/* ==========================================================================
   ROCKET ESPRESSO R58 TUNE — CINEMATIC SCROLLYTELLING STYLESHEET
   Aesthetic: Italian Performance Engineering x Luxury Industrial Design
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:ital,wght@0,300;0,400;0,500;0,600;0,700;0,800;1,300;1,400&family=Space+Mono:ital,wght@0,400;0,700;1,400&display=swap');

:root {
    --bg-primary: #050505;
    --bg-secondary: #0b0b0b;
    --bg-tertiary: #121212;
    --bg-card: rgba(18, 18, 18, 0.65);
    --bg-glass: rgba(8, 8, 8, 0.72);

    --metal-high: #f2f2f0;
    --metal-light: #e6e6e3;
    --metal-mid: #b9bbb8;
    --metal-dark: #777a7a;
    --metal-charcoal: #2a2a2a;

    --text-primary: rgba(255, 255, 255, 0.96);
    --text-secondary: rgba(255, 255, 255, 0.62);
    --text-muted: rgba(255, 255, 255, 0.38);
    --text-dim: rgba(255, 255, 255, 0.22);

    --accent-champagne: #c8a46a;
    --accent-brass: #9b7a4e;
    --accent-lime: #d7ff45;
    --accent-lime-dim: rgba(215, 255, 69, 0.18);

    --border-subtle: rgba(255, 255, 255, 0.08);
    --border-medium: rgba(255, 255, 255, 0.15);
    --border-bright: rgba(255, 255, 255, 0.35);

    --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --font-mono: 'Space Mono', SFMono-Regular, Menlo, Monaco, Consolas, monospace;

    --nav-height: 64px;
    --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-in-out-smooth: cubic-bezier(0.65, 0, 0.35, 1);
}

*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

html {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 16px;
    scroll-behavior: smooth;
    overflow-x: clip;
}

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: clip;
    position: relative;
}

main {
    overflow: visible;
    position: relative;
}


::selection {
    background: var(--accent-champagne);
    color: #000;
}

/* --------------------------------------------------------------------------
   PRELOADER
   -------------------------------------------------------------------------- */
#preloader {
    position: fixed;
    inset: 0;
    z-index: 9999;
    background-color: var(--bg-primary);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 28px;
    transition: opacity 0.8s var(--ease-out-expo), visibility 0.8s;
}

#preloader.loaded {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}

.preloader-brand {
    font-family: var(--font-sans);
    font-size: 1.1rem;
    letter-spacing: 0.32em;
    text-transform: uppercase;
    color: var(--text-primary);
    font-weight: 700;
}

.preloader-sub {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.2em;
    color: var(--text-muted);
    text-transform: uppercase;
}

.preloader-bar-wrap {
    width: 280px;
    height: 2px;
    background: rgba(255, 255, 255, 0.08);
    border-radius: 2px;
    overflow: hidden;
    position: relative;
}

.preloader-bar {
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, var(--metal-mid), var(--metal-high));
    box-shadow: 0 0 12px rgba(255, 255, 255, 0.4);
    transition: width 0.15s ease-out;
}

.preloader-percent {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--text-secondary);
    letter-spacing: 0.1em;
}

/* --------------------------------------------------------------------------
   APPLE-STYLE FIXED NAVIGATION BAR
   -------------------------------------------------------------------------- */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    z-index: 1000;
    transition: background-color 0.4s ease, backdrop-filter 0.4s ease, border-color 0.4s ease;
    border-bottom: 1px solid transparent;
}

.site-header.scrolled {
    background-color: var(--bg-glass);
    backdrop-filter: blur(24px) saturate(180%);
    -webkit-backdrop-filter: blur(24px) saturate(180%);
    border-bottom-color: var(--border-subtle);
}

.nav-container {
    max-width: 1440px;
    margin: 0 auto;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 32px;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 14px;
    text-decoration: none;
    color: var(--text-primary);
}

.nav-atlas-logo {
    height: 26px;
    width: auto;
    object-fit: contain;
    display: block;
    transition: opacity 0.3s ease;
}

.nav-brand:hover .nav-atlas-logo {
    opacity: 0.85;
}

.nav-brand-divider {
    width: 1px;
    height: 20px;
    background: var(--border-medium);
}

