/* ==========================================================================
   Layout — Structural components: nav, hero, sections, footer
   ========================================================================== */

/* ==========================================================================
   CONTAINER
   ========================================================================== */

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--space-xl);
}

.container-narrow {
    max-width: var(--max-width-narrow);
    margin: 0 auto;
    padding: 0 var(--space-xl);
}

.container-wide {
    max-width: var(--max-width-wide);
    margin: 0 auto;
    padding: 0 var(--space-xl);
}


/* ==========================================================================
   NAVIGATION
   ========================================================================== */

.site-nav {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.97);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    height: var(--nav-height);
}

.nav-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--space-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

/* Brand */
.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    text-decoration: none;
}

.nav-brand img {
    height: 28px;
}

.nav-brand-text {
    font-size: var(--text-base);
    font-weight: 600;
    color: var(--text-primary);
    letter-spacing: -0.01em;
}

/* Links */
.nav-links {
    display: flex;
    gap: var(--space-xl);
    align-items: center;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: var(--text-sm);
    transition: color var(--transition-fast);
    display: inline-flex;
    align-items: center;
    line-height: 1.5;
}

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

/* Dropdown */
.nav-dropdown {
    position: relative;
}

.nav-dropdown-trigger {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    cursor: pointer;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: var(--text-sm);
    line-height: 1.5;
    transition: color var(--transition-fast);
    background: none;
    border: none;
    padding: 0;
    font-family: inherit;
}

.nav-dropdown-trigger:hover,
.nav-dropdown-trigger.active {
    color: var(--accent);
}

.nav-dropdown-trigger svg {
    width: 14px;
    height: 14px;
    transition: transform var(--transition-base);
}

.nav-dropdown:hover .nav-dropdown-trigger svg {
    transform: rotate(180deg);
}

.nav-dropdown-menu {
    position: absolute;
    top: calc(100% + 0.5rem);
    left: 50%;
    transform: translateX(-50%);
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--border-radius);
    padding: var(--space-sm);
    min-width: 200px;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-fast), visibility var(--transition-fast);
    box-shadow: var(--shadow-md);
}

.nav-dropdown:hover .nav-dropdown-menu {
    opacity: 1;
    visibility: visible;
}

.nav-dropdown-menu a {
    display: block;
    padding: 0.5rem 0.75rem;
    font-size: var(--text-sm);
    border-radius: var(--border-radius-sm);
}

.nav-dropdown-menu a:hover {
    background: var(--accent-soft);
}

/* Language switcher */
.lang-switcher {
    display: inline-flex;
    gap: var(--space-xs);
    margin-left: var(--space-lg);
    align-items: center;
}

.lang-btn {
    padding: 0.3rem 0.6rem;
    background: transparent;
    border: 1px solid var(--border);
    border-radius: var(--border-radius-sm);
    color: var(--text-muted);
    cursor: pointer;
    font-size: var(--text-xs);
    font-weight: 500;
    transition: all var(--transition-fast);
    font-family: var(--font-sans);
}

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

.lang-btn.active {
    background: var(--text-primary);
    color: white;
    border-color: var(--text-primary);
}

/* Mobile menu toggle */
.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    z-index: 1001;
}

.menu-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-base);
}

.menu-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

.menu-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.4);
    z-index: 999;
    opacity: 0;
    transition: opacity var(--transition-base);
}

.menu-overlay.active {
    display: block;
    opacity: 1;
}


/* ==========================================================================
   HERO SECTION
   ========================================================================== */

.hero {
    margin-top: var(--nav-height);
    padding: var(--space-3xl) var(--space-xl) var(--space-2xl);
    text-align: center;
    background: var(--bg-white);
    border-bottom: 1px solid var(--border);
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-size: var(--text-3xl);
    margin-bottom: var(--space-md);
    line-height: var(--leading-tight);
}

.hero .subtitle {
    font-size: var(--text-lg);
    color: var(--text-muted);
    margin-bottom: var(--space-xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-actions {
    display: flex;
    gap: 0.75rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* ---- Hero Dark Variant ---- */

