/* ==========================================================================
   Lift Landing Page - Complete Stylesheet (Dark Mode Only)
   ========================================================================== */

/* ==========================================================================
   1. CSS Variables & Root Styles
   ========================================================================== */

:root {
    /* Colors */
    --color-bg: #000000;
    --color-bg-elevated: #1c1c1e;
    --color-bg-secondary: #2c2c2e;
    --color-bg-tertiary: #3a3a3c;

    --color-text-primary: #ffffff;
    --color-text-secondary: rgba(255, 255, 255, 0.7);
    --color-text-tertiary: rgba(255, 255, 255, 0.5);
    --color-text-quaternary: rgba(255, 255, 255, 0.3);

    --color-accent: #5ac8fa;
    --color-accent-secondary: #64d2ff;
    --color-success: #34c759;
    --color-success-secondary: #30d158;
    --color-warning: #ff9f0a;
    --color-warning-secondary: #ffb340;
    --color-error: #ff453a;
    --color-error-secondary: #ff6961;
    --color-purple: #5e5ce6;
    --color-purple-secondary: #7d7aff;

    --color-border: rgba(255, 255, 255, 0.08);
    --color-border-light: rgba(255, 255, 255, 0.06);
    --color-border-heavy: rgba(255, 255, 255, 0.12);

    /* Glass effect */
    --glass-bg: rgba(255, 255, 255, 0.03);
    --glass-bg-hover: rgba(255, 255, 255, 0.05);
    --glass-bg-elevated: rgba(255, 255, 255, 0.06);

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    --spacing-4xl: 6rem;

    /* Typography */
    --font-family:
        -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
        "Helvetica Neue", Helvetica, Arial, sans-serif;
    --font-size-xs: 0.65rem;
    --font-size-sm: 0.75rem;
    --font-size-base: 0.875rem;
    --font-size-md: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    --font-size-4xl: 2.5rem;
    --font-size-5xl: 3.5rem;

    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;

    --line-height-tight: 1.2;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.6;

    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-2xl: 20px;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.6);

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.2s ease;
    --transition-slow: 0.3s ease;

    /* Layout */
    --container-max-width: 1200px;
    --container-padding: 1.5rem;
    --nav-height: 60px;
}

/* ==========================================================================
   2. Reset & Base Styles
   ========================================================================== */

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

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-normal);
    line-height: var(--line-height-normal);
    color: var(--color-text-primary);
    background-color: var(--color-bg);
    min-height: 100vh;
    overflow-x: hidden;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: var(--color-accent);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-accent-secondary);
}

ul,
ol {
    list-style: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* ==========================================================================
   3. Typography
   ========================================================================== */

h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: var(--font-weight-semibold);
    line-height: var(--line-height-tight);
    color: var(--color-text-primary);
}

h1 {
    font-size: var(--font-size-5xl);
    font-weight: var(--font-weight-bold);
    letter-spacing: -0.02em;
}

h2 {
    font-size: var(--font-size-3xl);
    letter-spacing: -0.01em;
}

h3 {
    font-size: var(--font-size-xl);
}

h4 {
    font-size: var(--font-size-lg);
}

h5 {
    font-size: var(--font-size-md);
}

p {
    color: var(--color-text-secondary);
}

/* ==========================================================================
   4. Layout
   ========================================================================== */

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

section {
    padding: var(--spacing-4xl) 0;
}

.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto var(--spacing-3xl);
}

.section-header h2 {
    margin-bottom: var(--spacing-md);
}

.section-header p {
    font-size: var(--font-size-lg);
    color: var(--color-text-tertiary);
}

/* ==========================================================================
   5. Navigation
   ========================================================================== */

nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--color-border);
    z-index: 1000;
}

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

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-semibold);
    color: var(--color-text-primary);
}

.hero-logo {
    width: 32px;
    height: 32px;
    border-radius: var(--radius-sm);
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--color-text-primary);
    color: var(--color-bg);
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-medium);
    border-radius: var(--radius-full);
    transition: all var(--transition-normal);
}

.download-btn:hover {
    background: var(--color-text-secondary);
    color: var(--color-bg);
    transform: scale(1.02);
}

/* ==========================================================================
   6. Hero Section
   ========================================================================== */

.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: var(--nav-height);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(
        ellipse at 50% 0%,
        rgba(90, 200, 250, 0.15) 0%,
        transparent 60%
    );
    pointer-events: none;
}

