/* ============================================================
   Cloud Relay — System Explanation Page Styles
   ============================================================ */

:root {
    /* Colors */
    --bg-primary: #0a0e17;
    --bg-secondary: #111827;
    --bg-card: #1a2332;
    --bg-card-hover: #1e2a3d;
    --bg-glass: rgba(26, 35, 50, 0.7);

    --text-primary: #e2e8f0;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;

    --accent-primary: #3b82f6;
    --accent-secondary: #8b5cf6;
    --accent-gradient: linear-gradient(135deg, #3b82f6, #8b5cf6);
    --accent-glow: rgba(59, 130, 246, 0.3);

    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;

    --border: rgba(148, 163, 184, 0.1);
    --border-accent: rgba(59, 130, 246, 0.3);

    --radius: 12px;
    --radius-sm: 8px;
    --radius-lg: 16px;

    --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 8px 48px rgba(0, 0, 0, 0.4);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.7;
    overflow-x: hidden;
}

code {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85em;
    background: rgba(59, 130, 246, 0.15);
    color: var(--accent-primary);
    padding: 2px 6px;
    border-radius: 4px;
}

/* ============================================================
   Container & Section
   ============================================================ */
.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
}

.section {
    padding: 100px 0;
}

.section-dark {
    background: var(--bg-secondary);
}

.section-label {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 3px;
    color: var(--accent-primary);
    margin-bottom: 12px;
    padding: 4px 12px;
    border: 1px solid var(--border-accent);
    border-radius: 20px;
}

.section h2 {
    font-size: 2.2rem;
    font-weight: 700;
    margin-bottom: 48px;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ============================================================
   Navigation
   ============================================================ */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 32px;
    backdrop-filter: blur(20px);
    background: rgba(10, 14, 23, 0.8);
    border-bottom: 1px solid var(--border);
    transition: all 0.3s ease;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 10px;
}

.nav-icon { font-size: 1.5rem; }

.nav-title {
    font-size: 1.2rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    gap: 24px;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.2s;
}

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

/* ============================================================
   Hero
   ============================================================ */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 120px 24px 60px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 80% 60% at 50% -10%, rgba(59, 130, 246, 0.15), transparent),
        radial-gradient(ellipse 60% 60% at 80% 50%, rgba(139, 92, 246, 0.1), transparent);
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero-badge {
    display: inline-block;
    padding: 6px 16px;
    border: 1px solid var(--border-accent);
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--accent-primary);
    margin-bottom: 24px;
    backdrop-filter: blur(10px);
}

.hero h1 {
    font-size: 4.5rem;
    font-weight: 800;
    margin-bottom: 20px;
    background: linear-gradient(135deg, #fff, #94a3b8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.3rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 40px;
}

.hero-features {
    display: flex;
    gap: 32px;
    justify-content: center;
    flex-wrap: wrap;
}

.hero-feature {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background: var(--bg-glass);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 0.95rem;
    backdrop-filter: blur(10px);
    transition: border-color 0.3s;
}

.hero-feature:hover {
    border-color: var(--border-accent);
}

.hero-feature-icon {
    font-size: 1.2rem;
}

.hero-scroll {
    position: absolute;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
    color: var(--text-muted);
    font-size: 1.2rem;
}

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

/* ============================================================
   Problem Cards
   ============================================================ */
.problem-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.problem-card {
    padding: 32px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    transition: all 0.3s ease;
}

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

.problem-icon {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.problem-card h3 {
    font-size: 1.1rem;
    margin-bottom: 8px;
}

.problem-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* ============================================================
   Architecture Diagram
   ============================================================ */
.arch-diagram {
    display: flex;
    flex-direction: column;
    gap: 0;
    max-width: 900px;
    margin: 0 auto;
}

.arch-zone {
    padding: 28px;
    border-radius: var(--radius-lg);
    position: relative;
}

.arch-zone-label {
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 1px;
    margin-bottom: 20px;
    color: var(--text-secondary);
}

.arch-zone-external {
    text-align: center;
    padding-bottom: 0;
}

.arch-zone-cloud {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.08), rgba(139, 92, 246, 0.08));
    border: 1px solid var(--border-accent);
}

.arch-zone-onprem {
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.08), rgba(16, 185, 129, 0.04));
    border: 1px solid rgba(16, 185, 129, 0.3);
}

.arch-zone-tunnel {
    padding: 20px 0;
    text-align: center;
}

.arch-cloud-inner, .arch-onprem-inner {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    flex-wrap: wrap;
}

.arch-node {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px 20px;
    text-align: center;
    min-width: 140px;
    transition: all 0.3s;
}

.arch-node:hover {
    border-color: var(--border-accent);
    box-shadow: 0 0 20px var(--accent-glow);
}

.arch-node-icon {
    font-size: 1.8rem;
    margin-bottom: 6px;
}

.arch-node-name {
    font-weight: 600;
    font-size: 0.95rem;
}

.arch-node-detail {
    color: var(--text-muted);
    font-size: 0.8rem;
    margin-top: 2px;
}

