/* ========================================
   Purity Air LLC — Styles
   ======================================== */

/* --- Reset --- */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 70px;
}

/* --- Custom Properties --- */
:root {
    --color-navy: #0B2545;
    --color-blue: #1976D2;
    --color-blue-hover: #1565C0;
    --color-sky: #E3F2FD;
    --color-teal: #00897B;
    --color-white: #FFFFFF;
    --color-light: #F5F7FA;
    --color-slate: #64748B;
    --color-charcoal: #1E293B;
    --color-green: #2E7D32;

    --font-heading: 'Montserrat', sans-serif;
    --font-body: 'Inter', sans-serif;

    --section-padding: 5rem 1.5rem;
    --container-max: 1200px;
    --card-radius: 12px;
    --card-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    --transition: all 0.3s ease;
}

/* --- Base --- */
body {
    font-family: var(--font-body);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--color-charcoal);
    background: var(--color-white);
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3 {
    font-family: var(--font-heading);
    line-height: 1.2;
}

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

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

img {
    max-width: 100%;
    display: block;
}

/* --- Skip Link --- */
.skip-link {
    position: absolute;
    top: -100%;
    left: 1rem;
    background: var(--color-navy);
    color: var(--color-white);
    padding: 0.5rem 1rem;
    border-radius: 4px;
    z-index: 10000;
    font-size: 0.875rem;
}

.skip-link:focus {
    top: 0.5rem;
}

/* --- Container --- */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* --- Buttons --- */
.btn {
    display: inline-block;
    font-family: var(--font-heading);
    font-weight: 600;
    font-size: 1rem;
    padding: 0.875rem 2rem;
    border-radius: 8px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid transparent;
    text-decoration: none;
}

.btn-primary {
    background: var(--color-blue);
    color: var(--color-white);
    border-color: var(--color-blue);
}

.btn-primary:hover {
    background: var(--color-blue-hover);
    border-color: var(--color-blue-hover);
    color: var(--color-white);
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    color: var(--color-white);
    border-color: var(--color-white);
}

.btn-outline:hover {
    background: var(--color-white);
    color: var(--color-navy);
    transform: translateY(-2px);
}

.btn-full {
    width: 100%;
}

/* ========================================
   Navigation
   ======================================== */
.nav {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: var(--color-navy);
    padding: 0;
}

.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.nav-logo {
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--color-white);
    letter-spacing: 0.05em;
    text-decoration: none;
}

.nav-logo:hover {
    color: var(--color-sky);
}

.nav-toggle {
    display: none;
}

.nav-toggle-label {
    display: none;
    cursor: pointer;
    width: 30px;
    height: 24px;
    position: relative;
    z-index: 1001;
}

.hamburger,
.hamburger::before,
.hamburger::after {
    display: block;
    width: 30px;
    height: 3px;
    background: var(--color-white);
    border-radius: 2px;
    position: absolute;
    transition: var(--transition);
}

.hamburger {
    top: 50%;
    transform: translateY(-50%);
}

.hamburger::before {
    content: '';
    top: -9px;
}

.hamburger::after {
    content: '';
    top: 9px;
}

.nav-toggle:checked + .nav-toggle-label .hamburger {
    background: transparent;
}

.nav-toggle:checked + .nav-toggle-label .hamburger::before {
    top: 0;
    transform: rotate(45deg);
}

.nav-toggle:checked + .nav-toggle-label .hamburger::after {
    top: 0;
    transform: rotate(-45deg);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-links a {
    font-family: var(--font-body);
    font-weight: 500;
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
}

.nav-links a:hover {
    color: var(--color-white);
}

.nav-cta {
    background: var(--color-blue);
    color: var(--color-white) !important;
    padding: 0.5rem 1.25rem;
    border-radius: 6px;
    font-family: var(--font-heading) !important;
    font-weight: 600 !important;
    font-size: 0.875rem !important;
}

.nav-cta:hover {
    background: var(--color-blue-hover);
}

/* ========================================
   Hero
   ======================================== */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #0B2545 0%, #13407a 50%, #1976D2 100%);
    text-align: center;
    position: relative;
    padding: 2rem 1.5rem;
}

.hero-content {
    max-width: 800px;
}

.hero-title {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 700;
    color: var(--color-white);
    letter-spacing: 0.06em;
    margin-bottom: 1rem;
}

.hero-tagline {
    font-family: var(--font-heading);
    font-weight: 600;
    font-size: clamp(1.125rem, 3vw, 1.5rem);
    color: var(--color-white);
    margin-bottom: 0.5rem;
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--color-sky);
    margin-bottom: 2.5rem;
}

