/* ==========================================================================
   Reader App Landing Page Stylesheet
   Theme: Pure Core Text Aesthetic (Paper, Sepia, Dark, Black)
   ========================================================================== */

:root {
    /* Brand Core */
    --accent: #0A84FF;
    --accent-hover: #0071E3;
    --accent-soft: rgba(10, 132, 255, 0.12);
    --gold: #D4A359;
    
    /* Active Palette (Defaults to Sepia) */
    --bg-page: #FAF5EC;
    --bg-surface: #F5E8D1;
    --bg-surface-elevated: #EDE0C7;
    --bg-card: rgba(245, 232, 209, 0.7);
    --text-primary: #3D3021;
    --text-secondary: #705D47;
    --text-muted: #9E8972;
    --border-subtle: rgba(61, 48, 33, 0.12);
    --border-card: rgba(61, 48, 33, 0.08);
    --shadow-soft: 0 10px 30px rgba(61, 48, 33, 0.06);
    --shadow-elevated: 0 20px 45px rgba(61, 48, 33, 0.12);
    --glass-bg: rgba(250, 245, 236, 0.82);
    --glow-color: rgba(212, 163, 89, 0.15);
    
    /* Typography Stacks */
    --font-prose: 'Newsreader', Georgia, serif;
    --font-ui: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    
    /* Transitions */
    --ease-apple: cubic-bezier(0.16, 1, 0.3, 1);
    --transition-fast: 0.2s var(--ease-apple);
    --transition-base: 0.35s var(--ease-apple);
    --transition-slow: 0.6s var(--ease-apple);
}

/* Site Color Palettes */
[data-theme="paper"] {
    --bg-page: #F7F7F5;
    --bg-surface: #FCFCFA;
    --bg-surface-elevated: #F0F0EC;
    --bg-card: rgba(252, 252, 250, 0.85);
    --text-primary: #212124;
    --text-secondary: #5A5A60;
    --text-muted: #8E8E93;
    --border-subtle: rgba(33, 33, 36, 0.1);
    --border-card: rgba(33, 33, 36, 0.06);
    --shadow-soft: 0 10px 30px rgba(0, 0, 0, 0.04);
    --shadow-elevated: 0 20px 45px rgba(0, 0, 0, 0.08);
    --glass-bg: rgba(247, 247, 245, 0.85);
    --glow-color: rgba(0, 0, 0, 0.05);
}

[data-theme="sepia"] {
    --bg-page: #FAF5EC;
    --bg-surface: #F5E8D1;
    --bg-surface-elevated: #EDE0C7;
    --bg-card: rgba(245, 232, 209, 0.7);
    --text-primary: #3D3021;
    --text-secondary: #705D47;
    --text-muted: #9E8972;
    --border-subtle: rgba(61, 48, 33, 0.12);
    --border-card: rgba(61, 48, 33, 0.08);
    --shadow-soft: 0 10px 30px rgba(61, 48, 33, 0.06);
    --shadow-elevated: 0 20px 45px rgba(61, 48, 33, 0.12);
    --glass-bg: rgba(250, 245, 236, 0.85);
    --glow-color: rgba(212, 163, 89, 0.15);
}

[data-theme="dark"] {
    --bg-page: #19191B;
    --bg-surface: #212124;
    --bg-surface-elevated: #2C2C30;
    --bg-card: rgba(33, 33, 36, 0.75);
    --text-primary: #C7C7CC;
    --text-secondary: #98989D;
    --text-muted: #636366;
    --border-subtle: rgba(255, 255, 255, 0.08);
    --border-card: rgba(255, 255, 255, 0.05);
    --shadow-soft: 0 10px 30px rgba(0, 0, 0, 0.3);
    --shadow-elevated: 0 20px 45px rgba(0, 0, 0, 0.5);
    --glass-bg: rgba(25, 25, 27, 0.85);
    --glow-color: rgba(10, 132, 255, 0.12);
}