.hero-dark {
    background: linear-gradient(135deg, var(--hero-gradient-start) 0%, var(--hero-gradient-mid) 45%, var(--hero-gradient-end) 100%);
    border-bottom: 1px solid var(--border-dark);
    position: relative;
    overflow: hidden;
    padding: var(--space-6xl) var(--space-xl) var(--space-3xl);
}

.hero-dark::before {
    content: '';
    position: absolute;
    top: -40%;
    left: 40%;
    transform: translateX(-50%);
    width: 800px;
    height: 800px;
    background: radial-gradient(circle, var(--hero-glow) 0%, transparent 70%);
    pointer-events: none;
}

.hero-dark::after {
    content: '';
    position: absolute;
    bottom: -30%;
    right: -10%;
    width: 700px;
    height: 700px;
    background: radial-gradient(circle, var(--hero-glow-blue) 0%, transparent 70%);
    pointer-events: none;
}

.hero-dark h1 {
    color: var(--text-inverse);
    font-size: var(--text-5xl);
}

.hero-dark .subtitle {
    color: var(--text-inverse-muted);
}

.hero-dark .badge-accent {
    background: rgba(167, 139, 250, 0.18);
    color: #7c3aed;
}

.hero-dark .btn-secondary {
    border-color: var(--border-dark);
    color: var(--text-inverse);
    background: rgba(255, 255, 255, 0.5);
}

.hero-dark .btn-secondary:hover {
    border-color: var(--accent-purple);
    background: rgba(255, 255, 255, 0.75);
    color: var(--text-inverse);
}

/* Hero visual: instruction → ncds → graph */
.hero-visual {
    max-width: 1060px;
    margin: var(--space-2xl) auto 0;
    position: relative;
    z-index: 1;
}

.hero-visual-split {
    display: grid;
    grid-template-columns: 2fr 30px 2.5fr 30px 3fr;
    align-items: center;
}

.hero-visual-col {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.hero-visual-code {
    width: 100%;
}

.hero-visual-code .code-editor {
    font-size: var(--text-xs);
    text-align: left;
}

.hero-visual-code .code-editor pre {
    font-size: 0.78rem;
    line-height: 1.75;
    padding: 12px 16px;
}

.hero-visual-instruction {
    width: 100%;
}

.hero-visual-instruction .instruction-panel {
    text-align: left;
}

.hero-visual-arrow {
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--text-muted);
    padding-top: 1.2rem;
    user-select: none;
}

.hero-visual-graph {
    width: 100%;
}

.hero-visual-label {
    font-size: 0.7rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    font-weight: 600;
    margin-bottom: var(--space-sm);
    text-align: center;
}

/* Hero example rotation transition */
.hero-visual-split {
    transition: opacity 0.45s ease;
}

.hero-visual-split.transitioning {
    opacity: 0;
}

/* Hero example dot indicators */
.hero-visual-dots {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-top: var(--space-lg);
}

.hero-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    border: 2px solid var(--accent-purple);
    background: transparent;
    cursor: pointer;
    padding: 0;
    transition: background 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
}

.hero-dot:hover {
    transform: scale(1.3);
    background: rgba(167, 139, 250, 0.3);
}

.hero-dot.active {
    background: var(--accent-purple);
    transform: scale(1.25);
    box-shadow: 0 0 8px rgba(167, 139, 250, 0.4);
}


/* ==========================================================================
   SECTION COMPACT (less padding — for credibility)
   ========================================================================== */

.section-compact {
    padding: var(--space-2xl) var(--space-xl);
}


/* ==========================================================================
   SECTIONS
   ========================================================================== */

.section {
    padding: var(--space-3xl) var(--space-xl);
}

.section-alt {
    background: var(--bg-white);
}

.section-dark {
    background: var(--bg-dark);
    color: var(--text-inverse);
}

