/* ===================================
   NeurHelios Landing Page Styles
   =================================== */

/* CSS Custom Properties */
:root {
    /* Colors */
    --color-primary: #1a365d;
    --color-primary-light: #2c5282;
    --color-accent: #00d4aa;
    --color-accent-dark: #00b894;
    --color-text: #2d3748;
    --color-text-light: #718096;
    --color-background: #ffffff;
    --color-background-alt: #f7fafc;
    --color-background-dark: #1a202c;
    --color-border: #e2e8f0;

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-base: 16px;
    --line-height-base: 1.6;

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

    /* Layout */
    --container-max: 1200px;
    --navbar-height: 80px;

    /* Effects */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.15);
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --border-radius: 8px;
    --border-radius-lg: 16px;
}

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

html {
    scroll-behavior: smooth;
    font-size: var(--font-size-base);
}

body {
    font-family: var(--font-family);
    line-height: var(--line-height-base);
    color: var(--color-text);
    background-color: var(--color-background);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--color-primary);
}

h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.75rem, 4vw, 2.5rem); }
h3 { font-size: clamp(1.25rem, 3vw, 1.5rem); }
h4 { font-size: 1.125rem; }

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

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

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

/* Section Titles */
.section-title {
    text-align: center;
    margin-bottom: var(--spacing-sm);
}

.section-subtitle {
    text-align: center;
    color: var(--color-text-light);
    max-width: 700px;
    margin: 0 auto var(--spacing-xl);
    font-size: 1.125rem;
}

/* ===================================
   Navigation
   =================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--navbar-height);
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
    z-index: 1000;
    transition: all var(--transition-base);
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    text-decoration: none;
}

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

.logo-neur {
    color: var(--color-primary);
}

.logo-helios {
    color: var(--color-accent);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    list-style: none;
}

.nav-links a {
    color: var(--color-text);
    font-weight: 500;
    font-size: 0.9375rem;
    transition: color var(--transition-fast);
}

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

.nav-cta {
    background: var(--color-accent);
    color: var(--color-primary) !important;
    padding: 0.5rem 1.25rem;
    border-radius: var(--border-radius);
}

.nav-cta:hover {
    background: var(--color-accent-dark);
    color: var(--color-primary) !important;
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.mobile-menu-btn span {
    width: 24px;
    height: 2px;
    background: var(--color-primary);
    transition: all var(--transition-fast);
}

/* ===================================
   Hero Section (Performance + Building)
   =================================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: var(--navbar-height);
    overflow: hidden;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    overflow: hidden;
}

.particles {
    position: absolute;
    width: 100%;
    height: 100%;
    background-image:
        radial-gradient(circle at 20% 30%, rgba(0, 212, 170, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(0, 212, 170, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 50% 50%, rgba(255, 255, 255, 0.05) 0%, transparent 70%);
}

.hero .container {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: var(--spacing-2xl) var(--spacing-md);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-3xl);
}

/* Performance Section in Hero */
.hero-performance {
    flex: 1;
}

.hero-title {
    color: #ffffff;
    margin-bottom: var(--spacing-sm);
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.hero-title .highlight {
    color: var(--color-accent);
}

.hero-context {
    color: rgba(255, 255, 255, 0.8);
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xl);
}

/* Chart in Hero */
.hero .results-chart {
    max-width: 800px;
    margin: 0 auto;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-lg);
}

.chart-container {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.chart-row {
    display: grid;
    grid-template-columns: 180px 1fr 70px;
    align-items: center;
    gap: var(--spacing-md);
}

.chart-label {
    font-weight: 500;
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.9);
    text-align: left;
}

.chart-bar-container {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 4px;
    height: 36px;
    position: relative;
    overflow: hidden;
}

.chart-bar {
    height: 100%;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding-right: var(--spacing-sm);
    width: 0;
    transition: width 1.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.chart-bar.animated {
    width: var(--bar-width, 0%);
}

