/* ==============================================================================
   prodsec.fi — Design System & Stylesheet
   Modern, accessible, dark/light theme, typography & responsive layout
   ============================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=JetBrains+Mono:wght@400;500;600&display=swap');

/* --- Root Variables & Theme Tokens --- */
:root {
    color-scheme: light dark;

    /* Base Palette (Dark Default for Cybersecurity Aesthetic) */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;

    /* Dark Mode Tokens (Default) */
    --bg-page: #0b0f19;
    --bg-surface: #111827;
    --bg-surface-elevated: #1a2234;
    --bg-surface-glass: rgba(17, 24, 39, 0.75);
    --border-subtle: rgba(255, 255, 255, 0.08);
    --border-hover: rgba(0, 242, 254, 0.35);

    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;

    --brand-primary: #00f2fe;
    --brand-secondary: #0072ff;
    --brand-gradient: linear-gradient(135deg, #00f2fe 0%, #0072ff 100%);
    --brand-gradient-hover: linear-gradient(135deg, #38f9d7 0%, #43e97b 100%);
    --brand-glow: 0 0 25px rgba(0, 242, 254, 0.2);

    --accent-emerald: #10b981;
    --accent-amber: #f59e0b;
    --accent-rose: #f43f5e;
    --accent-purple: #8b5cf6;

    --card-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
    --header-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);

    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-full: 9999px;

    --container-max: 1140px;
    --article-max: 760px;
    --transition-fast: 0.15s ease;
    --transition-base: 0.25s ease;
}

/* Light Theme Override */
[data-theme="light"] {
    color-scheme: light;
    --bg-page: #f8fafc;
    --bg-surface: #ffffff;
    --bg-surface-elevated: #f1f5f9;
    --bg-surface-glass: rgba(255, 255, 255, 0.85);
    --border-subtle: rgba(0, 0, 0, 0.08);
    --border-hover: rgba(0, 114, 255, 0.4);

    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;

    --brand-primary: #0062d2;
    --brand-secondary: #0284c7;
    --brand-gradient: linear-gradient(135deg, #0062d2 0%, #0284c7 100%);
    --brand-glow: 0 0 20px rgba(0, 98, 210, 0.15);

    --card-shadow: 0 10px 30px -10px rgba(15, 23, 42, 0.08);
    --header-shadow: 0 4px 20px rgba(15, 23, 42, 0.05);
}

/* Explicit Dark Theme Selector */
[data-theme="dark"] {
    color-scheme: dark;
}

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

html {
    scroll-behavior: smooth;
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.6;
    background-color: var(--bg-page);
    color: var(--text-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background-color: var(--bg-page);
    color: var(--text-primary);
    transition: background-color var(--transition-base), color var(--transition-base);
}

a {
    color: var(--brand-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

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

/* --- Layout Container --- */
.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 1.5rem;
}

.article-container {
    width: 100%;
    max-width: var(--article-max);
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* --- Header & Navigation --- */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--bg-surface-glass);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-subtle);
    box-shadow: var(--header-shadow);
    transition: background var(--transition-base), border-color var(--transition-base);
}

.nav-wrapper {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.site-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 800;
    font-size: 1.25rem;
    letter-spacing: -0.02em;
    color: var(--text-primary);
}

.site-logo .logo-badge {
    background: var(--brand-gradient);
    color: #ffffff;
    font-size: 0.75rem;
    font-weight: 700;
    padding: 0.2rem 0.5rem;
    border-radius: var(--radius-sm);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.site-logo span.highlight {
    background: var(--brand-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-links {
    display: flex;
    align-items: center;
    list-style: none;
    gap: 1.75rem;
}

.nav-links a {
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.95rem;
    transition: color var(--transition-fast);
}

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

.nav-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

/* Theme Switcher Button */
.theme-toggle-btn {
    background: var(--bg-surface-elevated);
    border: 1px solid var(--border-subtle);
    color: var(--text-primary);
    width: 38px;
    height: 38px;
    border-radius: var(--radius-md);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background var(--transition-fast), border-color var(--transition-fast);
}

.theme-toggle-btn:hover {
    border-color: var(--border-hover);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.5rem;
    cursor: pointer;
}

/* --- Hero Section --- */
.hero {
    position: relative;
    padding: 5rem 0 4rem;
    overflow: hidden;
}