[data-theme="black"] {
    --bg-page: #000000;
    --bg-surface: #0A0A0B;
    --bg-surface-elevated: #151518;
    --bg-card: rgba(15, 15, 18, 0.8);
    --text-primary: #9E9EA3;
    --text-secondary: #737378;
    --text-muted: #48484A;
    --border-subtle: rgba(255, 255, 255, 0.07);
    --border-card: rgba(255, 255, 255, 0.04);
    --shadow-soft: 0 10px 30px rgba(0, 0, 0, 0.6);
    --shadow-elevated: 0 20px 45px rgba(0, 0, 0, 0.8);
    --glass-bg: rgba(0, 0, 0, 0.88);
    --glow-color: rgba(255, 255, 255, 0.04);
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
}

body {
    background-color: var(--bg-page);
    color: var(--text-primary);
    font-family: var(--font-ui);
    line-height: 1.55;
    overflow-x: hidden;
    transition: background-color var(--transition-base), color var(--transition-base);
    position: relative;
    min-height: 100vh;
}

/* Ambient Backdrops */
.ambient-glow {
    position: fixed;
    border-radius: 50%;
    filter: blur(140px);
    pointer-events: none;
    z-index: 0;
    transition: background var(--transition-slow);
}

.glow-top {
    top: -200px;
    left: 50%;
    transform: translateX(-50%);
    width: 800px;
    height: 500px;
    background: radial-gradient(circle, var(--glow-color) 0%, transparent 70%);
}

.glow-bottom {
    bottom: -150px;
    right: 5%;
    width: 600px;
    height: 400px;
    background: radial-gradient(circle, var(--glow-color) 0%, transparent 70%);
}

/* ==========================================================================
   Header & Navigation
   ========================================================================== */

.site-header {
    position: sticky;
    top: 0;
    width: 100%;
    z-index: 100;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-subtle);
    transition: background var(--transition-base), border-color var(--transition-base);
}

.nav-container {
    max-width: 1220px;
    margin: 0 auto;
    padding: 0.85rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.brand-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    color: inherit;
}

.app-icon-badge {
    width: 40px;
    height: 40px;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 4px 12px rgba(0,0,0,0.12);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform var(--transition-fast);
}

.brand-link:hover .app-icon-badge {
    transform: scale(1.05);
}

.icon-svg {
    width: 100%;
    height: 100%;
}

.brand-text {
    display: flex;
    flex-direction: column;
}

.brand-name {
    font-family: var(--font-prose);
    font-size: 1.25rem;
    font-weight: 700;
    line-height: 1.1;
    letter-spacing: -0.01em;
}

.brand-sub {
    font-size: 0.72rem;
    color: var(--text-muted);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 1.75rem;
}

.nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 0.92rem;
    font-weight: 500;
    transition: color var(--transition-fast);
}

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

.nav-actions {
    display: flex;
    align-items: center;
    gap: 1.1rem;
}

/* Site Theme Switcher */
.theme-selector {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    background: var(--border-subtle);
    padding: 4px 6px;
    border-radius: 999px;
}

.theme-dot {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    border: 2px solid transparent;
    cursor: pointer;
    transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.theme-dot:hover {
    transform: scale(1.18);
}

.theme-dot.active {
    border-color: var(--accent);
    transform: scale(1.15);
}

.dot-paper { background: #FCFCFA; box-shadow: inset 0 0 0 1px #D6D6D2; }
.dot-sepia { background: #F5E8D1; box-shadow: inset 0 0 0 1px #D6C2A0; }
.dot-dark  { background: #212124; }
.dot-black { background: #000000; box-shadow: inset 0 0 0 1px #333336; }

/* Action Buttons */
.cta-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    background: var(--text-primary);
    color: var(--bg-surface);
    text-decoration: none;
    font-weight: 600;
    border-radius: 999px;
    border: none;
    cursor: pointer;
    transition: transform var(--transition-fast), opacity var(--transition-fast), box-shadow var(--transition-fast);
}

.cta-btn:hover {
    transform: translateY(-2px);
    opacity: 0.92;
    box-shadow: 0 8px 20px rgba(0,0,0,0.18);
}