.hero-ctas {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.hero-scroll-indicator {
    position: absolute;
    bottom: 2rem;
    font-size: 2rem;
    color: rgba(255, 255, 255, 0.4);
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(8px); }
}

/* ========================================
   Sections (shared)
   ======================================== */
.section {
    padding: var(--section-padding);
}

.section-alt {
    background: var(--color-light);
}

.section-dark {
    background: var(--color-navy);
    color: var(--color-white);
}

.section-heading {
    font-size: clamp(1.75rem, 4vw, 2.25rem);
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--color-charcoal);
    position: relative;
    padding-bottom: 1rem;
}

.section-heading::after {
    content: '';
    display: block;
    width: 60px;
    height: 3px;
    background: var(--color-blue);
    margin: 0.75rem auto 0;
    border-radius: 2px;
}

.section-heading-light {
    color: var(--color-white);
}

.section-heading-light::after {
    background: var(--color-sky);
}

/* ========================================
   What We Do
   ======================================== */
.what-we-do-grid {
    display: grid;
    gap: 3rem;
}

.what-we-do-text p {
    font-size: 1.1rem;
    color: var(--color-slate);
    margin-bottom: 1rem;
    line-height: 1.7;
}

.what-we-do-features {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.feature {
    display: flex;
    gap: 1rem;
    align-items: flex-start;
}

.feature-icon {
    font-size: 1.5rem;
    color: var(--color-blue);
    flex-shrink: 0;
    margin-top: 0.1rem;
}

.feature h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
    color: var(--color-charcoal);
}

.feature p {
    color: var(--color-slate);
    font-size: 0.95rem;
}

/* ========================================
   Who We Serve
   ======================================== */
.badges {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1.25rem;
}

.badge {
    background: var(--color-white);
    padding: 1.25rem 1.75rem;
    border-radius: var(--card-radius);
    box-shadow: var(--card-shadow);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-family: var(--font-heading);
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--color-charcoal);
    transition: var(--transition);
}

.badge:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.12);
}

.badge-icon {
    font-size: 1.5rem;
}

/* ========================================
   Pricing Cards
   ======================================== */
.pricing-grid {
    display: grid;
    gap: 2rem;
    max-width: 1100px;
    margin: 0 auto;
}

.pricing-card {
    background: var(--color-white);
    border-radius: var(--card-radius);
    box-shadow: var(--card-shadow);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transition: var(--transition);
    position: relative;
}

.pricing-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
}

.pricing-card-header {
    padding: 2rem 1.5rem;
    text-align: center;
    color: var(--color-white);
}

.pricing-card-header h3 {
    font-size: 1.375rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.card-blue { background: var(--color-blue); }
.card-teal { background: var(--color-teal); }
.card-navy { background: var(--color-navy); }

.pricing-amount {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    font-weight: 700;
}

.pricing-amount span {
    font-size: 1rem;
    font-weight: 600;
    opacity: 0.8;
}

.pricing-note {
    font-size: 0.85rem;
    opacity: 0.75;
    margin-top: 0.25rem;
}

.pricing-features {
    list-style: none;
    padding: 1.5rem;
    flex: 1;
}

.pricing-features li {
    padding: 0.5rem 0;
    font-size: 0.95rem;
    color: var(--color-charcoal);
    border-bottom: 1px solid #f0f0f0;
}

.pricing-features li:last-child {
    border-bottom: none;
}

.pricing-cta {
    margin: 0 1.5rem 1.5rem;
    text-align: center;
}

.popular-badge {
    position: absolute;
    top: 0;
    right: 0;
    background: #FF6F00;
    color: var(--color-white);
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 0.75rem;
    padding: 0.4rem 1rem;
    border-radius: 0 var(--card-radius) 0 var(--card-radius);
    letter-spacing: 0.03em;
    text-transform: uppercase;
    z-index: 1;
}

/* ========================================
   Replacement & Emergency
   ======================================== */
.replacement-grid {
    display: grid;
    gap: 3rem;
}

.replacement-text p {
    font-size: 1.1rem;
    color: var(--color-slate);
    margin-bottom: 1rem;
    line-height: 1.7;
}

.replacement-text .btn {
    margin-top: 1rem;
}

.replacement-features {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.replacement-feature {
    background: var(--color-white);
    padding: 1.5rem;
    border-radius: var(--card-radius);
    box-shadow: var(--card-shadow);
    border-left: 4px solid var(--color-blue);
}

.replacement-feature h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--color-charcoal);
}

.replacement-feature p {
    color: var(--color-slate);
    font-size: 0.95rem;
}

/* ========================================
   Why Purity Air (trust section)
   ======================================== */
.trust-grid {
    display: grid;
    gap: 2rem;
}

