/* CSS Variables */
:root {
    --color-bg: #0a0a0f;
    --color-surface: #151520;
    --color-text: #e0e0e8;
    --color-text-muted: #a0a0b0;
    --color-accent-start: #00d4aa;
    --color-accent-end: #ff6b9d;
    --color-border: #2a2a35;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 3rem;
    --spacing-xl: 4rem;
    --border-radius: 12px;
    --transition: 0.2s ease;
}

@media (prefers-color-scheme: light) {
    :root {
        --color-bg: #fafafa;
        --color-surface: #ffffff;
        --color-text: #1a1a1f;
        --color-text-muted: #606070;
        --color-border: #e0e0e8;
    }
}

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

html {
    scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100vh;
}

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

/* Header */
.header {
    position: sticky;
    top: 0;
    background-color: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    z-index: 100;
    backdrop-filter: blur(10px);
    background-color: rgba(21, 21, 32, 0.9);
}

@media (prefers-color-scheme: light) {
    .header {
        background-color: rgba(255, 255, 255, 0.9);
    }
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-sm) var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    text-decoration: none;
    color: var(--color-text);
    font-weight: 600;
    font-size: 1.25rem;
    transition: opacity var(--transition);
}

.logo-link:hover,
.logo-link:focus-visible {
    opacity: 0.8;
    outline: 2px solid var(--color-accent-start);
    outline-offset: 4px;
    border-radius: 4px;
}

.logo-img {
    width: 32px;
    height: 32px;
    display: block;
}

.logo-text {
    background: linear-gradient(135deg, var(--color-accent-start), var(--color-accent-end));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.nav-link {
    color: var(--color-text-muted);
    text-decoration: none;
    font-size: 0.95rem;
    transition: color var(--transition);
    position: relative;
}

.nav-link:hover,
.nav-link:focus-visible {
    color: var(--color-text);
    outline: 2px solid var(--color-accent-start);
    outline-offset: 4px;
    border-radius: 4px;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--color-accent-start), var(--color-accent-end));
    transition: width var(--transition);
}

.nav-link:hover::after,
.nav-link:focus-visible::after {
    width: 100%;
}

/* Hero */
.hero {
    position: relative;
    min-height: 80vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xl) var(--spacing-md);
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, var(--color-accent-start), var(--color-accent-end));
    opacity: 0.1;
    animation: gradient-shift 8s ease infinite;
    z-index: -1;
}

@keyframes gradient-shift {
    0%, 100% {
        background: linear-gradient(135deg, var(--color-accent-start), var(--color-accent-end));
    }
    50% {
        background: linear-gradient(225deg, var(--color-accent-end), var(--color-accent-start));
    }
}

.hero-container {
    max-width: 800px;
    text-align: center;
    z-index: 1;
}

.hero-badge {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-sm);
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 20px;
    font-size: 0.85rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-md);
}

.hero-title {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    line-height: 1.2;
    background: linear-gradient(135deg, var(--color-accent-start), var(--color-accent-end));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: clamp(1.1rem, 2vw, 1.5rem);
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-lg);
}

.hero-cta {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    flex-wrap: wrap;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    transition: transform var(--transition), box-shadow var(--transition);
    border: none;
    cursor: pointer;
    font-family: inherit;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-accent-start), var(--color-accent-end));
    color: white;
}

.btn-primary:hover,
.btn-primary:focus-visible {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(0, 212, 170, 0.3);
    outline: 2px solid var(--color-accent-start);
    outline-offset: 2px;
}

.btn-secondary {
    background-color: var(--color-surface);
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

.btn-secondary:hover,
.btn-secondary:focus-visible {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    outline: 2px solid var(--color-accent-start);
    outline-offset: 2px;
}

.btn-card {
    width: 100%;
    margin-top: var(--spacing-sm);
}

.btn-google-play {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0.5rem;
    color: #fff;
}

.btn-google-play .google-play-icon {
    width: 200px;
    height: 70px;
    display: block;
}

.btn-disabled {
    opacity: 0.5;
    cursor: not-allowed;
    background-color: var(--color-surface);
    color: var(--color-text-muted);
    border: 1px solid var(--color-border);
}

.btn-disabled:hover {
    transform: none;
    box-shadow: none;
}

/* Sections */
section {
    padding: var(--spacing-xl) 0;
}

.section-title {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    margin-bottom: var(--spacing-lg);
    text-align: center;
}

/* Projects */
.projects {
    background-color: var(--color-surface);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
    max-width: 500px;
    margin: 0 auto;
}

.project-card {
    background-color: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: var(--spacing-md);
    position: relative;
    transition: transform var(--transition), box-shadow var(--transition);
}

@media (prefers-reduced-motion: no-preference) {
    .project-card:hover {
        transform: translateY(-4px);
        box-shadow: 0 8px 24px rgba(0, 212, 170, 0.15);
    }
}

.project-card-featured {
    border-color: var(--color-accent-start);
    border-width: 2px;
}

.card-ribbon {
    position: absolute;
    top: 0;
    right: 0;
    background: linear-gradient(135deg, var(--color-accent-start), var(--color-accent-end));
    color: white;
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 0 var(--border-radius) 0 var(--border-radius);
    clip-path: polygon(0 0, 100% 0, 100% 100%, 0 85%);
}

.project-badge {
    display: inline-block;
    padding: 4px var(--spacing-xs);
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 6px;
    font-size: 0.75rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-sm);
}

.project-title {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
}

.project-description {
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.card-note {
    font-size: 0.85rem;
    color: var(--color-text-muted);
    margin-top: var(--spacing-xs);
    font-style: italic;
}

/* About */
.about {
    background-color: var(--color-bg);
}

.about-text {
    max-width: 700px;
    margin: 0 auto var(--spacing-md);
    text-align: center;
    color: var(--color-text-muted);
    font-size: 1.1rem;
}

.values-list {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-md);
    max-width: 700px;
    margin: 0 auto;
}

.values-list li {
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    color: var(--color-text);
}

/* Footer */
.footer {
    background-color: var(--color-bg);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-md) 0;
}

.footer .container {
    display: flex;
    justify-content: center;
    align-items: center;
}

.footer-copyright {
    color: var(--color-text-muted);
    font-size: 0.9rem;
    text-align: center;
}

.footer-links {
    display: flex;
    gap: var(--spacing-md);
}

.footer-link {
    color: var(--color-text-muted);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color var(--transition);
}

.footer-link:hover,
.footer-link:focus-visible {
    color: var(--color-text);
    outline: 2px solid var(--color-accent-start);
    outline-offset: 4px;
    border-radius: 4px;
}

/* Responsive */
@media (max-width: 768px) {
    .header-container {
        flex-direction: column;
        gap: var(--spacing-sm);
    }

    .nav {
        justify-content: center;
    }

    .hero {
        min-height: 60vh;
    }

    .hero-cta {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }

    .projects-grid {
        grid-template-columns: 1fr;
    }

    .footer .container {
        flex-direction: column;
        text-align: center;
    }
}