/* ==========================================================================
   Shift Left or Stay Right? - Main Stylesheet
   A balanced deep-dive into Streaming vs Batch Processing
   ========================================================================== */

/* --------------------------------------------------------------------------
   CSS Variables & Tokens
   -------------------------------------------------------------------------- */
:root {
    /* Typography */
    --font-display: 'Playfair Display', Georgia, serif;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'SF Mono', monospace;

    /* Font Sizes */
    --text-xs: 0.75rem;
    --text-sm: 0.875rem;
    --text-base: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 2rem;
    --text-4xl: 2.5rem;
    --text-5xl: 3.25rem;

    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;
    --space-24: 6rem;
    --space-32: 8rem;

    /* Layout */
    --content-width: 680px;
    --wide-width: 920px;

    /* Animation */
    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
    --duration-fast: 150ms;
    --duration-normal: 300ms;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;
}

/* --------------------------------------------------------------------------
   Dark Theme
   -------------------------------------------------------------------------- */
[data-theme="dark"] {
    --color-bg-primary: #09090b;
    --color-bg-secondary: #0f0f12;
    --color-bg-tertiary: #16161a;
    --color-bg-elevated: #1c1c21;
    --color-bg-hover: #24242b;
    --color-bg-alt: #0c0c0f;
    --color-bg-alt-elevated: #121215;

    --color-text-primary: #f4f4f5;
    --color-text-secondary: #a1a1aa;
    --color-text-tertiary: #71717a;
    --color-text-muted: #52525b;

    --color-accent: #fb923c;
    --color-accent-muted: #f97316;
    --color-accent-subtle: rgba(251, 146, 60, 0.1);
    --color-accent-glow: rgba(251, 146, 60, 0.15);

    --color-secondary: #38bdf8;
    --color-secondary-muted: #0ea5e9;
    --color-secondary-subtle: rgba(56, 189, 248, 0.1);

    --color-batch: #a78bfa;
    --color-batch-muted: #8b5cf6;
    --color-batch-subtle: rgba(167, 139, 250, 0.1);

    --color-stream: #f472b6;
    --color-stream-muted: #ec4899;
    --color-stream-subtle: rgba(244, 114, 182, 0.1);

    --color-success: #4ade80;
    --color-success-muted: #22c55e;
    --color-success-subtle: rgba(74, 222, 128, 0.1);
    --color-warning: #fbbf24;
    --color-warning-muted: #f59e0b;
    --color-warning-subtle: rgba(251, 191, 36, 0.1);
    --color-error: #f87171;
    --color-error-muted: #ef4444;
    --color-error-subtle: rgba(248, 113, 113, 0.1);

    --color-border: rgba(255, 255, 255, 0.06);
    --color-border-strong: rgba(255, 255, 255, 0.12);
    --color-border-accent: rgba(251, 146, 60, 0.3);

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.5);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.5);
    --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.6);
    --shadow-glow: 0 0 40px rgba(251, 146, 60, 0.1);

    --gradient-radial: radial-gradient(ellipse 80% 50% at 50% -20%, rgba(251, 146, 60, 0.12), transparent 60%);
    --gradient-section: linear-gradient(180deg, var(--color-bg-alt) 0%, var(--color-bg-primary) 100%);
}

/* --------------------------------------------------------------------------
   Light Theme
   -------------------------------------------------------------------------- */
[data-theme="light"] {
    --color-bg-primary: #ffffff;
    --color-bg-secondary: #f8fafc;
    --color-bg-tertiary: #f1f5f9;
    --color-bg-elevated: #ffffff;
    --color-bg-hover: #e2e8f0;
    --color-bg-alt: #f1f5f9;
    --color-bg-alt-elevated: #ffffff;

    --color-text-primary: #0f172a;
    --color-text-secondary: #475569;
    --color-text-tertiary: #64748b;
    --color-text-muted: #94a3b8;

    --color-accent: #ea580c;
    --color-accent-muted: #c2410c;
    --color-accent-subtle: rgba(234, 88, 12, 0.08);
    --color-accent-glow: rgba(234, 88, 12, 0.1);

    --color-secondary: #0284c7;
    --color-secondary-muted: #0369a1;
    --color-secondary-subtle: rgba(2, 132, 199, 0.08);

    --color-batch: #7c3aed;
    --color-batch-muted: #6d28d9;
    --color-batch-subtle: rgba(124, 58, 237, 0.08);