.magicpattern {
    background:
        radial-gradient(
            circle at 20% 80%,
            rgba(94, 92, 230, 0.1) 0%,
            transparent 40%
        ),
        radial-gradient(
            circle at 80% 20%,
            rgba(90, 200, 250, 0.1) 0%,
            transparent 40%
        ),
        radial-gradient(
            circle at 50% 50%,
            rgba(52, 199, 89, 0.05) 0%,
            transparent 50%
        );
}

.ios-glass-card {
    text-align: center;
    padding: var(--spacing-3xl);
    background: var(--glass-bg);
    backdrop-filter: blur(40px);
    -webkit-backdrop-filter: blur(40px);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-2xl);
    max-width: 600px;
    margin: 0 var(--container-padding);
}

.ios-glass-card h1 {
    margin-bottom: var(--spacing-lg);
    background: linear-gradient(
        135deg,
        var(--color-text-primary) 0%,
        var(--color-text-secondary) 100%
    );
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.tagline {
    font-size: var(--font-size-xl);
    color: var(--color-text-tertiary);
    line-height: var(--line-height-relaxed);
}

/* ==========================================================================
   7. Features Section
   ========================================================================== */

.features {
    background: var(--color-bg);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.feature-card {
    padding: var(--spacing-xl);
    background: var(--glass-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    transition: all var(--transition-normal);
}

.feature-card:hover {
    background: var(--glass-bg-hover);
    border-color: var(--color-border-heavy);
    transform: translateY(-2px);
}

.feature-icon {
    width: 40px;
    height: 40px;
    margin-bottom: var(--spacing-md);
    opacity: 0.9;
    filter: brightness(0) invert(1);
}

.feature-card h3 {
    margin-bottom: var(--spacing-sm);
    font-size: var(--font-size-md);
}

.feature-card p {
    font-size: var(--font-size-base);
    color: var(--color-text-tertiary);
    line-height: var(--line-height-relaxed);
}

/* ==========================================================================
   8. Core Features Section
   ========================================================================== */

.core-features {
    background: linear-gradient(
        180deg,
        var(--color-bg) 0%,
        var(--color-bg-elevated) 50%,
        var(--color-bg) 100%
    );
}

.feature-showcase {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: center;
    margin-bottom: var(--spacing-4xl);
}

.feature-showcase:nth-child(even) {
    direction: rtl;
}

.feature-showcase:nth-child(even) > * {
    direction: ltr;
}

.feature-showcase:last-child {
    margin-bottom: 0;
}

.feature-content h3 {
    font-size: var(--font-size-2xl);
    margin-bottom: var(--spacing-sm);
}

.feature-content > p {
    font-size: var(--font-size-lg);
    color: var(--color-text-tertiary);
    margin-bottom: var(--spacing-xl);
}

.feature-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.feature-list li {
    position: relative;
    padding-left: var(--spacing-lg);
    color: var(--color-text-secondary);
    font-size: var(--font-size-base);
    line-height: var(--line-height-relaxed);
}

.feature-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0.5em;
    width: 6px;
    height: 6px;
    background: var(--color-accent);
    border-radius: var(--radius-full);
}

.feature-visual {
    display: flex;
    align-items: center;
    justify-content: center;
}

/* ==========================================================================
   9. Interactive Card Components
   ========================================================================== */

.interactive-card {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-2xl);
    padding: var(--spacing-lg);
    width: 100%;
    max-width: 340px;
    margin: 0 auto;
}

.interactive-card-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--color-border-light);
}

.interactive-card-icon {
    width: 44px;
    height: 44px;
    border-radius: var(--radius-md);
    background: linear-gradient(
        135deg,
        rgba(255, 255, 255, 0.1),
        rgba(255, 255, 255, 0.05)
    );
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-xl);
}

.interactive-card-title {
    font-size: var(--font-size-md);
    font-weight: var(--font-weight-semibold);
    color: var(--color-text-primary);
    margin: 0;
}

.interactive-card-subtitle {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
    margin: 0;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
}

.stat-item {
    background: rgba(255, 255, 255, 0.04);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    text-align: center;
}

.stat-label {
    font-size: var(--font-size-xs);
    color: var(--color-text-quaternary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: var(--spacing-xs);
}

.stat-value {
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-semibold);
    color: var(--color-text-primary);
}

.stat-value.positive {
    color: var(--color-success);
}

.stat-value.accent {
    color: var(--color-accent);
}

/* Expandable Sections */
.expandable-section {
    background: var(--glass-bg);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-sm);
    overflow: hidden;
}

.expandable-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md);
    cursor: pointer;
    transition: background var(--transition-normal);
}