.nav-brand-model {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.18em;
    color: var(--accent-champagne);
    text-transform: uppercase;
    font-weight: 700;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 36px;
    list-style: none;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.82rem;
    font-weight: 500;
    letter-spacing: 0.06em;
    transition: color 0.25s ease;
    position: relative;
    padding: 6px 0;
}

.nav-link:hover {
    color: var(--text-primary);
}

.nav-link.active {
    color: var(--text-primary);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: var(--metal-light);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}

.btn-sound-toggle {
    background: transparent;
    border: 1px solid var(--border-subtle);
    border-radius: 20px;
    color: var(--text-secondary);
    font-size: 0.72rem;
    font-family: var(--font-mono);
    padding: 7px 14px;
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    transition: all 0.25s ease;
}

.btn-sound-toggle:hover {
    border-color: var(--border-medium);
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.03);
}

.sound-wave {
    display: flex;
    align-items: center;
    gap: 2px;
    height: 12px;
}

.sound-bar {
    width: 2px;
    height: 4px;
    background: var(--metal-dark);
    border-radius: 1px;
    transition: height 0.2s ease, background-color 0.2s ease;
}

.btn-sound-toggle.active .sound-bar {
    background: var(--accent-champagne);
    animation: soundBounce 1.2s ease-in-out infinite alternate;
}

.btn-sound-toggle.active .sound-bar:nth-child(1) {
    animation-delay: 0.0s;
    height: 10px;
}

.btn-sound-toggle.active .sound-bar:nth-child(2) {
    animation-delay: 0.3s;
    height: 6px;
}

.btn-sound-toggle.active .sound-bar:nth-child(3) {
    animation-delay: 0.6s;
    height: 12px;
}

@keyframes soundBounce {
    0% {
        height: 3px;
    }

    100% {
        height: 12px;
    }
}

.btn-nav-cta {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.12) 0%, rgba(255, 255, 255, 0.04) 100%);
    border: 1px solid var(--border-medium);
    border-radius: 20px;
    color: var(--text-primary);
    font-size: 0.78rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-decoration: none;
    text-transform: uppercase;
    padding: 8px 18px;
    transition: all 0.3s var(--ease-out-expo);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.5);
}

.btn-nav-cta:hover {
    border-color: var(--metal-light);
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.2) 0%, rgba(255, 255, 255, 0.08) 100%);
    transform: translateY(-1px);
    box-shadow: 0 4px 18px rgba(255, 255, 255, 0.12);
}

.nav-progress-bar {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0%;
    height: 1.5px;
    background: linear-gradient(90deg, var(--metal-dark), var(--metal-high), var(--accent-champagne));
    transition: width 0.1s linear;
}

/* --------------------------------------------------------------------------
   SCROLLYTELLING CONTAINER (STICKY CANVAS + VERTICAL TIMELINE)
   -------------------------------------------------------------------------- */
.scrollytelling-section {
    position: relative;
    width: 100%;
    height: 480vh;
}

.canvas-sticky-wrapper {
    position: -webkit-sticky;
    position: sticky;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    height: 100dvh;
    overflow: hidden;
    background-color: var(--bg-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1;
}

/* Studio Canvas */
#sequence-canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: contain;
    display: block;
}

/* Cinematic Studio Vignette Overlay */
.studio-vignette {
    position: absolute;
    inset: 0;
    pointer-events: none;
    background: radial-gradient(circle at 50% 50%, transparent 45%, rgba(5, 5, 5, 0.45) 75%, #050505 100%);
    z-index: 2;
}

/* Telemetry HUD in Canvas Viewport */
.canvas-hud {
    position: absolute;
    inset: 0;
    pointer-events: none;
    z-index: 10;
    padding: calc(var(--nav-height) + 24px) 40px 40px 40px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.hud-top {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}

.hud-pill {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(15, 15, 15, 0.6);
    border: 1px solid var(--border-subtle);
    backdrop-filter: blur(12px);
    padding: 6px 14px;
    border-radius: 100px;
    font-family: var(--font-mono);
    font-size: 0.7rem;
    letter-spacing: 0.12em;
    color: var(--text-secondary);
}

.hud-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background-color: var(--metal-mid);
}

.hud-dot.active-lime {
    background-color: var(--accent-lime);
    box-shadow: 0 0 8px var(--accent-lime);
}

