/* CSS Variables & Base DNA */
:root {
    --color-primary: #65bae5;
    --color-primary-dark: #4a9bc5;
    --color-primary-light: #e0f2fb;
    --color-text-main: #1e293b;
    --color-text-muted: #64748b;
    --color-bg-page: #f8fafc;
    --color-bg-surface: #ffffff;
    --radius-base: 12px;
    --radius-large: 24px;
    --shadow-soft: 0 10px 25px -5px rgba(101, 186, 229, 0.15), 0 8px 10px -6px rgba(101, 186, 229, 0.1);
    --shadow-hover: 0 20px 35px -5px rgba(101, 186, 229, 0.25), 0 12px 15px -6px rgba(101, 186, 229, 0.15);
    --transition: all 0.25s ease;
    --font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
    margin: 0;
    padding: 0;
    font-family: var(--font-family);
    color: var(--color-text-main);
    background-color: var(--color-bg-page);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

/* Mandatory Text Rules */
* {
    box-sizing: border-box;
    word-break: break-word;
    overflow-wrap: break-word;
}
p, span, div, a {
    word-break: keep-all; 
}
h1, h2, h3, h4 {
    white-space: normal;
    color: #0f172a;
    margin-top: 0;
}

/* Mandatory Flex Rules */
.batch, .bind, .case, .tape, .cable, .mosaic-case, .route-grid, .ground-grid, .tail-bind {
    display: flex;
    flex-wrap: wrap;
}
.batch > *, .bind > *, .case > *, .tape > *, .cable > *, .mosaic-tick, .route-node, .gram, .tail-tick {
    min-width: 0;
}

/* Typography & Layout Utility */
.case {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}
.lead-h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -0.02em;
    margin-bottom: 1.5rem;
}
.lead-h2 {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
}
.lead-h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}
.code-sheath {
    font-size: 1.125rem;
    color: var(--color-text-muted);
    margin-bottom: 2rem;
}
.code-muted {
    font-size: 0.95rem;
    color: var(--color-text-muted);
}
.lead-accent {
    color: var(--color-primary);
}

/* Header Reused Styles */
.peak {
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(101, 186, 229, 0.1);
    position: sticky;
    top: 0;
    z-index: 100;
    padding: 1rem 0;
}
.cable {
    justify-content: space-between;
    align-items: center;
    width: 100%;
}
.seal img {
    height: 32px;
    width: auto;
    display: block;
}
.tape {
    gap: 2rem;
    align-items: center;
}
.tie {
    text-decoration: none;
    color: var(--color-text-main);
    font-weight: 500;
    font-size: 1rem;
    transition: var(--transition);
    position: relative;
}
.tie:hover {
    color: var(--color-primary);
    transform: translateY(-1px);
}
.tie.active {
    color: var(--color-primary);
    font-weight: 600;
}
.tie.active::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--color-primary);
    border-radius: 2px;
}

/* Buttons */
.tap {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 1rem 2rem;
    font-weight: 600;
    border-radius: var(--radius-base);
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
    border: none;
    font-size: 1rem;
}
.tap-primary {
    background-color: var(--color-primary);
    color: white;
    box-shadow: 0 4px 14px 0 rgba(101, 186, 229, 0.39);
}
.tap-primary:hover, .tap-primary:focus {
    background-color: var(--color-primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px 0 rgba(101, 186, 229, 0.5);
    color: white;
}
.tap-secondary {
    background-color: var(--color-bg-surface);
    color: var(--color-primary);
    border: 1px solid var(--color-primary-light);
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
.tap-secondary:hover, .tap-secondary:focus {
    border-color: var(--color-primary);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(101, 186, 229, 0.15);
}

/* Section Containers */
.desk {
    display: block;
    width: 100%;
}
.sheath {
    padding: 6rem 0;
    position: relative;
}