.expandable-header:hover {
    background: rgba(255, 255, 255, 0.02);
}

.expandable-title {
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-medium);
    color: var(--color-text-secondary);
}

.expandable-chevron {
    font-size: var(--font-size-sm);
    color: var(--color-text-quaternary);
    transition: transform var(--transition-slow);
}

.expandable-section.expanded .expandable-chevron {
    transform: rotate(180deg);
}

.expandable-content {
    max-height: 0;
    overflow: hidden;
    transition:
        max-height var(--transition-slow),
        padding var(--transition-slow);
}

.expandable-section.expanded .expandable-content {
    max-height: 200px;
}

.expandable-content-inner {
    padding: 0 var(--spacing-md) var(--spacing-md);
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
    line-height: var(--line-height-relaxed);
}

.expandable-content-inner ol,
.expandable-content-inner ul {
    margin: 0;
    padding-left: var(--spacing-lg);
}

.expandable-content-inner li {
    margin-bottom: var(--spacing-xs);
}

.expandable-content-inner ol {
    list-style: decimal;
}

.expandable-content-inner ul {
    list-style: disc;
}

/* Mesocycle Visualization */
.mesocycle-weeks {
    display: flex;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-lg);
}

.meso-week {
    flex: 1;
    height: 8px;
    border-radius: 4px;
    background: rgba(255, 255, 255, 0.1);
    position: relative;
    overflow: hidden;
}

.meso-week.completed {
    background: linear-gradient(
        90deg,
        var(--color-success),
        var(--color-success-secondary)
    );
}

.meso-week.current {
    background: linear-gradient(
        90deg,
        var(--color-accent),
        var(--color-accent-secondary)
    );
    animation: pulse-glow 2s ease-in-out infinite;
}

@keyframes pulse-glow {
    0%,
    100% {
        opacity: 1;
    }
    50% {
        opacity: 0.7;
    }
}

.meso-week.deload {
    background: linear-gradient(
        90deg,
        var(--color-warning),
        var(--color-warning-secondary)
    );
}

.week-labels {
    display: flex;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-sm);
}

.week-label {
    flex: 1;
    text-align: center;
    font-size: var(--font-size-xs);
    color: var(--color-text-quaternary);
}

/* Volume Bars */
.volume-section {
    margin-bottom: var(--spacing-md);
}

.volume-label {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
    margin-bottom: var(--spacing-sm);
}

.volume-bar-container {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

.volume-bar-label {
    font-size: var(--font-size-xs);
    color: var(--color-text-tertiary);
    width: 50px;
    flex-shrink: 0;
}

.volume-bar-track {
    flex: 1;
    height: 6px;
    background: var(--color-border);
    border-radius: 3px;
    overflow: hidden;
}

.volume-bar-fill {
    height: 100%;
    border-radius: 3px;
    transition: width 0.5s ease;
}

.volume-bar-fill.chest {
    background: linear-gradient(
        90deg,
        var(--color-error),
        var(--color-error-secondary)
    );
}

.volume-bar-fill.back {
    background: linear-gradient(
        90deg,
        var(--color-success-secondary),
        var(--color-success)
    );
}

.volume-bar-fill.legs {
    background: linear-gradient(
        90deg,
        var(--color-purple),
        var(--color-purple-secondary)
    );
}

.volume-bar-fill.shoulders {
    background: linear-gradient(
        90deg,
        var(--color-warning),
        var(--color-warning-secondary)
    );
}

.volume-bar-value {
    font-size: var(--font-size-xs);
    color: var(--color-text-tertiary);
    width: 40px;
    text-align: right;
    flex-shrink: 0;
}

/* RIR Section */
.rir-section {
    margin-bottom: var(--spacing-lg);
}

.rir-label-row {
    display: flex;
    justify-content: space-between;
    margin-bottom: var(--spacing-sm);
}

.rir-label {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
}

.rir-value {
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-semibold);
    color: var(--color-warning);
}

.rir-track {
    height: 6px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 3px;
    position: relative;
}

.rir-fill {
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 70%;
    background: linear-gradient(
        90deg,
        var(--color-error),
        var(--color-warning)
    );
    border-radius: 3px;
}

.rir-thumb {
    position: absolute;
    right: 30%;
    top: 50%;
    transform: translate(50%, -50%);
    width: 16px;
    height: 16px;
    background: var(--color-text-primary);
    border-radius: var(--radius-full);
    box-shadow: var(--shadow-sm);
}

/* Set List */
.set-list {
    margin-bottom: var(--spacing-md);
}

.set-row {
    display: flex;
    align-items: center;
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid var(--color-border-light);
}