.hud-frame-counter {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--text-muted);
    letter-spacing: 0.15em;
    background: rgba(15, 15, 15, 0.6);
    border: 1px solid var(--border-subtle);
    padding: 6px 14px;
    border-radius: 100px;
    backdrop-filter: blur(12px);
}

.hud-bottom {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
}

.hud-scroll-hint {
    display: flex;
    align-items: center;
    gap: 12px;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--text-muted);
    transition: opacity 0.4s ease;
}

.scroll-line-anim {
    width: 38px;
    height: 1px;
    background: var(--border-subtle);
    position: relative;
    overflow: hidden;
}

.scroll-line-anim::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: var(--metal-light);
    animation: lineScan 2s cubic-bezier(0.65, 0, 0.35, 1) infinite;
}

@keyframes lineScan {
    0% {
        left: -100%;
    }

    100% {
        left: 100%;
    }
}

/* --------------------------------------------------------------------------
   STORY CHAPTERS (OVERLAYS)
   -------------------------------------------------------------------------- */
.story-layers-container {
    position: absolute;
    inset: 0;
    pointer-events: none;
    z-index: 20;
}

.story-chapter {
    position: absolute;
    inset: 0;
    padding: 0 8vw;
    display: flex;
    align-items: center;
    opacity: 0;
    visibility: hidden;
    transform: translateY(24px);
    transition: opacity 0.6s var(--ease-out-expo), transform 0.6s var(--ease-out-expo), visibility 0.6s;
    pointer-events: none;
}

.story-chapter.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
    pointer-events: auto;
}

.chapter-content {
    max-width: 580px;
    background: rgba(5, 5, 5, 0.65);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 36px 40px;
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.7);
}

.chapter-content.center-aligned {
    max-width: 840px;
    margin: 0 auto;
    text-align: center;
    background: rgba(5, 5, 5, 0.75);
}

.chapter-content.right-aligned {
    margin-left: auto;
    text-align: left;
}

/* Micro Eyebrows */
.eyebrow {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    letter-spacing: 0.28em;
    text-transform: uppercase;
    color: var(--accent-champagne);
    margin-bottom: 14px;
    display: inline-flex;
    align-items: center;
    gap: 10px;
}

.eyebrow::before {
    content: '';
    display: inline-block;
    width: 16px;
    height: 1px;
    background: var(--accent-champagne);
}

.eyebrow-white {
    color: var(--text-secondary);
}

.eyebrow-white::before {
    background: var(--text-muted);
}

/* Massive Editorial Headlines */
.headline-hero {
    font-size: clamp(3.2rem, 7vw, 6.8rem);
    font-weight: 800;
    line-height: 0.95;
    letter-spacing: -0.04em;
    color: var(--metal-high);
    margin-bottom: 20px;
    background: linear-gradient(180deg, #ffffff 0%, var(--metal-mid) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.headline-chapter {
    font-size: clamp(2.4rem, 4.2vw, 4.2rem);
    font-weight: 700;
    line-height: 1.05;
    letter-spacing: -0.035em;
    color: var(--metal-high);
    margin-bottom: 20px;
}

.subheadline {
    font-size: clamp(1.15rem, 1.8vw, 1.5rem);
    font-weight: 400;
    color: var(--text-secondary);
    line-height: 1.4;
    letter-spacing: -0.015em;
    margin-bottom: 24px;
}

.body-copy {
    font-size: 1.02rem;
    color: var(--text-secondary);
    line-height: 1.68;
    max-width: 520px;
    margin-bottom: 28px;
}

/* Chapter 02: Technical Floating Annotations */
.technical-annotations-cloud {
    position: absolute;
    inset: 0;
    pointer-events: none;
}

.annotation-pin {
    position: absolute;
    display: flex;
    align-items: center;
    gap: 12px;
    opacity: 0;
    transform: scale(0.95);
    transition: opacity 0.5s ease, transform 0.5s ease;
}

.story-chapter.active .annotation-pin {
    opacity: 1;
    transform: scale(1);
}

.annotation-pin[data-pos="pin-group"] {
    top: 38%;
    right: 28%;
}

.annotation-pin[data-pos="pin-boilers"] {
    top: 48%;
    left: 24%;
}

.annotation-pin[data-pos="pin-pump"] {
    bottom: 32%;
    left: 30%;
}

.annotation-pin[data-pos="pin-pod"] {
    top: 22%;
    left: 26%;
}

.annotation-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--metal-high);
    border: 2px solid #000;
    box-shadow: 0 0 0 2px var(--border-bright);
    position: relative;
}

