/* style.css */
:root {
    --primary: #f5c242; /* Construction Yellow */
    --dark: #1a1a1a;    /* Asphalt Black */
    --light: #f4f4f4;   /* Concrete Grey */
    --white: #ffffff;
    --text: #333333;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
    color: var(--text);
    background-color: var(--light);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.container {
    width: 90%;
    max-width: 1100px;
    margin: auto;
    overflow: hidden;
    padding: 0 20px;
}

/* --- IMPROVED HEADER & NAV --- */
header {
    background: var(--dark);
    padding: 1rem 0;
    border-bottom: 4px solid var(--primary);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap; 
}

.logo-box { text-decoration: none; }
.logo-box h1 {
    margin: 0;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: var(--white);
    font-size: 1.8rem;
    line-height: 1;
}
.logo-box .tagline {
    font-size: 0.75rem;
    letter-spacing: 3px;
    color: #ccc;
    display: block;
    margin-top: 3px;
}
.logo-box span.highlight { color: var(--primary); }

header nav {
    display: flex;
    gap: 20px;
}

header nav a {
    color: var(--white);
    text-decoration: none;
    font-weight: bold;
    font-size: 1rem;
    padding: 10px 5px; /* Bigger touch target */
    transition: color 0.3s ease;
}

header nav a:hover { color: var(--primary); }

/* --- CALCULATOR STYLES --- */
.calc-container {
    max-width: 500px; /* Slightly wider for better mobile view */
    margin: 0 auto;
    background: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    border: 1px solid #ddd;
}

/* New Content Block for Calculator SEO */
.content-block {
    max-width: 800px;
    margin: 40px auto;
    background: #fff;
    padding: 30px;
    border-radius: 8px;
    border-left: 5px solid var(--primary);
}
.content-block h3 { color: var(--dark); margin-top: 0; }

.toggle-group {
    margin-bottom: 15px;
}

.btn-toggle {
    flex: 1;
    padding: 10px;
    border: 1px solid #ccc;
    background: #f9f9f9;
    cursor: pointer;
    font-weight: bold;
}
.btn-toggle.active {
    background: var(--primary);
    border-color: var(--primary);
    color: var(--dark);
}

.form-group {
    margin-bottom: 15px;
}

label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
    font-size: 0.9rem;
    color: #444;
}

input, select {
    width: 100%;
    padding: 12px;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 1rem;
    box-sizing: border-box;
}

input:focus {
    border-color: var(--primary);
    outline: none;
}

.section-title {
    background: #eee;
    padding: 5px 10px;
    margin: 20px -20px 15px -20px;
    font-size: 0.85rem;
    font-weight: bold;
    text-transform: uppercase;
    color: #666;
    letter-spacing: 1px;
}

.btn {
    display: block;
    width: 100%;
    background: var(--primary);
    color: var(--dark);
    padding: 15px;
    border: none;
    text-decoration: none;
    font-weight: bold;
    border-radius: 5px;
    cursor: pointer;
    text-transform: uppercase;
    text-align: center;
    font-size: 1.1rem;
    margin-top: 20px;
}
.btn:hover { background: #e0b030; }

.result-box {
    background: var(--dark);
    color: #fff;
    padding: 20px;
    margin-top: 25px;
    border-radius: 5px;
    display: none;
}

.math-explanation {
    margin-top: 20px;
    font-size: 0.8rem;
    background: rgba(255,255,255,0.1);
    padding: 10px;
    border-radius: 4px;
    color: #ccc;
    font-family: monospace;
}

/* --- GENERAL --- */
.hero {
    /* Added a fallback background color while image loads */
    background: linear-gradient(rgba(0,0,0,0.8), rgba(0,0,0,0.8)), url('https://images.unsplash.com/photo-1584463635676-4f4007d47d4e?auto=format&fit=crop&w=1600&q=80');
    background-color: #333;
    background-size: cover;
    background-position: center;
    padding: 80px 20px;
    color: var(--white);
    text-align: center;
}
.hero h2 { margin-top: 0; font-size: 2rem; }

section { padding: 40px 0; background: var(--white); }
footer { background: var(--dark); color: var(--white); text-align: center; padding: 40px 20px; margin-top: auto; }

/* Grid for Blog */
.grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
    margin-top: 25px;
}
.card {
    background: #fff; padding: 25px; border-radius: 8px; border: 1px solid #eee; box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.card a { color: var(--primary); font-weight: bold; text-decoration: none; }

/* Author Byline Style */
.author-byline {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 15px;
    font-style: italic;
    border-bottom: 1px solid #eee;
    padding-bottom: 10px;
}

/* Mobile Responsive */
@media (max-width: 768px) {
    header .container {
        flex-direction: column;
        align-items: center;
    }
    header nav {
        margin-top: 15px;
        flex-direction: column;
        width: 100%;
        text-align: center;
        gap: 0;
    }
    header nav a {
        display: block;
        border-bottom: 1px solid #333;
    }
}