/* Block 1: Intro (Hero Mosaic Collage) */
.station {
    padding: 6rem 0 4rem;
    background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
    position: relative;
    overflow: hidden;
}
.spark::before {
    content: '';
    position: absolute;
    top: -20%;
    right: -10%;
    width: 60%;
    height: 80%;
    background: radial-gradient(circle, rgba(101, 186, 229, 0.08) 0%, rgba(255,255,255,0) 70%);
    border-radius: 50%;
    z-index: 0;
}
.mosaic-case {
    gap: 4rem;
    align-items: center;
    position: relative;
    z-index: 1;
}
.mosaic-sheath {
    flex: 1 1 45%;
}
.mosaic-visual {
    flex: 1 1 45%;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
    position: relative;
}
/* Mosaic Grammar */
.gram {
    background: var(--color-bg-surface);
    padding: 2.5rem;
    border-radius: var(--radius-large);
    box-shadow: var(--shadow-soft);
    border: 1px solid rgba(101, 186, 229, 0.05);
    transition: var(--transition);
}
.gram:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-4px);
}
.collage-1 {
    grid-column: 1 / 3;
    background: linear-gradient(145deg, var(--color-primary), var(--color-primary-dark));
    color: white;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.collage-1 .lead-h3 {
    color: white;
    margin: 0;
}
.collage-2 {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: flex-start;
}
.collage-3 {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: flex-start;
    background: var(--color-primary-light);
    border: none;
}
.mark {
    width: 48px;
    height: 48px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 16px;
    margin-bottom: 1.5rem;
    background: rgba(101, 186, 229, 0.1);
    color: var(--color-primary);
}
.collage-1 .mark {
    background: rgba(255,255,255,0.2);
    color: white;
    margin-bottom: 0;
}

/* Block 2: Topic Focus */
.sheath-focus {
    background-color: var(--color-bg-surface);
}
.focus-lead {
    text-align: center;
    max-width: 800px;
    margin: 0 auto 4rem;
}
.focus-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

/* Block 3: Key Path */
.route {
    background: var(--color-bg-page);
}
.route-grid {
    gap: 2rem;
    align-items: stretch;
}
.route-node {
    flex: 1 1 300px;
    position: relative;
}
.sheet {
    background: var(--color-bg-surface);
    padding: 3rem 2rem;
    border-radius: var(--radius-large);
    border: 1px solid rgba(101, 186, 229, 0.1);
    height: 100%;
    display: flex;
    flex-direction: column;
    position: relative;
    z-index: 2;
    transition: var(--transition);
}
.sheet:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-soft);
}
.route-step {
    position: absolute;
    top: -20px;
    left: 2rem;
    background: var(--color-primary);
    color: white;
    font-size: 0.875rem;
    font-weight: 700;
    padding: 0.5rem 1.25rem;
    border-radius: 20px;
    box-shadow: 0 4px 10px rgba(101, 186, 229, 0.3);
}
.sheet .mark {
    margin-top: 1rem;
}

/* Block 4: Usage Context */
.ground-sheath {
    background: var(--color-bg-surface);
    border-top: 1px solid rgba(101, 186, 229, 0.05);
}
.ground-grid {
    gap: 2rem;
}
.ground-tick {
    flex: 1 1 400px;
    background: var(--color-bg-page);
    padding: 2.5rem;
    border-radius: var(--radius-large);
    border-left: 4px solid var(--color-primary);
}

/* Footer */
.tail {
    background-color: #0f172a;
    color: #94a3b8;
    padding: 4rem 0 2rem;
}
.tail-bind {
    gap: 4rem;
    justify-content: space-between;
    margin-bottom: 4rem;
}
.tail-tick {
    flex: 1 1 240px;
}
.tail-lead {
    color: #ffffff;
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
}
.tail-tape {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}
.tail-tie {
    color: #94a3b8;
    text-decoration: none;
    transition: var(--transition);
    display: inline-block;
}
.tail-tie:hover {
    color: var(--color-primary);
    transform: translateX(4px);
}
.tail-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding-top: 2rem;
    text-align: center;
    font-size: 0.875rem;
}

/* Responsive */
@media (max-width: 1024px) {
    .mosaic-case { gap: 2rem; }
}
@media (max-width: 768px) {
    .sheath { padding: 4rem 0; }
    .station { padding: 4rem 0 3rem; }
    .mosaic-sheath, .mosaic-visual { flex: 1 1 100%; }
    .mosaic-visual { order: -1; margin-bottom: 2rem; }
    .tape { display: none; /* In a real scenario, JS would toggle a mobile menu. Hiding for raw HTML structural compliance as per constraints without complex logic */ }
    .route-node { flex: 1 1 100%; }
    .ground-tick { flex: 1 1 100%; }
}