.annotation-line {
    height: 1px;
    width: 48px;
    background: linear-gradient(90deg, var(--border-bright), transparent);
}

.annotation-label {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--metal-light);
    background: rgba(10, 10, 10, 0.75);
    padding: 4px 10px;
    border: 1px solid var(--border-subtle);
    border-radius: 4px;
    backdrop-filter: blur(8px);
}

/* Chapter 03: Dual Boilers Telemetry */
.boiler-specs-row {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-top: 32px;
}

.boiler-spec-card {
    background: rgba(15, 15, 15, 0.6);
    border: 1px solid var(--border-subtle);
    padding: 20px;
    border-radius: 8px;
    backdrop-filter: blur(12px);
    position: relative;
    overflow: hidden;
}

.boiler-spec-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 32px;
    height: 2px;
    background: var(--accent-champagne);
}

.spec-val-giant {
    font-family: var(--font-sans);
    font-size: 2.2rem;
    font-weight: 800;
    color: var(--metal-high);
    line-height: 1;
    margin-bottom: 8px;
    letter-spacing: -0.03em;
}

.spec-lbl-tech {
    font-family: var(--font-mono);
    font-size: 0.68rem;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--text-muted);
}

/* --------------------------------------------------------------------------
   CHAPTER 04: TUNE TECHNOLOGY (CENTERPIECE EXTRACTION PRESSURE CURVE)
   -------------------------------------------------------------------------- */
.tune-curve-wrapper {
    background: rgba(12, 12, 12, 0.75);
    border: 1px solid var(--border-medium);
    border-radius: 12px;
    padding: 28px;
    backdrop-filter: blur(20px);
    margin-top: 24px;
    max-width: 620px;
    box-shadow: 0 16px 40px rgba(0, 0, 0, 0.6);
}

.tune-curve-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 18px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-subtle);
}

.tune-curve-title {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 8px;
}

.tune-curve-svg-box {
    width: 100%;
    height: 180px;
    position: relative;
}

.tune-svg {
    width: 100%;
    height: 100%;
    overflow: visible;
}

.pressure-grid-line {
    stroke: rgba(255, 255, 255, 0.07);
    stroke-dasharray: 4, 4;
}

.pressure-curve-path {
    fill: none;
    stroke: url(#curveGrad);
    stroke-width: 3;
    stroke-linecap: round;
    filter: drop-shadow(0 0 8px rgba(215, 255, 69, 0.4));
    transition: stroke-dashoffset 0.1s linear;
}

.pressure-tracer-dot {
    fill: var(--accent-lime);
    filter: drop-shadow(0 0 10px var(--accent-lime));
    transition: transform 0.05s linear;
}

.tune-phases-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
    margin-top: 18px;
}

.tune-phase-box {
    background: rgba(20, 20, 20, 0.5);
    border: 1px solid var(--border-subtle);
    padding: 12px;
    border-radius: 6px;
    transition: border-color 0.3s ease, background-color 0.3s ease;
}

.tune-phase-box.highlight {
    border-color: var(--accent-lime);
    background: rgba(215, 255, 69, 0.05);
}

.phase-num {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    color: var(--accent-lime);
    letter-spacing: 0.1em;
    margin-bottom: 4px;
}

.phase-name {
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--metal-light);
    letter-spacing: -0.01em;
    margin-bottom: 2px;
}

.phase-bar-val {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--text-muted);
}

/* --------------------------------------------------------------------------
   CHAPTER 05: PID TEMPERATURE STEPPER
   -------------------------------------------------------------------------- */
.pid-temperature-display {
    display: inline-flex;
    align-items: baseline;
    gap: 8px;
    margin: 16px 0 24px 0;
    background: rgba(15, 15, 15, 0.8);
    border: 1px solid var(--border-medium);
    padding: 14px 28px;
    border-radius: 10px;
    backdrop-filter: blur(16px);
}

.temp-digits {
    font-family: var(--font-mono);
    font-size: 3.6rem;
    font-weight: 700;
    color: var(--accent-lime);
    line-height: 1;
    letter-spacing: -0.05em;
    text-shadow: 0 0 20px rgba(215, 255, 69, 0.3);
}