.cta-btn-sm {
    font-size: 0.85rem;
    padding: 0.45rem 1rem;
}

.cta-btn-lg {
    font-size: 1.05rem;
    padding: 0.9rem 1.8rem;
    background: var(--accent);
    color: #FFFFFF;
}

.cta-btn-lg:hover {
    background: var(--accent-hover);
    box-shadow: 0 10px 25px rgba(10, 132, 255, 0.35);
}

.cta-secondary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    background: var(--border-subtle);
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 600;
    font-size: 1.05rem;
    padding: 0.9rem 1.8rem;
    border-radius: 999px;
    transition: background var(--transition-fast), transform var(--transition-fast);
}

.cta-secondary:hover {
    background: var(--bg-surface-elevated);
    transform: translateY(-2px);
}

/* ==========================================================================
   Hero Section
   ========================================================================== */

.hero-section {
    position: relative;
    padding: 4.5rem 1.5rem 3rem;
    z-index: 1;
}

.hero-container {
    max-width: 1100px;
    margin: 0 auto;
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.35rem 0.9rem;
    border-radius: 999px;
    background: var(--border-subtle);
    color: var(--text-secondary);
    font-size: 0.82rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    margin-bottom: 1.5rem;
    border: 1px solid var(--border-card);
}

.badge-dot {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: #34C759;
    box-shadow: 0 0 8px #34C759;
}

.hero-title {
    font-family: var(--font-prose);
    font-size: clamp(2.4rem, 5.5vw, 4.4rem);
    font-weight: 700;
    line-height: 1.12;
    letter-spacing: -0.025em;
    max-width: 860px;
    margin-bottom: 1.3rem;
    color: var(--text-primary);
}

.hero-subtitle {
    font-size: clamp(1.05rem, 2vw, 1.28rem);
    color: var(--text-secondary);
    max-width: 680px;
    line-height: 1.6;
    margin-bottom: 2.2rem;
}

.hero-cta-group {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 3.5rem;
    flex-wrap: wrap;
    justify-content: center;
}

/* ==========================================================================
   Interactive Reader Showcase Device
   ========================================================================== */

.interactive-showcase {
    width: 100%;
    max-width: 820px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.25rem;
}

.device-toolbar-controls {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1.5rem;
    flex-wrap: wrap;
    background: var(--bg-card);
    padding: 0.65rem 1.25rem;
    border-radius: 999px;
    border: 1px solid var(--border-subtle);
    box-shadow: var(--shadow-soft);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}

.control-group {
    display: flex;
    align-items: center;
    gap: 0.6rem;
}

.control-label {
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.reader-theme-pills, .font-toggle-group, .turn-toggle-group {
    display: flex;
    background: var(--border-subtle);
    padding: 2px;
    border-radius: 999px;
}

.theme-pill, .font-btn, .turn-btn {
    border: none;
    background: transparent;
    color: var(--text-secondary);
    padding: 0.25rem 0.65rem;
    font-size: 0.78rem;
    font-weight: 600;
    border-radius: 999px;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.theme-pill.active, .font-btn.active, .turn-btn.active {
    background: var(--bg-surface);
    color: var(--text-primary);
    box-shadow: 0 2px 6px rgba(0,0,0,0.08);
}

.size-stepper {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    background: var(--border-subtle);
    padding: 2px 6px;
    border-radius: 999px;
    font-size: 0.8rem;
    font-weight: 600;
}

.size-stepper button {
    border: none;
    background: transparent;
    cursor: pointer;
    color: var(--text-primary);
    font-weight: 700;
    padding: 0.1rem 0.35rem;
    border-radius: 4px;
}

.size-stepper button:hover {
    background: var(--bg-surface);
}

/* Device Frame Mockup */
.device-frame {
    position: relative;
    width: 100%;
    max-width: 680px;
    height: 640px;
    background: #1C1C1E;
    border-radius: 42px;
    padding: 14px;
    box-shadow: 0 30px 90px rgba(0,0,0,0.35), 0 0 0 1px rgba(255,255,255,0.15) inset;
    overflow: hidden;
    user-select: none;
}

