/* ===========================================
   Target Heart Rate Calculator - Tool Specific Styles
   =========================================== */

/* Tool Layout */
.hr-box {
    max-width: 750px;
    margin: 0 auto;
}

/* Controls and Inputs */
.hr-controls {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    background: #f0fdf4; /* Light Mint/Spring Green BG */
    padding: 30px;
    border-radius: 12px;
    border: 1px solid #a7f3d0;
    margin-bottom: 30px;
}

.hr-input-group {
    display: flex;
    flex-direction: column;
}

.hr-label {
    font-size: 0.9rem;
    font-weight: 600;
    color: #065f46; /* Dark Green Label */
    margin-bottom: 6px;
}

.hr-input, .hr-select {
    padding: 10px;
    border: 1px solid #34d399; /* Medium Green Border */
    border-radius: 6px;
    font-size: 1rem;
    color: #1f2937;
    width: 100%;
}

/* Intensity Slider */
.hr-intensity-group {
    grid-column: 1 / -1;
    margin-top: 10px;
}

.hr-slider-control {
    display: flex;
    align-items: center;
    gap: 15px;
}

#intensitySlider {
    flex-grow: 1;
}

#intensityDisplay {
    font-size: 1.2rem;
    font-weight: 700;
    color: #059669;
    min-width: 60px;
    text-align: right;
}

/* Calculate Button */
.hr-btn-calc {
    grid-column: 1 / -1;
    padding: 12px 20px;
    font-size: 1.1rem;
    font-weight: 700;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    background: #10b981; /* Primary Emerald Green Button */
    color: white;
    transition: background 0.2s;
    margin-top: 10px;
}
.hr-btn-calc:hover {
    background: #059669;
}

/* --- Results Section --- */

.hr-results-section {
    margin-top: 30px;
    text-align: center;
}

.hr-summary-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-bottom: 30px;
}

.hr-card {
    background: #ffffff;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
    border-top: 4px solid #10b981;
}

.hr-card-title {
    font-size: 0.9rem;
    text-transform: uppercase;
    color: #6b7280;
    margin-bottom: 5px;
}

.hr-value {
    font-size: 2.5rem;
    font-weight: 800;
    color: #1f2937;
    line-height: 1.1;
}
.hr-value.max {
    color: #dc2626; /* Red for Maximum */
}
.hr-value.zone {
    color: #10b981; /* Emerald Green for Zone */
}

.hr-unit {
    font-size: 1rem;
    font-weight: 500;
    color: #4b5563;
}

/* Responsive Styling */
@media (max-width: 600px) {
    .hr-controls {
        grid-template-columns: 1fr;
    }
    .hr-summary-cards {
        grid-template-columns: 1fr;
    }
}