:root {
    --primary: #2c3e32;
    --secondary: #658C6E;
    --bg-color: #EFF9E8;
    --card-bg: #ffffff;
    --text-color: #3a4f40;
    --text-muted: #658C6E;
    --border-color: #85A898;
    --accent-light: #F5E2B0;
    --accent-gold: #DFCD80;
}

@media (prefers-color-scheme: dark) {
    :root {
        --primary: #EFF9E8;
        --secondary: #DFCD80;
        --bg-color: #1a251d;
        --card-bg: #223026;
        --text-color: #EFF9E8;
        --text-muted: #85A898;
        --border-color: #658C6E;
        --accent-light: #85A898;
        --accent-gold: #DFCD80;
    }
}

@media (prefers-color-scheme: light) {
    :root {
        --primary: #2c3e32;
        --secondary: #658C6E;
        --bg-color: #EFF9E8;
        --card-bg: #ffffff;
        --text-color: #3a4f40;
        --text-muted: #658C6E;
        --border-color: #85A898;
        --accent-light: #F5E2B0;
        --accent-gold: #DFCD80;
    }
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body { 
    font-family: 'Inter', system-ui, sans-serif; 
    background-color: var(--bg-color); 
    color: var(--text-color); 
    line-height: 1.6; 
}

/* Pro Max Accessibility Defaults */
a:focus-visible, button:focus-visible, input:focus-visible {
    outline: 2px solid var(--secondary);
    outline-offset: 4px;
    border-radius: 4px;
}

/* MOBILE FIRST BASE STYLES */

header { 
    background: rgba(255, 255, 255, 0.85); 
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    padding: 1rem; 
    display: flex; 
    flex-direction: column; 
    gap: 1rem;
    align-items: center; 
    border: 1px solid var(--border-color); 
    border-radius: 16px;
    margin: 1rem;
    box-shadow: 0 4px 20px -2px rgba(0, 0, 0, 0.05);
    position: sticky;
    top: 1rem;
    z-index: 50;
    transition: all 0.3s ease;
}
@media (prefers-color-scheme: dark) {
    header {
        background: rgba(34, 48, 38, 0.75); /* Dark mode glass */
        box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
        border-color: rgba(255, 255, 255, 0.08);
    }
}
header .logo { 
    font-size: 1.5rem; 
    font-weight: 700; 
    color: var(--primary); 
    text-decoration: none; 
}
nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
}
nav a { 
    color: var(--text-color); 
    text-decoration: none; 
    font-weight: 500; 
    transition: color 0.3s; 
    position: relative;
    padding-bottom: 2px;
}
nav a:hover, nav a.active { 
    color: var(--secondary); 
}
nav a.active::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--secondary);
    border-radius: 2px;
    box-shadow: 0 2px 4px rgba(101, 140, 110, 0.4);
}

.container { 
    width: 100%; 
    padding: 1rem; /* Smaller padding on mobile */
    margin: 0 auto;
}

/* Hero */
.hero { 
    text-align: center; 
    padding: 2.5rem 1rem; 
    background: linear-gradient(145deg, var(--card-bg), var(--bg-color)); 
    border-radius: 24px; 
    margin-top: 1rem; 
    border: 1px solid var(--border-color); 
    box-shadow: 0 10px 30px -10px rgba(0,0,0,0.05);
}
.hero h1 { 
    font-size: 1.75rem; 
    color: var(--primary); 
    margin-bottom: 1rem; 
    line-height: 1.2;
    letter-spacing: -0.02em;
}
.hero p { 
    font-size: 1rem; 
    margin: 0 auto 1.5rem; 
    color: var(--text-color);
}
.phone-banner { 
    background: var(--primary); 
    color: var(--bg-color); 
    padding: 0.75rem 1.25rem; 
    border-radius: 12px; 
    display: inline-block; 
    font-size: 1.25rem; 
    font-weight: bold; 
    width: 100%; /* Full width banner on mobile */
    text-decoration: none;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}
.phone-banner:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 16px rgba(0,0,0,0.15);
}
.instructions { 
    margin-top: 2rem; 
    text-align: left; 
}
.instructions h3 { 
    color: var(--secondary); 
    margin-bottom: 0.75rem; 
}
.instructions ul { 
    padding-left: 1.25rem; 
    margin-bottom: 1rem; 
}
.instructions li { 
    margin-bottom: 0.5rem; 
    font-size: 0.95rem;
}

/* Grid / Cards */
.grid { 
    display: grid; 
    grid-template-columns: 1fr; /* Single column on mobile */
    gap: 1.5rem; 
    margin-top: 1.5rem; 
}
.card { 
    background: var(--card-bg); 
    padding: 1.25rem; 
    border-radius: 16px; 
    border: 1px solid var(--border-color); 
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1); 
    cursor: pointer;
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.02);
}
.card:hover { 
    transform: translateY(-6px); 
    box-shadow: 0 20px 25px -5px rgba(0,0,0,0.1), 0 10px 10px -5px rgba(0,0,0,0.04); 
    border-color: var(--secondary);
}
.card h3 { 
    margin-bottom: 0.5rem; 
    color: var(--primary); 
    font-size: 1.1rem; 
}
.card p {
    color: var(--text-muted);
}
.price { 
    font-size: 1.25rem; 
    font-weight: 700; 
    color: var(--secondary); 
    margin-bottom: 0.75rem; 
}
.tag { 
    display: inline-block; 
    background: var(--accent-light); 
    color: #2c3e32; 
    padding: 0.25rem 0.75rem; 
    border-radius: 9999px; /* Pill shape */
    font-size: 0.75rem; 
    font-weight: 600;
    border: 1px solid var(--accent-gold);
}
.out-of-stock { 
    background: rgba(239, 68, 68, 0.1); 
    color: #ef4444; 
}