.temp-unit {
    font-family: var(--font-sans);
    font-size: 1.4rem;
    color: var(--text-secondary);
    font-weight: 600;
}

.roast-tune-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-top: 16px;
}

.roast-step {
    font-size: 1.05rem;
    font-weight: 500;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 12px;
    transition: color 0.3s ease, transform 0.3s ease;
}

.roast-step.active {
    color: var(--metal-high);
    transform: translateX(8px);
}

.roast-step.active::before {
    content: '';
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--accent-champagne);
}

/* --------------------------------------------------------------------------
   CHAPTER 07: COMMUNICATION POD PREVIEW
   -------------------------------------------------------------------------- */
.pod-interface-card {
    background: #0d0e10;
    border: 1.5px solid rgba(255, 255, 255, 0.2);
    border-radius: 14px;
    padding: 24px;
    width: 380px;
    box-shadow: 0 25px 60px rgba(0, 0, 0, 0.8), 0 0 0 1px rgba(0, 0, 0, 0.5);
    margin-top: 24px;
    position: relative;
    overflow: hidden;
}

.pod-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 12px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    margin-bottom: 16px;
}

.pod-screen-brand {
    font-family: var(--font-sans);
    font-size: 0.75rem;
    font-weight: 800;
    letter-spacing: 0.2em;
    color: var(--metal-light);
}

.pod-metrics-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-bottom: 16px;
}

.pod-metric {
    background: rgba(255, 255, 255, 0.04);
    padding: 10px 14px;
    border-radius: 6px;
    border: 1px solid rgba(255, 255, 255, 0.06);
}

.pod-metric-lbl {
    font-family: var(--font-mono);
    font-size: 0.62rem;
    color: var(--text-muted);
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.pod-metric-val {
    font-family: var(--font-mono);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--accent-lime);
}

/* --------------------------------------------------------------------------
   CHAPTER 08: PUSH-TURN INTERACTION CONCEPT
   -------------------------------------------------------------------------- */
.push-turn-interactive-demo {
    display: flex;
    align-items: center;
    gap: 24px;
    background: rgba(15, 15, 15, 0.7);
    border: 1px solid var(--border-medium);
    border-radius: 12px;
    padding: 24px;
    backdrop-filter: blur(16px);
    margin-top: 24px;
    max-width: 500px;
}

.tactile-knob {
    width: 76px;
    height: 76px;
    border-radius: 50%;
    background: radial-gradient(circle at 35% 35%, #4a4a4a, #1a1a1a 70%, #0d0d0d);
    border: 2px solid var(--metal-mid);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.7), inset 0 2px 4px rgba(255, 255, 255, 0.3);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    position: relative;
    transition: transform 0.2s var(--ease-out-expo), box-shadow 0.2s ease;
    user-select: none;
}

.tactile-knob:active,
.tactile-knob.pushed {
    transform: scale(0.92);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.9), inset 0 3px 8px rgba(0, 0, 0, 0.8);
}

.tactile-knob.turned {
    transform: rotate(45deg);
}

.knob-logo {
    font-family: var(--font-sans);
    font-weight: 900;
    font-size: 1.8rem;
    color: var(--metal-high);
}

.knob-explainer-steps {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.knob-action-pill {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    letter-spacing: 0.14em;
    color: var(--text-secondary);
}

.knob-action-pill strong {
    color: var(--metal-high);
    background: rgba(255, 255, 255, 0.08);
    padding: 3px 8px;
    border-radius: 4px;
    margin-right: 6px;
}

/* --------------------------------------------------------------------------
   CHAPTER 09: REASSEMBLY HERO FINALE CTAs
   -------------------------------------------------------------------------- */
.cta-buttons-group {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 18px;
    margin-top: 36px;
}

.btn-primary-large {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background: linear-gradient(180deg, #ffffff 0%, var(--metal-light) 100%);
    color: #050505;
    font-weight: 700;
    font-size: 0.92rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    padding: 16px 36px;
    border-radius: 100px;
    text-decoration: none;
    border: none;
    cursor: pointer;
    box-shadow: 0 4px 24px rgba(255, 255, 255, 0.25);
    transition: all 0.3s var(--ease-out-expo);
}

