:root {
    /* Material 3 Inspired Colors */
    --md-sys-color-primary: #D0BCFF;
    --md-sys-color-on-primary: #381E72;
    --md-sys-color-primary-container: #4F378B;
    --md-sys-color-on-primary-container: #EADDFF;

    --md-sys-color-secondary: #CCC2DC;
    --md-sys-color-on-secondary: #332D41;
    --md-sys-color-secondary-container: #4A4458;
    --md-sys-color-on-secondary-container: #E8DEF8;

    --md-sys-color-tertiary: #EFB8C8;
    --md-sys-color-on-tertiary: #492532;
    --md-sys-color-tertiary-container: #633B48;
    --md-sys-color-on-tertiary-container: #FFD8E4;

    --md-sys-color-background: #1C1B1F;
    --md-sys-color-on-background: #E6E1E5;
    --md-sys-color-surface: #1C1B1F;
    --md-sys-color-on-surface: #E6E1E5;
    --md-sys-color-surface-variant: #49454F;
    --md-sys-color-on-surface-variant: #CAC4D0;
    --md-sys-color-outline: #938F99;

    /* Typography */
    --md-sys-typescale-display-large: 400 57px/64px 'Inter', sans-serif;
    --md-sys-typescale-display-medium: 400 45px/52px 'Inter', sans-serif;
    --md-sys-typescale-display-small: 400 36px/44px 'Inter', sans-serif;

    --md-sys-typescale-headline-large: 400 32px/40px 'Inter', sans-serif;
    --md-sys-typescale-headline-medium: 400 28px/36px 'Inter', sans-serif;
    --md-sys-typescale-headline-small: 400 24px/32px 'Inter', sans-serif;

    --md-sys-typescale-title-large: 400 22px/28px 'Inter', sans-serif;
    --md-sys-typescale-title-medium: 500 16px/24px 'Inter', sans-serif;
    --md-sys-typescale-title-small: 500 14px/20px 'Inter', sans-serif;

    --md-sys-typescale-body-large: 400 16px/24px 'Inter', sans-serif;
    --md-sys-typescale-body-medium: 400 14px/20px 'Inter', sans-serif;
    --md-sys-typescale-body-small: 400 12px/16px 'Inter', sans-serif;

    --md-sys-typescale-label-large: 500 14px/20px 'Inter', sans-serif;
    --md-sys-typescale-label-medium: 500 12px/16px 'Inter', sans-serif;
    --md-sys-typescale-label-small: 500 11px/16px 'Inter', sans-serif;

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-xxl: 48px;
    --spacing-giant: 96px;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 28px;
    --radius-full: 9999px;
}

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

body {
    background-color: var(--md-sys-color-background);
    color: var(--md-sys-color-on-background);
    font-family: 'Inter', sans-serif;
    -webkit-font-smoothing: antialiased;
    line-height: 1.5;
    overflow-x: hidden;
}

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

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

/* Utilities */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.material-symbols-rounded {
    font-variation-settings:
        'FILL' 0,
        'wght' 400,
        'GRAD' 0,
        'opsz' 24
}

/* Header */
.site-header {
    padding: var(--spacing-md) 0;
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 10;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--md-sys-color-on-background);
    font-weight: 700;
    font-size: 20px;
}

.logo-icon {
    color: var(--md-sys-color-primary);
    font-size: 32px;
}

/* Typography Classes */
.display-large {
    font: var(--md-sys-typescale-display-large);
}

.headline-small {
    font: var(--md-sys-typescale-headline-small);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    padding-top: 80px;
    /* Space for header */
}

/* Background Gradient Effect */
.hero::before {
    content: '';
    position: absolute;
    top: -20%;
    right: -10%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, var(--md-sys-color-primary-container) 0%, transparent 70%);
    filter: blur(80px);
    opacity: 0.5;
    z-index: -1;
}

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

.hero-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.hero-content h1 {
    color: var(--md-sys-color-on-background);
    background: linear-gradient(135deg, var(--md-sys-color-on-background) 0%, var(--md-sys-color-primary) 100%);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Features Section */
.features {
    padding: var(--spacing-giant) 0;
    background-color: var(--md-sys-color-background);
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-xxl);
}

.section-header h2 {
    margin-bottom: var(--spacing-sm);
    color: var(--md-sys-color-on-background);
}

.section-header p {
    color: var(--md-sys-color-on-surface-variant);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

.feature-card {
    background-color: var(--md-sys-color-surface-variant);
    /* Using surface variant for card bg */
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    transition: transform 0.2s, background-color 0.2s;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    border: 1px solid transparent;
}

.feature-card:hover {
    transform: translateY(-4px);
    background-color: var(--md-sys-color-surface);
    border-color: var(--md-sys-color-outline);
}

.feature-icon {
    font-size: 40px;
    color: var(--md-sys-color-primary);
    margin-bottom: var(--spacing-xs);
}

