: 0;
    padding: 0;
    font-family: Arial, sans-serif;
    color: var(--text-primary);
    background-color: var(--bg-primary);
}

/* Layout */
.container {
    display: flex;
    min-height: 100vh;
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
}

/* Sidebar */
.sidebar {
    width: 200px;
    background-color: var(--bg-secondary);
    padding: 20px;
    border-right: 1px solid var(--border-primary);
}

.sidebar h2 {
    margin-top: 0;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.calculator-list {
    list-style-type: none;
    padding: 0;
    margin: 0;
}

.calculator-item {
    padding: 12px;
    margin-bottom: 5px;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s, padding-left 0.2s;
    border-left: 3px solid transparent;
}

.calculator-item:hover {
    background-color: var(--bg-tertiary);
    padding-left: 15px;
}

.calculator-item.active {
    background-color: var(--accent-secondary);
    color: var(--text-on-accent);
    border-left-color: var(--text-on-accent);
    font-weight: 600;
}

/* Main content area */
.main-content {
    flex: 1;
    padding: 20px;
    overflow-x: auto;
    min-width: 950px;
}

.main-content h2 {
    margin-top: 0;
    margin-bottom: 25px;
    color: var(--text-primary);
    font-size: 1.8em;
    border-bottom: 2px solid var(--border-primary);
    padding-bottom: 10px;
}

/* Calculator styles */
.calculator {
    display: none;
}

.calculator.active {
    display: block;
}

/* Input groups */
.input-group {
    margin-bottom: 8px;
    display: grid;
    grid-template-columns: 150px 140px 70px 100px auto;
    align-items: center;
    gap: 10px;
}

.input-group label {
    font-weight: bold;
}

.input-group input {
    width: 100%;
    padding: 5px;
    border: 1px solid var(--border-secondary);
    border-radius: 4px;
    box-sizing: border-box;
    height: 32px;
    background-color: var(--bg-input);
    color: var(--text-primary);
    transition: border-color 0.2s, background-color 0.2s;
}

.input-group input:focus {
    outline: none;
    border-color: var(--accent-secondary);
    background-color: var(--bg-tertiary);
}

.input-group input:read-only {
    background-color: var(--bg-readonly);
    cursor: not-allowed;
    opacity: 0.8;
}

.input-group input:read-only:focus {
    border-color: var(--border-secondary);
    background-color: var(--bg-readonly);
}

.unit {
    min-width: 40px;
    margin-left: 5px;
    margin-right: 10px;
}

.unit-select {
    min-width: 70px;
    margin-left: 5px;
    margin-right: 10px;
    padding: 5px;
    border: 1px solid var(--border-secondary);
    border-radius: 4px;
    background-color: var(--bg-input);
    color: var(--text-primary);
    height: 32px;
    cursor: pointer;
    transition: border-color 0.2s, background-color 0.2s;
}

.unit-select:focus {
    outline: none;
    border-color: var(--accent-secondary);
    background-color: var(--bg-tertiary);
}

.unit-select:hover {
    border-color: var(--border-primary);
}

/* Wafer size select styling */
.wafer-size-select {
    width: 140px;
    height: 32px;
    padding: 5px;
    border: 1px solid var(--border-secondary);
    border-radius: 4px;
    background-color: var(--bg-input);
    color: var(--text-primary);
    cursor: pointer;
    transition: border-color 0.2s, background-color 0.2s;
}

.wafer-size-select:focus {
    outline: none;
    border-color: var(--accent-secondary);
    background-color: var(--bg-tertiary);
}

.wafer-size-select:hover {
    border-color: var(--border-primary);
}

.calc-button {
    padding: 5px 10px;
    background-color: var(--accent-primary);
    color: var(--text-on-accent);
    border: none;
    border-radius: 4px;
    cursor: pointer;
    width: fit-content;
    transition: background-color 0.2s, transform 0.1s;
    font-weight: 500;
}

.calc-button:hover {
    background-color: var(--accent-primary-hover);
    transform: translateY(-1px);
}

