/*
============================================
BMR Calculator Styles
============================================
*/

/* 1. CSS Variables & Global Styles
-------------------------------------------- */
:root {
    /* Color Palette */
    --primary-color: #4682B4; /* SteelBlue */
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --error-color: #dc3545;
    --info-color: #17a2b8;
    --warning-color: #ffc107;

    /* Light Mode */
    --bg-primary-light: #f5f5f5;
    --bg-secondary-light: #ffffff;
    --bg-tertiary-light: #e9ecef;
    --text-primary-light: #212529;
    --text-secondary-light: #6c757d;
    --border-color-light: #dee2e6;
    --input-bg-light: #ffffff;

    /* Dark Mode */
    --bg-primary-dark: #000000;
    --bg-secondary-dark: #1a1a1a;
    --bg-tertiary-dark: #333333;
    --text-primary-dark: #f8f9fa;
    --text-secondary-dark: #adb5bd;
    --border-color-dark: #444444;
    --input-bg-dark: #2c2c2c;

    /* Shadows & Transitions */
    --box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    --box-shadow-hover: 0 8px 24px rgba(0, 0, 0, 0.12);
    --transition-speed: 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);

    /* Shimmer Effect */
    --shimmer-color-light: #e0e0e0;
    --shimmer-bg-light: #f0f0f0;
    --shimmer-color-dark: #333;
    --shimmer-bg-dark: #222;
}

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

body {
    font-family: 'Poppins', 'Cairo', sans-serif;
    background-color: var(--bg-primary-light);
    color: var(--text-primary-light);
    line-height: 1.7;
    padding-top: 100px; /* CRITICAL: Prevents header overlap */
    transition: background-color var(--transition-speed), color var(--transition-speed);
}

/* Dark Mode Styles */
@media (prefers-color-scheme: dark) {
    :root {
        --bg-primary-light: var(--bg-primary-dark);
        --bg-secondary-light: var(--bg-secondary-dark);
        --bg-tertiary-light: var(--bg-tertiary-dark);
        --text-primary-light: var(--text-primary-dark);
        --text-secondary-light: var(--text-secondary-dark);
        --border-color-light: var(--border-color-dark);
        --input-bg-light: var(--input-bg-dark);
        --shimmer-color-light: var(--shimmer-color-dark);
        --shimmer-bg-light: var(--shimmer-bg-dark);
    }
}

.dark-mode {
    --bg-primary-light: var(--bg-primary-dark);
    --bg-secondary-light: var(--bg-secondary-dark);
    --bg-tertiary-light: var(--bg-tertiary-dark);
    --text-primary-light: var(--text-primary-dark);
    --text-secondary-light: var(--text-secondary-dark);
    --border-color-light: var(--border-color-dark);
    --input-bg-light: var(--input-bg-dark);
    --shimmer-color-light: var(--shimmer-color-dark);
    --shimmer-bg-light: var(--shimmer-bg-dark);
}

/* General Typography & Links */
h1, h2, h3, h4, h5, h6 {
    font-family: 'Poppins', sans-serif;
    font-weight: 600;
    color: var(--text-primary-light);
    margin-bottom: 0.75em;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color var(--transition-speed);
}

a:hover {
    text-decoration: underline;
}

/* Main Container */
.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

/* Ensure lists are left-aligned */
ul, ol {
    text-align: left;
    padding-left: 20px;
}

li {
    text-align: left;
    margin-bottom: 0.5rem;
}

/* 2. Page Header & Card Layout
-------------------------------------------- */
.tool-header {
    text-align: center;
    margin-bottom: 2rem;
}

.tool-header h1 {
    font-size: 2.8rem;
    font-weight: 700;
    color: var(--text-primary-light);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
}

.tool-header h1 i {
    color: var(--primary-color);
    font-size: 2.5rem;
}

.tool-header p {
    font-size: 1.1rem;
    max-width: 700px;
    margin: 0.5rem auto 0;
    color: var(--text-secondary-light);
}