.device-notch {
    position: absolute;
    top: 22px;
    left: 50%;
    transform: translateX(-50%);
    width: 120px;
    height: 18px;
    background: #000000;
    border-radius: 20px;
    z-index: 50;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding-right: 14px;
}

.camera-lens {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: #111424;
    box-shadow: 0 0 2px rgba(255,255,255,0.2) inset;
}

/* Reader Screen Surface */
.reader-surface {
    position: relative;
    width: 100%;
    height: 100%;
    border-radius: 30px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    background: var(--bg-surface);
    color: var(--text-primary);
    transition: background var(--transition-base), color var(--transition-base);
}

/* Reader App Specific Palettes Inside Frame */
.device-frame[data-theme="paper"] .reader-surface {
    --reader-bg: #FCFCFA;
    --reader-text: #212124;
    --reader-sub: #8E8E93;
    --reader-shadow: rgba(0,0,0,0.06);
    background: #FCFCFA;
    color: #212124;
}

.device-frame[data-theme="sepia"] .reader-surface {
    --reader-bg: #F5E8D1;
    --reader-text: #3D3021;
    --reader-sub: #9E8972;
    --reader-shadow: rgba(61,48,33,0.12);
    background: #F5E8D1;
    color: #3D3021;
}

.device-frame[data-theme="dark"] .reader-surface {
    --reader-bg: #212124;
    --reader-text: #C7C7CC;
    --reader-sub: #7A7A80;
    --reader-shadow: rgba(0,0,0,0.4);
    background: #212124;
    color: #C7C7CC;
}

.device-frame[data-theme="black"] .reader-surface {
    --reader-bg: #000000;
    --reader-text: #9E9EA3;
    --reader-sub: #555558;
    --reader-shadow: rgba(0,0,0,0.8);
    background: #000000;
    color: #9E9EA3;
}

/* In-App Header */
.inapp-header {
    height: 52px;
    padding: 0 28px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--text-muted);
    border-bottom: 1px solid rgba(0,0,0,0.04);
    z-index: 10;
}

.inapp-chapter {
    letter-spacing: 0.02em;
    font-style: italic;
    font-family: var(--font-prose);
    font-size: 0.95rem;
}

.inapp-meta {
    display: flex;
    gap: 0.75rem;
    font-variant-numeric: tabular-nums;
}

/* Page Paper Body */
.page-paper {
    position: relative;
    flex: 1;
    padding: 30px 42px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.page-body {
    flex: 1;
    font-family: var(--font-prose);
    font-size: 1.15rem;
    line-height: 1.7;
    text-align: justify;
    hyphens: auto;
    transition: opacity var(--transition-fast), font-family var(--transition-fast), font-size var(--transition-fast);
}

.page-body.font-serif { font-family: var(--font-prose); }
.page-body.font-sans  { font-family: var(--font-ui); text-align: left; }
.page-body.font-mono  { font-family: var(--font-mono); font-size: 0.98rem; text-align: left; }

.prose-h2 {
    font-size: 1.45em;
    font-weight: 700;
    margin-bottom: 0.6em;
    letter-spacing: -0.015em;
    text-align: left;
}

.prose-p {
    margin-bottom: 0.85em;
    text-indent: 1.4em;
}

.prose-p.no-indent {
    text-indent: 0;
}

/* Interactive Selected Text & Floating Action Bar */
.selected-sample {
    background-color: rgba(10, 132, 255, 0.28);
    border-radius: 2px;
    position: relative;
    cursor: pointer;
}

.highlight-sample {
    background-color: rgba(255, 214, 10, 0.35);
    border-radius: 2px;
}

.selection-overlay-container {
    position: absolute;
    top: 110px;
    left: 42px;
    z-index: 25;
    pointer-events: auto;
    transition: all var(--transition-base);
}