    --color-stream: #db2777;
    --color-stream-muted: #be185d;
    --color-stream-subtle: rgba(219, 39, 119, 0.08);

    --color-success: #16a34a;
    --color-success-muted: #15803d;
    --color-success-subtle: rgba(22, 163, 74, 0.08);
    --color-warning: #d97706;
    --color-warning-muted: #b45309;
    --color-warning-subtle: rgba(217, 119, 6, 0.08);
    --color-error: #dc2626;
    --color-error-muted: #b91c1c;
    --color-error-subtle: rgba(220, 38, 38, 0.08);

    --color-border: rgba(15, 23, 42, 0.08);
    --color-border-strong: rgba(15, 23, 42, 0.15);
    --color-border-accent: rgba(234, 88, 12, 0.3);

    --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.05);
    --shadow-md: 0 4px 16px rgba(15, 23, 42, 0.08);
    --shadow-lg: 0 16px 48px rgba(15, 23, 42, 0.12);
    --shadow-glow: 0 0 40px rgba(234, 88, 12, 0.06);

    --gradient-radial: radial-gradient(ellipse 80% 50% at 50% -20%, rgba(234, 88, 12, 0.08), transparent 60%);
    --gradient-section: linear-gradient(180deg, var(--color-bg-alt) 0%, var(--color-bg-primary) 100%);
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 100px;
}

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
}

body {
    font-family: var(--font-body);
    background: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.7;
    font-size: var(--text-base);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

::selection {
    background: var(--color-accent);
    color: white;
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: none; cursor: pointer; }

/* --------------------------------------------------------------------------
   Skip Link (Accessibility)
   -------------------------------------------------------------------------- */
.skip-link {
    position: absolute;
    top: -100%;
    left: 50%;
    transform: translateX(-50%);
    background: var(--color-accent);
    color: white;
    padding: var(--space-3) var(--space-6);
    border-radius: var(--radius-md);
    font-weight: 600;
    z-index: 10000;
}
.skip-link:focus { top: var(--space-4); }

/* --------------------------------------------------------------------------
   Progress Bar
   -------------------------------------------------------------------------- */
.progress-bar {
    position: fixed;
    top: 0;
    left: 0;
    width: 0%;
    height: 2px;
    background: var(--color-accent);
    z-index: 9999;
}

/* --------------------------------------------------------------------------
   Header
   -------------------------------------------------------------------------- */
.header {
    position: fixed;
    inset: 0 0 auto;
    z-index: 1000;
    padding: var(--space-4) var(--space-6);
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--space-8);
    transition: all var(--duration-normal) ease;
    opacity: 0;
    transform: translateY(-20px);
    pointer-events: none;
}

.header.is-visible {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
    background: color-mix(in srgb, var(--color-bg-primary) 92%, transparent);
    backdrop-filter: blur(16px) saturate(180%);
    border-bottom: 1px solid var(--color-border);
}

.header__nav {
    display: none;
    align-items: center;
    gap: var(--space-8);
    list-style: none;
}
@media (min-width: 900px) { .header__nav { display: flex; } }

.header__link {
    font-size: var(--text-sm);
    color: var(--color-text-tertiary);
    transition: color var(--duration-fast) ease;
}
.header__link:hover { color: var(--color-text-primary); }

.header__actions {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

/* --------------------------------------------------------------------------
   Theme Toggle
   -------------------------------------------------------------------------- */
.theme-toggle {
    width: 36px;
    height: 36px;
    display: grid;
    place-items: center;
    border-radius: var(--radius-md);
    color: var(--color-text-tertiary);
    transition: all var(--duration-fast) ease;
}
.theme-toggle:hover {
    background: var(--color-bg-tertiary);
    color: var(--color-text-primary);
}
.theme-toggle svg { width: 18px; height: 18px; }

[data-theme="dark"] .theme-toggle__sun { display: block; }
[data-theme="dark"] .theme-toggle__moon { display: none; }
[data-theme="light"] .theme-toggle__sun { display: none; }
[data-theme="light"] .theme-toggle__moon { display: block; }

/* --------------------------------------------------------------------------
   Mobile Menu
   -------------------------------------------------------------------------- */
.mobile-menu-toggle {
    display: none;
    width: 36px;
    height: 36px;
    place-items: center;
    border-radius: var(--radius-md);
    color: var(--color-text-tertiary);
}
.mobile-menu-toggle svg { width: 18px; height: 18px; }
@media (max-width: 899px) { .mobile-menu-toggle { display: grid; } }