.set-row:last-child {
    border-bottom: none;
}

.set-number {
    width: 24px;
    height: 24px;
    border-radius: var(--radius-sm);
    background: var(--color-border);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-xs);
    font-weight: var(--font-weight-semibold);
    color: var(--color-text-tertiary);
    margin-right: var(--spacing-sm);
}

.set-details {
    flex: 1;
    display: flex;
    gap: var(--spacing-md);
}

.set-detail {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

.set-detail span {
    color: var(--color-text-quaternary);
    font-size: var(--font-size-xs);
}

.set-check {
    width: 20px;
    height: 20px;
    border-radius: var(--radius-full);
    background: var(--color-success);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-xs);
    color: var(--color-text-primary);
}

.set-check.pending {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid var(--color-border-heavy);
}

.set-check.pending::after {
    content: none;
}

/* Chart Container */
.chart-container {
    height: 120px;
    position: relative;
    margin-bottom: var(--spacing-md);
}

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

.chart-labels {
    display: flex;
    justify-content: space-between;
    font-size: var(--font-size-xs);
    color: var(--color-text-quaternary);
    margin-top: var(--spacing-sm);
}

.chart-legend {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    margin-top: var(--spacing-sm);
}

.legend-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: var(--font-size-xs);
    color: var(--color-text-tertiary);
}

.legend-dot {
    width: 8px;
    height: 8px;
    border-radius: var(--radius-full);
}

.legend-dot.raw {
    background: var(--color-text-quaternary);
}

.legend-dot.smoothed {
    background: var(--color-accent);
}

/* Feedback Section */
.feedback-section {
    margin-bottom: var(--spacing-md);
}

.feedback-label {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
    margin-bottom: var(--spacing-sm);
}

.feedback-pills {
    display: flex;
    gap: var(--spacing-sm);
}

.feedback-pill {
    flex: 1;
    padding: var(--spacing-sm);
    border-radius: var(--radius-md);
    background: rgba(255, 255, 255, 0.05);
    text-align: center;
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
    cursor: pointer;
    transition: all var(--transition-normal);
}

.feedback-pill.selected {
    background: rgba(90, 200, 250, 0.2);
    color: var(--color-accent);
}

.feedback-pill:hover {
    background: var(--color-border);
}

/* ==========================================================================
   10. Tracking Modes Section
   ========================================================================== */

.tracking-modes {
    background: var(--color-bg);
}

.modes-list {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.mode-item {
    padding: var(--spacing-xl);
    background: var(--glass-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    text-align: center;
    transition: all var(--transition-normal);
}

.mode-item:hover {
    background: var(--glass-bg-hover);
    border-color: var(--color-border-heavy);
}

.mode-item h4 {
    margin-bottom: var(--spacing-sm);
    color: var(--color-text-primary);
}

.mode-item p {
    font-size: var(--font-size-base);
    color: var(--color-text-tertiary);
    line-height: var(--line-height-relaxed);
}

/* ==========================================================================
   11. Analytics Section
   ========================================================================== */

.analytics {
    background: linear-gradient(
        180deg,
        var(--color-bg) 0%,
        var(--color-bg-elevated) 100%
    );
}

.analytics-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

.analytics-content h3 {
    font-size: var(--font-size-2xl);
    margin-bottom: var(--spacing-xl);
}

.analytics-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.analytics-list li {
    position: relative;
    padding-left: var(--spacing-lg);
    color: var(--color-text-secondary);
    font-size: var(--font-size-base);
    line-height: var(--line-height-relaxed);
}

.analytics-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0.5em;
    width: 6px;
    height: 6px;
    background: var(--color-success);
    border-radius: var(--radius-full);
}

.analytics-visual {
    display: flex;
    align-items: center;
    justify-content: center;
}

/* ==========================================================================
   12. Privacy Section
   ========================================================================== */

.privacy {
    background: var(--color-bg);
}

.privacy-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.privacy-card {
    padding: var(--spacing-xl);
    background: var(--glass-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    text-align: center;
    transition: all var(--transition-normal);
}

.privacy-card:hover {
    background: var(--glass-bg-hover);
    border-color: var(--color-border-heavy);
}

.privacy-card .feature-icon {
    margin: 0 auto var(--spacing-md);
}

.privacy-card h3 {
    margin-bottom: var(--spacing-sm);
    font-size: var(--font-size-md);
}

.privacy-card p {
    font-size: var(--font-size-base);
    color: var(--color-text-tertiary);
    line-height: var(--line-height-relaxed);
}