.selection-action-bar {
    display: inline-flex;
    align-items: center;
    background: rgba(255, 255, 255, 0.88);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
    padding: 5px 8px;
    border-radius: 10px;
    box-shadow: 0 8px 24px rgba(0,0,0,0.18), 0 0 0 0.5px rgba(0,0,0,0.06);
    gap: 4px;
    color: #000000;
    transform: translateY(-44px);
    animation: barFloat 0.3s var(--ease-apple);
}

.device-frame[data-theme="dark"] .selection-action-bar,
.device-frame[data-theme="black"] .selection-action-bar {
    background: rgba(40, 40, 44, 0.9);
    color: #FFFFFF;
    box-shadow: 0 8px 24px rgba(0,0,0,0.45), 0 0 0 0.5px rgba(255,255,255,0.1);
}

.bar-btn {
    display: flex;
    align-items: center;
    gap: 4px;
    background: transparent;
    border: none;
    color: inherit;
    font-size: 0.76rem;
    font-weight: 500;
    padding: 3px 6px;
    border-radius: 6px;
    cursor: pointer;
    transition: background var(--transition-fast);
}

.bar-btn:hover {
    background: rgba(0,0,0,0.08);
}

.device-frame[data-theme="dark"] .bar-btn:hover,
.device-frame[data-theme="black"] .bar-btn:hover {
    background: rgba(255,255,255,0.12);
}

.bar-divider {
    width: 1px;
    height: 16px;
    background: rgba(0,0,0,0.15);
}

.device-frame[data-theme="dark"] .bar-divider,
.device-frame[data-theme="black"] .bar-divider {
    background: rgba(255,255,255,0.18);
}

@keyframes barFloat {
    from { opacity: 0; transform: translateY(-38px) scale(0.94); }
    to { opacity: 1; transform: translateY(-44px) scale(1); }
}

/* Page Curl Shader Simulation */
.curl-shadow-layer {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    width: 0;
    background: linear-gradient(to right, transparent, rgba(0,0,0,0.25));
    pointer-events: none;
    transition: width var(--transition-base);
    z-index: 20;
}

.curl-leaf {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    width: 0;
    background: inherit;
    box-shadow: -15px 0 30px rgba(0,0,0,0.2);
    pointer-events: none;
    overflow: hidden;
    transition: width var(--transition-base);
    z-index: 21;
}

.device-frame.curling .curl-shadow-layer {
    width: 180px;
}

.device-frame.curling .curl-leaf {
    width: 120px;
}

/* Bottom In-App Scrubber & Footer */
.inapp-footer {
    height: 48px;
    padding: 0 28px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 6px;
    border-top: 1px solid rgba(0,0,0,0.04);
    z-index: 10;
}

.scrubber-track {
    position: relative;
    width: 100%;
    height: 3px;
    background: rgba(0,0,0,0.08);
    border-radius: 2px;
}

.device-frame[data-theme="dark"] .scrubber-track,
.device-frame[data-theme="black"] .scrubber-track {
    background: rgba(255,255,255,0.12);
}

.scrubber-fill {
    height: 100%;
    background: var(--accent);
    border-radius: 2px;
    transition: width var(--transition-fast);
}

.footer-info {
    display: flex;
    justify-content: space-between;
    font-size: 0.72rem;
    color: var(--text-muted);
    font-weight: 500;
}

/* Interactive Tap Zones */
.tap-zone {
    position: absolute;
    top: 52px;
    bottom: 48px;
    cursor: pointer;
    z-index: 15;
    display: flex;
    align-items: center;
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.tap-zone:hover {
    opacity: 1;
}

.zone-left {
    left: 0;
    width: 25%;
    padding-left: 14px;
    background: linear-gradient(to right, rgba(0,0,0,0.03), transparent);
}

.zone-right {
    right: 0;
    width: 25%;
    justify-content: flex-end;
    padding-right: 14px;
    background: linear-gradient(to left, rgba(0,0,0,0.03), transparent);
}

.zone-center {
    left: 25%;
    width: 50%;
}

.zone-hint {
    font-size: 0.72rem;
    font-weight: 600;
    padding: 4px 8px;
    background: rgba(0,0,0,0.65);
    color: #FFFFFF;
    border-radius: 6px;
    backdrop-filter: blur(8px);
}

