/* ========================================
   CSS Custom Properties (Design Tokens)
   ======================================== */

:root {
    /* Color Palette (from SPEC.md) */
    --color-dark: #07070F;
    --color-cyan: #00D9FF;
    --color-purple: #A855F7;
    --color-white: #FFFFFF;
    --color-gray: #9CA3AF;

    /* Spacing Scale */
    --spacing-xs: 0.5rem;    /* 8px */
    --spacing-sm: 1rem;      /* 16px */
    --spacing-md: 1.5rem;    /* 24px */
    --spacing-lg: 2rem;      /* 32px */
    --spacing-xl: 3rem;      /* 48px */
    --spacing-2xl: 4rem;     /* 64px */
    --spacing-3xl: 6rem;     /* 96px */

    /* Typography Scale */
    --font-size-xs: 0.875rem;   /* 14px */
    --font-size-sm: 1rem;       /* 16px */
    --font-size-md: 1.125rem;   /* 18px */
    --font-size-lg: 1.25rem;    /* 20px */
    --font-size-xl: 1.5rem;     /* 24px */
    --font-size-2xl: 2rem;      /* 32px */
    --font-size-3xl: 2.5rem;    /* 40px */
    --font-size-4xl: 3rem;      /* 48px */
    --font-size-5xl: 4rem;      /* 64px */

    /* Font Weights */
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    --font-weight-black: 900;

    /* Font Families */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, 'Courier New', monospace;

    /* Border Radius */
    --radius-sm: 0.25rem;   /* 4px */
    --radius-md: 0.5rem;    /* 8px */
    --radius-lg: 1rem;      /* 16px */
    --radius-xl: 1.5rem;    /* 24px */
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;

    /* Container */
    --container-max-width: 1200px;
    --container-padding: var(--spacing-md);
}

/* ========================================
   Base Styles
   ======================================== */

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-normal);
    line-height: 1.6;
    color: var(--color-white);
    background-color: var(--color-dark);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Loading state - prevent flash of unstyled content */
body.loading {
    opacity: 0;
    transition: opacity 0.3s ease-in;
}

body.loaded {
    opacity: 1;
}

/* ========================================
   Typography
   ======================================== */

h1, h2, h3, h4, h5, h6 {
    font-weight: var(--font-weight-bold);
    line-height: 1.2;
    color: var(--color-white);
}

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

h2 {
    font-size: var(--font-size-3xl);
    font-weight: var(--font-weight-bold);
}

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

p {
    color: var(--color-gray);
    margin-bottom: var(--spacing-sm);
}

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

a:hover {
    color: var(--color-purple);
}

a:focus {
    outline: 2px solid var(--color-cyan);
    outline-offset: 2px;
}

/* Remove default focus outline for mouse users, keep for keyboard */
a:focus:not(:focus-visible) {
    outline: none;
}

a:focus-visible {
    outline: 2px solid var(--color-cyan);
    outline-offset: 2px;
}

/* ========================================
   Layout Utilities
   ======================================== */

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

/* ========================================
   Accessibility
   ======================================== */

/* Skip to content link for keyboard navigation */
.skip-to-content {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--color-cyan);
    color: var(--color-dark);
    padding: var(--spacing-xs) var(--spacing-md);
    font-weight: var(--font-weight-bold);
    z-index: 100;
    transition: top var(--transition-fast);
}

.skip-to-content:focus {
    top: 0;
}

/* ========================================
   Animations
   ======================================== */

/* Fade-in animation for scroll-triggered elements */
.fade-in-element {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in-element.fade-in-visible {
    opacity: 1;
    transform: translateY(0);
}

/* ========================================
   Section Styles
   ======================================== */

section {
    padding: var(--spacing-3xl) 0;
}

.section-title {
    text-align: center;
    margin-bottom: var(--spacing-lg);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.section-description {
    text-align: center;
    max-width: 600px;
    margin: 0 auto var(--spacing-xl) auto;
    font-size: var(--font-size-md);
}

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

.hero-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xl) 0;
    position: relative;
    overflow: hidden;
}

.hero-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-2xl);
    align-items: center;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

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

.app-icon {
    width: 300px;
    height: 300px;
    border-radius: var(--radius-xl);
    box-shadow:
        0 0 60px rgba(0, 217, 255, 0.3),
        0 0 120px rgba(168, 85, 247, 0.2);
    animation: pulse-glow 3s ease-in-out infinite;
    transition: transform var(--transition-base);
}

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

@keyframes pulse-glow {
    0%, 100% {
        box-shadow:
            0 0 60px rgba(0, 217, 255, 0.3),
            0 0 120px rgba(168, 85, 247, 0.2);
    }
    50% {
        box-shadow:
            0 0 80px rgba(0, 217, 255, 0.5),
            0 0 160px rgba(168, 85, 247, 0.3);
    }
}