.btn-primary-large:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 32px rgba(255, 255, 255, 0.4);
}

.btn-secondary-large {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background: rgba(255, 255, 255, 0.06);
    color: var(--metal-high);
    font-weight: 600;
    font-size: 0.92rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    padding: 16px 34px;
    border-radius: 100px;
    text-decoration: none;
    border: 1px solid var(--border-medium);
    cursor: pointer;
    transition: all 0.3s var(--ease-out-expo);
}

.btn-secondary-large:hover {
    background: rgba(255, 255, 255, 0.12);
    border-color: var(--metal-light);
    transform: translateY(-2px);
}

/* --------------------------------------------------------------------------
   EDITORIAL PRODUCT DETAIL CHAPTERS (POST-SCROLLYTELLING)
   -------------------------------------------------------------------------- */
.editorial-section {
    position: relative;
    z-index: 5;
    background-color: var(--bg-primary);
    padding: 140px 8vw;
    border-top: 1px solid var(--border-subtle);
    overflow: hidden;
}

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

.editorial-grid {
    max-width: 1400px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.editorial-visual-wrapper {
    position: relative;
    border-radius: 12px;
    overflow: hidden;
    border: 1px solid var(--border-subtle);
    background: #020202;
    box-shadow: 0 30px 80px rgba(0, 0, 0, 0.8);
}

.editorial-img {
    width: 100%;
    height: auto;
    display: block;
    object-fit: cover;
    transition: transform 0.8s var(--ease-out-expo);
}

.editorial-visual-wrapper:hover .editorial-img {
    transform: scale(1.02);
}

/* Technical Leader Annotations on Macro */
.macro-pin {
    position: absolute;
    display: flex;
    align-items: center;
    gap: 8px;
    pointer-events: auto;
}

.macro-pin[data-pos="collar"] {
    top: 34%;
    right: 28%;
}

.macro-pin[data-pos="spout"] {
    bottom: 26%;
    left: 35%;
}

.macro-pin-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--metal-high);
    box-shadow: 0 0 12px rgba(255, 255, 255, 0.8);
    animation: pulseGlow 2.5s infinite;
}

@keyframes pulseGlow {
    0% {
        transform: scale(1);
        box-shadow: 0 0 0 0 rgba(255, 255, 255, 0.6);
    }

    70% {
        transform: scale(1.2);
        box-shadow: 0 0 0 10px rgba(255, 255, 255, 0);
    }

    100% {
        transform: scale(1);
        box-shadow: 0 0 0 0 rgba(255, 255, 255, 0);
    }
}

.macro-pin-tag {
    font-family: var(--font-mono);
    font-size: 0.68rem;
    letter-spacing: 0.14em;
    background: rgba(10, 10, 10, 0.85);
    border: 1px solid var(--border-subtle);
    padding: 4px 10px;
    border-radius: 4px;
    color: var(--metal-light);
    backdrop-filter: blur(8px);
}

/* Split Water Architecture Diagram */
.water-arch-toggle-box {
    display: flex;
    gap: 12px;
    margin: 28px 0;
}

.btn-water-mode {
    flex: 1;
    background: rgba(20, 20, 20, 0.6);
    border: 1px solid var(--border-subtle);
    color: var(--text-secondary);
    padding: 14px 20px;
    border-radius: 8px;
    font-family: var(--font-mono);
    font-size: 0.78rem;
    letter-spacing: 0.12em;
    cursor: pointer;
    transition: all 0.25s ease;
    text-align: left;
}

.btn-water-mode:hover {
    border-color: var(--border-medium);
    color: var(--text-primary);
}

.btn-water-mode.active {
    border-color: var(--accent-champagne);
    color: var(--metal-high);
    background: rgba(200, 164, 106, 0.08);
}

.water-diagram-canvas-box {
    height: 320px;
    background: #05070a;
    border: 1px solid var(--border-subtle);
    border-radius: 12px;
    position: relative;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Interactive TUNE Profiler Sandbox */
.tune-sandbox-section {
    max-width: 1400px;
    margin: 0 auto;
}

.tune-sandbox-container {
    background: #080808;
    border: 1px solid var(--border-medium);
    border-radius: 16px;
    padding: 48px;
    margin-top: 48px;
    box-shadow: 0 30px 80px rgba(0, 0, 0, 0.8);
}