.showcase-caption {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.88rem;
    color: var(--text-muted);
    text-align: center;
}

.caption-icon {
    color: var(--gold);
}

/* ==========================================================================
   Features Grid: Why Core Text Matters
   ========================================================================== */

.features-section {
    padding: 6rem 1.5rem;
    position: relative;
    z-index: 1;
}

.section-container {
    max-width: 1140px;
    margin: 0 auto;
}

.section-header {
    text-align: center;
    max-width: 740px;
    margin: 0 auto 3.8rem;
}

.section-tag {
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    color: var(--accent);
    display: block;
    margin-bottom: 0.8rem;
}

.section-title {
    font-family: var(--font-prose);
    font-size: clamp(2rem, 3.8vw, 3rem);
    font-weight: 700;
    line-height: 1.18;
    letter-spacing: -0.02em;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.section-desc {
    font-size: 1.08rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 1.75rem;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    border-radius: 24px;
    padding: 2.2rem;
    box-shadow: var(--shadow-soft);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    display: flex;
    flex-direction: column;
    transition: transform var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.feature-card:hover {
    transform: translateY(-4px);
    border-color: var(--border-subtle);
    box-shadow: var(--shadow-elevated);
}

.feature-icon-box {
    width: 48px;
    height: 48px;
    border-radius: 14px;
    background: var(--accent-soft);
    color: var(--accent);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.4rem;
}

.feature-heading {
    font-family: var(--font-prose);
    font-size: 1.38rem;
    font-weight: 700;
    margin-bottom: 0.65rem;
    letter-spacing: -0.01em;
}

.feature-body {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1.5rem;
    flex: 1;
}

.feature-metric {
    display: flex;
    align-items: baseline;
    gap: 0.5rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-subtle);
}

.metric-num {
    font-family: var(--font-mono);
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--accent);
}

.metric-label {
    font-size: 0.78rem;
    color: var(--text-muted);
    font-weight: 500;
}

/* ==========================================================================
   WiFi Transfer Spotlight
   ========================================================================== */

.wifi-section {
    padding: 4rem 1.5rem 6rem;
    position: relative;
    z-index: 1;
}

.wifi-card-banner {
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    border-radius: 32px;
    padding: 3.5rem;
    display: grid;
    grid-template-columns: 1.1fr 1fr;
    gap: 3rem;
    align-items: center;
    box-shadow: var(--shadow-elevated);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}

.wifi-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    color: var(--accent);
    margin-bottom: 1rem;
}

.wifi-title {
    font-family: var(--font-prose);
    font-size: clamp(2rem, 3vw, 2.8rem);
    font-weight: 700;
    line-height: 1.18;
    margin-bottom: 1.2rem;
    letter-spacing: -0.02em;
}

.wifi-desc {
    font-size: 1.05rem;
    color: var(--text-secondary);
    line-height: 1.65;
    margin-bottom: 1.8rem;
}

.wifi-desc code {
    font-family: var(--font-mono);
    background: var(--border-subtle);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 0.9em;
}

.wifi-checklist {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.wifi-checklist li {
    display: flex;
    align-items: center;
    gap: 0.65rem;
    font-size: 0.95rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.wifi-checklist li span {
    color: #34C759;
    font-weight: 800;
}

/* Browser Mockup Dropzone */
.browser-window {
    background: var(--bg-surface-elevated);
    border-radius: 18px;
    overflow: hidden;
    border: 1px solid var(--border-subtle);
    box-shadow: 0 15px 40px rgba(0,0,0,0.15);
}

.browser-titlebar {
    height: 38px;
    padding: 0 14px;
    background: rgba(0,0,0,0.04);
    display: flex;
    align-items: center;
    gap: 12px;
    border-bottom: 1px solid var(--border-subtle);
}

.window-dots {
    display: flex;
    gap: 6px;
}

.window-dots span {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}

.dot-red { background: #FF5F56; }
.dot-yellow { background: #FFBD2E; }
.dot-green { background: #27C93F; }

