/* Susan Gao - Professional CEO Website Styles */

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

:root {
    --primary-color: #4F46E5;
    --primary-dark: #4338CA;
    --secondary-color: #7C3AED;
    --text-dark: #1F2937;
    --text-gray: #6B7280;
    --bg-light: #F9FAFB;
    --white: #FFFFFF;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.7;
    color: var(--text-dark);
    background: var(--bg-light);
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Header */
header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

header.scrolled {
    box-shadow: var(--shadow-md);
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1.25rem 2rem;
}

nav h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    letter-spacing: -0.5px;
}

nav a {
    color: var(--text-gray);
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    padding: 0.5rem;
    border-radius: 8px;
}

nav a:hover {
    color: var(--primary-color);
    background: rgba(79, 70, 229, 0.1);
    transform: translateY(-2px);
}

/* Hero Section */
.hero {
    position: relative;
    min-height: 85vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    overflow: hidden;
    padding: 4rem 2rem;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg"><defs><pattern id="grid" width="100" height="100" patternUnits="userSpaceOnUse"><path d="M 100 0 L 0 0 0 100" fill="none" stroke="rgba(255,255,255,0.05)" stroke-width="1"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 900px;
    margin: 0 auto;
    animation: fadeInUp 0.8s ease-out;
}

.profile-img {
    width: 220px;
    height: 220px;
    border-radius: 50%;
    object-fit: cover;
    border: 5px solid rgba(255, 255, 255, 0.95);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    margin: 0 auto 2.5rem;
    transition: transform 0.3s ease;
    animation: fadeInScale 1s ease-out;
}

.profile-img:hover {
    transform: scale(1.05);
}

.hero h2 {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    letter-spacing: -1px;
    text-shadow: 0 2px 20px rgba(0, 0, 0, 0.2);
    line-height: 1.2;
}

.hero .title {
    font-size: 1.75rem;
    font-weight: 500;
    margin-bottom: 1.5rem;
    opacity: 0.95;
    letter-spacing: 0.5px;
}

.hero .subtitle {
    font-size: 1.25rem;
    line-height: 1.8;
    opacity: 0.9;
    max-width: 700px;
    margin: 0 auto;
    font-weight: 300;
}

/* Main Content */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

section {
    padding: 5rem 0;
}

.section-title {
    font-size: 2.75rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3.5rem;
    color: var(--text-dark);
    letter-spacing: -1px;
}

/* Cards */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 4rem;
}

.card {
    background: var(--white);
    padding: 2.5rem;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    border-top: 4px solid var(--primary-color);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.card:hover::before {
    transform: scaleX(1);
}

.card h4 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.card .role {
    font-size: 1.1rem;
    color: var(--text-gray);
    margin-bottom: 1rem;
    font-weight: 500;
}

.card p {
    color: var(--text-gray);
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

.card a {
    color: var(--primary-color);
    font-weight: 600;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.3s ease;
}

.card a:hover {
    color: var(--primary-dark);
    gap: 0.75rem;
}

.card a::after {
    content: '→';
    transition: transform 0.3s ease;
}

.card a:hover::after {
    transform: translateX(4px);
}

/* About Section */
.about-card {
    background: var(--white);
    padding: 3.5rem;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
    margin-bottom: 3rem;
}

.about-card h3 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 2rem;
    color: var(--text-dark);
    letter-spacing: -0.5px;
}

.about-card p {
    font-size: 1.125rem;
    line-height: 1.9;
    color: var(--text-gray);
    margin-bottom: 1.5rem;
}

/* Contact Section */
.contact-card {
    background: linear-gradient(135deg, rgba(79, 70, 229, 0.05) 0%, rgba(124, 58, 237, 0.05) 100%);
    padding: 3.5rem;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
    border: 1px solid rgba(79, 70, 229, 0.1);
}

.contact-card h3 {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 2.5rem;
    color: var(--text-dark);
}

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

.contact-item p {
    color: var(--text-gray);
    margin-bottom: 0.75rem;
    font-size: 0.95rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 600;
    font-size: 0.875rem;
}

.contact-item a {
    color: var(--primary-color);
    font-size: 1.25rem;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
    display: inline-block;
}

.contact-item a:hover {
    color: var(--primary-dark);
    transform: translateY(-2px);
}

/* Footer */
footer {
    background: #1F2937;
    color: #9CA3AF;
    text-align: center;
    padding: 3rem 2rem;
    margin-top: 4rem;
}

footer p {
    margin-bottom: 1rem;
    font-size: 0.95rem;
}

footer .links {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1.5rem;
    flex-wrap: wrap;
}

footer a {
    color: #D1D5DB;
    text-decoration: none;
    transition: all 0.3s ease;
    font-weight: 500;
}

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

footer .separator {
    color: #4B5563;
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInScale {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.fade-in {
    animation: fadeInUp 0.6s ease-out;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero {
        min-height: 75vh;
        padding: 3rem 1.5rem;
    }

    .hero h2 {
        font-size: 2.5rem;
    }

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

    .hero .subtitle {
        font-size: 1.1rem;
    }

    .profile-img {
        width: 180px;
        height: 180px;
    }

    .section-title {
        font-size: 2.25rem;
    }

    .card-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .card {
        padding: 2rem;
    }

    .about-card {
        padding: 2rem;
    }

    .contact-card {
        padding: 2rem;
    }

    nav {
        padding: 1rem 1.5rem;
    }

    nav h1 {
        font-size: 1.25rem;
    }
}

@media (max-width: 480px) {
    .hero h2 {
        font-size: 2rem;
    }

    .section-title {
        font-size: 1.875rem;
    }

    .card h4 {
        font-size: 1.25rem;
    }
}

/* Smooth transitions for all interactive elements */
a, button, .card {
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Focus states for accessibility */
a:focus-visible,
button:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
    border-radius: 4px;
}