.mobile-menu {
    display: none;
    position: fixed;
    top: 68px;
    left: 0;
    right: 0;
    background: color-mix(in srgb, var(--color-bg-primary) 98%, transparent);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-4) var(--space-6);
    z-index: 999;
}
.mobile-menu.is-open { display: block; }
.mobile-menu__list { list-style: none; display: flex; flex-direction: column; gap: var(--space-1); }
.mobile-menu__link {
    display: block;
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    border-radius: var(--radius-md);
    transition: all var(--duration-fast) ease;
}
.mobile-menu__link:hover { background: var(--color-bg-tertiary); color: var(--color-text-primary); }

/* --------------------------------------------------------------------------
   Table of Contents (Sidebar)
   -------------------------------------------------------------------------- */
.toc {
    position: fixed;
    left: var(--space-6);
    top: 50%;
    transform: translateY(-50%);
    z-index: 100;
    display: none;
}
@media (min-width: 1280px) { .toc { display: block; } }

.toc__list {
    list-style: none;
    border-left: 1px solid var(--color-border);
    padding-left: var(--space-4);
}
.toc__item { margin-bottom: var(--space-1); }
.toc__link {
    display: block;
    padding: var(--space-1) 0;
    font-size: 11px;
    color: var(--color-text-muted);
    transition: all var(--duration-fast) ease;
    position: relative;
}
.toc__link::before {
    content: '';
    position: absolute;
    left: calc(-1 * var(--space-4) - 1px);
    top: 50%;
    transform: translateY(-50%);
    width: 2px;
    height: 0;
    background: var(--color-accent);
    transition: height var(--duration-normal) var(--ease-out);
}
.toc__link:hover { color: var(--color-text-secondary); }
.toc__link.is-active { color: var(--color-text-primary); font-weight: 500; }
.toc__link.is-active::before { height: 100%; }

/* --------------------------------------------------------------------------
   Intro Section (Fullscreen Hero)
   -------------------------------------------------------------------------- */
.intro {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: var(--space-8) var(--space-6);
    position: relative;
    overflow: hidden;
}

.intro::before {
    content: '';
    position: absolute;
    top: -30%;
    left: 50%;
    transform: translateX(-50%);
    width: 180%;
    max-width: 1600px;
    height: 100%;
    background: radial-gradient(ellipse 60% 40% at 50% 30%, var(--color-accent-glow), transparent 70%);
    pointer-events: none;
}

.intro__content {
    max-width: 900px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.intro__tag {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-6);
    background: var(--color-accent-subtle);
    border: 1px solid var(--color-border-accent);
    border-radius: var(--radius-full);
    font-size: 11px;
    font-weight: 600;
    color: var(--color-accent);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: var(--space-12);
}

.intro__title {
    font-family: var(--font-display);
    font-size: 4.5rem;
    font-weight: 400;
    line-height: 1.05;
    letter-spacing: -0.03em;
    margin-bottom: var(--space-8);
    color: var(--color-text-primary);
}
@media (min-width: 768px) {
    .intro__title { font-size: 6rem; }
}
@media (min-width: 1024px) {
    .intro__title { font-size: 7rem; }
}

.intro__title em {
    font-style: italic;
    color: var(--color-accent);
}

.intro__subtitle {
    font-size: var(--text-lg);
    line-height: 1.8;
    color: var(--color-text-secondary);
    max-width: 640px;
    margin: 0 auto var(--space-12);
}
@media (min-width: 768px) {
    .intro__subtitle { font-size: var(--text-xl); }
}

.intro__author {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-4);
    margin-bottom: var(--space-8);
}

.intro__author-avatar {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-full);
    background: var(--color-bg-tertiary);
    border: 2px solid var(--color-border);
    display: grid;
    place-items: center;
    font-size: var(--text-lg);
    font-weight: 700;
    color: var(--color-accent);
    overflow: hidden;
}

.intro__author-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: var(--radius-full);
}

.intro__author-info {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    text-align: left;
}

.intro__author-name {
    font-size: var(--text-base);
    font-weight: 600;
    color: var(--color-text-primary);
}