.hero-glow {
    position: absolute;
    top: -100px;
    left: 50%;
    transform: translateX(-50%);
    width: 700px;
    height: 350px;
    background: radial-gradient(circle, rgba(0, 242, 254, 0.15) 0%, rgba(0, 114, 255, 0.05) 50%, transparent 70%);
    filter: blur(60px);
    pointer-events: none;
    z-index: 0;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 840px;
    margin: 0 auto;
}

.hero-tag {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.35rem 0.9rem;
    background: var(--bg-surface-elevated);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-full);
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.hero-tag .dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--accent-emerald);
    box-shadow: 0 0 8px var(--accent-emerald);
}

.hero-title {
    font-size: clamp(2.25rem, 5vw, 3.5rem);
    font-weight: 800;
    line-height: 1.15;
    letter-spacing: -0.03em;
    margin-bottom: 1.25rem;
}

.hero-title .gradient-text {
    background: var(--brand-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-description {
    font-size: clamp(1.1rem, 2vw, 1.25rem);
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 2rem;
    max-width: 680px;
    margin-left: auto;
    margin-right: auto;
}

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

/* --- Buttons --- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
    font-size: 0.95rem;
    padding: 0.75rem 1.4rem;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast), opacity var(--transition-fast);
    border: none;
    text-decoration: none;
}

.btn:hover {
    transform: translateY(-2px);
}

.btn-primary {
    background: var(--brand-gradient);
    color: #ffffff;
    box-shadow: var(--brand-glow);
}

.btn-primary:hover {
    color: #ffffff;
    opacity: 0.95;
}

.btn-secondary {
    background: var(--bg-surface-elevated);
    border: 1px solid var(--border-subtle);
    color: var(--text-primary);
}

.btn-secondary:hover {
    border-color: var(--border-hover);
    color: var(--text-primary);
}

/* --- Badges & Tags --- */
.badge {
    display: inline-block;
    padding: 0.2rem 0.6rem;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    text-transform: uppercase;
}

.badge-cyan {
    background: rgba(0, 242, 254, 0.1);
    color: var(--brand-primary);
    border: 1px solid rgba(0, 242, 254, 0.2);
}

.badge-emerald {
    background: rgba(16, 185, 129, 0.1);
    color: var(--accent-emerald);
    border: 1px solid rgba(16, 185, 129, 0.2);
}

.badge-purple {
    background: rgba(139, 92, 246, 0.1);
    color: var(--accent-purple);
    border: 1px solid rgba(139, 92, 246, 0.2);
}

/* --- Section Layouts --- */
.section {
    padding: 4rem 0;
}

.section-header {
    margin-bottom: 2.5rem;
}

.section-header.text-center {
    text-align: center;
}

.section-tag {
    font-size: 0.85rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--brand-primary);
    margin-bottom: 0.5rem;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 0.75rem;
}

.section-subtitle {
    color: var(--text-secondary);
    font-size: 1.05rem;
    max-width: 620px;
}

.section-header.text-center .section-subtitle {
    margin: 0 auto;
}

/* --- Grid Systems & Cards --- */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 1.75rem;
}

.card {
    background: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: 2rem;
    transition: transform var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base);
    box-shadow: var(--card-shadow);
    display: flex;
    flex-direction: column;
}

.card:hover {
    transform: translateY(-4px);
    border-color: var(--border-hover);
}

.card-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    background: var(--bg-surface-elevated);
    border: 1px solid var(--border-subtle);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: 1.25rem;
}

.card-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.card-body {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
    margin-bottom: 1.5rem;
    flex-grow: 1;
}

.card-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 1rem;
    border-top: 1px solid var(--border-subtle);
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* Article Card in Blog Grid */
.article-card {
    background: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: transform var(--transition-base), border-color var(--transition-base);
    display: flex;
    flex-direction: column;
}

.article-card:hover {
    transform: translateY(-4px);
    border-color: var(--border-hover);
}

.article-card-content {
    padding: 1.75rem;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.article-meta {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
}

.article-card-title {
    font-size: 1.3rem;
    font-weight: 700;
    line-height: 1.35;
    margin-bottom: 0.75rem;
}

.article-card-title a {
    color: var(--text-primary);
}

.article-card-title a:hover {
    color: var(--brand-primary);
}

.article-excerpt {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
    margin-bottom: 1.5rem;
    flex-grow: 1;
}

/* --- Distinction Matrix: ProdSec vs AppSec --- */
.matrix-table-wrapper {
    background: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    overflow-x: auto;
    box-shadow: var(--card-shadow);
}

.matrix-table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
    font-size: 0.95rem;
}