.chart-bar.baseline {
    background: rgba(255, 255, 255, 0.4);
}

.chart-bar.rule-based {
    background: rgba(255, 255, 255, 0.5);
}

.chart-bar.mpc {
    background: rgba(255, 255, 255, 0.6);
}

.chart-bar.neurhelios {
    background: linear-gradient(90deg, var(--color-accent), var(--color-accent-dark));
}

.chart-bar.optimum {
    background: rgba(255, 255, 255, 0.9);
}

.chart-value {
    color: var(--color-primary);
    font-weight: 600;
    font-size: 0.8125rem;
    white-space: nowrap;
}

.chart-bar.baseline .chart-value,
.chart-bar.rule-based .chart-value,
.chart-bar.mpc .chart-value {
    color: var(--color-primary);
}

.chart-percent {
    font-weight: 600;
    color: rgba(255, 255, 255, 0.7);
    text-align: right;
    font-size: 0.875rem;
}

.chart-percent.highlight {
    color: var(--color-accent);
    font-size: 1rem;
}

.highlight-row {
    background: rgba(0, 212, 170, 0.15);
    padding: var(--spacing-xs) var(--spacing-sm);
    margin: 0 calc(-1 * var(--spacing-sm));
    border-radius: var(--border-radius);
}

.highlight-row .chart-label {
    color: var(--color-accent);
    font-weight: 600;
}

/* Building a Company */
.building-company {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.building-label {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1.125rem;
    font-weight: 500;
    margin-bottom: var(--spacing-sm);
}

.building-progress {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 100px;
    height: 12px;
    overflow: hidden;
    margin-bottom: var(--spacing-sm);
}

.building-progress-bar {
    width: 0;
    height: 100%;
    background: linear-gradient(90deg, var(--color-accent), var(--color-accent-dark));
    border-radius: 100px;
    transition: width 2s cubic-bezier(0.4, 0, 0.2, 1);
}

.building-progress-bar.animated {
    width: 80%;
}

.building-status {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: rgba(255, 255, 255, 0.8);
    font-size: 1rem;
    font-family: 'Courier New', monospace;
}

.building-word {
    display: inline;
}

.building-dots {
    display: inline;
    width: 1.5em;
    text-align: left;
}

/* ===================================
   What We Do Section
   =================================== */
.what-we-do {
    padding: var(--spacing-3xl) 0;
    background: var(--color-background);
}

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

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

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-accent);
}

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-md);
    color: var(--color-accent);
}

.feature-icon svg {
    width: 100%;
    height: 100%;
}

.feature-card h3 {
    margin-bottom: var(--spacing-sm);
}

.feature-card p {
    color: var(--color-text-light);
    margin-bottom: 0;
}

/* Staggered animations */
.feature-card.fade-in:nth-child(2) { transition-delay: 0.1s; }
.feature-card.fade-in:nth-child(3) { transition-delay: 0.2s; }

/* ===================================
   Research Section
   =================================== */
.research {
    padding: var(--spacing-3xl) 0;
    background: var(--color-background-alt);
}

.publications {
    max-width: 900px;
    margin: 0 auto;
}

.publication-year {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
    margin-top: var(--spacing-xl);
    padding-bottom: var(--spacing-xs);
    border-bottom: 2px solid var(--color-accent);
    display: inline-block;
}

.publication-year:first-child {
    margin-top: 0;
}

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

.publication-card {
    display: block;
    background: var(--color-background);
    border-radius: var(--border-radius);
    padding: var(--spacing-md);
    border: 1px solid var(--color-border);
    transition: all var(--transition-base);
    text-decoration: none;
}

.publication-card:hover {
    transform: translateX(8px);
    border-color: var(--color-accent);
    box-shadow: var(--shadow-md);
}

.publication-card h4 {
    color: var(--color-text);
    margin-bottom: var(--spacing-xs);
    font-weight: 500;
    line-height: 1.4;
}

.publication-card:hover h4 {
    color: var(--color-primary);
}

.publication-venue {
    color: var(--color-accent);
    font-size: 0.875rem;
    font-weight: 600;
}