.intro__author-role {
    font-size: var(--text-sm);
    color: var(--color-text-tertiary);
}

.intro__meta {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-8);
    color: var(--color-text-tertiary);
    font-size: var(--text-sm);
}

.intro__meta-item {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.intro__meta-item svg {
    width: 16px;
    height: 16px;
    opacity: 0.6;
}

.intro__scroll {
    position: absolute;
    bottom: var(--space-8);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-2);
    color: var(--color-text-muted);
    font-size: 11px;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    animation: scrollBounce 2s ease-in-out infinite;
}

.intro__scroll svg {
    width: 20px;
    height: 20px;
}

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

/* Intro Mobile Styles */
@media (max-width: 640px) {
    .intro__title {
        font-size: 2.75rem;
    }

    .intro__subtitle {
        font-size: var(--text-base);
    }

    .intro__tag {
        padding: var(--space-2) var(--space-4);
        font-size: 10px;
        margin-bottom: var(--space-8);
    }

    .intro__author-avatar {
        width: 48px;
        height: 48px;
    }

    .intro__meta {
        flex-direction: column;
        gap: var(--space-3);
    }
}

/* --------------------------------------------------------------------------
   Content & Sections
   -------------------------------------------------------------------------- */
.content {
    max-width: var(--content-width);
    margin: 0 auto;
    padding: 0 var(--space-6);
}

.section {
    padding: var(--space-20) 0;
    position: relative;
}

/* Alternating section backgrounds */
.section--alt {
    background: var(--color-bg-alt);
}
.section--alt .content {
    position: relative;
    z-index: 1;
}
.section--alt::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--color-border-strong), transparent);
}
.section--alt::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--color-border-strong), transparent);
}

/* --------------------------------------------------------------------------
   Typography
   -------------------------------------------------------------------------- */
.article h2 {
    font-family: var(--font-display);
    font-size: var(--text-3xl);
    font-weight: 400;
    line-height: 1.2;
    letter-spacing: -0.01em;
    margin-bottom: var(--space-6);
    scroll-margin-top: 100px;
}
.article h2 em { font-style: italic; color: var(--color-accent); }

.article h3 {
    font-size: var(--text-lg);
    font-weight: 600;
    margin-top: var(--space-12);
    margin-bottom: var(--space-4);
    color: var(--color-text-primary);
}

.article h4 {
    font-size: var(--text-xs);
    font-weight: 700;
    margin-top: var(--space-8);
    margin-bottom: var(--space-3);
    color: var(--color-accent);
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.article p {
    margin-bottom: var(--space-5);
    color: var(--color-text-secondary);
}
.article p strong { color: var(--color-text-primary); font-weight: 600; }
.article .accent { color: var(--color-accent); font-weight: 500; }
.article .batch { color: var(--color-batch); font-weight: 500; }
.article .stream { color: var(--color-stream); font-weight: 500; }

.lead {
    font-size: var(--text-lg);
    line-height: 1.7;
    color: var(--color-text-primary);
}

.article ul, .article ol {
    margin-bottom: var(--space-5);
    padding-left: var(--space-6);
    color: var(--color-text-secondary);
}
.article li { margin-bottom: var(--space-2); }
.article li::marker { color: var(--color-accent); }

.divider {
    border: none;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--color-border-strong), transparent);
    margin: var(--space-12) 0;
}

.section--alt .divider {
    display: none;
}

/* --------------------------------------------------------------------------
   Pullquote
   -------------------------------------------------------------------------- */
.pullquote {
    margin: var(--space-12) 0;
    padding: var(--space-8) var(--space-10);
    background: linear-gradient(135deg, var(--color-accent-subtle) 0%, transparent 60%);
    border-left: 3px solid var(--color-accent);
    border-radius: 0 var(--radius-xl) var(--radius-xl) 0;
    position: relative;
}
.pullquote::before {
    content: '"';
    position: absolute;
    top: var(--space-4);
    left: var(--space-4);
    font-family: var(--font-display);
    font-size: 4rem;
    color: var(--color-accent);
    opacity: 0.2;
    line-height: 1;
}
.pullquote p {
    font-family: var(--font-display);
    font-size: var(--text-xl);
    font-style: italic;
    line-height: 1.6;
    color: var(--color-text-primary);
    margin-bottom: 0;
    position: relative;
    z-index: 1;
}