.browser-url-pill {
    flex: 1;
    background: var(--bg-surface);
    height: 24px;
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    font-family: var(--font-mono);
    font-size: 0.74rem;
    color: var(--text-muted);
}

.dropzone-body {
    padding: 2rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    align-items: center;
}

.dropzone-dashed {
    width: 100%;
    border: 2px dashed var(--accent);
    background: var(--accent-soft);
    border-radius: 14px;
    padding: 2.2rem 1.5rem;
    text-align: center;
    cursor: pointer;
    transition: transform var(--transition-fast), background var(--transition-fast);
}

.dropzone-dashed:hover {
    transform: scale(1.02);
    background: rgba(10, 132, 255, 0.18);
}

.upload-icon-pulse {
    color: var(--accent);
    margin-bottom: 0.8rem;
    animation: bounce 2s infinite ease-in-out;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-6px); }
}

.dropzone-dashed h4 {
    font-size: 1.05rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.dropzone-dashed p {
    font-size: 0.82rem;
    color: var(--text-muted);
    margin-bottom: 1rem;
}

.format-tags {
    display: flex;
    gap: 0.4rem;
    justify-content: center;
    flex-wrap: wrap;
}

.fmt-tag {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    padding: 2px 7px;
    border-radius: 4px;
    background: rgba(0,0,0,0.06);
    color: var(--text-secondary);
    font-weight: 600;
}

.dropzone-success-card {
    width: 100%;
    display: flex;
    align-items: center;
    gap: 0.85rem;
    background: var(--bg-surface);
    padding: 0.75rem 1rem;
    border-radius: 10px;
    border: 1px solid var(--border-subtle);
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
}

.book-mini-cover {
    font-size: 1.6rem;
}

.book-mini-meta {
    display: flex;
    flex-direction: column;
}

.book-mini-title {
    font-size: 0.88rem;
    font-weight: 600;
}

.book-mini-status {
    font-size: 0.76rem;
    color: #34C759;
    font-weight: 600;
}

/* ==========================================================================
   Formats Deck
   ========================================================================== */

.formats-section {
    padding: 5rem 1.5rem;
    position: relative;
    z-index: 1;
}

.formats-deck {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

.format-card {
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    border-radius: 20px;
    padding: 1.8rem 1.4rem;
    box-shadow: var(--shadow-soft);
    display: flex;
    flex-direction: column;
    transition: transform var(--transition-fast);
}

.format-card:hover {
    transform: translateY(-4px);
}

.format-badge {
    align-self: flex-start;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--accent);
    background: var(--accent-soft);
    padding: 3px 8px;
    border-radius: 6px;
    margin-bottom: 1.1rem;
}

.format-card h3 {
    font-family: var(--font-prose);
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.format-card p {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.55;
}

/* ==========================================================================
   Specifications Table
   ========================================================================== */

.specs-section {
    padding: 5rem 1.5rem;
    position: relative;
    z-index: 1;
}

.specs-table-wrapper {
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    border-radius: 24px;
    overflow: hidden;
    box-shadow: var(--shadow-soft);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
}

.specs-table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
    font-size: 0.94rem;
}

.specs-table th {
    padding: 1.1rem 1.5rem;
    background: var(--border-subtle);
    color: var(--text-muted);
    font-size: 0.76rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    font-weight: 700;
    border-bottom: 1px solid var(--border-subtle);
}

.specs-table td {
    padding: 1.15rem 1.5rem;
    border-bottom: 1px solid var(--border-subtle);
    color: var(--text-secondary);
}

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

.specs-table tr:hover td {
    background: var(--border-subtle);
}

.specs-table strong {
    color: var(--text-primary);
}

.specs-table code {
    font-family: var(--font-mono);
    font-size: 0.85em;
    background: var(--border-subtle);
    padding: 2px 6px;
    border-radius: 4px;
}

/* ==========================================================================
   Call to Action (Download) Section
   ========================================================================== */

.cta-section {
    padding: 6rem 1.5rem;
    position: relative;
    z-index: 1;
}