.card {
    background-color: var(--bg-secondary-light);
    border-radius: 12px;
    border: 1px solid var(--border-color-light);
    box-shadow: var(--box-shadow);
    padding: 2rem;
    margin-bottom: 2rem;
    transition: box-shadow var(--transition-speed);
}

.card:hover {
    box-shadow: var(--box-shadow-hover);
}

/* 3. 'How to Use' Section
-------------------------------------------- */
.how-to-use {
    background-color: var(--bg-tertiary-light);
    border-left: 5px solid var(--primary-color);
    padding: 1.5rem;
    margin-bottom: 2rem;
    border-radius: 8px;
}

.how-to-use h2 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.how-to-use h2 i {
    color: var(--primary-color);
}

.how-to-use ul {
    list-style-type: none;
    padding-left: 0;
}

.how-to-use li {
    margin-bottom: 0.5rem;
    font-size: 1.05rem;
}

.how-to-use li::before {
    content: '✓';
    color: var(--success-color);
    font-weight: bold;
    display: inline-block;
    width: 1.2em;
    margin-left: -1.2em;
}

/* 4. Form & Input Styles
-------------------------------------------- */
.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-secondary-light);
}

.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.form-control {
    width: 100%;
    padding: 0.8rem 1rem;
    font-size: 1rem;
    border: 1px solid var(--border-color-light);
    border-radius: 8px;
    background-color: var(--input-bg-light);
    color: var(--text-primary-light);
    transition: border-color var(--transition-speed), box-shadow var(--transition-speed);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(70, 130, 180, 0.2);
}

.form-control.error {
    border-color: var(--error-color);
}

.error-message {
    color: var(--error-color);
    font-size: 0.875rem;
    margin-top: 0.25rem;
    display: none; /* Hidden by default */
}

/* Unit & Gender Toggles */
.unit-toggle, .gender-selection {
    display: flex;
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid var(--border-color-light);
}

.unit-option, .gender-option {
    flex: 1;
    position: relative;
}

.unit-option input, .gender-option input {
    position: absolute;
    opacity: 0;
    width: 100%;
    height: 100%;
    cursor: pointer;
}

.unit-label, .gender-label {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0.8rem 1rem;
    text-align: center;
    background-color: var(--bg-secondary-light);
    color: var(--text-secondary-light);
    transition: background-color var(--transition-speed), color var(--transition-speed);
    font-weight: 500;
}

.unit-option input:checked + .unit-label,
.gender-option input:checked + .gender-label {
    background-color: var(--primary-color);
    color: #ffffff;
}

.gender-label i {
    margin-right: 0.5rem;
}

/* Action Buttons */
.action-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
    flex-wrap: wrap;
}

.btn {
    padding: 0.9rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 8px;
    border: none;
    cursor: pointer;
    transition: all var(--transition-speed);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    text-decoration: none;
}

.btn-primary {
    background-color: var(--primary-color);
    color: #ffffff;
}

.btn-primary:hover {
    background-color: #366a94; /* Darker SteelBlue */
    transform: translateY(-2px);
    box-shadow: var(--box-shadow-hover);
}

.btn-secondary {
    background-color: var(--bg-tertiary-light);
    color: var(--text-primary-light);
    border: 1px solid var(--border-color-light);
}

.btn-secondary:hover {
    background-color: #d3d9df;
}

.dark-mode .btn-secondary:hover {
    background-color: #444;
}

/* 5. Results Section
-------------------------------------------- */
.results-section {
    display: none; /* Hidden by default */
    animation: fadeIn 0.5s ease-in-out;
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.result-card {
    background-color: var(--bg-tertiary-light);
    padding: 1.5rem;
    border-radius: 8px;
    text-align: center;
    border-bottom: 4px solid var(--primary-color);
}

.result-card h3 {
    font-size: 1.1rem;
    color: var(--text-secondary-light);
    margin-bottom: 0.5rem;
}

.result-card .value {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    line-height: 1.2;
}