.matrix-table th,
.matrix-table td {
    padding: 1.1rem 1.5rem;
    border-bottom: 1px solid var(--border-subtle);
}

.matrix-table th {
    background: var(--bg-surface-elevated);
    font-weight: 700;
    color: var(--text-primary);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

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

.matrix-table tr:hover td {
    background: rgba(255, 255, 255, 0.02);
}

/* --- Article Detail View --- */
.article-header {
    padding: 3.5rem 0 2rem;
    text-align: center;
    border-bottom: 1px solid var(--border-subtle);
    margin-bottom: 2.5rem;
}

.article-breadcrumbs {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 1.25rem;
}

.article-breadcrumbs a {
    color: var(--text-secondary);
}

.article-headline {
    font-size: clamp(2rem, 4vw, 2.75rem);
    font-weight: 800;
    line-height: 1.2;
    letter-spacing: -0.02em;
    margin-bottom: 1rem;
}

.article-lead {
    font-size: 1.2rem;
    color: var(--text-secondary);
    line-height: 1.6;
    max-width: 680px;
    margin: 0 auto 1.75rem;
}

.article-author-bar {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1.5rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.author-info {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.author-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--brand-gradient);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #ffffff;
    font-weight: 700;
    font-size: 0.85rem;
}

.author-link {
    color: inherit;
    text-decoration: none;
    transition: color var(--transition-fast);
}

.author-link:hover,
.author-link:focus-visible {
    color: var(--color-primary);
    text-decoration: underline;
}

/* Article Prose / Markdown Styling */
.article-content {
    font-size: 1.1rem;
    line-height: 1.75;
    color: var(--text-secondary);
}

.article-content h2 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
    margin: 2.5rem 0 1rem;
    letter-spacing: -0.02em;
}

.article-content h3 {
    font-size: 1.35rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 2rem 0 0.75rem;
}

.article-content p {
    margin-bottom: 1.5rem;
}

.article-content ul,
.article-content ol {
    margin-bottom: 1.5rem;
    padding-left: 1.75rem;
}

.article-content li {
    margin-bottom: 0.5rem;
}

.article-content strong {
    color: var(--text-primary);
}

.article-content blockquote {
    border-left: 3px solid var(--brand-primary);
    padding: 1rem 1.5rem;
    margin: 2rem 0;
    background: var(--bg-surface-elevated);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    font-style: italic;
    color: var(--text-primary);
}

.article-content pre {
    background: var(--bg-surface-elevated);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    padding: 1.25rem;
    overflow-x: auto;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    margin: 1.5rem 0;
    color-scheme: dark;
}

.article-content code {
    font-family: var(--font-mono);
    font-size: 0.9em;
    background: var(--bg-surface-elevated);
    padding: 0.15rem 0.4rem;
    border-radius: var(--radius-sm);
    color: var(--brand-primary);
}

.article-content pre code {
    background: transparent;
    padding: 0;
    color: var(--text-primary);
}

/* Callout Box */
.callout {
    background: var(--bg-surface-elevated);
    border: 1px solid var(--border-subtle);
    border-left: 4px solid var(--brand-primary);
    border-radius: var(--radius-md);
    padding: 1.25rem 1.5rem;
    margin: 2rem 0;
}

.callout-title {
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.4rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* --- Footer --- */
.site-footer {
    margin-top: auto;
    background: var(--bg-surface);
    border-top: 1px solid var(--border-subtle);
    padding: 3.5rem 0 2rem;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 3rem;
    margin-bottom: 2.5rem;
}

.footer-brand p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
    margin-top: 0.75rem;
    max-width: 340px;
}

.footer-col h4 {
    color: var(--text-primary);
    font-size: 0.95rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 1rem;
}

.footer-col ul {
    list-style: none;
}

.footer-col li {
    margin-bottom: 0.5rem;
}

.footer-col a {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.footer-col a:hover {
    color: var(--brand-primary);
}

.footer-bottom {
    padding-top: 2rem;
    border-top: 1px solid var(--border-subtle);
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.85rem;
    color: var(--text-muted);
    flex-wrap: wrap;
    gap: 1rem;
}

/* --- Responsive Adjustments --- */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .nav-links.open {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: var(--bg-surface);
        padding: 1.5rem;
        border-bottom: 1px solid var(--border-subtle);
        box-shadow: var(--card-shadow);
        gap: 1rem;
    }

    .mobile-menu-btn {
        display: block;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .hero {
        padding: 3rem 0;
    }

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