:root {
    --deep-dark: #FFFFFF;
    --surface-dark: #F9FAFB;
    --neo-blue: #1D4ED8;
    --cyan-glow: #0EA5E9;
    --text-primary: #111827;
    --text-secondary: #4B5563;
    --glass-bg: rgba(0, 0, 0, 0.02);
    --glass-border: rgba(0, 0, 0, 0.08);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background-color: var(--deep-dark);
    color: var(--text-primary);
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    overflow-x: hidden;
}

h1, h2, h3, .logo {
    font-family: 'Outfit', sans-serif;
}

/* Navbar */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 5%;
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--glass-border);
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: -1px;
}

.logo span {
    color: var(--neo-blue);
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-secondary);
    transition: 0.3s;
    font-weight: 500;
}

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

.btn-join {
    background: transparent;
    border: 1px solid var(--neo-blue);
    color: var(--neo-blue);
    padding: 0.6rem 1.5rem;
    border-radius: 50px;
    cursor: pointer;
    transition: 0.3s;
}

.btn-join:hover {
    background: var(--neo-blue);
    color: white;
    box-shadow: 0 0 15px var(--neo-blue);
}

.mobile-only {
    display: none !important;
}

.desktop-only {
    display: inline-block !important;
}

/* Hamburger Menu Toggle */
.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 24px;
    height: 18px;
    background: transparent;
    border: none;
    cursor: pointer;
    z-index: 1001;
}

.menu-toggle .bar {
    height: 2px;
    width: 100%;
    background-color: var(--text-primary);
    border-radius: 2px;
    transition: all 0.3s cubic-bezier(0.645, 0.045, 0.355, 1);
}

/* Hero Section */
.hero {
    height: 100vh;
    height: 100dvh;
    position: relative;
    overflow: hidden;
    display: flex;
    align-items: center;
    padding: 0 10%;
    background: radial-gradient(circle at 70% 30%, rgba(29, 78, 216, 0.06), transparent 50%);
}

.hero-content h1 {
    font-size: 4rem;
    line-height: 1.1;
    margin-bottom: 1.5rem;
}

.hero-content h1 span {
    color: var(--neo-blue);
    text-shadow: 0 0 30px rgba(45, 91, 255, 0.5);
}

.hero-content p {
    font-size: 1.2rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin-bottom: 2rem;
}

.hero-btns {
    display: flex;
    gap: 1rem;
}

.btn-primary {
    background: var(--neo-blue);
    color: white;
    border: none;
    padding: 1rem 2.5rem;
    border-radius: 8px;
    font-weight: 700;
    cursor: pointer;
    transition: 0.3s;
    box-shadow: 0 4px 15px rgba(45, 91, 255, 0.4);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(45, 91, 255, 0.6);
}

.btn-secondary {
    background: var(--surface-dark);
    color: white;
    border: 1px solid var(--glass-border);
    padding: 1rem 2.5rem;
    border-radius: 8px;
    font-weight: 700;
    cursor: pointer;
    transition: 0.3s;
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
}

/* Glow Sphere */
.glow-sphere {
    width: 300px;
    height: 300px;
    background: var(--neo-blue);
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.12;
    position: absolute;
    right: 15%;
    top: 25%;
    animation: pulse 5s infinite alternate;
}

@keyframes pulse {
    from { scale: 1; opacity: 0.2; }
    to { scale: 1.2; opacity: 0.4; }
}

/* Values Grid */
.values {
    padding: 8rem 10%;
    text-align: center;
}

.values h2 {
    font-size: 2.5rem;
    margin-bottom: 4rem;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    padding: 3rem 2rem;
    border-radius: 20px;
    backdrop-filter: blur(5px);
    transition: 0.4s;
}

.card:hover {
    border-color: var(--neo-blue);
    transform: translateY(-10px);
    background: rgba(45, 91, 255, 0.05);
}

.card .icon {
    font-size: 3rem;
    margin-bottom: 1.5rem;
}

.card h3 {
    margin-bottom: 1rem;
}

.card p {
    color: var(--text-secondary);
}

.footer {
    padding: 3rem;
    text-align: center;
    border-top: 1px solid var(--glass-border);
    color: var(--text-secondary);
}

/* Responsive Design (Mobile & Tablet) */
@media (max-width: 768px) {
    .desktop-only {
        display: none !important;
    }

    .mobile-only {
        display: block !important;
    }

    /* Navbar Mobile Styles */
    .navbar {
        padding: 1rem max(1rem, 5%);
    }

    .logo {
        font-size: 1.3rem;
    }

    .menu-toggle {
        display: flex;
    }

    /* Hamburger Active Animations */
    .menu-toggle.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .menu-toggle.active .bar:nth-child(2) {
        opacity: 0;
        transform: translateX(-20px);
    }

    .menu-toggle.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    .nav-links {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100vh;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        display: flex;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 2.5rem;
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        pointer-events: none;
        transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.3s ease, visibility 0.3s ease;
        z-index: 999;
        padding: 2rem;
        margin: 0;
    }

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

    .nav-links a {
        font-size: 1.5rem;
        font-weight: 600;
        color: var(--text-primary);
    }

    .mobile-join {
        display: inline-block !important;
        margin-top: 1rem;
        font-size: 1.1rem;
        padding: 0.8rem 2.5rem;
    }

    /* Hero Section Mobile Styles */
    .hero {
        min-height: 100vh !important;
        min-height: 100svh !important;
        min-height: 100dvh !important;
        height: auto !important;
        padding: calc(88px + env(safe-area-inset-top)) 6% max(48px, calc(40px + env(safe-area-inset-bottom))) !important;
        flex-direction: column;
        justify-content: center;
        text-align: center;
        position: relative;
        overflow: hidden;
        background: radial-gradient(circle at 50% 30%, rgba(45, 91, 255, 0.12), transparent 50%);
    }