/* ===================================
   Contact Section (Combined)
   =================================== */
.contact {
    padding: var(--spacing-3xl) 0;
    background: var(--color-background);
}

.contact .section-title {
    color: var(--color-primary);
}

.contact .section-subtitle {
    color: var(--color-text-light);
}

.team-grid {
    display: flex;
    justify-content: center;
    gap: var(--spacing-3xl);
    margin-bottom: var(--spacing-xl);
    flex-wrap: wrap;
}

.team-member {
    text-align: center;
}

.team-photo {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--spacing-md);
    box-shadow: var(--shadow-lg);
    transition: transform var(--transition-base);
}

.team-member:hover .team-photo {
    transform: scale(1.05);
}

.team-initials {
    color: white;
    font-size: 2.5rem;
    font-weight: 700;
}

.team-member h3 {
    margin-bottom: var(--spacing-xs);
}

.team-role {
    color: var(--color-accent);
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
}

.team-email {
    color: var(--color-text-light);
    font-size: 0.9375rem;
    display: block;
    transition: color var(--transition-fast);
}

.team-email:hover {
    color: var(--color-accent);
}

.team-quote {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
    font-size: 1.125rem;
    font-style: italic;
    color: var(--color-text-light);
    padding: var(--spacing-lg);
    border-left: 4px solid var(--color-accent);
    background: var(--color-background-alt);
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
}

/* ===================================
   Footer
   =================================== */
.footer {
    background: var(--color-background-dark);
    color: rgba(255, 255, 255, 0.8);
    padding: var(--spacing-xl) 0;
}

.footer-content {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.footer-logo {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.footer-logo .logo-neur {
    color: white;
}

.footer-tagline {
    font-size: 0.875rem;
    margin-bottom: 0;
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    font-size: 0.875rem;
    margin-bottom: 0;
}

/* ===================================
   Animations
   =================================== */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ===================================
   Responsive Design
   =================================== */

/* Tablet */
@media (max-width: 1024px) {
    .chart-row {
        grid-template-columns: 150px 1fr 60px;
    }
}

/* Mobile */
@media (max-width: 768px) {
    :root {
        --navbar-height: 70px;
    }

    .nav-links {
        position: fixed;
        top: var(--navbar-height);
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: var(--spacing-lg);
        gap: var(--spacing-md);
        box-shadow: var(--shadow-lg);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-base);
    }

    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

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

    .mobile-menu-btn.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .mobile-menu-btn.active span:nth-child(2) {
        opacity: 0;
    }

    .mobile-menu-btn.active span:nth-child(3) {
        transform: rotate(-45deg) translate(5px, -5px);
    }

    .hero {
        min-height: auto;
        padding: calc(var(--navbar-height) + var(--spacing-xl)) 0 var(--spacing-xl);
    }

    .hero .container {
        gap: var(--spacing-2xl);
    }

    .hero-title {
        font-size: 1.75rem;
    }

    .hero-context {
        font-size: 1rem;
    }

    .hero .results-chart {
        padding: var(--spacing-md);
    }

    .chart-row {
        grid-template-columns: 1fr;
        gap: var(--spacing-xs);
    }

    .chart-label {
        font-size: 0.8125rem;
        text-align: center;
    }

    .chart-percent {
        text-align: center;
        font-size: 0.8125rem;
    }

    .highlight-row {
        margin: 0;
        padding: var(--spacing-sm);
    }

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

    .team-grid {
        gap: var(--spacing-xl);
    }

    .team-photo {
        width: 120px;
        height: 120px;
    }

    .team-initials {
        font-size: 2rem;
    }

    .building-company {
        max-width: 100%;
    }

    .building-status {
        font-size: 0.875rem;
    }

    .building-word {
        min-width: 110px;
    }
}

/* Small mobile */
@media (max-width: 480px) {
    .hero-title {
        font-size: 1.5rem;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .publication-card {
        padding: var(--spacing-sm);
    }

    .publication-card h4 {
        font-size: 1rem;
    }
}