.calc-button:active {
    transform: translateY(0);
}

/* Standard values section */
.standard-values-group {
    margin-top: 20px;
    margin-bottom: 15px;
}

.standard-values-group label {
    display: block;
    margin-bottom: 10px;
    font-weight: bold;
}

.standard-buttons {
    display: flex;
    gap: 10px;
}

.standard-button {
    padding: 10px 20px;
    background-color: var(--accent-primary);
    color: var(--text-on-accent);
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

.standard-button:hover {
    background-color: var(--accent-primary-hover);
}

.standard-button.active {
    background-color: var(--accent-secondary);
}

.standard-button.active:hover {
    background-color: var(--accent-secondary-hover);
}

/* Solve-for dimension toggle buttons */
.solve-for-buttons {
    display: flex;
    gap: 4px;
    width: 100%;
}

.solve-for-btn {
    flex: 1;
    padding: 4px 0;
    background-color: var(--bg-input);
    color: var(--text-primary);
    border: 1px solid var(--border-secondary);
    border-radius: 4px;
    cursor: pointer;
    font-size: 13px;
    font-weight: bold;
    height: 28px;
}

.solve-for-btn:hover {
    border-color: var(--accent-secondary);
}

.solve-for-btn.active {
    background-color: var(--accent-secondary);
    color: var(--text-on-accent);
    border-color: var(--accent-secondary);
    outline: 2px solid var(--accent-secondary);
    outline-offset: 1px;
}

/* Inductor volume dual-column layout */
.indvol-columns {
    display: flex;
    gap: 12px;
}

.indvol-column {
    flex: 1;
    min-width: 0;
    overflow: hidden;
}

.indvol-column .input-group {
    grid-template-columns: 140px 100px 70px;
    gap: 6px;
    margin-bottom: 6px;
}

.indvol-column .calculator-section {
    margin-bottom: 0;
}

.indvol-column .calculator-section + .calculator-section {
    padding-top: 12px;
    margin-top: 12px;
}

.indvol-column .calculator-section + .calculator-section::before {
    width: 100%;
}

.indvol-column .calculator-section h3 {
    padding-bottom: 4px;
    margin-bottom: 8px;
    font-size: 0.95em;
}

/* Table styles */
.table-container {
    width: 100%;
    margin-bottom: 20px;
}

.standard-pairs-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 10px;
    font-size: 14px;
}

/* Column width specifications */
.standard-pairs-table th:nth-child(1), /* Top R */
.standard-pairs-table th:nth-child(2) { /* Bottom R */
    width: 17%;
}

.standard-pairs-table th:nth-child(3) { /* Ratio */
    width: 10%;
}

.standard-pairs-table th:nth-child(4), /* Ratio Error */
.standard-pairs-table th:nth-child(7) { /* Current Error */
    width: 12%;
}

.standard-pairs-table th:nth-child(5), /* Vmid */
.standard-pairs-table th:nth-child(6) { /* Current */
    width: 16%;
}

.standard-pairs-table th {
    background-color: var(--bg-secondary);
    font-weight: 600;
    white-space: nowrap;
}

.standard-pairs-table th, 
.standard-pairs-table td {
    border: 1px solid var(--border-primary);
    padding: 8px 6px;
    text-align: center;
}

#placeholder-row td {
    text-align: center;
    padding: 20px;
    color: var(--text-secondary);
    font-style: italic;
}

/* Error classes for color coding */
.error-excellent {
    color: var(--error-excellent);
    font-weight: 600;
}

.error-good {
    color: var(--error-good);
    font-weight: 500;
}

.error-acceptable {
    color: var(--error-acceptable);
    font-weight: 500;
}

.error-poor {
    color: var(--error-poor);
    font-weight: 500;
}

/* Current error colors */
.current-error-excellent {
    color: var(--error-excellent);
    font-weight: 600;
}

.current-error-good {
    color: var(--error-good);
    font-weight: 500;
}

.current-error-acceptable {
    color: var(--error-acceptable);
    font-weight: 500;
}