.result-card .unit {
    font-size: 0.9rem;
    color: var(--text-secondary-light);
}

/* TDEE Table */
.tdee-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1.5rem;
}

.tdee-table th, .tdee-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color-light);
}

.tdee-table th {
    font-weight: 600;
    color: var(--text-secondary-light);
}

.tdee-table td:last-child {
    font-weight: 600;
    color: var(--primary-color);
}

/* 6. Educational Content, FAQ, Ads, Disclaimer
-------------------------------------------- */
.content-section h2 {
    font-size: 1.6rem;
    border-bottom: 2px solid var(--border-color-light);
    padding-bottom: 0.5rem;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.content-section h2 i {
    color: var(--primary-color);
}

.content-section p, .content-section ul {
    margin-bottom: 1rem;
}

/* FAQ Section */
.faq-item {
    border-bottom: 1px solid var(--border-color-light);
}

.faq-question {
    width: 100%;
    background: none;
    border: none;
    text-align: left;
    font-size: 1.1rem;
    font-weight: 600;
    padding: 1.25rem 0;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--text-primary-light);
}

.faq-question::after {
    content: '+';
    font-size: 1.5rem;
    color: var(--primary-color);
    transition: transform var(--transition-speed);
}

.faq-question[aria-expanded="true"]::after {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease-in-out;
}

.faq-answer p {
    padding: 0 0 1.25rem 0;
    margin: 0;
}

/* Ad Placeholders */
.ad-placeholder {
    width: 100%;
    min-height: 100px;
    background-color: var(--bg-tertiary-light);
    border: 2px dashed var(--border-color-light);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary-light);
    font-weight: 500;
    border-radius: 8px;
    margin: 2rem 0;
}

/* Recommended Tools */
.recommended-tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1.5rem;
}

.tool-card-link {
    display: block;
    background-color: var(--bg-secondary-light);
    border: 1px solid var(--border-color-light);
    border-radius: 8px;
    padding: 1.5rem;
    text-align: center;
    transition: all var(--transition-speed);
    text-decoration: none;
}

.tool-card-link:hover {
    transform: translateY(-5px);
    box-shadow: var(--box-shadow-hover);
    border-color: var(--primary-color);
}

.tool-card-link i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.tool-card-link h4 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary-light);
}

/* Disclaimer */
.disclaimer {
    background-color: #fff3cd; /* Light yellow */
    color: #664d03;
    border: 1px solid #ffecb5;
    border-left: 5px solid var(--warning-color);
    padding: 1.5rem;
    border-radius: 8px;
}

.dark-mode .disclaimer {
    background-color: #332701;
    color: #ffc107;
    border-color: #4d3802;
}

/* 7. Animations & Media Queries
-------------------------------------------- */

/* Keyframe Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes shimmer {
    0% {
        background-position: -468px 0;
    }
    100% {
        background-position: 468px 0;
    }
}

.shimmer-effect {
    animation: shimmer 1.5s linear infinite;
    background: linear-gradient(to right, var(--shimmer-bg-light) 8%, var(--shimmer-color-light) 18%, var(--shimmer-bg-light) 33%);
    background-size: 800px 104px;
    position: relative;
}

/* Responsive Design */
@media (max-width: 768px) {
    body {
        padding-top: 80px; /* Adjust for smaller header */
    }

    .container {
        padding: 1rem;
    }

    .tool-header h1 {
        font-size: 2rem;
    }

    .form-grid {
        grid-template-columns: 1fr; /* Stack form elements */
    }

    .action-buttons {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }

    .results-grid {
        grid-template-columns: 1fr; /* Stack result cards */
    }
}

@media (max-width: 480px) {
    .card {
        padding: 1.5rem;
    }

    .tool-header h1 {
        font-size: 1.8rem;
        gap: 0.5rem;
    }

    .tool-header h1 i {
        font-size: 1.5rem;
    }

    .unit-label, .gender-label {
        font-size: 0.9rem;
        padding: 0.7rem;
    }
}