.trust-item {
    text-align: center;
}

.trust-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.trust-item h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--color-white);
}

.trust-item p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.95rem;
    max-width: 280px;
    margin: 0 auto;
}

/* ========================================
   Service Area
   ======================================== */
.area-pills {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.area-pill {
    background: var(--color-sky);
    color: var(--color-navy);
    font-family: var(--font-heading);
    font-weight: 600;
    font-size: 1rem;
    padding: 0.625rem 1.5rem;
    border-radius: 50px;
}

.area-tagline {
    text-align: center;
    color: var(--color-slate);
    font-size: 1.05rem;
}

/* ========================================
   Contact
   ======================================== */
.contact-subtitle {
    text-align: center;
    color: var(--color-slate);
    font-size: 1.1rem;
    margin-top: -1.5rem;
    margin-bottom: 2.5rem;
}

.contact-grid {
    display: grid;
    gap: 3rem;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.375rem;
}

.form-group label {
    font-weight: 500;
    font-size: 0.9rem;
    color: var(--color-charcoal);
}

.form-group input,
.form-group select,
.form-group textarea {
    font-family: var(--font-body);
    font-size: 1rem;
    padding: 0.75rem 1rem;
    border: 1.5px solid #d1d5db;
    border-radius: 8px;
    background: var(--color-white);
    color: var(--color-charcoal);
    transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--color-blue);
    box-shadow: 0 0 0 3px rgba(25, 118, 210, 0.15);
}

.form-group textarea {
    resize: vertical;
}

.contact-info {
    padding: 2rem;
    background: var(--color-white);
    border-radius: var(--card-radius);
    box-shadow: var(--card-shadow);
}

.contact-info h3 {
    font-size: 1.375rem;
    font-weight: 700;
    color: var(--color-charcoal);
    margin-bottom: 1.5rem;
}

.contact-detail {
    margin-bottom: 1.25rem;
    font-size: 1rem;
    line-height: 1.6;
}

.contact-detail a {
    font-size: 1.125rem;
    font-weight: 500;
    color: var(--color-blue);
}

.contact-detail a:hover {
    color: var(--color-blue-hover);
}

.contact-response {
    margin-top: 1.5rem;
    font-size: 0.95rem;
    color: var(--color-slate);
    font-style: italic;
}

/* ========================================
   Footer
   ======================================== */
.footer {
    background: var(--color-navy);
    padding: 2rem 1.5rem;
    text-align: center;
}

.footer p {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.875rem;
    line-height: 1.8;
}

/* ========================================
   Responsive — Tablet (768px+)
   ======================================== */
@media (min-width: 768px) {
    .what-we-do-grid {
        grid-template-columns: 1fr 1fr;
    }

    .pricing-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .replacement-grid {
        grid-template-columns: 1fr 1fr;
        align-items: start;
    }

    .trust-grid {
        grid-template-columns: 1fr 1fr;
    }

    .contact-grid {
        grid-template-columns: 1.2fr 0.8fr;
        align-items: start;
    }
}

/* ========================================
   Responsive — Desktop (1024px+)
   ======================================== */
@media (min-width: 1024px) {
    .trust-grid {
        grid-template-columns: repeat(4, 1fr);
    }

    .pricing-card-popular {
        transform: scale(1.05);
        box-shadow: 0 8px 40px rgba(0, 0, 0, 0.15);
        z-index: 1;
    }

    .pricing-card-popular:hover {
        transform: scale(1.05) translateY(-4px);
    }
}

/* ========================================
   Responsive — Mobile (< 768px)
   ======================================== */
@media (max-width: 767px) {
    :root {
        --section-padding: 3.5rem 1.25rem;
    }

    .nav-toggle-label {
        display: block;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--color-navy);
        flex-direction: column;
        padding: 1rem 1.5rem 1.5rem;
        gap: 0;
        border-top: 1px solid rgba(255, 255, 255, 0.1);
        box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
    }

    .nav-toggle:checked ~ .nav-links {
        display: flex;
    }

    .nav-links a {
        padding: 0.875rem 0;
        border-bottom: 1px solid rgba(255, 255, 255, 0.08);
        width: 100%;
    }

    .nav-links a:last-child {
        border-bottom: none;
    }

    .nav-cta {
        margin-top: 0.5rem;
        text-align: center;
    }

    .hero-ctas {
        flex-direction: column;
        align-items: center;
    }

    .hero-ctas .btn {
        width: 100%;
        max-width: 300px;
    }

    .section-heading {
        margin-bottom: 2rem;
    }

    .badge {
        width: 100%;
        justify-content: center;
    }
}

/* --- Focus states for accessibility --- */
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
    outline: 2px solid var(--color-blue);
    outline-offset: 2px;
}