.current-error-poor {
    color: var(--error-poor);
    font-weight: 500;
}

/* Voltage input container styles */
.voltage-input-container {
    position: relative;
    display: flex;
    align-items: center;
    width: 100%;
}

.negative-sign {
    position: absolute;
    left: -14px;
    font-weight: bold;
}

.voltage-input-container input {
    width: 100%;
    margin: 0;
}

/* Power and current info displays */
.power-info, .current-info, .ratio-info {
    color: var(--info-text);
    margin-left: 10px;
}

/* Calculator section styles */
.calculator-section {
    margin-bottom: 25px;
}

/* Add divider for sections */
.calculator-section + .calculator-section {
    border-top: none;
    padding-top: 20px;
    margin-top: 20px;
    position: relative;
}

.calculator-section + .calculator-section::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 570px; /* Width that extends just past the Calculate button */
    height: 1px;
    background-color: var(--border-primary);
}

.calculator-section h3 {
    margin-top: 0;
    color: var(--text-primary);
    padding-bottom: 8px;
    margin-bottom: 15px;
}

/* Styles for Scientific Notation Input Groups */
.input-group-sci,
.result-group-sci {
    display: flex;
    align-items: center; /* Vertically align items */
    margin-bottom: 15px; /* Space between rows */
    flex-wrap: nowrap; /* Prevent wrapping */
}

.input-group-sci label,
.result-group-sci label {
    min-width: 180px; /* Adjust as needed for consistent label width */
    margin-right: 10px;
    text-align: right;
}

.input-group-sci input[type="number"],
.result-group-sci input[type="number"] {
    padding: 8px;
    border: 1px solid var(--border-secondary);
    border-radius: 4px;
    font-size: 14px;
    margin-right: 5px; /* Space between inputs/spans */
    background-color: var(--bg-input);
    color: var(--text-primary);
}

/* Style for the value input field */
.input-group-sci input[id$="-val"],
.result-group-sci input[id$="-val"] {
    width: 100px; /* Adjust width for value */
}

/* Style for the exponent input field */
.input-group-sci input[id$="-exp"],
.result-group-sci input[id$="-exp"] {
    width: 60px; /* Adjust width for exponent */
}

.exponent-label {
    margin: 0 5px; /* Space around the 'x 10^' text */
    white-space: nowrap;
}

.input-group-sci .unit,
.result-group-sci .unit {
    margin-left: 5px; /* Space before the unit */
    min-width: 25px; /* Ensure space for units */
    text-align: left;
}

/* Optional: Hide number input spinners */
.input-group-sci input[type="number"]::-webkit-outer-spin-button,
.input-group-sci input[type="number"]::-webkit-inner-spin-button,
.result-group-sci input[type="number"]::-webkit-outer-spin-button,
.result-group-sci input[type="number"]::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

.input-group-sci input[type="number"],
.result-group-sci input[type="number"] {
    -moz-appearance: textfield; /* Firefox */
}

/* Readonly styles for result groups */
.result-group-sci input[readonly] {
    background-color: var(--bg-readonly);
    cursor: default;
}

/* Adjust button margin if needed */
#rc-calc .calc-button {
    margin-left: 190px; /* Align button roughly under inputs */
    margin-bottom: 15px;
}

/* Align the calculate button container (used in Coupled Inductor calc) */
.calc-button-container {
    display: flex;
    /* Align with the labels of input groups (adjust margin-left as needed based on label width) */
    margin-left: 190px; 
    margin-top: 15px;  /* Add some space above the button */
    margin-bottom: 15px; /* Space below the button */
}

.results-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 15px;
    font-size: 0.9em;
}

.results-table th, .results-table td {
    border: 1px solid var(--border-primary);
    padding: 8px 10px;
    text-align: right;
    color: var(--text-primary);
}

.results-table th {
    background-color: var(--bg-secondary);
    font-weight: 600;
    text-align: center;
}

