/* ===== CSS Variables ===== */
:root {
    /* Colors */
    --color-primary: #2563eb;
    --color-primary-dark: #1d4ed8;
    --color-primary-light: #3b82f6;

    --color-bg: #ffffff;
    --color-bg-alt: #f8fafc;
    --color-bg-dark: #0f172a;

    --color-text: #1e293b;
    --color-text-muted: #64748b;
    --color-text-light: #94a3b8;
    --color-text-inverse: #ffffff;

    --color-border: #e2e8f0;
    --color-border-light: #f1f5f9;

    --color-success: #10b981;
    --color-error: #ef4444;

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    --font-size-5xl: 3rem;
    --font-size-6xl: 3.75rem;

    /* Spacing */
    --spacing-1: 0.25rem;
    --spacing-2: 0.5rem;
    --spacing-3: 0.75rem;
    --spacing-4: 1rem;
    --spacing-5: 1.25rem;
    --spacing-6: 1.5rem;
    --spacing-8: 2rem;
    --spacing-10: 2.5rem;
    --spacing-12: 3rem;
    --spacing-16: 4rem;
    --spacing-20: 5rem;
    --spacing-24: 6rem;

    /* Layout */
    --container-max: 1200px;
    --container-padding: var(--spacing-6);

    /* Borders */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;
}

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

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
}

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

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

ul {
    list-style: none;
}

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

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

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-2);
    font-weight: 500;
    border-radius: var(--radius-lg);
    transition: all var(--transition-base);
    white-space: nowrap;
}

.btn-sm {
    padding: var(--spacing-2) var(--spacing-4);
    font-size: var(--font-size-sm);
}

.btn-md {
    padding: var(--spacing-3) var(--spacing-5);
    font-size: var(--font-size-base);
}

.btn-lg {
    padding: var(--spacing-4) var(--spacing-6);
    font-size: var(--font-size-base);
}

.btn-primary {
    background: var(--color-primary);
    color: var(--color-text-inverse);
}

.btn-primary:hover {
    background: var(--color-primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

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

.btn-secondary:hover {
    background: var(--color-bg-alt);
    border-color: var(--color-text-muted);
}

/* ===== Header & Navigation ===== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border-light);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
}

.logo-icon {
    width: 36px;
    height: 36px;
}

.logo-text {
    font-size: var(--font-size-xl);
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--color-text);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--spacing-8);
}

.nav-links a {
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--color-text-muted);
    transition: color var(--transition-fast);
}

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

.nav-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-4);
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: var(--spacing-2);
}

.mobile-menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text);
    transition: all var(--transition-fast);
}

/* ===== Hero Section ===== */
.hero {
    padding-top: calc(72px + var(--spacing-16));
    padding-bottom: var(--spacing-16);
    background: linear-gradient(180deg, var(--color-bg-alt) 0%, var(--color-bg) 100%);
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-16);
    align-items: center;
}

.hero-badge {
    display: inline-block;
    padding: var(--spacing-2) var(--spacing-4);
    background: var(--color-primary);
    color: var(--color-text-inverse);
    font-size: var(--font-size-xs);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border-radius: var(--radius-full);
    margin-bottom: var(--spacing-6);
}

.hero-title {
    font-size: var(--font-size-5xl);
    font-weight: 700;
    line-height: 1.1;
    letter-spacing: -0.02em;
    margin-bottom: var(--spacing-6);
}

.gradient-text {
    background: linear-gradient(135deg, var(--color-primary) 0%, #7c3aed 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-description {
    font-size: var(--font-size-lg);
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-8);
    max-width: 540px;
}

.hero-actions {
    display: flex;
    gap: var(--spacing-4);
    margin-bottom: var(--spacing-10);
}

.hero-stats {
    display: flex;
    gap: var(--spacing-10);
}

.stat {
    display: flex;
    flex-direction: column;
}

.stat-value {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-text);
}

.stat-label {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}

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

.hero-image-container {
    width: 100%;
    aspect-ratio: 16 / 10;
    background: var(--color-bg-dark);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-xl);
}

.hero-screenshot {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-base);
}

.screenshot-link {
    display: block;
    width: 100%;
    height: 100%;
    cursor: zoom-in;
}

.screenshot-link:hover .hero-screenshot {
    transform: scale(1.02);
}

/* ===== Lightbox ===== */
.lightbox {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.9);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-8);
    cursor: zoom-out;
}

.lightbox.active {
    display: flex;
}

.lightbox img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
}

.lightbox-close {
    position: absolute;
    top: var(--spacing-6);
    right: var(--spacing-6);
    width: 48px;
    height: 48px;
    background: rgba(255, 255, 255, 0.1);
    color: white;
    font-size: 32px;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: background var(--transition-fast);
}

.lightbox-close:hover {
    background: rgba(255, 255, 255, 0.2);
}

/* ===== Section Styles ===== */
.section-header {
    text-align: center;
    max-width: 640px;
    margin: 0 auto var(--spacing-12);
}

.section-title {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: var(--spacing-4);
}

.section-description {
    font-size: var(--font-size-lg);
    color: var(--color-text-muted);
}

/* ===== Features Section ===== */
.features {
    padding: var(--spacing-24) 0;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-8);
}

.feature-card {
    padding: var(--spacing-8);
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    transition: all var(--transition-base);
}

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

.feature-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    background: var(--color-bg-alt);
    border-radius: var(--radius-lg);
    color: var(--color-primary);
    margin-bottom: var(--spacing-5);
}

.feature-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: var(--spacing-3);
}

.feature-description {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    line-height: 1.7;
}

/* ===== Why ODIN Section ===== */
.why-odin {
    padding: var(--spacing-24) 0;
    background: var(--color-bg-alt);
}