.sandbox-controls-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-top: 32px;
}

.sandbox-preset-btn {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-subtle);
    padding: 20px;
    border-radius: 10px;
    cursor: pointer;
    text-align: left;
    transition: all 0.3s var(--ease-out-expo);
}

.sandbox-preset-btn:hover {
    background: rgba(255, 255, 255, 0.07);
    border-color: var(--border-medium);
}

.sandbox-preset-btn.active {
    border-color: var(--accent-lime);
    background: rgba(215, 255, 69, 0.06);
}

.preset-name {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--metal-light);
    margin-bottom: 6px;
}

.preset-desc {
    font-size: 0.82rem;
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: 12px;
}

.preset-telemetry {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--accent-lime);
    letter-spacing: 0.1em;
}

/* --------------------------------------------------------------------------
   ARCHITECTURAL SPECIFICATIONS GRID
   -------------------------------------------------------------------------- */
.specs-architectural-grid {
    max-width: 1400px;
    margin: 64px auto 0 auto;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1px;
    background-color: var(--border-subtle);
    border: 1px solid var(--border-subtle);
    border-radius: 12px;
    overflow: hidden;
}

.spec-cell {
    background-color: var(--bg-primary);
    padding: 48px 36px;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    min-height: 220px;
    position: relative;
    transition: background-color 0.3s ease;
}

.spec-cell:hover {
    background-color: #0b0b0b;
}

.spec-cell-num {
    font-family: var(--font-sans);
    font-size: clamp(2.4rem, 3.8vw, 3.8rem);
    font-weight: 800;
    letter-spacing: -0.04em;
    color: var(--metal-high);
    line-height: 1;
    margin-bottom: 12px;
}

.spec-cell-label {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--text-muted);
}

.spec-cell-note {
    font-size: 0.8rem;
    color: var(--text-dim);
    margin-top: 8px;
}

/* --------------------------------------------------------------------------
   FOOTER
   -------------------------------------------------------------------------- */
.site-footer {
    background-color: #020202;
    border-top: 1px solid var(--border-subtle);
    padding: 100px 8vw 48px 8vw;
    color: var(--text-secondary);
}

.footer-top {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    padding-bottom: 60px;
    border-bottom: 1px solid var(--border-subtle);
}

.footer-brand-title {
    font-size: 1.4rem;
    font-weight: 800;
    letter-spacing: 0.16em;
    color: var(--metal-high);
    margin-bottom: 8px;
}

.footer-brand-coordinates {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    color: var(--accent-champagne);
    letter-spacing: 0.18em;
}

.footer-links-grid {
    display: flex;
    gap: 60px;
}

.footer-col-title {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--text-muted);
    margin-bottom: 20px;
}

.footer-nav-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.86rem;
    transition: color 0.2s ease;
}

.footer-nav-link:hover {
    color: var(--metal-high);
}

.footer-bottom {
    max-width: 1400px;
    margin: 40px auto 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.75rem;
    color: var(--text-dim);
    font-family: var(--font-mono);
}

/* --------------------------------------------------------------------------
   RESPONSIVE DESIGN SYSTEM
   -------------------------------------------------------------------------- */
@media (max-width: 1100px) {
    .editorial-grid {
        grid-template-columns: 1fr;
        gap: 48px;
    }

    .specs-architectural-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .sandbox-controls-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    :root {
        --nav-height: 56px;
    }

    .nav-atlas-logo {
        height: 20px;
    }

    .nav-links {
        display: none;
    }

    .story-chapter {
        padding: 0 24px;
    }

    .chapter-content {
        max-width: 100%;
    }

    .headline-hero {
        font-size: 3rem;
    }

    .headline-chapter {
        font-size: 2.2rem;
    }

    .boiler-specs-row {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .tune-phases-grid {
        grid-template-columns: 1fr;
        gap: 8px;
    }

    .specs-architectural-grid {
        grid-template-columns: 1fr;
    }

    .footer-top {
        flex-direction: column;
        gap: 40px;
    }

    .footer-links-grid {
        flex-direction: column;
        gap: 30px;
    }

    .cta-buttons-group {
        flex-direction: column;
        width: 100%;
    }

    .btn-primary-large,
    .btn-secondary-large {
        width: 100%;
        justify-content: center;
    }

    .hud-frame-counter {
        display: none;
    }
}