    .hero-content {
        width: 100%;
        display: flex;
        flex-direction: column;
        align-items: center;
        z-index: 2;
    }

    .hero-content h1 {
        font-size: clamp(2.2rem, 8vw, 3.2rem);
        line-height: 1.2;
        margin-bottom: 1.2rem;
    }

    .hero-content p {
        font-size: clamp(0.95rem, 4vw, 1.1rem);
        margin-bottom: 2rem;
        max-width: 100%;
        word-break: keep-all;
        overflow-wrap: normal;
    }

    .hero-btns {
        flex-direction: column;
        width: 100%;
        gap: 1rem;
        max-width: 320px;
    }

    .btn-primary, .btn-secondary {
        width: 100%;
        padding: 0.8rem 2rem;
        font-size: 1rem;
        text-align: center;
    }

    /* Hero Visual Container Absolute Layer */
    .hero-visual {
        position: absolute;
        inset: 0;
        width: 100%;
        height: 100%;
        overflow: hidden;
        pointer-events: none;
        z-index: 1;
    }

    /* Centered Background Glow on Mobile */
    .glow-sphere {
        width: min(240px, 72vw);
        height: min(240px, 72vw);
        position: absolute;
        left: 50%;
        top: 46%;
        right: auto;
        translate: -50% -50%;
        transform: none;
        filter: blur(60px);
        opacity: 0.25;
        z-index: -1;
    }

    /* Values Section Mobile Styles */
    .values {
        padding: 5rem 6%;
    }

    .values h2 {
        font-size: 2rem;
        margin-bottom: 2.5rem;
    }

    .grid {
        gap: 1.5rem;
        grid-template-columns: minmax(0, 1fr);
    }

    .card {
        width: 100%;
        min-width: 0;
        padding: 2.5rem 1.5rem;
    }
}

/* Extra-small phones and narrow embedded views */
@media (max-width: 480px) {
    .hero {
        padding-inline: 5% !important;
    }

    .hero-content h1 {
        font-size: clamp(2rem, 10.5vw, 2.6rem);
        line-height: 1.15;
        margin-bottom: 1rem;
    }

    .hero-content p {
        font-size: 0.95rem;
        line-height: 1.5;
        margin-bottom: 1.5rem;
    }

    .hero-btns {
        gap: 0.8rem;
        max-width: 300px;
    }

    .btn-primary, .btn-secondary {
        padding: 0.75rem 1.5rem;
    }
}

/* Short mobile viewports: avoid clipping behind browser UI/address bars */
@media (max-width: 768px) and (max-height: 560px) {
    .hero {
        min-height: auto !important;
        padding-top: calc(78px + env(safe-area-inset-top)) !important;
        padding-bottom: max(32px, calc(28px + env(safe-area-inset-bottom))) !important;
        justify-content: flex-start;
        overflow: visible;
    }

    .hero-content h1 {
        font-size: clamp(1.85rem, 9vw, 2.35rem);
        margin-bottom: 0.75rem;
    }

    .hero-content p {
        margin-bottom: 1.1rem;
    }

    .hero-btns {
        gap: 0.7rem;
    }

    .glow-sphere {
        top: 50%;
        filter: blur(52px);
    }
}

/* PhD Stats Section styling */
.stats-section {
    padding: 6rem 10%;
    background-color: var(--deep-dark);
    border-top: 1px solid var(--glass-border);
}

.stats-container {
    max-width: 1200px;
    margin: 0 auto;
    text-align: left;
}

.stats-container h2 {
    font-size: 2.5rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-weight: 800;
}

.stats-subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 3.5rem;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
    margin-bottom: 4rem;
}

.stats-card {
    background: var(--surface-dark);
    border: 1px solid var(--glass-border);
    padding: 2.2rem;
    border-radius: 12px;
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
    transition: 0.3s;
}

.stats-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.03);
}

.highlight-card {
    border: 2px solid var(--neo-blue);
    background: rgba(29, 78, 216, 0.02);
}

.card-badge {
    align-self: flex-start;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    color: var(--text-secondary);
    background: var(--glass-border);
    padding: 0.3rem 0.8rem;
    border-radius: 50px;
}

.highlight-badge {
    color: white;
    background: var(--neo-blue);
}

.stats-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

.card-stat {
    font-size: 1.6rem;
    font-weight: 800;
    color: var(--neo-blue);
}

.card-stat span {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.card-desc {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* Regression Table Styles */
.table-container {
    background: var(--surface-dark);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    padding: 2.5rem;
    margin-top: 2rem;
}

.table-container h3 {
    font-size: 1.4rem;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    font-weight: 700;
}

.table-scroll {
    overflow-x: auto;
    margin-bottom: 1rem;
}

.stats-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.95rem;
    text-align: left;
}

.stats-table th, .stats-table td {
    padding: 1rem;
    border-bottom: 1px solid var(--glass-border);
}

.stats-table th {
    font-weight: 700;
    color: var(--text-primary);
    background: var(--glass-bg);
}

.stats-table td {
    color: var(--text-secondary);
}

.stats-table .var-name {
    font-weight: 600;
    color: var(--text-primary);
}

.highlight-cell {
    background: rgba(29, 78, 216, 0.03);
    color: var(--text-primary) !important;
}

.summary-row {
    background: var(--glass-bg);
}

.summary-row td {
    font-weight: 700;
}

.table-note {
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
}

@media (max-width: 768px) {
    .stats-section {
        padding: 4rem 6%;
    }
    
    .stats-container h2 {
        font-size: 2rem;
    }
    
    .table-container {
        padding: 1.5rem;
    }
}