/* ==========================================
   MERIDIAN LANDING PAGE
   Professional Cognitive Training Platform
   ========================================== */

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

:root {
    /* Color System - Soft Palette */
    --color-primary: #7c9cbf;
    --color-primary-dark: #5a7a9c;
    --color-primary-light: #a4c4e0;
    --color-secondary: #b8a99d;
    --color-accent: #90c9b3;
    --color-warm: #d4b5a0;
    --color-cool: #9db5c8;
    --color-sage: #a8c5b0;
    --color-mauve: #c4b0bf;
    --color-sand: #d9c7b8;

    /* Neutrals */
    --color-dark: #2a3442;
    --color-dark-mid: #3d4a5a;
    --color-dark-light: #566272;
    --color-gray: #7a8899;
    --color-gray-light: #c5cdd8;
    --color-white: #ffffff;
    --color-off-white: #f8fafb;

    /* Gradients - Each section gets unique soft gradient */
    --gradient-hero: linear-gradient(135deg, #3d4a5a 0%, #566272 25%, #7c9cbf 50%, #a4c4e0 100%);
    --gradient-value: linear-gradient(135deg, #566272 0%, #7c9cbf 50%, #90c9b3 100%);
    --gradient-method: linear-gradient(135deg, #3d4a5a 0%, #7a8899 50%, #b8a99d 100%);
    --gradient-features: linear-gradient(135deg, #566272 0%, #9db5c8 50%, #a8c5b0 100%);
    --gradient-science: linear-gradient(135deg, #3d4a5a 0%, #7c9cbf 50%, #c4b0bf 100%);
    --gradient-cases: linear-gradient(135deg, #566272 0%, #90c9b3 50%, #d4b5a0 100%);
    --gradient-cta: linear-gradient(135deg, #7c9cbf 0%, #a4c4e0 50%, #90c9b3 100%);
    --gradient-accent: linear-gradient(135deg, #7c9cbf 0%, #a4c4e0 100%);

    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    --font-serif: 'Georgia', 'Times New Roman', serif;

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

    /* Layout */
    --container-width: 1200px;
    --section-padding: 100px;
    --border-radius: 12px;
    --border-radius-lg: 16px;

    /* Transitions */
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

body {
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.7;
    color: var(--color-white);
    background: var(--color-dark);
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-serif);
    font-weight: 600;
    line-height: 1.3;
    letter-spacing: -0.02em;
    color: var(--color-white);
}

h1 { font-size: clamp(2.25rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.875rem, 4vw, 2.75rem); }
h3 { font-size: clamp(1.375rem, 3vw, 1.75rem); }
h4 { font-size: clamp(1.125rem, 2vw, 1.375rem); }

p {
    margin-bottom: var(--space-md);
}

a {
    color: var(--color-primary-light);
    text-decoration: none;
    transition: color var(--transition-base);
}

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

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

/* ==========================================
   NAVIGATION
   ========================================== */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(15, 23, 42, 0.9);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    padding: 1rem 0;
    transition: background var(--transition-base);
}

.nav-container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.nav-logo {
    width: 32px;
    height: 32px;
}

.nav-title {
    font-family: var(--font-serif);
    font-size: 1.375rem;
    font-weight: 600;
    color: var(--color-white);
}

.nav-cta {
    padding: 0.625rem 1.5rem;
    background: var(--gradient-accent);
    color: var(--color-white);
    border-radius: 6px;
    font-weight: 500;
    font-size: 0.9375rem;
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.nav-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(124, 156, 191, 0.4);
    color: var(--color-white);
}

/* ==========================================
   HERO SECTION
   ========================================== */

.hero {
    min-height: 100vh;
    padding: 140px 0 100px;
    background: var(--gradient-hero);
    background-size: 200% 200%;
    animation: gradientFlow 20s ease infinite;
    position: relative;
    display: flex;
    align-items: center;
    overflow: hidden;
}

@keyframes gradientFlow {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image:
        radial-gradient(circle at 20% 30%, rgba(164, 196, 224, 0.2) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(144, 201, 179, 0.15) 0%, transparent 50%);
    pointer-events: none;
}

.hero-container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 2rem;
    width: 100%;
}

.hero-content {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    align-items: center;
    gap: 4rem;
    position: relative;
    z-index: 1;
}

.hero-text {
    max-width: 640px;
}

.hero-text h1 {
    margin-bottom: var(--space-lg);
    text-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.hero-lead {
    font-size: clamp(1.0625rem, 2vw, 1.25rem);
    line-height: 1.7;
    color: rgba(255, 255, 255, 0.92);
    margin-bottom: var(--space-xl);
    font-weight: 300;
}

.hero-stats {
    display: flex;
    gap: 2rem;
    margin-bottom: var(--space-xl);
    padding: var(--space-lg) 0;
    border-top: 1px solid rgba(255, 255, 255, 0.15);
    border-bottom: 1px solid rgba(255, 255, 255, 0.15);
}