.section-dark h2,
.section-dark h3 {
    color: var(--text-inverse);
}

.section-dark p {
    color: var(--text-inverse-muted);
}


/* ==========================================================================
   PAGE HEADER (for inner pages: docs, about)
   ========================================================================== */

.page-header {
    margin-top: var(--nav-height);
    padding: var(--space-2xl) var(--space-xl);
    text-align: center;
    background: var(--bg-white);
    border-bottom: 1px solid var(--border);
}

.page-header h1 {
    font-size: var(--text-3xl);
    margin-bottom: var(--space-sm);
}

.page-header p {
    color: var(--text-muted);
    font-size: var(--text-lg);
    max-width: 600px;
    margin: 0 auto;
}


/* ==========================================================================
   VIDEO SECTION
   ========================================================================== */

.video-container {
    max-width: var(--max-width);
    margin: 0 auto;
    border-radius: var(--border-radius);
    overflow: hidden;
    border: 1px solid var(--border);
    background: #0a0a0a;
    position: relative;
    cursor: pointer;
}

.video-container video {
    width: 100%;
    display: block;
}

.video-poster {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--space-md);
    background: linear-gradient(135deg, #0f1419 0%, #1a1f26 50%, #0f1419 100%);
    transition: opacity var(--transition-slow);
    z-index: 5;
}

.video-poster.hidden {
    opacity: 0;
    pointer-events: none;
}

.video-play-btn {
    width: 64px;
    height: 64px;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    transition: transform var(--transition-base);
}

.video-container:hover .video-play-btn {
    transform: scale(1.08);
}

.video-play-btn svg {
    width: 28px;
    height: 28px;
    margin-left: 3px;
    color: var(--text-primary);
}

.video-poster span {
    color: rgba(255, 255, 255, 0.9);
    font-size: var(--text-sm);
    font-weight: 500;
}


/* ==========================================================================
   PIPELINE DIAGRAM
   ========================================================================== */

.pipeline {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0;
    max-width: 500px;
    margin: var(--space-xl) auto;
}

.pipeline-step {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100%;
}

.pipeline-step-box {
    background: var(--bg-white);
    border: 2px solid var(--border);
    border-radius: var(--border-radius);
    padding: 0.65rem 1.25rem;
    font-weight: 600;
    font-size: var(--text-sm);
    text-align: center;
    width: 100%;
    max-width: 380px;
    position: relative;
    z-index: 1;
}

.pipeline-step-box.phase {
    background: var(--accent-soft);
    border-color: var(--accent-border);
    color: var(--accent);
}

.pipeline-step-box.final {
    background: rgba(34, 197, 94, 0.08);
    border-color: rgba(34, 197, 94, 0.3);
    color: var(--success);
}

.pipeline-arrow {
    width: 2px;
    height: 24px;
    background: var(--border-strong);
    position: relative;
}

.pipeline-arrow::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    border-left: 5px solid transparent;
    border-right: 5px solid transparent;
    border-top: 6px solid var(--border-strong);
}

.pipeline-note {
    font-size: var(--text-xs);
    color: var(--text-muted);
    margin-top: var(--space-xs);
    font-style: italic;
}


/* ==========================================================================
   FOOTER
   ========================================================================== */

.site-footer {
    background: var(--bg-dark);
    padding: var(--space-2xl) var(--space-xl);
    text-align: center;
    color: var(--text-inverse-muted);
    font-size: var(--text-sm);
    border-top: 1px solid var(--border-dark);
}

.site-footer p {
    margin-bottom: var(--space-sm);
    color: var(--text-inverse-muted);
}

.site-footer strong {
    color: var(--text-inverse);
}

.site-footer a {
    color: var(--text-inverse);
    transition: opacity var(--transition-fast);
}

.site-footer a:hover {
    opacity: 0.8;
}

.footer-links {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    flex-wrap: wrap;
    margin-top: var(--space-md);
}

.footer-links a {
    color: var(--text-inverse-muted);
    font-size: var(--text-sm);
}

.footer-links a:hover {
    color: var(--text-inverse);
}