/* --------------------------------------------------------------------------
   Callout
   -------------------------------------------------------------------------- */
.callout {
    display: flex;
    gap: var(--space-4);
    padding: var(--space-5) var(--space-6);
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    margin: var(--space-8) 0;
    position: relative;
    overflow: hidden;
}
.callout::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
}
.callout--warning { border-color: rgba(251, 191, 36, 0.3); background: var(--color-warning-subtle); }
.callout--warning::before { background: var(--color-warning); }
.callout--insight { border-color: rgba(56, 189, 248, 0.3); background: var(--color-secondary-subtle); }
.callout--insight::before { background: var(--color-secondary); }
.callout--success { border-color: rgba(74, 222, 128, 0.3); background: var(--color-success-subtle); }
.callout--success::before { background: var(--color-success); }
.callout--batch { border-color: rgba(167, 139, 250, 0.3); background: var(--color-batch-subtle); }
.callout--batch::before { background: var(--color-batch); }
.callout--stream { border-color: rgba(244, 114, 182, 0.3); background: var(--color-stream-subtle); }
.callout--stream::before { background: var(--color-stream); }

.callout__icon {
    flex-shrink: 0;
    width: 22px;
    height: 22px;
    color: var(--color-text-tertiary);
    margin-top: 2px;
}
.callout--warning .callout__icon { color: var(--color-warning); }
.callout--insight .callout__icon { color: var(--color-secondary); }
.callout--success .callout__icon { color: var(--color-success); }
.callout--batch .callout__icon { color: var(--color-batch); }
.callout--stream .callout__icon { color: var(--color-stream); }

.callout__content p { margin-bottom: 0; font-size: var(--text-sm); color: var(--color-text-secondary); }
.callout__content strong { color: var(--color-text-primary); }

/* --------------------------------------------------------------------------
   Code Block
   -------------------------------------------------------------------------- */
.code-block {
    margin: var(--space-8) 0;
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
}
.code-block__header {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3) var(--space-4);
    background: var(--color-bg-tertiary);
    border-bottom: 1px solid var(--color-border);
}
.code-block__dots { display: flex; gap: 6px; }
.code-block__dot { width: 10px; height: 10px; border-radius: 50%; background: var(--color-text-muted); opacity: 0.4; }
.code-block__dot:first-child { background: var(--color-error); opacity: 0.6; }
.code-block__dot:nth-child(2) { background: var(--color-warning); opacity: 0.6; }
.code-block__dot:nth-child(3) { background: var(--color-success); opacity: 0.6; }
.code-block__filename { font-family: var(--font-mono); font-size: 11px; color: var(--color-text-tertiary); }
.code-block__lang { margin-left: auto; font-size: 10px; font-weight: 600; color: var(--color-text-muted); text-transform: uppercase; letter-spacing: 0.05em; }
.code-block__copy {
    display: flex;
    align-items: center;
    gap: var(--space-1);
    margin-left: var(--space-3);
    padding: var(--space-1) var(--space-2);
    font-size: 11px;
    font-weight: 500;
    color: var(--color-text-tertiary);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    transition: all var(--duration-fast) ease;
}
.code-block__copy:hover { color: var(--color-text-primary); border-color: var(--color-border-strong); }
.code-block__copy svg { width: 12px; height: 12px; }
.code-block__copy.is-copied { color: var(--color-success); border-color: var(--color-success); }
.code-block pre { padding: var(--space-5); overflow-x: auto; font-family: var(--font-mono); font-size: var(--text-sm); line-height: 1.8; color: var(--color-text-secondary); }

/* Syntax highlighting */
.syn-kw { color: #c678dd; }
.syn-fn { color: var(--color-secondary); }
.syn-str { color: var(--color-success); }
.syn-cmt { color: var(--color-text-muted); font-style: italic; }
.syn-type { color: var(--color-accent); }
.syn-num { color: var(--color-warning); }

.article code:not(pre code) {
    font-family: var(--font-mono);
    font-size: 0.875em;
    padding: 0.15em 0.4em;
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-sm);
    color: var(--color-secondary);
}

/* --------------------------------------------------------------------------
   Cards Grid
   -------------------------------------------------------------------------- */
.card-grid {
    display: grid;
    gap: var(--space-5);
    margin: var(--space-10) 0;
}
@media (min-width: 640px) { .card-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 900px) { .card-grid--3 { grid-template-columns: repeat(3, 1fr); } }