.stat-item {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.stat-item strong {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-white);
}

.stat-item span {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.75);
}

.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    overflow: visible;
}

.hero-image {
    width: 140%;
    max-width: none;
    height: auto;
    transform: scale(1.2);
    filter: drop-shadow(0 25px 50px rgba(0, 0, 0, 0.5));
}

.btn-primary {
    display: inline-block;
    transition: transform var(--transition-base);
}

.btn-primary:hover {
    transform: translateY(-3px);
}

.app-store-badge {
    height: 56px;
    width: auto;
}

/* ==========================================
   SECTION CONTAINERS
   ========================================== */

.section-container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 2rem;
}

.section-header {
    text-align: center;
    max-width: 800px;
    margin: 0 auto var(--space-3xl);
}

.section-subtitle {
    font-size: clamp(1rem, 2vw, 1.2rem);
    color: rgba(255, 255, 255, 0.8);
    margin-top: var(--space-md);
    font-weight: 300;
}

/* ==========================================
   VALUE PROPOSITION SECTION
   ========================================== */

.value-prop {
    padding: var(--section-padding) 0;
    background: var(--gradient-value);
    background-size: 200% 200%;
    animation: gradientFlow 25s ease infinite;
    position: relative;
}

.value-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.value-card {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--border-radius-lg);
    padding: var(--space-xl);
    transition: all var(--transition-base);
}

.value-card:hover {
    background: rgba(255, 255, 255, 0.06);
    border-color: rgba(144, 201, 179, 0.4);
    transform: translateY(-4px);
}

.value-card h3 {
    margin-bottom: var(--space-md);
    color: var(--color-primary-light);
    font-size: 1.375rem;
}

.value-card p {
    color: rgba(255, 255, 255, 0.85);
    line-height: 1.75;
    margin-bottom: 0;
}

/* ==========================================
   METHOD SECTION
   ========================================== */

.method {
    padding: var(--section-padding) 0;
    background: var(--gradient-method);
    background-size: 200% 200%;
    animation: gradientFlow 30s ease infinite;
}

.method-content {
    display: grid;
    grid-template-columns: 0.9fr 1.1fr;
    gap: 5rem;
    align-items: center;
}

.method-visual {
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    overflow: visible;
}

.method-image {
    width: 140%;
    max-width: none;
    height: auto;
    transform: scale(1.2);
    filter: drop-shadow(0 20px 40px rgba(0, 0, 0, 0.4));
}

.method-text h2 {
    margin-bottom: var(--space-lg);
}

.method-intro {
    font-size: 1.125rem;
    color: rgba(255, 255, 255, 0.85);
    margin-bottom: var(--space-2xl);
    line-height: 1.7;
}

.method-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-xl);
}

.method-item {
    display: flex;
    gap: var(--space-lg);
    align-items: flex-start;
}

.method-number {
    font-family: var(--font-serif);
    font-size: 2rem;
    font-weight: 600;
    color: var(--color-primary-light);
    min-width: 60px;
    opacity: 0.7;
}

.method-details h3 {
    margin-bottom: var(--space-sm);
    font-size: 1.25rem;
}

.method-details p {
    color: rgba(255, 255, 255, 0.82);
    line-height: 1.7;
    margin-bottom: 0;
}

/* ==========================================
   FEATURES SECTION
   ========================================== */

.features {
    padding: var(--section-padding) 0;
    background: var(--gradient-features);
    background-size: 200% 200%;
    animation: gradientFlow 28s ease infinite;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--border-radius);
    padding: var(--space-xl);
    transition: all var(--transition-base);
}

.feature-card:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(168, 197, 176, 0.4);
}

.feature-card h3 {
    margin-bottom: var(--space-md);
    font-size: 1.25rem;
    color: var(--color-white);
}

.feature-card p {
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.7;
    margin-bottom: 0;
    font-size: 0.9375rem;
}

/* ==========================================
   SCIENCE SECTION
   ========================================== */

.science {
    padding: var(--section-padding) 0;
    background: var(--gradient-science);
    background-size: 200% 200%;
    animation: gradientFlow 32s ease infinite;
}

.science-content {
    max-width: 1000px;
    margin: 0 auto;
    text-align: center;
}

.science-content h2 {
    margin-bottom: var(--space-lg);
}

.science-intro {
    font-size: 1.125rem;
    color: rgba(255, 255, 255, 0.85);
    margin-bottom: var(--space-2xl);
}

.science-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 2rem;
    text-align: left;
}

.science-point {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--border-radius);
    padding: var(--space-lg);
}

.science-point h4 {
    margin-bottom: var(--space-sm);
    color: var(--color-accent);
}

.science-point p {
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.7;
    margin-bottom: 0;
    font-size: 0.9375rem;
}