.feature-card h3 {
    color: var(--md-sys-color-on-surface);
}

.feature-card p {
    color: var(--md-sys-color-on-surface-variant);
}

/* Showcase Section */
.showcase {
    padding: var(--spacing-giant) 0;
    background-color: var(--md-sys-color-surface);
}

.showcase-grid {
    display: flex;
    justify-content: center;
    gap: var(--spacing-xl);
    flex-wrap: wrap;
}

.mockup-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
}

.mockup-screen {
    width: 240px;
    height: 480px;
    background: var(--md-sys-color-background);
    border-radius: 24px;
    border: 4px solid var(--md-sys-color-outline);
    overflow: hidden;
    position: relative;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    transition: transform 0.3s;
}

.mockup-card:hover .mockup-screen {
    transform: translateY(-10px);
}

.mockup-card p {
    color: var(--md-sys-color-on-surface);
}

/* Small UI Placeholders */
.ui-header-small {
    font-size: 14px;
    font-weight: 500;
    color: var(--md-sys-color-on-surface-variant);
    margin-bottom: var(--spacing-md);
}

.ui-display-small {
    font-size: 32px;
    text-align: right;
    margin-bottom: var(--spacing-md);
    color: var(--md-sys-color-on-background);
}

.ui-keypad-small {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 8px;
    height: 200px;
    background: var(--md-sys-color-surface-variant);
    border-radius: 12px;
    opacity: 0.5;
}

.ui-row {
    display: flex;
    justify-content: space-between;
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid var(--md-sys-color-outline);
    color: var(--md-sys-color-on-surface);
}

.ui-total {
    margin-top: var(--spacing-lg);
    display: flex;
    justify-content: space-between;
    font-weight: 700;
    font-size: 18px;
    color: var(--md-sys-color-primary);
}

.ui-input-group {
    background: var(--md-sys-color-surface-variant);
    padding: var(--spacing-md);
    border-radius: var(--radius-sm);
    display: flex;
    justify-content: space-between;
    margin-bottom: var(--spacing-sm);
    color: var(--md-sys-color-on-surface);
}

/* Footer */
.site-footer {
    padding: var(--spacing-xl) 0;
    background-color: var(--md-sys-color-background);
    border-top: 1px solid var(--md-sys-color-outline);
    margin-top: auto;
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-lg);
    text-align: center;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--md-sys-color-on-background);
    font-weight: 700;
}

.footer-links {
    display: flex;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
    justify-content: center;
}

.footer-links a {
    color: var(--md-sys-color-on-surface-variant);
    font-size: 14px;
    transition: color 0.2s;
}

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

/* Animations */
.fade-in-section {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
    will-change: opacity, visibility;
}

.fade-in-section.is-visible {
    opacity: 1;
    transform: none;
}

/* Buttons */
.btn-google-play {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    background-color: var(--md-sys-color-primary);
    color: var(--md-sys-color-on-primary);
    padding: 8px 24px;
    border-radius: var(--radius-full);
    transition: transform 0.2s, box-shadow 0.2s;
    width: fit-content;
}

.btn-google-play:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(208, 188, 255, 0.3);
}

.btn-text {
    display: flex;
    flex-direction: column;
    line-height: 1.2;
}

.btn-text .caption {
    font-size: 10px;
    text-transform: uppercase;
    font-weight: 500;
}

.btn-text .title {
    font-size: 18px;
    font-weight: 600;
}

/* Phone Mockup */
.hero-visual {
    display: flex;
    justify-content: center;
    perspective: 1000px;
}

.phone-mockup {
    width: 300px;
    height: 600px;
    background: var(--md-sys-color-surface-variant);
    border-radius: 40px;
    border: 8px solid var(--md-sys-color-outline);
    position: relative;
    transform: rotateY(-15deg) rotateX(5deg);
    box-shadow: 20px 20px 60px rgba(0, 0, 0, 0.5);
    overflow: hidden;
}

.screen {
    width: 100%;
    height: 100%;
    background: var(--md-sys-color-background);
    border-radius: 32px;
    overflow: hidden;
    position: relative;
}

/* UI Placeholder */
.app-ui-placeholder {
    padding: 20px;
    height: 100%;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.ui-display {
    font-size: 48px;
    text-align: right;
    margin-top: 60px;
    color: var(--md-sys-color-on-background);
}

.ui-keypad {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
    margin-top: auto;
}

.key {
    aspect-ratio: 1;
    background: var(--md-sys-color-surface-variant);
    border-radius: 50%;
}

.key:nth-child(4n) {
    background: var(--md-sys-color-primary-container);
}

/* Responsive */
@media (max-width: 768px) {
    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-content {
        align-items: center;
    }

    .hero-visual {
        margin-top: var(--spacing-xl);
    }

    .phone-mockup {
        transform: none;
    }
}