.results-table tr:nth-child(even) {
    background-color: var(--bg-tertiary);
}

.results-table tr:hover {
    background-color: var(--border-secondary);
}

.highlight-closest {
    background-color: var(--accent-primary) !important;
    color: var(--text-on-accent) !important;
    font-weight: bold;
}

/* Generic inline error text */
.error-message {
    color: var(--error-poor);
    margin-top: 8px;
    margin-bottom: 0;
    min-height: 18px;
    font-size: 0.95em;
}

/* ================================
   RESPONSIVE DESIGN
   ================================ */

/* Tablet and smaller desktop */
@media (max-width: 1200px) {
    .main-content {
        min-width: 700px;
    }
    
    .input-group {
        grid-template-columns: 140px 120px 60px 90px auto;
    }
}

/* Tablet portrait */
@media (max-width: 900px) {
    .container {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        border-right: none;
        border-bottom: 1px solid var(--border-primary);
        padding: 15px;
    }
    
    .sidebar h2 {
        margin-bottom: 10px;
    }
    
    .calculator-list {
        display: flex;
        flex-wrap: wrap;
        gap: 5px;
    }
    
    .calculator-item {
        padding: 8px 12px;
        margin-bottom: 0;
        font-size: 0.9em;
    }
    
    .calculator-item:hover {
        padding-left: 12px;
    }
    
    .main-content {
        min-width: unset;
        width: 100%;
        padding: 15px;
    }
    
    .input-group {
        grid-template-columns: 130px 1fr 50px auto;
        gap: 8px;
    }
    
    .calculator-section + .calculator-section::before {
        width: 100%;
    }

    .indvol-columns {
        flex-direction: column;
    }
}

/* Mobile */
@media (max-width: 600px) {
    .main-content h2 {
        font-size: 1.4em;
    }
    
    .calculator-list {
        flex-direction: column;
    }
    
    .calculator-item {
        padding: 10px 12px;
    }
    
    .input-group {
        grid-template-columns: 1fr;
        gap: 5px;
        margin-bottom: 15px;
    }
    
    .input-group label {
        margin-bottom: 3px;
    }
    
    .input-group input {
        width: 100%;
    }
    
    .unit {
        display: inline-block;
        margin-top: 5px;
    }
    
    .calc-button {
        width: 100%;
        margin-top: 5px;
        padding: 10px;
    }
    
    .standard-buttons {
        flex-wrap: wrap;
    }
    
    .standard-button {
        flex: 1;
        min-width: 60px;
    }
    
    /* Scientific notation inputs for mobile */
    .input-group-sci,
    .result-group-sci {
        flex-wrap: wrap;
    }
    
    .input-group-sci label,
    .result-group-sci label {
        min-width: 100%;
        text-align: left;
        margin-bottom: 5px;
    }
    
    .input-group-sci input[id$="-val"],
    .result-group-sci input[id$="-val"] {
        width: 80px;
    }
    
    .input-group-sci input[id$="-exp"],
    .result-group-sci input[id$="-exp"] {
        width: 50px;
    }
    
    /* Tables on mobile */
    .results-table,
    .standard-pairs-table {
        font-size: 0.8em;
    }
    
    .results-table th, 
    .results-table td,
    .standard-pairs-table th, 
    .standard-pairs-table td {
        padding: 5px 3px;
    }
    
    .results-table-container {
        overflow-x: auto;
    }
}

/* Accessibility - reduce motion */
@media (prefers-reduced-motion: reduce) {
    .calculator-item,
    .calc-button,
    .input-group input {
        transition: none;
    }
}

/* Focus states for accessibility */
.calculator-item:focus {
    outline: 2px solid var(--accent-secondary);
    outline-offset: 2px;
}

.calc-button:focus,
.standard-button:focus {
    outline: 2px solid var(--accent-primary-hover);
    outline-offset: 2px;
}

input:focus,
select:focus {
    outline: none;
    border-color: var(--accent-secondary);
    box-shadow: 0 0 0 2px rgba(0, 123, 255, 0.25);
}