/* ==========================================================================
   13. CTA Section
   ========================================================================== */

.cta {
    background: linear-gradient(
        180deg,
        var(--color-bg-elevated) 0%,
        var(--color-bg) 100%
    );
    text-align: center;
    padding: var(--spacing-4xl) 0;
}

.cta h2 {
    font-size: var(--font-size-3xl);
    margin-bottom: var(--spacing-md);
}

.cta p {
    font-size: var(--font-size-lg);
    color: var(--color-text-tertiary);
    margin-bottom: var(--spacing-xl);
}

.app-store-badge {
    display: inline-block;
    transition: all var(--transition-normal);
}

.app-store-badge:hover {
    transform: scale(1.05);
    opacity: 0.9;
}

.app-store-badge img {
    height: 54px;
    width: auto;
}

/* ==========================================================================
   14. Footer
   ========================================================================== */

footer {
    background: var(--color-bg);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-3xl) 0 var(--spacing-xl);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: var(--spacing-3xl);
    margin-bottom: var(--spacing-2xl);
}

.footer-section h4 {
    font-size: var(--font-size-xl);
    margin-bottom: var(--spacing-md);
}

.footer-section h5 {
    font-size: var(--font-size-base);
    color: var(--color-text-tertiary);
    margin-bottom: var(--spacing-md);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.footer-tagline {
    font-size: var(--font-size-base);
    color: var(--color-text-tertiary);
    line-height: var(--line-height-relaxed);
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.footer-links a {
    color: var(--color-text-secondary);
    font-size: var(--font-size-base);
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--color-border);
}

.footer-bottom p {
    font-size: var(--font-size-sm);
    color: var(--color-text-quaternary);
}

.footer-legal {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.footer-legal a {
    color: var(--color-text-quaternary);
    font-size: var(--font-size-sm);
}

.footer-legal a:hover {
    color: var(--color-text-secondary);
}

.footer-legal .separator {
    color: var(--color-text-quaternary);
}

/* ==========================================================================
   15. Responsive Design
   ========================================================================== */

@media (max-width: 1024px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .feature-showcase {
        gap: var(--spacing-2xl);
    }

    .modes-list,
    .privacy-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .modes-list .mode-item:last-child,
    .privacy-grid .privacy-card:last-child {
        grid-column: span 2;
        max-width: 50%;
        justify-self: center;
    }

    .footer-content {
        grid-template-columns: 1fr 1fr;
        gap: var(--spacing-2xl);
    }

    .footer-content .footer-section:first-child {
        grid-column: span 2;
    }
}

@media (max-width: 768px) {
    :root {
        --font-size-5xl: 2.5rem;
        --font-size-3xl: 1.75rem;
        --font-size-2xl: 1.25rem;
        --spacing-4xl: 4rem;
        --spacing-3xl: 3rem;
    }

    .features-grid,
    .modes-list,
    .privacy-grid {
        grid-template-columns: 1fr;
    }

    .modes-list .mode-item:last-child,
    .privacy-grid .privacy-card:last-child {
        grid-column: span 1;
        max-width: 100%;
    }

    .feature-showcase {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }

    .feature-showcase:nth-child(even) {
        direction: ltr;
    }

    .feature-visual {
        order: -1;
    }

    .analytics-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }

    .analytics-visual {
        order: -1;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }

    .footer-content .footer-section:first-child {
        grid-column: span 1;
    }

    .footer-bottom {
        flex-direction: column;
        gap: var(--spacing-md);
        text-align: center;
    }

    .ios-glass-card {
        padding: var(--spacing-2xl);
    }

    .interactive-card {
        max-width: 100%;
    }
}

@media (max-width: 480px) {
    :root {
        --container-padding: 1rem;
        --font-size-5xl: 2rem;
        --font-size-3xl: 1.5rem;
    }

    .tagline {
        font-size: var(--font-size-md);
    }

    .section-header p {
        font-size: var(--font-size-base);
    }

    .feature-card,
    .mode-item,
    .privacy-card {
        padding: var(--spacing-lg);
    }

    .stats-grid {
        gap: var(--spacing-xs);
    }

    .stat-item {
        padding: var(--spacing-sm);
    }

    .set-details {
        gap: var(--spacing-sm);
    }

    .feedback-pills {
        flex-direction: column;
    }
}

/* ==========================================================================
   16. Utility Classes
   ========================================================================== */

.text-center {
    text-align: center;
}

.text-left {
    text-align: left;
}

.text-right {
    text-align: right;
}

.hidden {
    display: none !important;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}