.arch-arrow {
    color: var(--text-muted);
    font-size: 0.75rem;
    display: flex;
    align-items: center;
}

.arch-arrow-down {
    justify-content: center;
    flex-direction: column;
    padding: 8px 0;
}

.arch-arrow-down::before {
    content: '↓';
    font-size: 1.2rem;
    color: var(--accent-primary);
}

.arch-arrow-right span {
    padding: 0 4px;
}

.arch-arrow-right::before,
.arch-arrow-right::after {
    content: '';
    width: 20px;
    height: 2px;
    background: var(--accent-primary);
    opacity: 0.5;
}

.arch-arrow-right::after {
    clip-path: polygon(0 0, 100% 50%, 0 100%);
    width: 8px;
    height: 8px;
    background: var(--accent-primary);
}

.arch-tunnel-line {
    position: relative;
    padding: 16px 24px;
    border: 2px dashed var(--accent-primary);
    border-radius: var(--radius);
    display: inline-block;
    overflow: hidden;
}

.arch-tunnel-pulse {
    position: absolute;
    inset: 0;
    background: linear-gradient(90deg, transparent, var(--accent-glow), transparent);
    animation: tunnelPulse 3s linear infinite;
}

@keyframes tunnelPulse {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.arch-tunnel-label {
    position: relative;
    font-weight: 600;
    color: var(--accent-primary);
    font-size: 0.95rem;
}

.arch-tunnel-direction {
    position: relative;
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: 4px;
}

.arch-onprem-note {
    margin-top: 16px;
    padding: 10px 16px;
    background: rgba(16, 185, 129, 0.1);
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    color: var(--success);
    display: flex;
    align-items: center;
    gap: 8px;
}

/* ============================================================
   Steps
   ============================================================ */
.steps-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
}

.step-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 32px;
    position: relative;
    transition: all 0.3s;
}

.step-card:hover {
    border-color: var(--border-accent);
    transform: translateY(-2px);
}

.step-number {
    width: 40px;
    height: 40px;
    background: var(--accent-gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.1rem;
    margin-bottom: 16px;
}

.step-content h3 {
    font-size: 1.05rem;
    margin-bottom: 8px;
}

.step-content p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 16px;
}

.step-code {
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 10px 14px;
    overflow-x: auto;
}

.step-code code {
    background: none;
    padding: 0;
    font-size: 0.8rem;
    color: var(--success);
}

.step-visual {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
}

.visual-cloud, .visual-onprem {
    padding: 6px 14px;
    border-radius: var(--radius-sm);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    font-weight: 500;
}

.visual-cloud {
    background: rgba(59, 130, 246, 0.15);
    color: var(--accent-primary);
    border: 1px solid var(--border-accent);
}

.visual-onprem {
    background: rgba(16, 185, 129, 0.15);
    color: var(--success);
    border: 1px solid rgba(16, 185, 129, 0.3);
}

.visual-arrow {
    color: var(--text-muted);
    font-weight: 600;
    letter-spacing: 2px;
}

.visual-tag {
    display: inline-block;
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

.visual-tag-encrypted {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success);
    border: 1px solid rgba(16, 185, 129, 0.3);
}

/* ============================================================
   Comparison Table
   ============================================================ */
.comparison-table-wrapper {
    overflow-x: auto;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
}

.comparison-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

.comparison-table th,
.comparison-table td {
    padding: 14px 20px;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

.comparison-table th {
    background: var(--bg-card);
    font-weight: 600;
    font-size: 0.85rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.comparison-table td {
    color: var(--text-secondary);
}

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

.comparison-table tr:hover td {
    background: rgba(59, 130, 246, 0.03);
}

.selected-col {
    background: rgba(59, 130, 246, 0.06) !important;
    color: var(--text-primary) !important;
    border-left: 2px solid var(--accent-primary);
    border-right: 2px solid var(--accent-primary);
}

th.selected-col {
    border-top: 2px solid var(--accent-primary);
}

tr:last-child td.selected-col {
    border-bottom: 2px solid var(--accent-primary) !important;
}

.badge {
    display: inline-block;
    padding: 3px 10px;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 600;
}

.badge-success {
    background: rgba(16, 185, 129, 0.15);
    color: var(--success);
}

.badge-warning {
    background: rgba(245, 158, 11, 0.15);
    color: var(--warning);
}

/* ============================================================
   Security
   ============================================================ */
.security-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 24px;
}

.security-card {
    padding: 28px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    transition: all 0.3s;
}

.security-card:hover {
    border-color: var(--border-accent);
    transform: translateY(-2px);
}

.security-icon {
    font-size: 2rem;
    margin-bottom: 12px;
}

.security-card h3 {
    font-size: 1.05rem;
    margin-bottom: 12px;
}

.security-card ul {
    list-style: none;
}

.security-card li {
    position: relative;
    padding-left: 18px;
    margin-bottom: 6px;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.security-card li::before {
    content: '›';
    position: absolute;
    left: 0;
    color: var(--accent-primary);
    font-weight: 700;
}