.card {
    padding: var(--space-6);
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    transition: all var(--duration-normal) ease;
    position: relative;
    overflow: hidden;
}
.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--color-accent), var(--color-secondary));
    opacity: 0;
    transition: opacity var(--duration-normal) ease;
}
.card:hover {
    border-color: var(--color-border-strong);
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}
.card:hover::before {
    opacity: 1;
}

.section--alt .card {
    background: var(--color-bg-alt-elevated);
}

/* Card variants */
.card--batch::before { background: var(--color-batch); opacity: 1; }
.card--stream::before { background: var(--color-stream); opacity: 1; }

.card__header {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    margin-bottom: var(--space-4);
}
.card__icon {
    width: 40px;
    height: 40px;
    display: grid;
    place-items: center;
    background: var(--color-accent-subtle);
    border-radius: var(--radius-md);
    color: var(--color-accent);
    border: 1px solid var(--color-border);
}
.card__icon svg { width: 20px; height: 20px; }
.card__icon--batch { background: var(--color-batch-subtle); color: var(--color-batch); }
.card__icon--stream { background: var(--color-stream-subtle); color: var(--color-stream); }
.card__number { font-family: var(--font-mono); font-size: 11px; color: var(--color-text-muted); }
.card__title { font-size: var(--text-base); font-weight: 600; margin-bottom: var(--space-2); color: var(--color-text-primary); }
.card__desc { font-size: var(--text-sm); color: var(--color-text-secondary); line-height: 1.7; }

/* --------------------------------------------------------------------------
   Comparison Flow
   -------------------------------------------------------------------------- */
.comparison-flow {
    margin: var(--space-12) 0;
    display: grid;
    gap: var(--space-6);
}
@media (min-width: 768px) { .comparison-flow { grid-template-columns: 1fr 1fr; } }

.comparison-flow__item {
    padding: var(--space-6);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
}
.comparison-flow__item--batch { border-color: rgba(167, 139, 250, 0.3); }
.comparison-flow__item--stream { border-color: rgba(244, 114, 182, 0.3); }
.comparison-flow__header { display: flex; align-items: center; gap: var(--space-3); margin-bottom: var(--space-4); }
.comparison-flow__badge {
    font-size: 10px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    padding: var(--space-1) var(--space-2);
    border-radius: var(--radius-sm);
}
.comparison-flow__item--batch .comparison-flow__badge { background: var(--color-batch-subtle); color: var(--color-batch); }
.comparison-flow__item--stream .comparison-flow__badge { background: var(--color-stream-subtle); color: var(--color-stream); }
.comparison-flow__title { font-size: var(--text-sm); font-weight: 600; color: var(--color-text-primary); }
.comparison-flow__steps { display: flex; flex-direction: column; gap: var(--space-2); }
.comparison-flow__step {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3);
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-md);
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
}
.comparison-flow__step-icon {
    width: 22px;
    height: 22px;
    display: grid;
    place-items: center;
    background: var(--color-bg-elevated);
    border-radius: var(--radius-sm);
    font-size: 11px;
    font-weight: 600;
    color: var(--color-text-muted);
}
.comparison-flow__arrow { text-align: center; color: var(--color-text-muted); padding: var(--space-1) 0; font-size: var(--text-sm); }
.comparison-flow__result {
    margin-top: var(--space-4);
    padding: var(--space-3);
    border-radius: var(--radius-md);
    font-size: var(--text-sm);
    font-weight: 500;
}
.comparison-flow__item--batch .comparison-flow__result { background: var(--color-batch-subtle); color: var(--color-batch); }
.comparison-flow__item--stream .comparison-flow__result { background: var(--color-stream-subtle); color: var(--color-stream); }

/* --------------------------------------------------------------------------
   Comparison Table
   -------------------------------------------------------------------------- */
.comparison-table-wrapper {
    margin: var(--space-8) 0;
    overflow-x: auto;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
}
.comparison-table { width: 100%; border-collapse: collapse; font-size: var(--text-sm); }
.comparison-table th {
    text-align: left;
    padding: var(--space-4);
    background: var(--color-bg-tertiary);
    color: var(--color-text-tertiary);
    font-weight: 600;
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    border-bottom: 1px solid var(--color-border);
}
.comparison-table td { padding: var(--space-4); border-bottom: 1px solid var(--color-border); color: var(--color-text-secondary); }
.comparison-table tr:last-child td { border-bottom: none; }
.comparison-table .highlight { font-weight: 600; color: var(--color-text-primary); }
.comparison-table .batch { color: var(--color-batch); font-weight: 600; }
.comparison-table .stream { color: var(--color-stream); font-weight: 600; }
.comparison-table .yes { color: var(--color-success); font-weight: 600; }
.comparison-table .no { color: var(--color-error); font-weight: 600; }
.comparison-table .neutral { color: var(--color-warning); font-weight: 600; }