/* FAQ Tabs (Segmented Control) */
.faq-tabs {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.5rem;
    margin-bottom: 2rem;
    background: var(--card-bg);
    padding: 0.5rem;
    border-radius: 16px;
    border: 1px solid var(--border-color);
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.05);
}

.faq-tab {
    padding: 0.6rem 0.5rem;
    border: none;
    background: transparent;
    color: var(--text-color);
    cursor: pointer;
    font-weight: 500;
    border-radius: 12px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    white-space: nowrap;
    font-size: 0.85rem;
    display: flex;
    align-items: center;
    justify-content: center;
}
.faq-tab:hover {
    color: var(--secondary);
}
.faq-tab.active {
    background: var(--secondary);
    color: #ffffff;
    box-shadow: 0 4px 12px rgba(101, 140, 110, 0.3);
}

.faq-section {
    animation: fadeIn 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    background: var(--card-bg);
    padding: 1.25rem; /* Smaller padding for mobile text spacing */
    border-radius: 16px;
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.02);
}
.faq-section h2 {
    color: var(--primary);
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
    text-transform: capitalize;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.75rem;
}
.faq-content {
    font-size: 0.95rem;
}
.faq-content p {
    color: var(--text-muted);
    line-height: 1.7;
    margin-bottom: 1rem;
}
.faq-keyword {
    color: var(--secondary);
    font-size: 1.05rem;
    font-weight: 600;
    margin-top: 1.5rem;
    margin-bottom: 0.5rem;
}
.faq-bullet, .faq-numbered {
    color: var(--text-muted);
    margin-bottom: 0.5rem;
    padding-left: 0.5rem;
    line-height: 1.6;
}

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

/* Architecture Timeline */
.timeline {
    position: relative;
    max-width: 800px;
    margin: 3rem auto;
    padding-left: 2rem;
}

.timeline::before {
    content: '';
    position: absolute;
    top: 0;
    left: 7px;
    height: 100%;
    width: 2px;
    background: var(--border-color);
}

.timeline-step {
    position: relative;
    margin-bottom: 2.5rem;
}

.timeline-step:last-child {
    margin-bottom: 0;
}

.timeline-step::before {
    content: '';
    position: absolute;
    left: -2rem;
    top: 0.25rem;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--accent-gold);
    border: 3px solid var(--bg-color);
    box-shadow: 0 0 0 2px var(--border-color);
}

.timeline-content h3 {
    margin: 0 0 0.5rem 0;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.timeline-content p {
    margin: 0;
    color: var(--text-color);
    font-size: 0.95rem;
    line-height: 1.6;
}

.architecture-scroll {
    margin: 3rem 0;
    overflow-x: auto;
    overflow-y: hidden;
    -webkit-overflow-scrolling: touch;
}

.architecture-scroll svg {
    display: block;
    margin: 0;
}

/* Footer */
footer {
    text-align: center;
    padding: 2.5rem 1rem;
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-top: 4rem;
    border-top: 1px solid var(--border-color);
}


/* TABLET & DESKTOP STYLES (min-width: 768px) */
@media (min-width: 768px) {
    header { 
        padding: 1rem 2rem; 
        flex-direction: row; 
        justify-content: space-between;
        margin: 1.5rem auto;
        max-width: 1200px;
        border-radius: 100px; /* Pill shape for desktop navbar */
    }
    nav {
        gap: 0;
    }
    nav a { 
        margin-left: 2rem; 
        font-size: 0.95rem;
    }

    .container { 
        max-width: 1200px; 
        padding: 0 2rem 2rem 2rem; 
    }

    .hero { 
        padding: 2.5rem 2rem; 
        margin: 2rem auto 0; 
        max-width: 800px;
    }
    .hero h1 { 
        font-size: 1.8rem; 
    }
    .hero p { 
        font-size: 1.05rem; 
        max-width: 550px; 
    }
    .phone-banner { 
        width: auto; /* Revert to inline block width */
        padding: 0.75rem 1.5rem; 
        font-size: 1.2rem; 
    }
    .instructions { 
        margin-top: 2rem; 
        max-width: 550px; 
        margin-left: auto; 
        margin-right: auto; 
    }
    .instructions li { 
        font-size: 0.9rem;
    }

    .grid { 
        grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); 
        gap: 2rem; 
        margin-top: 2rem; 
    }
    .card {
        padding: 2rem;
    }
    .card h3 {
        font-size: 1.25rem;
        line-height: 1.4;
    }
    .card .price {
        font-size: 1.35rem;
    }
    .tag {
        font-size: 0.85rem;
    }
    .card:hover { 
        transform: translateY(-8px); 
    }

    .faq-tabs {
        display: flex;
        border-radius: 999px; /* Pill shape on desktop */
    }
    .faq-tab {
        flex: 1; /* Stretch on desktop */
        font-size: 0.95rem;
        padding: 0.75rem 1.5rem;
        border-radius: 999px;
    }

    .faq-section { 
        margin-bottom: 3rem; 
        padding: 2.5rem; /* Larger padding on desktop */
    }
    .faq-section h2 { 
        font-size: 1.5rem;
        margin-bottom: 1.5rem; 
    }
    .faq-content { 
        font-size: 1rem;
    }

    .architecture-scroll svg {
        margin: 0 auto;
    }
}