/* --- CSS Variables for Easy Theming --- */
:root {
    --primary-blue: #23538a;
    --primary-hover: #1a3d66;
    --accent-blue: #4a90e2;
    --bg-page: #f8fafc;        /* Soft, bright background */
    --surface-card: #ffffff;   /* Pure white cards/panels */
    --text-primary: #1e293b;   /* Slate dark text */
    --text-muted: #64748b;     /* Neutral gray for secondary text */
    --border-color: #e2e8f0;   /* Light gray borders */
    --shadow-subtle: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
    --shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
    --border-radius: 12px;
}

/* --- Base Styles --- */
body {
    background-color: var(--bg-page);
    color: var(--text-primary);
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    margin: 0;
    padding: 0;
    line-height: 1.6;
}

.container {
    width: 90%;
    max-width: 900px;
    margin: 90px auto 30px auto; /* Accounts for fixed header */
    padding: 20px;
}

/* --- Content Sections --- */
section {
    background-color: var(--surface-card);
    border: 1px solid var(--border-color);
    padding: 30px;
    margin-bottom: 25px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-subtle);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

section:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
}

h1, h2, h3 {
    color: var(--primary-blue);
    margin-top: 0;
    font-weight: 700;
}

ul {
    list-style-type: disc;
    padding-left: 20px;
    color: var(--text-primary);
}

a {
    color: var(--primary-blue);
    text-decoration: none;
    transition: color 0.2s ease;
}

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

/* --- Navigation (Desktop & Mobile) --- */
.top-nav {
    background-color: rgba(255, 255, 255, 0.95);
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    backdrop-filter: blur(8px);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 15px 20px;
}

.logo {
    font-weight: 800;
    font-size: 1.3rem;
    color: var(--primary-blue);
    letter-spacing: 0.5px;
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 15px;
    margin: 0;
    padding: 0;
}

.nav-links li a {
    padding: 8px 14px;
    border-radius: 6px;
    font-weight: 600;
    color: var(--text-primary);
    transition: background-color 0.2s ease, color 0.2s ease;
}

.nav-links li a:hover {
    background-color: rgba(35, 83, 138, 0.08);
    color: var(--primary-blue);
}

/* Hamburger Control (Pure CSS Checkbox Hack) */
.hamburger {
    display: none;
    font-size: 1.8rem;
    color: var(--primary-blue);
    cursor: pointer;
    user-select: none;
}

.menu-checkbox {
    display: none;
}

/* --- Mobile Responsiveness --- */
@media (max-width: 768px) {
    .hamburger {
        display: block;
    }

    .nav-links {
        display: none; /* Hidden until checkbox is checked */
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: var(--surface-card);
        border-bottom: 1px solid var(--border-color);
        box-shadow: 0 10px 15px rgba(0, 0, 0, 0.08);
        padding: 15px 0;
    }

    .nav-links li {
        text-align: center;
        padding: 8px 0;
    }

    /* Keep the CSS checkbox toggle functionality */
    .menu-checkbox:checked ~ .nav-links {
        display: flex;
    }
}

/* --- Utilities & Tables --- */
.footer {
    text-align: center;
    padding: 25px 0;
    color: var(--text-muted);
    font-size: 0.9rem;
}

table {
    width: 100%;
    border-collapse: collapse;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    background-color: var(--surface-card);
}

table, th, td {
    padding: 12px 16px;
    text-align: left;
}

th {
    background-color: #f1f5f9;
    color: var(--text-primary);
    font-weight: 600;
    border-bottom: 1px solid var(--border-color);
}

td {
    border-bottom: 1px solid var(--border-color);
}

tr:last-child td {
    border-bottom: none;
}

/* --- Media & Buttons --- */
.project-gallery {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    margin-top: 20px;
}

.term-img {
    max-width: 100%;
    height: auto;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    box-shadow: var(--shadow-subtle);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    flex: 1 1 calc(50% - 20px);
}

.term-img:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
}

.term-video {
    width: 100%;
    max-width: 800px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    box-shadow: var(--shadow-subtle);
    margin-bottom: 20px;
}