/* ==========================================
   USE CASES SECTION
   ========================================== */

.use-cases {
    padding: var(--section-padding) 0;
    background: var(--gradient-cases);
    background-size: 200% 200%;
    animation: gradientFlow 26s ease infinite;
}

.use-cases h2 {
    text-align: center;
    margin-bottom: var(--space-3xl);
}

.cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.case-card {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius);
    padding: var(--space-xl);
    transition: all var(--transition-base);
}

.case-card:hover {
    background: rgba(255, 255, 255, 0.06);
    transform: translateY(-3px);
}

.case-card h3 {
    margin-bottom: var(--space-md);
    font-size: 1.25rem;
}

.case-card p {
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.7;
    margin-bottom: 0;
}

/* ==========================================
   CTA SECTION
   ========================================== */

.cta {
    padding: calc(var(--section-padding) * 1.2) 0;
    background: var(--gradient-cta);
    background-size: 200% 200%;
    animation: gradientFlow 22s ease infinite;
    position: relative;
    overflow: hidden;
}

.cta::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 30% 50%, rgba(255, 255, 255, 0.08) 0%, transparent 50%);
    pointer-events: none;
}

.cta-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 2rem;
}

.cta-content {
    text-align: center;
    position: relative;
    z-index: 1;
}

.cta-content h2 {
    margin-bottom: var(--space-lg);
}

.cta-content p {
    font-size: 1.2rem;
    color: rgba(255, 255, 255, 0.95);
    margin-bottom: var(--space-xl);
}

.cta-footnote {
    margin-top: var(--space-lg);
    font-size: 0.9375rem;
    color: rgba(255, 255, 255, 0.85);
    margin-bottom: 0;
}

/* ==========================================
   FOOTER
   ========================================== */

.footer {
    background: var(--color-dark);
    padding: var(--space-2xl) 0;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 2rem;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--space-xl);
}

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

.footer-logo {
    width: 48px;
    height: 48px;
}

.footer-tagline {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.9375rem;
    margin: 0;
}

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

.footer-info p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.9375rem;
    margin-bottom: var(--space-sm);
}

.footer-copy {
    margin-bottom: 0;
}

.footer a {
    color: var(--color-primary-light);
}

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

/* ==========================================
   RESPONSIVE DESIGN
   ========================================== */

@media (max-width: 1024px) {
    :root {
        --section-padding: 80px;
    }

    .hero-content {
        gap: 3rem;
    }

    .method-content {
        gap: 3rem;
    }

    .value-grid,
    .features-grid,
    .cases-grid {
        grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: 60px;
    }

    .nav-container {
        padding: 0 1.5rem;
    }

    .nav-cta {
        padding: 0.5rem 1.25rem;
        font-size: 0.875rem;
    }

    .hero {
        min-height: auto;
        padding: 120px 0 60px;
    }

    .hero-container {
        padding: 0 1.5rem;
    }

    .hero-content {
        grid-template-columns: 1fr;
        gap: 2.5rem;
        text-align: center;
    }

    .hero-text {
        max-width: 100%;
    }

    .hero-stats {
        justify-content: center;
        gap: 1.5rem;
        flex-wrap: wrap;
    }

    .hero-visual {
        order: -1;
    }

    .hero-image {
        width: 120%;
        transform: scale(1.1);
    }

    .section-container {
        padding: 0 1.5rem;
    }

    .method-content {
        grid-template-columns: 1fr;
        gap: 2.5rem;
        text-align: center;
    }

    .method-visual {
        order: -1;
    }

    .method-image {
        width: 120%;
        transform: scale(1.1);
    }

    .method-item {
        flex-direction: column;
        text-align: left;
        gap: var(--space-md);
    }

    .method-number {
        min-width: auto;
    }

    .value-grid,
    .features-grid,
    .science-grid,
    .cases-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

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

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

@media (max-width: 480px) {
    :root {
        --section-padding: 50px;
    }

    .nav-container {
        padding: 0 1rem;
    }

    .nav-title {
        font-size: 1.125rem;
    }

    .nav-logo {
        width: 28px;
        height: 28px;
    }

    .hero {
        padding: 100px 0 50px;
    }

    .hero-container,
    .section-container {
        padding: 0 1rem;
    }

    .hero-stats {
        gap: 1rem;
    }

    .stat-item strong {
        font-size: 1.125rem;
    }

    .stat-item span {
        font-size: 0.8125rem;
    }

    .hero-image {
        width: 110%;
        transform: scale(1.05);
    }

    .method-image {
        width: 110%;
        transform: scale(1.05);
    }

    .app-store-badge {
        height: 50px;
    }

    .value-card,
    .feature-card,
    .case-card {
        padding: var(--space-lg);
    }
}

/* ==========================================
   ACCESSIBILITY & PERFORMANCE
   ========================================== */

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus styles for keyboard navigation */
a:focus-visible,
button:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}