/* --------------------------------------------------------------------------
   Tech Cards
   -------------------------------------------------------------------------- */
.tech-showcase {
    display: grid;
    gap: var(--space-6);
    margin: var(--space-12) 0;
}
@media (min-width: 768px) { .tech-showcase { grid-template-columns: repeat(2, 1fr); } }

.tech-card {
    padding: var(--space-8);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    transition: all var(--duration-normal) ease;
}
.tech-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); }
.tech-card__logo { width: 40px; height: 40px; margin-bottom: var(--space-4); color: var(--color-accent); }
.tech-card--batch .tech-card__logo { color: var(--color-batch); }
.tech-card--stream .tech-card__logo { color: var(--color-stream); }
.tech-card__name { font-size: var(--text-xl); font-weight: 700; color: var(--color-text-primary); margin-bottom: var(--space-1); }
.tech-card__tagline { font-size: var(--text-sm); color: var(--color-text-tertiary); margin-bottom: var(--space-4); }
.tech-card__features { list-style: none; }
.tech-card__feature {
    display: flex;
    align-items: flex-start;
    gap: var(--space-2);
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    margin-bottom: var(--space-2);
}
.tech-card__feature::before { content: '+'; color: var(--color-success); font-weight: 600; }

/* --------------------------------------------------------------------------
   Practices Grid
   -------------------------------------------------------------------------- */
.practices-grid {
    display: grid;
    gap: var(--space-3);
    margin: var(--space-10) 0;
}
@media (min-width: 768px) { .practices-grid { grid-template-columns: repeat(2, 1fr); } }

.practice-card {
    display: flex;
    gap: var(--space-4);
    padding: var(--space-5);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    transition: all var(--duration-fast) ease;
}
.practice-card:hover { border-color: var(--color-border-strong); }
.practice-card--batch { border-left: 2px solid var(--color-batch); }
.practice-card--stream { border-left: 2px solid var(--color-stream); }
.practice-card--do { border-left: 2px solid var(--color-success); }
.practice-card--dont { border-left: 2px solid var(--color-error); }
.practice-card__icon {
    flex-shrink: 0;
    width: 24px;
    height: 24px;
    display: grid;
    place-items: center;
    border-radius: var(--radius-sm);
}
.practice-card--batch .practice-card__icon { background: var(--color-batch-subtle); color: var(--color-batch); }
.practice-card--stream .practice-card__icon { background: var(--color-stream-subtle); color: var(--color-stream); }
.practice-card--do .practice-card__icon { background: var(--color-success-subtle); color: var(--color-success); }
.practice-card--dont .practice-card__icon { background: var(--color-error-subtle); color: var(--color-error); }
.practice-card__icon svg { width: 14px; height: 14px; }
.practice-card__content { flex: 1; }
.practice-card__title { font-size: var(--text-sm); font-weight: 600; color: var(--color-text-primary); margin-bottom: var(--space-1); }
.practice-card__desc { font-size: var(--text-sm); color: var(--color-text-tertiary); line-height: 1.6; }

/* --------------------------------------------------------------------------
   Back to Top
   -------------------------------------------------------------------------- */
.back-to-top {
    position: fixed;
    bottom: var(--space-6);
    right: var(--space-6);
    z-index: 100;
    width: 40px;
    height: 40px;
    display: grid;
    place-items: center;
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    color: var(--color-text-tertiary);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all var(--duration-normal) var(--ease-out);
}
.back-to-top:hover { color: var(--color-accent); border-color: var(--color-accent); }
.back-to-top.is-visible { opacity: 1; visibility: visible; transform: translateY(0); }
.back-to-top svg { width: 18px; height: 18px; }

