/* ==== Symbolic Equation Calculator Styles ==== */
body.sec-active-page {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
  background-color: #eef1f5; /* Light neutral background */
  margin: 0;
  color: #333;
  padding: 20px;
  box-sizing: border-box;
}

.sec-container {
  background-color: #ffffff;
  padding: 25px 30px;
  border-radius: 12px;
  box-shadow: 0 8px 25px rgba(0, 30, 80, 0.07);
  width: 100%;
  max-width: 750px;
  text-align: center;
}

.sec-title {
  font-size: 1.9rem;
  color: #1a2533;
  margin-top: 0;
  margin-bottom: 8px;
}

.sec-subtitle {
  font-size: 1rem;
  color: #52616e;
  margin-top: 0;
  margin-bottom: 30px;
}

.sec-variables-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 25px;
  margin-bottom: 25px;
}

@media (min-width: 650px) {
  .sec-variables-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.sec-variable-group {
  background-color: #f8f9fa;
  padding: 15px;
  border-radius: 8px;
  border: 1px solid #e9ecef;
}

.sec-variable-label {
  font-size: 1.1rem;
  color: #343a40;
  margin-top: 0;
  margin-bottom: 15px;
}
.sec-variable-label span {
  font-weight: bold;
  color: #007bff;
}

.sec-symbol-options {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(60px, 1fr));
  gap: 10px;
  justify-items: center;
}

.sec-symbol-option {
  width: 60px; 
  height: 60px;
  border: 2px solid #ced4da;
  border-radius: 8px;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  transition: border-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
  background-color: #fff;
}

.sec-symbol-option svg {
  width: 70%;
  height: 70%;
  stroke-width: 2; /* Consistent stroke for SVGs */
  fill: none;
  stroke: #495057;
}

.sec-symbol-option:hover {
  border-color: #adb5bd;
  transform: translateY(-2px);
  box-shadow: 0 3px 8px rgba(0,0,0,0.08);
}

.sec-symbol-option.selected {
  border-color: #007bff;
  background-color: #e7f3ff;
  box-shadow: 0 0 10px rgba(0, 123, 255, 0.3);
}
.sec-symbol-option.selected svg {
  stroke: #007bff;
}

.sec-controls {
  margin-bottom: 25px;
}

.sec-button {
  border: none;
  padding: 10px 20px;
  font-size: 0.95rem;
  font-weight: 500;
  border-radius: 6px;
  cursor: pointer;
  transition: background-color 0.2s ease, transform 0.1s ease;
}
.sec-button-secondary {
  background-color: #6c757d;
  color: white;
}
.sec-button-secondary:hover {
  background-color: #5a6268;
}
.sec-button-secondary:active {
  transform: scale(0.97);
}

.sec-results-area {
  background-color: #e6f7ff;
  padding: 15px 20px;
  border-radius: 8px;
  border: 1px solid #b3e0ff;
  text-align: left;
}

.sec-results-title {
  font-size: 1.2rem;
  color: #0056b3;
  margin-top: 0;
  margin-bottom: 10px;
}

.sec-result-item {
  font-size: 1rem;
  color: #212529;
  margin: 5px 0;
}
.sec-result-item strong {
  color: #004085;
  font-weight: bold;
}

document.addEventListener('DOMContentLoaded', function() {
    const optionsContainerX = document.getElementById('optionsX');
    const optionsContainerY = document.getElementById('optionsY');
    const optionsContainerZ = document.getElementById('optionsZ');

    const selectedXValueEl = document.getElementById('selectedXValue');
    const selectedYValueEl = document.getElementById('selectedYValue');
    const selectedZValueEl = document.getElementById('selectedZValue');

    const result1El = document.getElementById('secResult1');
    const result2El = document.getElementById('secResult2');
    const result3El = document.getElementById('secResult3');
    const resetButton = document.getElementById('secResetButton');

    let selectedValues = { x: null, y: null, z: null };

