/* --- Global Styles & Variables --- */
:root {
    --primary-color: #007bff;
    --secondary-color: #6c757d;
    --background-color: #f8f9fa;
    --card-background: #ffffff;
    --text-color: #212529;
    --heading-color: #000;
    --border-color: #dee2e6;
    --box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    --dark-background: #212529;
    --dark-text-color: #f8f9fa;
    --dark-link-color: #007bff;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    line-height: 1.6;
}

.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* --- Header & Footer --- */
.main-header {
    background-color: var(--card-background);
    padding: 1rem 0;
    border-bottom: 1px solid var(--border-color);
}
.main-footer {
    background-color: var(--dark-background);
    color: var(--dark-text-color);
    padding: 2rem 0;
    border-top: 1px solid #343a40;
    font-size: 0.9rem;
}
.main-footer .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.main-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--heading-color);
    text-decoration: none;
}
.main-nav a {
    margin-left: 1.5rem;
    text-decoration: none;
    color: var(--secondary-color);
    transition: color 0.2s;
}
.main-nav a:hover {
    color: var(--primary-color);
}
.footer-nav a {
    margin-left: 1.5rem;
    text-decoration: none;
    color: var(--dark-link-color);
    transition: color 0.2s;
}
.footer-nav a:hover {
    color: #a0caff;
}

/* --- Homepage Hero Section --- */
.hero-section {
    background: linear-gradient(135deg, #6a11cb 0%, #2575fc 100%);
    color: white;
    padding: 4rem 0;
    text-align: center;
}
.hero-section h1 {
    color: white;
    font-size: 3rem;
    margin-bottom: 1rem;
}
.hero-section .subtitle {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1.2rem;
    margin-bottom: 3rem;
}

.calculator-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
    text-align: left;
}
.calculator-grid .card {
    background: var(--card-background);
    border-radius: 15px;
    padding: 2rem;
    text-decoration: none;
    color: var(--text-color);
    box-shadow: var(--box-shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    position: relative;
    overflow: hidden;
}
.calculator-grid .card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0) 100%);
    opacity: 0;
    transition: opacity 0.3s ease;
}
.calculator-grid .card:hover::before {
    opacity: 1;
}
.calculator-grid .card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
}
.calculator-grid .card i {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: white;
    padding: 1rem;
    border-radius: 50%;
    background-color: var(--primary-color);
    transition: transform 0.3s ease;
}
.calculator-grid .card:hover i {
    transform: scale(1.1);
}
.calculator-grid .card h3 {
    margin-top: 0.5rem;
    color: var(--heading-color);
    font-size: 1.5rem;
}
.calculator-grid .card p {
    color: var(--secondary-color);
}

/* Specific Card Gradients */
.mortgage-card i { background: linear-gradient(45deg, #ff6b6b, #ee4266); }
.calorie-card i { background: linear-gradient(45deg, #2ecc71, #27ae60); }
.bmi-card i { background: linear-gradient(45deg, #3498db, #2980b9); }

/* --- Info Sections (How to Use, Why Choose Us, About, FAQs) --- */
.info-section {
    padding: 4rem 0;
    background-color: var(--card-background);
    margin-top: 2rem;
    border-radius: 15px;
    box-shadow: var(--box-shadow);
}
.info-section h2 {
    text-align: center;
    font-size: 2.5rem;
    color: var(--heading-color);
    margin-bottom: 3rem;
}
.info-cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}
.info-card {
    background-color: var(--background-color);
    border-radius: 10px;
    padding: 1.5rem;
    text-align: center;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    transition: transform 0.2s ease;
}
.info-card:hover {
    transform: translateY(-5px);
}
.info-card i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}
.info-card h3 {
    font-size: 1.25rem;
    color: var(--heading-color);
    margin-top: 0;
}
.info-card p {
    font-size: 0.95rem;
    color: var(--secondary-color);
}