/* --------------------------------------------------------------------------
   CTA Section
   -------------------------------------------------------------------------- */
.cta {
    text-align: center;
    padding: var(--space-24) var(--space-6);
    background: var(--color-bg-alt);
    position: relative;
    overflow: hidden;
}
.cta::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--color-border-strong), transparent);
}
.cta__content {
    position: relative;
    z-index: 1;
}
.cta__title {
    font-family: var(--font-display);
    font-size: var(--text-3xl);
    font-weight: 400;
    margin-bottom: var(--space-4);
}
.cta__title em { font-style: italic; color: var(--color-accent); }
.cta__subtitle {
    font-size: var(--text-lg);
    color: var(--color-text-secondary);
    margin-bottom: var(--space-8);
    max-width: 480px;
    margin-left: auto;
    margin-right: auto;
}
.cta__buttons { display: flex; gap: var(--space-4); justify-content: center; flex-wrap: wrap; }

/* --------------------------------------------------------------------------
   Buttons
   -------------------------------------------------------------------------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-4) var(--space-6);
    border-radius: var(--radius-lg);
    font-size: var(--text-sm);
    font-weight: 600;
    transition: all var(--duration-fast) ease;
}
.btn--primary {
    background: linear-gradient(135deg, var(--color-accent), var(--color-accent-muted));
    color: white;
    box-shadow: 0 4px 16px var(--color-accent-glow);
}
.btn--primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 24px var(--color-accent-glow);
}
.btn--secondary {
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    color: var(--color-text-primary);
}
.btn--secondary:hover {
    background: var(--color-bg-hover);
    border-color: var(--color-border-strong);
    transform: translateY(-2px);
}
.btn svg { width: 16px; height: 16px; }

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
.footer {
    padding: var(--space-12) var(--space-6);
    border-top: 1px solid var(--color-border);
}
.footer__inner {
    max-width: var(--content-width);
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.footer__links {
    display: flex;
    gap: var(--space-6);
    justify-content: center;
    list-style: none;
    margin-bottom: var(--space-4);
    flex-wrap: wrap;
}
.footer__links a { font-size: var(--text-sm); color: var(--color-text-tertiary); transition: color var(--duration-fast) ease; }
.footer__links a:hover { color: var(--color-accent); }
.footer__copy { font-size: var(--text-xs); color: var(--color-text-muted); }

/* --------------------------------------------------------------------------
   Reveal Animation
   -------------------------------------------------------------------------- */
.reveal {
    opacity: 0;
    transform: translateY(16px);
    transition: opacity 0.5s var(--ease-out), transform 0.5s var(--ease-out);
}
.reveal.is-visible { opacity: 1; transform: translateY(0); }

/* --------------------------------------------------------------------------
   Mobile Optimizations
   -------------------------------------------------------------------------- */
@media (max-width: 640px) {
    :root {
        --text-5xl: 2.25rem;
        --text-4xl: 1.875rem;
        --text-3xl: 1.5rem;
        --text-2xl: 1.25rem;
        --space-20: 3rem;
        --space-24: 4rem;
    }

    .hero {
        min-height: auto;
        padding-top: 120px;
        padding-bottom: var(--space-16);
    }

    .hero__title {
        font-size: 2.25rem;
    }

    .hero__subtitle {
        font-size: var(--text-base);
    }

    .content {
        padding: 0 var(--space-4);
    }

    .section {
        padding: var(--space-12) 0;
    }

    .pullquote {
        padding: var(--space-6);
        margin: var(--space-8) 0;
    }

    .pullquote::before {
        font-size: 3rem;
    }

    .pullquote p {
        font-size: var(--text-lg);
    }

    .code-block pre {
        font-size: var(--text-xs);
        padding: var(--space-4);
    }

    .card {
        padding: var(--space-5);
    }

    .card-grid {
        gap: var(--space-4);
    }

    .comparison-flow {
        gap: var(--space-4);
    }

    .cta {
        padding: var(--space-16) var(--space-4);
    }

    .cta__title {
        font-size: var(--text-2xl);
    }

    .footer {
        padding: var(--space-8) var(--space-4);
    }

    .footer__links {
        gap: var(--space-4);
    }
}

/* --------------------------------------------------------------------------
   Touch-friendly targets
   -------------------------------------------------------------------------- */
@media (pointer: coarse) {
    .btn {
        min-height: 44px;
    }

    .theme-toggle,
    .mobile-menu-toggle {
        min-width: 44px;
        min-height: 44px;
    }
}