    const symbolValues = [0, 10, 11, 20, 21, 22];
    const svgTemplates = [
        // Value 0: Empty circle
        '<svg viewBox="0 0 24 24"><circle cx="12" cy="12" r="8"/></svg>',
        // Value 10: Circle with horizontal line
        '<svg viewBox="0 0 24 24"><circle cx="12" cy="12" r="8"/><line x1="6" y1="12" x2="18" y2="12"/></svg>',
        // Value 11: Circle with vertical line
        '<svg viewBox="0 0 24 24"><circle cx="12" cy="12" r="8"/><line x1="12" y1="6" x2="12" y2="18"/></svg>',
        // Value 20: Empty square
        '<svg viewBox="0 0 24 24"><rect x="6" y="6" width="12" height="12" rx="1"/></svg>',
        // Value 21: Square with diagonal line
        '<svg viewBox="0 0 24 24"><rect x="6" y="6" width="12" height="12" rx="1"/><line x1="7" y1="7" x2="17" y2="17"/></svg>',
        // Value 22: Square with cross
        '<svg viewBox="0 0 24 24"><rect x="6" y="6" width="12" height="12" rx="1"/><line x1="6" y1="12" x2="18" y2="12"/><line x1="12" y1="6" x2="12" y2="18"/></svg>'
    ];

    function createSymbolOption(value, svgHtml, variableName) {
        const optionDiv = document.createElement('div');
        optionDiv.classList.add('sec-symbol-option');
        optionDiv.innerHTML = svgHtml;
        optionDiv.dataset.value = value;
        optionDiv.dataset.variable = variableName;
        optionDiv.setAttribute('title', `Select ${value} for ${variableName.toUpperCase()}`);

        optionDiv.addEventListener('click', function() {
            handleSelection(variableName, value, this);
        });
        return optionDiv;
    }

    function populateOptions(container, variableName) {
        if (!container) return;
        symbolValues.forEach((val, index) => {
            const svg = svgTemplates[index] || svgTemplates[0]; // Fallback to first SVG
            container.appendChild(createSymbolOption(val, svg, variableName));
        });
    }

    populateOptions(optionsContainerX, 'x');
    populateOptions(optionsContainerY, 'y');
    populateOptions(optionsContainerZ, 'z');

    function handleSelection(variableName, value, selectedElement) {
        selectedValues[variableName] = value;

        // Update displayed selected value
        if (variableName === 'x') selectedXValueEl.textContent = value;
        if (variableName === 'y') selectedYValueEl.textContent = value;
        if (variableName === 'z') selectedZValueEl.textContent = value;

        // Update visual selection
        const parentContainer = selectedElement.parentElement;
        parentContainer.querySelectorAll('.sec-symbol-option').forEach(opt => {
            opt.classList.remove('selected');
        });
        selectedElement.classList.add('selected');

        // Calculate if all selected
        if (selectedValues.x !== null && selectedValues.y !== null && selectedValues.z !== null) {
            calculateResults();
        }
    }

    function calculateResults() {
        const x = selectedValues.x;
        const y = selectedValues.y;
        const z = selectedValues.z;

        const res1 = (x * 2) + 11;
        const res2 = ((z * 2) + y) - 5;
        const res3 = Math.abs((z + y) - x);

        result1El.textContent = res1;
        result2El.textContent = res2;
        result3El.textContent = res3;
    }

    function resetSelections() {
        selectedValues = { x: null, y: null, z: null };
        selectedXValueEl.textContent = '-';
        selectedYValueEl.textContent = '-';
        selectedZValueEl.textContent = '-';

        document.querySelectorAll('.sec-symbol-option.selected').forEach(opt => {
            opt.classList.remove('selected');
        });

        result1El.textContent = '?';
        result2El.textContent = '?';
        result3El.textContent = '?';
    }

    if (resetButton) resetButton.addEventListener('click', resetSelections);

    // Add class to body for specific page styling
    if (document.querySelector('.sec-container')) {
        document.body.classList.add('sec-active-page');
    }

    // Initial reset to set default display states
    resetSelections();
});