/* ============================================================
   Redundancy
   ============================================================ */
.redundancy-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: center;
}

.redundancy-diagram {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.rd-cloud, .rd-onprem {
    padding: 20px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
}

.rd-cloud {
    background: rgba(59, 130, 246, 0.06);
    border-color: var(--border-accent);
}

.rd-onprem {
    background: rgba(16, 185, 129, 0.06);
    border-color: rgba(16, 185, 129, 0.3);
}

.rd-label {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-muted);
    margin-bottom: 12px;
}

.rd-nginx {
    background: var(--bg-card);
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
}

.rd-upstream {
    margin-top: 8px;
}

.rd-upstream-label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-bottom: 6px;
}

.rd-server {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 4px 0;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
}

.rd-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
}

.rd-dot-green { background: var(--success); box-shadow: 0 0 8px var(--success); }
.rd-dot-yellow { background: var(--warning); }

.rd-tag, .rd-tag-backup {
    font-size: 0.7rem;
    padding: 1px 6px;
    border-radius: 4px;
    margin-left: 4px;
}

.rd-tag { background: rgba(16, 185, 129, 0.15); color: var(--success); }
.rd-tag-backup { background: rgba(245, 158, 11, 0.15); color: var(--warning); }

.rd-config {
    margin-top: 8px;
    font-size: 0.8rem;
}

.rd-config code {
    font-size: 0.75rem;
}

.rd-tunnels {
    display: flex;
    flex-direction: column;
    gap: 6px;
    padding: 4px 24px;
}

.rd-tunnel {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.8rem;
    color: var(--text-muted);
}

.rd-tunnel-line {
    flex: 1;
    height: 2px;
    background: repeating-linear-gradient(90deg, var(--accent-primary) 0, var(--accent-primary) 6px, transparent 6px, transparent 10px);
    opacity: 0.5;
}

.rd-services {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.rd-service {
    background: var(--bg-card);
    padding: 8px 12px;
    border-radius: var(--radius-sm);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.rd-service-api {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success);
}

.redundancy-info h3 {
    font-size: 1.2rem;
    margin-bottom: 16px;
}

.redundancy-info ol {
    padding-left: 0;
    counter-reset: step;
    list-style: none;
}

.redundancy-info li {
    counter-increment: step;
    padding: 8px 0 8px 40px;
    position: relative;
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.redundancy-info li::before {
    content: counter(step);
    position: absolute;
    left: 0;
    top: 6px;
    width: 26px;
    height: 26px;
    background: var(--accent-gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 700;
    color: white;
}

/* ============================================================
   Status
   ============================================================ */
.status-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 24px;
    margin-bottom: 24px;
}

.status-card {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 24px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
}

.status-indicator {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    flex-shrink: 0;
}

.status-checking {
    background: var(--text-muted);
    animation: pulse 1.5s infinite;
}

.status-up {
    background: var(--success);
    box-shadow: 0 0 12px var(--success);
}

.status-down {
    background: var(--danger);
    box-shadow: 0 0 12px var(--danger);
}

.status-unknown {
    background: var(--warning);
}

@keyframes pulse {
    0%, 100% { opacity: 0.5; }
    50% { opacity: 1; }
}

.status-info h3 {
    font-size: 0.95rem;
    margin-bottom: 2px;
}

.status-detail {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.status-note {
    font-size: 0.85rem;
    color: var(--text-muted);
    text-align: center;
}

/* ============================================================
   Tech Stack
   ============================================================ */
.tech-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 16px;
}

.tech-card {
    padding: 24px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    text-align: center;
    transition: all 0.3s;
}

.tech-card:hover {
    border-color: var(--border-accent);
    transform: translateY(-2px);
}

.tech-name {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 4px;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.tech-role {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* ============================================================
   Footer
   ============================================================ */
.footer {
    padding: 40px 0;
    text-align: center;
    border-top: 1px solid var(--border);
    color: var(--text-muted);
    font-size: 0.9rem;
}

.footer-sub {
    font-size: 0.75rem;
    margin-top: 4px;
    opacity: 0.6;
}

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 768px) {
    .nav-links { display: none; }
    .hero h1 { font-size: 2.8rem; }
    .hero-subtitle { font-size: 1.1rem; }
    .hero-features { flex-direction: column; align-items: center; }
    .section h2 { font-size: 1.7rem; }
    .section { padding: 60px 0; }
    .arch-cloud-inner, .arch-onprem-inner { flex-direction: column; }
    .arch-arrow-right { transform: rotate(90deg); }
    .redundancy-layout { grid-template-columns: 1fr; }
    .comparison-table { font-size: 0.8rem; }
    .comparison-table th, .comparison-table td { padding: 10px 12px; }
}