.cta-box {
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    border-radius: 36px;
    padding: 4.5rem 2rem;
    text-align: center;
    max-width: 860px;
    margin: 0 auto;
    box-shadow: var(--shadow-elevated);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.app-icon-large {
    width: 84px;
    height: 84px;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 12px 35px rgba(0,0,0,0.2);
    margin-bottom: 1.8rem;
}

.cta-heading {
    font-family: var(--font-prose);
    font-size: clamp(2.2rem, 4vw, 3.2rem);
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 1rem;
}

.cta-text {
    font-size: 1.15rem;
    color: var(--text-secondary);
    max-width: 580px;
    margin-bottom: 2.4rem;
}

.download-badges {
    display: flex;
    gap: 1.25rem;
    margin-bottom: 2.5rem;
    flex-wrap: wrap;
    justify-content: center;
}

.badge-item {
    display: flex;
    align-items: center;
    gap: 0.8rem;
    background: var(--bg-surface);
    padding: 0.8rem 1.4rem;
    border-radius: 16px;
    border: 1px solid var(--border-subtle);
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
}

.platform-icon {
    font-size: 1.6rem;
}

.platform-meta {
    display: flex;
    flex-direction: column;
    text-align: left;
}

.platform-name {
    font-weight: 700;
    font-size: 0.95rem;
}

.platform-spec {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.build-instructions-box {
    width: 100%;
    max-width: 620px;
    background: #19191C;
    border-radius: 14px;
    overflow: hidden;
    text-align: left;
    box-shadow: 0 15px 35px rgba(0,0,0,0.3);
}

.build-header {
    height: 34px;
    padding: 0 14px;
    background: #121214;
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.75rem;
    color: #8E8E93;
    font-weight: 600;
}

.code-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: #34C759;
}

.build-instructions-box pre {
    padding: 1.1rem 1.4rem;
    color: #F2F2F7;
    font-family: var(--font-mono);
    font-size: 0.86rem;
    line-height: 1.65;
    overflow-x: auto;
}

.c-comment {
    color: #6E6E73;
}

/* ==========================================================================
   Footer
   ========================================================================== */

.site-footer {
    border-top: 1px solid var(--border-subtle);
    padding: 4.5rem 1.5rem 3rem;
    background: var(--bg-surface);
    transition: background var(--transition-base);
}

.footer-container {
    max-width: 1140px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1.2fr 2fr;
    gap: 4rem;
}

.brand-row {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.footer-logo {
    font-family: var(--font-prose);
    font-size: 1.4rem;
    font-weight: 700;
}

.footer-badge {
    font-size: 0.72rem;
    padding: 2px 7px;
    border-radius: 999px;
    background: var(--border-subtle);
    color: var(--text-muted);
    font-weight: 600;
}

.footer-desc {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1.5rem;
    max-width: 320px;
}

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

.footer-links-group {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
}

.footer-col h4 {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-muted);
    margin-bottom: 1rem;
    font-weight: 700;
}

.footer-col a {
    display: block;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.92rem;
    margin-bottom: 0.65rem;
    transition: color var(--transition-fast);
}

.footer-col a:hover {
    color: var(--text-primary);
}

.kbd-row {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.84rem;
    color: var(--text-secondary);
    margin-bottom: 0.6rem;
}

kbd {
    font-family: var(--font-mono);
    font-size: 0.76rem;
    background: var(--border-subtle);
    border: 1px solid var(--border-card);
    padding: 1px 5px;
    border-radius: 4px;
    color: var(--text-primary);
    font-weight: 600;
}

/* ==========================================================================
   Responsive Adaptations
   ========================================================================== */

@media (max-width: 960px) {
    .wifi-card-banner {
        grid-template-columns: 1fr;
        padding: 2.5rem;
    }
    .footer-container {
        grid-template-columns: 1fr;
        gap: 2.5rem;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    .hero-title {
        font-size: 2.5rem;
    }
    .device-frame {
        height: 560px;
        border-radius: 32px;
        padding: 10px;
    }
    .page-paper {
        padding: 20px 24px;
    }
    .footer-links-group {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
}