.about-calculators p {
    text-align: justify;
    margin-bottom: 1rem;
    font-size: 1.1rem;
    line-height: 1.8;
}

.faqs-section .faq-item {
    background-color: var(--background-color);
    border-radius: 10px;
    padding: 1.5rem;
    margin-bottom: 1rem;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}
.faqs-section .faq-item h3 {
    margin-top: 0;
    color: var(--primary-color);
    font-size: 1.2rem;
}
.faqs-section .faq-item p {
    margin-bottom: 0;
    color: var(--text-color);
}

/* --- Main Calculator Layout (unchanged for now, will update in next phase) --- */
main { padding: 3rem 0; }
.calculator-container { display: grid; grid-template-columns: 1fr 1fr; gap: 2rem; background-color: var(--card-background); border-radius: 12px; box-shadow: var(--box-shadow); overflow: hidden; }
.calculator-inputs { padding: 2.5rem; }
.calculator-results { background-color: var(--primary-color); color: white; padding: 2.5rem; display: flex; flex-direction: column; justify-content: center; }

/* --- Input & Form Styles --- */
h1 { font-size: 2.25rem; font-weight: 700; color: var(--heading-color); margin-top: 0; margin-bottom: 0.5rem; }
.subtitle { color: var(--secondary-color); margin-bottom: 2.5rem; }
.input-group { margin-bottom: 1.5rem; }
.input-group label { display: block; font-weight: 600; margin-bottom: 0.5rem; }
.input-group input, .input-group select { width: 100%; padding: 0.75rem 1rem; border: 1px solid var(--border-color); border-radius: 8px; font-size: 1rem; box-sizing: border-box; }
.input-group input:focus { outline: none; border-color: var(--primary-color); box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.25); }

/* --- Slider Styles --- */
.input-with-slider { display: flex; flex-direction: column; }
.input-with-slider input[type="range"] { width: 100%; margin-top: 0.75rem; -webkit-appearance: none; appearance: none; height: 8px; background: #ddd; border-radius: 5px; outline: none; opacity: 0.7; transition: opacity .2s; }
.input-with-slider input[type="range"]:hover { opacity: 1; }
.input-with-slider input[type="range"]::-webkit-slider-thumb { -webkit-appearance: none; appearance: none; width: 20px; height: 20px; background: var(--primary-color); border-radius: 50%; cursor: pointer; }
.input-with-slider input[type="range"]::-moz-range-thumb { width: 20px; height: 20px; background: var(--primary-color); border-radius: 50%; cursor: pointer; }

/* --- Results Display --- */
.calculator-results h2 { margin-top: 0; font-size: 1.5rem; font-weight: 600; opacity: 0.8; }
.result-display { display: flex; align-items: baseline; margin-bottom: 2rem; }
.result-display .currency, .result-display .unit { font-size: 2rem; font-weight: 600; margin-right: 0.5rem; }
.result-display .value { font-size: 3.5rem; font-weight: 700; line-height: 1; }
.result-display .period { font-size: 1.25rem; font-weight: 600; opacity: 0.8; margin-left: 0.5rem; }
.breakdown p { margin: 0.5rem 0; font-size: 1rem; opacity: 0.9; }

/* --- Ad Placeholders & Content Sections --- */
.adsense-placeholder { width:100%; background-color:#e9ecef; text-align:center; color: #6c757d; font-weight: bold; display: flex; align-items: center; justify-content: center; border-radius: 8px; }
.content-section { margin-top: 3rem; background: var(--card-background); padding: 2rem; border-radius: 12px; }
.content-page { background: var(--card-background); padding: 2rem; border-radius: 12px; }

/* --- Responsive Design --- */
@media (max-width: 768px) {
    .calculator-container { grid-template-columns: 1fr; }
    h1 { font-size: 1.8rem; }
    .result-display .value { font-size: 2.8rem; }
    .hero-section h1 { font-size: 2.2rem; }
    .info-section h2 { font-size: 2rem; }
}