.why-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-16);
    align-items: start;
}

.why-content .section-title {
    text-align: left;
    margin-bottom: var(--spacing-4);
}

.why-intro {
    font-size: var(--font-size-lg);
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-8);
}

.why-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-5);
}

.why-list li {
    display: flex;
    gap: var(--spacing-4);
}

.why-item-icon {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    background: var(--color-success);
    color: white;
    border-radius: var(--radius-full);
}

.why-item-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-1);
}

.why-item-content strong {
    font-weight: 600;
}

.why-item-content span {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}

.why-visual {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-6);
}

.comparison-card {
    padding: var(--spacing-6);
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
}

.comparison-highlight {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.comparison-header {
    font-weight: 600;
    margin-bottom: var(--spacing-4);
    padding-bottom: var(--spacing-4);
    border-bottom: 1px solid var(--color-border);
}

.comparison-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-3);
}

.comparison-list li {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
    font-size: var(--font-size-sm);
}

.comparison-list li::before {
    content: '';
    width: 8px;
    height: 8px;
    border-radius: var(--radius-full);
}

.comparison-negative li::before {
    background: var(--color-error);
}

.comparison-positive li::before {
    background: var(--color-success);
}

/* ===== Download Section ===== */
.download {
    padding: var(--spacing-24) 0;
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-6);
    margin-bottom: var(--spacing-8);
}

.download-card {
    display: flex;
    align-items: center;
    gap: var(--spacing-5);
    padding: var(--spacing-6);
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    transition: all var(--transition-base);
}

.download-card:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-md);
}

.download-content {
    flex: 1;
}

.download-content h3 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: var(--spacing-1);
}

.download-content p {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}

.download-arrow {
    color: var(--color-text-light);
    transition: all var(--transition-fast);
}

.download-card:hover .download-arrow {
    color: var(--color-primary);
    transform: translateX(4px);
}

.download-note {
    text-align: center;
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}

.download-note a {
    color: var(--color-primary);
    font-weight: 500;
}

.download-note a:hover {
    text-decoration: underline;
}

/* ===== Community Section ===== */
.community {
    padding: var(--spacing-24) 0;
    background: var(--color-bg-dark);
    color: var(--color-text-inverse);
}

.community-content {
    text-align: center;
    max-width: 640px;
    margin: 0 auto;
}

.community .section-title {
    color: var(--color-text-inverse);
}

.community .section-description {
    color: var(--color-text-light);
    margin-bottom: var(--spacing-10);
}

.community-links {
    display: flex;
    justify-content: center;
    gap: var(--spacing-6);
}

.community-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
    padding: var(--spacing-4) var(--spacing-6);
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    font-weight: 500;
    transition: all var(--transition-base);
}

.community-link:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

/* ===== Footer ===== */
.footer {
    padding: var(--spacing-16) 0 var(--spacing-8);
    background: var(--color-bg-alt);
    border-top: 1px solid var(--color-border);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 3fr;
    gap: var(--spacing-12);
    margin-bottom: var(--spacing-12);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
    margin-bottom: var(--spacing-3);
}

.footer-brand .logo-text {
    margin-bottom: 0;
}

.footer-brand p {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    max-width: 280px;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-8);
}

.footer-column h4 {
    font-size: var(--font-size-sm);
    font-weight: 600;
    margin-bottom: var(--spacing-4);
}

.footer-column ul {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-3);
}

.footer-column a {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    padding-top: var(--spacing-8);
    border-top: 1px solid var(--color-border);
    text-align: center;
}

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

.footer-bottom a {
    color: var(--color-text-muted);
    transition: color var(--transition-fast);
}

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

/* ===== Responsive Design ===== */
@media (max-width: 1024px) {
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-description {
        margin-left: auto;
        margin-right: auto;
    }

    .hero-actions {
        justify-content: center;
    }

    .hero-stats {
        justify-content: center;
    }

    .hero-visual {
        order: -1;
        max-width: 600px;
        margin: 0 auto;
    }

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

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

    .why-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-10);
    }

    .why-content .section-title {
        text-align: center;
    }

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

    .why-visual {
        flex-direction: row;
    }

    .comparison-card {
        flex: 1;
    }
}

@media (max-width: 768px) {
    :root {
        --container-padding: var(--spacing-4);
    }

    .nav-links {
        display: none;
    }

    .mobile-menu-toggle {
        display: flex;
    }

    .nav-actions .btn {
        display: none;
    }

    .hero {
        padding-top: calc(72px + var(--spacing-10));
        padding-bottom: var(--spacing-10);
    }

    .hero-title {
        font-size: var(--font-size-4xl);
    }

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

    .hero-stats {
        flex-wrap: wrap;
        gap: var(--spacing-6);
    }

    .section-title {
        font-size: var(--font-size-3xl);
    }

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

    .feature-card {
        padding: var(--spacing-6);
    }

    .why-visual {
        flex-direction: column;
    }

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

    .community-links {
        flex-direction: column;
        align-items: center;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .footer-brand {
        margin-bottom: var(--spacing-8);
    }

    .footer-logo {
        justify-content: center;
    }

    .footer-brand p {
        margin: 0 auto;
    }

    .footer-links {
        grid-template-columns: 1fr;
        gap: var(--spacing-6);
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: var(--font-size-3xl);
    }

    .hero-badge {
        font-size: 0.65rem;
    }

    .stat-value {
        font-size: var(--font-size-xl);
    }
}

/* ===== Mobile Menu (JavaScript controlled) ===== */
.nav-links.active {
    display: flex;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--color-bg);
    padding: var(--spacing-6);
    border-bottom: 1px solid var(--color-border);
    gap: var(--spacing-4);
}

/* ===== Utilities ===== */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}