:root {
    --c-primary: #0a192f;
    --c-secondary: #1a3a6e;
    --c-accent: #00aaff;
    --c-accent-glow: rgba(0, 170, 255, 0.5);
    --c-text: #e6f1ff;
    --c-text-muted: #a8b2d1;
    --c-bg: #0a192f;
    --c-bg-light: #f0f8ff;
    --c-card-bg: rgba(26, 58, 110, 0.5);
    --c-card-border: rgba(0, 170, 255, 0.2);
    --c-shadow: rgba(0, 0, 0, 0.2);
    --f-main: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
    --shadow-sm: 0 2px 4px var(--c-shadow);
    --shadow-md: 0 4px 8px var(--c-shadow);
    --transition-fast: 0.2s ease;
    --transition-med: 0.4s ease;
}

[data-theme="light"] {
    --c-primary: #f0f8ff;
    --c-secondary: #e6f1ff;
    --c-accent: #0077cc;
    --c-accent-glow: rgba(0, 119, 204, 0.4);
    --c-text: #0a192f;
    --c-text-muted: #4a5568;
    --c-bg: #f0f8ff;
    --c-bg-light: #ffffff;
    --c-card-bg: rgba(255, 255, 255, 0.6);
    --c-card-border: rgba(0, 119, 204, 0.2);
    --c-shadow: rgba(10, 25, 47, 0.1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--f-main);
    background: radial-gradient(circle at top left, var(--c-primary) 0%, var(--c-bg) 75%);
    color: var(--c-text);
    line-height: 1.7;
    font-size: 18px;
    transition: background-color var(--transition-med), color var(--transition-med);
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

a {
    color: var(--c-accent);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover, a:focus {
    color: var(--c-text);
    outline: 2px solid transparent;
    outline-offset: 2px;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
    border-radius: var(--radius-md);
}

h1, h2, h3, h4, h5, h6 {
    color: var(--c-text);
    margin-bottom: 1rem;
    line-height: 1.3;
    font-weight: 700;
}

h1 { font-size: clamp(2.5rem, 5vw, 3.5rem); }
h2 { font-size: clamp(2rem, 4vw, 2.75rem); }
p { margin-bottom: 1.5rem; color: var(--c-text-muted); }

/* Header & Nav */
.main-header {
    position: sticky;
    top: 0;
    z-index: 100;
    padding: 1rem 0;
    background: rgba(10, 25, 47, 0.85);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--c-card-border);
    transition: background-color var(--transition-med);
}

[data-theme="light"] .main-header {
    background: rgba(240, 248, 255, 0.85);
}

.main-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo a {
    display: flex;
    align-items: center;
    font-weight: 700;
    font-size: 1.2rem;
    color: var(--c-text);
}

.nav-logo img {
    height: 32px;
    margin-right: 0.5rem;
    border-radius: var(--radius-sm);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    list-style: none;
}

.nav-links a {
    color: var(--c-text-muted);
    font-weight: 600;
    font-size: 0.9rem;
    padding: 0.5rem;
    border-radius: var(--radius-sm);
    transition: color var(--transition-fast), background-color var(--transition-fast);
}

.nav-links a:hover, .nav-links a.active {
    color: var(--c-text);
}

.nav-toggle, .theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--c-text-muted);
    padding: 0.5rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: color var(--transition-fast), background-color var(--transition-fast);
}

.nav-toggle:hover, .theme-toggle:hover {
    color: var(--c-text);
    background-color: var(--c-secondary);
}

.theme-toggle .icon-sun, .theme-toggle .icon-moon {
    width: 24px;
    height: 24px;
}

.icon-moon { display: none; }
[data-theme="light"] .icon-sun { display: none; }
[data-theme="light"] .icon-moon { display: block; }

.nav-toggle { display: none; } /* For mobile */

/* CTA Button */
.cta-btn {
    display: inline-block;
    font-weight: 700;
    font-size: 1rem;
    color: var(--c-bg);
    background: linear-gradient(45deg, var(--c-accent), #00c0ff);
    padding: 0.8rem 1.8rem;
    border-radius: var(--radius-md);
    border: 2px solid transparent;
    cursor: pointer;
    text-align: center;
    text-transform: uppercase;
    letter-spacing: 1px;
    box-shadow: 0 0 20px var(--c-accent-glow);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast), background-color var(--transition-fast);
}

.cta-btn:hover, .cta-btn:focus {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 0 30px var(--c-accent-glow);
    background: var(--c-text);
    color: var(--c-primary) !important;
    outline: none;
}

/* Main Content & Cards */
main {
    padding: 2rem 0;
}

.card {
    background: linear-gradient(135deg, rgba(26, 58, 110, 0.55), rgba(26, 58, 110, 0.45));
    border: 1px solid var(--c-card-border);
    border-radius: var(--radius-lg);
    padding: 2rem;
    margin-bottom: 2rem;
    backdrop-filter: blur(5px);
    box-shadow: var(--shadow-md);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px var(--c-shadow);
}

/* Footer */
.main-footer {
    padding: 3rem 0;
    text-align: center;
    border-top: 1px solid var(--c-card-border);
    margin-top: 4rem;
}

.footer-nav {
    margin-bottom: 1.5rem;
}

.footer-nav a {
    margin: 0 1rem;
    color: var(--c-text-muted);
    font-size: 0.9rem;
}

.footer-disclaimer {
    font-size: 0.8rem;
    color: var(--c-text-muted);
    max-width: 800px;
    margin: 0 auto;
}