@media (max-width: 768px) {
    .term-img {
        flex: 1 1 100%;
    }
}

/* Standardized Buttons */
.term-btn {
    display: inline-block;
    padding: 10px 20px;
    margin-top: 15px;
    background-color: var(--primary-blue);
    color: #ffffff;
    font-weight: 600;
    border: 1px solid var(--primary-blue);
    border-radius: 6px;
    cursor: pointer;
    transition: background-color 0.2s ease, border-color 0.2s ease;
}

.term-btn:hover {
    background-color: var(--primary-hover);
    border-color: var(--primary-hover);
    color: #ffffff;
    text-decoration: none;
}

/* --- Digital Business Card Layout --- */
.digital-business-card {
    position: relative;
    background: linear-gradient(135deg, #ffffff 0%, #f0f4f8 100%);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    box-shadow: var(--shadow-hover);
    padding: 30px;
    max-width: 700px;
    margin: 20px auto;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    gap: 20px;
    z-index: 1;
}

/* Background SVG Hose */
.card-hose {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 2;
    opacity: 0.6;
}

/* Branding */
.card-top-row {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}

.card-logo {
    font-size: 3.5rem;
    line-height: 1;
    margin: 0;
    letter-spacing: -1px;
}

.card-sublogo {
    font-size: 1.4rem;
    color: var(--text-primary);
    margin: 0;
    letter-spacing: 1px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.wind-icon { font-size: 1.2rem; }

/* Vacuum Image Area */
.card-vac-container {
    width: 160px;
    height: 160px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.vac-placeholder {
    background: #e2e8f0;
    color: var(--text-muted);
    padding: 20px;
    border-radius: 8px;
    text-align: center;
    font-size: 0.8rem;
}

/* Quote */
.card-quote {
    background: rgba(255, 255, 255, 0.8);
    padding: 15px;
    border-left: 4px solid var(--primary-blue);
    border-radius: 4px;
    max-width: 350px;
    font-size: 1.1rem;
    backdrop-filter: blur(4px);
}

.quote-author {
    font-size: 0.9rem;
    color: var(--text-muted);
    font-style: italic;
}

/* Bottom Row (Vent & Contacts) */
.card-bottom-row {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    margin-top: 10px;
}

/* CSS Vent Graphic */
.card-vent-graphic {
    width: 80px;
    height: 50px;
    border: 3px solid var(--text-primary);
    border-radius: 4px;
    background: var(--surface-card);
    padding: 4px;
    display: flex;
    align-items: center;
}

.vent-grill {
    display: flex;
    gap: 4px;
    width: 100%;
    height: 100%;
}

.vent-grill span {
    flex: 1;
    background-color: var(--text-primary);
    border-radius: 2px;
}

/* Interactive Contact Buttons */
.card-contacts {
    display: flex;
    flex-direction: column;
    gap: 8px;
    align-items: flex-end;
}

.contact-btn {
    display: inline-block;
    padding: 6px 12px;
    background: var(--surface-card);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-primary);
    box-shadow: var(--shadow-subtle);
    transition: all 0.2s ease;
}

.contact-btn:hover {
    background: var(--bg-page);
    transform: translateY(-1px);
    box-shadow: var(--shadow-hover);
}

.phone-group {
    display: flex;
    gap: 8px;
    margin-top: 4px;
}

.primary-action {
    background: var(--primary-blue);
    color: #fff;
    border-color: var(--primary-blue);
}

.primary-action:hover {
    background: var(--primary-hover);
    color: #fff;
}

/* Mobile Responsiveness for the Card */
@media (max-width: 600px) {
    .card-top-row { flex-direction: column; align-items: center; text-align: center; }
    .card-logo { font-size: 2.8rem; }
    .card-bottom-row { flex-direction: column; align-items: center; gap: 20px; }
    .card-contacts { align-items: center; width: 100%; }
    .contact-btn { width: 100%; text-align: center; }
    .phone-group { width: 100%; flex-direction: column; }
    .card-hose { display: none; /* Hide hose on mobile to keep layout clean */ }
}