.hero-text {
    max-width: 600px;
}

.hero-title {
    margin-bottom: var(--spacing-sm);
    background: linear-gradient(135deg, var(--color-cyan), var(--color-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.hero-tagline {
    font-size: var(--font-size-2xl);
    font-weight: var(--font-weight-bold);
    color: var(--color-purple);
    margin-bottom: var(--spacing-md);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.hero-description {
    font-size: var(--font-size-lg);
    color: var(--color-gray);
    margin-bottom: var(--spacing-xl);
    line-height: 1.8;
}

/* ========================================
   CTA Buttons
   ======================================== */

.cta-buttons {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--radius-md);
    font-weight: var(--font-weight-semibold);
    font-size: var(--font-size-md);
    transition: all var(--transition-base);
    cursor: pointer;
    border: 2px solid transparent;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.btn-primary {
    background: var(--color-cyan);
    color: var(--color-dark);
}

.btn-primary:hover {
    background: transparent;
    border-color: var(--color-cyan);
    color: var(--color-cyan);
    transform: scale(1.05);
    box-shadow: 0 0 20px rgba(0, 217, 255, 0.4);
}

.btn-secondary {
    background: transparent;
    border-color: var(--color-purple);
    color: var(--color-purple);
}

.btn-secondary:hover {
    background: var(--color-purple);
    color: var(--color-white);
    transform: scale(1.05);
    box-shadow: 0 0 20px rgba(168, 85, 247, 0.4);
}

.btn:active {
    transform: scale(0.98);
}

.btn:focus {
    outline: 2px solid var(--color-cyan);
    outline-offset: 4px;
}

.btn:focus:not(:focus-visible) {
    outline: none;
}

.btn:focus-visible {
    outline: 2px solid var(--color-cyan);
    outline-offset: 4px;
}

/* ========================================
   About/Features Section
   ======================================== */

.about-section {
    background: rgba(255, 255, 255, 0.02);
}

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

.feature-item {
    text-align: center;
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    background: rgba(255, 255, 255, 0.03);
    transition: all var(--transition-base);
}

.feature-item:hover {
    background: rgba(0, 217, 255, 0.1);
    transform: translateY(-4px);
}

.feature-icon {
    font-size: var(--font-size-3xl);
    color: var(--color-cyan);
    margin-bottom: var(--spacing-sm);
}

.feature-title {
    margin-bottom: var(--spacing-xs);
    color: var(--color-white);
}

.feature-description {
    font-size: var(--font-size-sm);
    margin-bottom: 0;
}

/* ========================================
   How to Play Section
   ======================================== */

.instructions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-lg);
}

.instruction-item {
    text-align: center;
    padding: var(--spacing-lg);
}

.instruction-number {
    width: 64px;
    height: 64px;
    margin: 0 auto var(--spacing-md) auto;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-2xl);
    font-weight: var(--font-weight-bold);
    border-radius: var(--radius-full);
    background: linear-gradient(135deg, var(--color-cyan), var(--color-purple));
    color: var(--color-white);
}

.instruction-title {
    margin-bottom: var(--spacing-xs);
    color: var(--color-white);
}

.instruction-description {
    font-size: var(--font-size-sm);
    margin-bottom: 0;
}

/* ========================================
   Gallery Section
   ======================================== */

.gallery-section {
    background: rgba(255, 255, 255, 0.02);
}

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

.screenshot-item {
    position: relative;
    overflow: hidden;
    border-radius: var(--radius-lg);
    background: rgba(255, 255, 255, 0.05);
    transition: transform var(--transition-base);
}

.screenshot-item:hover {
    transform: translateY(-8px);
}

.screenshot-image {
    width: 100%;
    height: auto;
    display: block;
    border-radius: var(--radius-lg);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    transition: all var(--transition-base);
}

.screenshot-item:hover .screenshot-image {
    box-shadow:
        0 8px 30px rgba(0, 217, 255, 0.3),
        0 4px 20px rgba(168, 85, 247, 0.2);
}

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

.footer-section {
    padding: var(--spacing-2xl) 0;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

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

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

.footer-links a {
    font-weight: var(--font-weight-medium);
}

.footer-contact {
    margin-bottom: var(--spacing-md);
}

.footer-attribution {
    margin-bottom: var(--spacing-md);
    font-style: italic;
    color: var(--color-gray);
}

.footer-attribution p {
    margin-bottom: 0;
}

.footer-copyright {
    font-size: var(--font-size-xs);
    color: var(--color-gray);
}

.footer-copyright p {
    margin-bottom: 0;
}