.cable-peak .cable-case{
            max-width: 1320px;
            margin: 0 auto;
            padding: 0 5vw;
        }

.cable-peak{
            background: rgba(255, 255, 255, 0.9);
            backdrop-filter: blur(10px);
            position: sticky;
            top: 0;
            z-index: 100;
            border-bottom: 1px solid rgba(101, 186, 229, 0.1);
        }

.cable-peak .cable-cable{
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            justify-content: space-between;
            min-width: 0;
            height: 80px;
        }

.cable-peak .cable-seal{
            display: flex;
            align-items: center;
            min-width: 0;
        }

.cable-peak .cable-seal img{
            height: 36px;
            width: auto;
        }

.cable-peak .cable-tape{
            display: flex;
            flex-wrap: wrap;
            gap: 2rem;
            min-width: 0;
        }

.cable-peak .cable-tie{
            font-weight: 500;
            color: #1e293b;
            transition: all 0.25s ease;
            position: relative;
            padding: 0.5rem 0;
        }

.cable-peak .cable-tie:hover{
            color: #65bae5;
        }

.cable-peak .cable-tie.active{
            color: #65bae5;
        }

.cable-peak .cable-tie.active::after{
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 100%;
            height: 2px;
            background-color: #65bae5;
            border-radius: 2px;
        }

@media (max-width: 768px){.cable-peak .cable-tape{
                display: none; 
            }}

.cable-peak {
    background: rgb(255, 255, 255);
    background-image: none;
}

.ground-ground {
    font-family: var(--font-sans);
    line-height: 1.7;
    color: var(--color-text-main);
}
.ground-ground,
.ground-ground *,
.ground-ground *::before,
.ground-ground *::after {
    box-sizing: border-box;
}

.ground-ground [role="navigation"],
.ground-ground div,
.ground-ground section,
.ground-ground article,
.ground-ground aside,
.ground-ground p,
.ground-ground h1,
.ground-ground h2,
.ground-ground h3,
.ground-ground h4,
.ground-ground h5,
.ground-ground h6,
.ground-ground a {
    margin: 0;
    padding: 0;
    font: inherit;
    color: inherit;
    letter-spacing: inherit;
    line-height: inherit;
}

.ground-ground p,
.ground-ground h1,
.ground-ground h2,
.ground-ground h3,
.ground-ground h4,
.ground-ground h5,
.ground-ground h6 {
    text-decoration: none;
}

.ground-ground img {
    display: block;
    max-width: 100%;
    height: auto;
    border: 0;
}

.ground-ground {
    box-shadow: none;
    filter: none;
    text-shadow: none;
    background-image: none;
    border-top: none;
    border-left: none;
    border-right: none;
    outline: none;
}

.ground-ground a,
.ground-ground a:hover,
.ground-ground a:focus,
.ground-ground a:active {
    background: transparent;
    box-shadow: none;
    outline: none;
    text-decoration: none;
}

.ground-ground .ground-case{
            max-width: 1320px;
            margin: 0 auto;
            padding: 0 5vw;
        }

.ground-ground{
            background-color: #020617;
            color: #94a3b8;
            padding: 4rem 0 2rem;
            border-top: 1px solid rgba(255, 255, 255, 0.05);
        }

.ground-ground .ground-ground-layout{
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            gap: 3rem;
            min-width: 0;
            margin-bottom: 3rem;
        }

.ground-ground .ground-ground-brand{
            font-size: 1.5rem;
            font-weight: 700;
            color: white;
            margin-bottom: 1rem;
        }

.ground-ground .ground-ground-code{
            max-width: 400px;
            margin-bottom: 1.5rem;
        }

.ground-ground .ground-ground-tape{
            display: flex;
            flex-direction: column;
            gap: 1rem;
            min-width: 0;
        }

.ground-ground .ground-ground-lead{
            color: white;
            font-weight: 600;
            margin-bottom: 0.5rem;
        }

.ground-ground .ground-ground-tie{
            transition: all 0.25s ease;
        }

.ground-ground .ground-ground-tie:hover{
            color: #65bae5;
        }

.ground-ground .ground-ground-bottom{
            padding-top: 2rem;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            align-items: center;
            min-width: 0;
            gap: 1rem;
            font-size: 0.875rem;
        }