/* Article specific styles */
.article-header {
    text-align: center;
    margin-bottom: 3rem;
}

.article-header h1 {
    margin-bottom: 0.5rem;
}

.article-header .meta {
    color: var(--c-text-muted);
    font-size: 0.9rem;
}

.article-content img {
    margin: 2rem 0;
}

/* Responsive */
@media (max-width: 768px) {
    body {
        font-size: 16px;
    }

    .container {
        padding: 0 1rem;
    }

    .main-nav {
        flex-wrap: wrap;
        justify-content: space-between;
    }

    .nav-logo {
        flex-grow: 1;
    }

    .nav-links {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100vh;
        flex-direction: column;
        justify-content: center;
        background: var(--c-primary);
        box-shadow: -5px 0 15px rgba(0,0,0,0.2);
        transition: transform var(--transition-med) ease-in-out;
        transform: translateX(100%); /* Start off-screen to the right */
        padding-top: 60px; /* Space for header */
        z-index: 99; /* Ensure it's above content but below sticky banner */
    }

    .nav-links.open {
        transform: translateX(0); /* Slide in */
        overflow-y: auto; /* Enable scrolling for long nav menus */
    }

    body.nav-open {
        overflow: hidden; /* Prevent scrolling when nav is open */
    }

    .nav-links li {
        margin-bottom: 1rem;
    }

    .nav-links a {
        font-size: 1.2rem;
    }

    .nav-toggle {
        display: flex;
        z-index: 101;
    }

    .theme-toggle {
        order: 1; /* Place theme toggle before nav toggle */
        margin-right: 0.5rem;
    }

    h1 { font-size: clamp(2rem, 6vw, 2.5rem); }
    h2 { font-size: clamp(1.75rem, 5vw, 2rem); }

        main {
        padding: 2rem 0; /* Adjust main padding for mobile */
    }

    .card {
        padding: 1.5rem; /* Adjust card padding for mobile */
    }

    /* Table responsiveness */
    .comparison-table {
        display: block;
        overflow-x: auto;
        white-space: nowrap; /* Prevent text wrapping */
    }

    .comparison-table thead, .comparison-table tbody, .comparison-table th, .comparison-table td, .comparison-table tr {
        display: block;
    }

    .comparison-table th {
        text-align: right;
        padding-right: 1rem;
    }

    .comparison-table td {
        border-bottom: none;
        position: relative;
        padding-left: 50%; /* Space for pseudo-element label */
        text-align: left;
    }

    .comparison-table td::before {
        content: attr(data-label);
        position: absolute;
        left: 0;
        width: 45%;
        padding-right: 10px;
        white-space: nowrap;
        text-align: right;
        font-weight: 600;
        color: var(--c-text);
    }

    .comparison-table tr {
        margin-bottom: 1rem;
        border: 1px solid var(--c-card-border);
        border-radius: var(--radius-md);
        overflow: hidden;
    }

    .comparison-table th:not(:first-child) {
        display: none; /* Hide all but the first header on mobile */
    }

    .comparison-table td:first-child {
        background-color: var(--c-secondary);
        color: var(--c-text);
        font-weight: 700;
        text-align: center;
        padding: 0.8rem;
        border-bottom: 1px solid var(--c-card-border);
    }

    .sticky-banner .cta-btn {
        width: auto; /* Allow button to size naturally */
        padding: 0.6rem 1rem;
        font-size: 0.9rem;
    }
}

/* Utility */
.text-center { text-align: center; }
.mt-4 { margin-top: 4rem; }

/* Table Styles */
.comparison-table {
    width: 100%;
    border-collapse: collapse;
    margin: 2rem 0;
    font-size: 0.9rem;
}

.comparison-table th, .comparison-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--c-card-border);
}

.comparison-table th {
    background-color: var(--c-secondary);
    color: var(--c-text);
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.comparison-table tbody tr:last-child td {
    border-bottom: none;
}

.comparison-table td:first-child {
    font-weight: 600;
    color: var(--c-text);
}

[data-theme="light"] .comparison-table th {
    background-color: var(--c-secondary);
}

/* Video Container */
.video-container {
    position: relative;
    padding-bottom: 56.25%; /* 16:9 */
    height: 0;
    overflow: hidden;
    max-width: 100%;
    background: #000;
    border-radius: var(--radius-md);
    margin: 2rem 0;
}

.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: 0;
}

/* Sticky Banner */
.sticky-banner {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    background: var(--c-accent);
    color: var(--c-primary);
    padding: 1rem 1.5rem;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1.5rem;
    box-shadow: 0 -2px 10px rgba(0,0,0,0.1);
    z-index: 1000;
    transform: translateY(0);
    transition: transform 0.5s ease-out;
}

.sticky-banner.hide {
    transform: translateY(100%);
}

.banner-message {
    font-weight: 600;
    font-size: 1.1rem;
}

.banner-close {
    background: none;
    border: none;
    color: var(--c-primary);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: background-color 0.3s ease;
}

.banner-close:hover {
    background-color: rgba(0,0,0,0.1);
}

@media (max-width: 768px) {
    .sticky-banner {
        flex-direction: column;
        text-align: center;
        gap: 0.8rem;
        padding: 0.8rem 1rem;
    }
    .banner-message {
        font-size: 1rem;
    }
    .sticky-banner .cta-btn {
        width: 100%;
        padding: 0.6rem 1rem;
        color: var(--c-text) !important;
    }
}