:root {
    --bg-color: #f4f9f4; 
    --container-bg: #ffffff;
    --text-color: #4a4e4d; 
    --border-color: #cce3de; 
    --btn-bg: #a8d5e2; 
    --btn-hover: #8ebcd0;
    --fault-color: #ff4d4d; /* NEW: Strong Red for clarity */
    --hit-color: #e2f0cb; 
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    padding: 20px;
    line-height: 1.6;
}

.container {
    max-width: 950px;
    margin: 0 auto;
    background-color: var(--container-bg);
    padding: 30px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 15px rgba(0,0,0,0.03);
}

h1 {
    text-align: center;
    color: #6b8c85; 
    margin-bottom: 20px;
}

h2 {
    color: #557a71;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 5px;
    margin-top: 30px;
    font-size: 20px;
}

.concept-cards {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
    margin-bottom: 20px;
}

.card {
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 15px;
    flex: 1;
    min-width: 250px;
}

.card h3 {
    margin-top: 0;
    color: #557a71;
    font-size: 16px;
    border-bottom: 1px dashed var(--border-color);
    padding-bottom: 5px;
}

.card p { font-size: 13px; margin: 8px 0; }

.input-section {
    background-color: #fafdfc;
    padding: 20px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
}

.input-group {
    margin-bottom: 15px;
    display: flex;
    flex-direction: column;
}

.grid-inputs {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
}

.mode-selectors {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    background-color: var(--bg-color);
    padding: 10px;
    border-radius: 4px;
    margin-bottom: 15px;
}

label {
    margin-bottom: 5px;
    font-weight: bold;
    font-size: 14px;
}

input, select {
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 15px;
    color: var(--text-color);
    background-color: #fff;
}

input:focus, select:focus {
    outline: none;
    border-color: var(--btn-bg);
}

button {
    background-color: var(--btn-bg);
    color: #333;
    border: none;
    padding: 15px 20px;
    font-size: 16px;
    border-radius: 4px;
    cursor: pointer;
    width: 100%;
    font-weight: bold;
    transition: background-color 0.2s;
    margin-top: 10px;
}

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

/* NEW: Preset Button Styling */
.preset-btn {
    background-color: #ffd166;
    width: auto;
    margin: 0;
    padding: 8px 15px;
    font-size: 14px;
}
.preset-btn:hover { background-color: #ffc233; }

.results {
    margin-top: 30px;
    display: none;
}

.graph-section {
    display: flex;
    flex-direction: column;
    gap: 30px;
    margin-bottom: 30px;
}

.chart-wrapper {
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 20px;
    position: relative;
    height: 350px;
}

.chart-wrapper h3 {
    text-align: center;
    margin-top: 0;
    color: #4a4e4d;
}

.summary-box {
    background-color: var(--bg-color);
    padding: 20px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    margin-bottom: 20px;
}

/* NEW: Best Algorithm Conclusion Box */
.best-algo-box {
    background-color: #d4edda;
    color: #155724;
    padding: 15px;
    border-radius: 8px;
    margin-top: 20px;
    text-align: center;
    font-size: 18px;
    font-weight: bold;
    border: 1px solid #c3e6cb;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 10px;
    text-align: center;
    font-size: 14px; 
}

th, td {
    border: 1px solid var(--border-color);
    padding: 8px 5px;
}

th {
    background-color: #eaf2f1;
    font-weight: bold;
}

/* UPDATED: Strong Red for Faults */
.fault { 
    background-color: var(--fault-color); 
    color: white;
    font-weight: bold;
}
.hit { background-color: var(--hit-color); }

.legend {
    margin: 20px 0;
    display: flex;
    gap: 15px;
    justify-content: center;
    font-size: 14px;
}

.legend-box {
    display: inline-block;
    width: 15px;
    height: 15px;
    margin-right: 5px;
    vertical-align: middle;
    border: 1px solid #ccc;
}

.fault-box { background-color: var(--fault-color); }
.hit-box { background-color: var(--hit-color); }

.algo-section { margin-bottom: 40px; }

.step-details {
    margin-top: 15px;
    background-color: #fafdfc;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 10px;
}

.step-details summary {
    cursor: pointer;
    font-weight: bold;
    color: #557a71;
    outline: none;
}

.step-log {
    margin-top: 10px;
    font-size: 14px;
    max-height: 250px;
    overflow-y: auto;
    padding-right: 10px;
}

.step-log p {
    margin: 5px 0;
    border-bottom: 1px dashed #e0e0e0;
    padding-bottom: 8px;
}

.text-hit { color: #438a3e; font-weight: bold; }
.text-fault { color: #d65538; font-weight: bold; }