:root {
    --bg-color: #f8fafc;
    --surface-color: #ffffff;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --accent-color: #2563eb;
    --accent-hover: #1d4ed8;
    --border-color: #e2e8f0;
    --font-main: 'Inter', sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

section {
    scroll-margin-top: 80px;
}

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

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

ul {
    list-style: none;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Typography */
h1,
h2,
h3,
h4 {
    color: var(--text-primary);
    line-height: 1.2;
    margin-bottom: 1rem;
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
}

h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
    text-align: center;
}

h3 {
    font-size: 1.25rem;
    font-weight: 600;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 6px;
    font-weight: 600;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background-color: var(--accent-color);
    color: white;
    box-shadow: 0 4px 6px rgba(234, 88, 12, 0.2);
}

.btn-primary:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(234, 88, 12, 0.3);
}

.btn-primary:active {
    transform: translateY(0);
}

/* Header */
header {
    padding: 20px 0;
    background-color: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
}

/* Mobile Menu */
.menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 10px;
    z-index: 101;
}

.hamburger {
    display: block;
    width: 25px;
    height: 3px;
    background-color: var(--text-primary);
    position: relative;
    transition: all 0.3s ease;
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    width: 25px;
    height: 3px;
    background-color: var(--text-primary);
    transition: all 0.3s ease;
    left: 0;
}

.hamburger::before {
    transform: translateY(-8px);
}

.hamburger::after {
    transform: translateY(8px);
}

.menu-toggle.active .hamburger {
    background-color: transparent;
}

.menu-toggle.active .hamburger::before {
    transform: rotate(45deg);
}

.menu-toggle.active .hamburger::after {
    transform: rotate(-45deg);
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.5px;
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 30px;
    align-items: center;
}

.nav-links a:not(.btn-nav) {
    position: relative;
    font-weight: 500;
    color: var(--text-secondary);
    transition: all 0.3s ease;
    cursor: pointer;
}

.nav-links a:not(.btn-nav)::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -4px;
    left: 0;
    background-color: var(--accent-color);
    transition: width 0.3s ease;
    opacity: 0;
}

.nav-links a:not(.btn-nav):hover {
    color: var(--text-primary);
}

.nav-links a:not(.btn-nav):hover::after {
    width: 100%;
    opacity: 1;
}

.btn-nav {
    background-color: var(--accent-color);
    color: white;
    padding: 8px 16px;
    border-radius: 4px;
    font-size: 0.9rem;
}

.btn-nav:hover {
    background-color: var(--accent-hover);
}

#hero {
    padding: 100px 0 80px;
    text-align: left;
    background-color: var(--bg-color);
    background-image: radial-gradient(circle at 70% 30%, rgba(37, 99, 235, 0.05) 0%, transparent 40%);
    color: var(--text-primary);
    position: relative;
    overflow: hidden;
}

#hero h1 {
    font-size: 3.5rem;
    letter-spacing: -0.03em;
    line-height: 1.1;
    background: linear-gradient(to right, #0f172a, #475569);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 1.5rem;
}

#hero p {
    color: var(--text-secondary);
}

.hero-layout {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 60px;
}

.hero-content {
    flex: 1;
    max-width: 650px;
}

.subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
    font-weight: 400;
}

/* Problems Section */
/* Problems Section */
#problems {
    padding: 80px 0;
    background-color: var(--surface-color);
    /* White background */
    border-top: 1px solid var(--border-color);
}

.problem-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-bottom: 2rem;
}

.problem-item {
    padding: 30px;
    border: none;
    background-color: #f1f5f9;
    /* Slate 100 */
    border-radius: 50px;
    /* Circular/Pill look */
    display: flex;
    align-items: center;
    /* Center vertically */
    gap: 20px;
    transition: all 0.3s ease;
    box-shadow: none;
}

.problem-item:hover {
    transform: translateY(-5px);
    background-color: #e2e8f0;
    /* Slate 200 on hover */
    box-shadow: none;
}

.problem-icon {
    width: 60px;
    height: 60px;
    background-color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.problem-icon svg {
    width: 28px;
    height: 28px;
    stroke: var(--accent-color);
    transition: all 0.3s ease;
}

.problem-item:hover .problem-icon svg {
    transform: scale(1.1);
}

.problem-content {
    flex: 1;
}

.problem-item h3 {
    margin-bottom: 0.5rem;
    font-size: 1.25rem;
    color: var(--text-primary);
}

.problem-item p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.target-audience {
    text-align: center;
    font-weight: 500;
    color: var(--text-secondary);
    margin-top: 3rem;
}

/* Services Section */
#services {
    padding: 60px 0;
    background-color: var(--bg-color);
    color: var(--text-primary);
    border-top: 1px solid var(--border-color);
}

#services h2 {
    color: var(--text-primary);
}

.service-category {
    margin-bottom: 80px;
}

.category-title {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 30px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 15px;
    text-align: center;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
}

.category-icon {
    color: var(--accent-color);
    width: 24px;
    height: 24px;
    flex-shrink: 0;
}

.service-grid {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 40px;
    /* Increased gap for clarity */
}

.service-card {
    background-color: var(--surface-color);
    padding: 40px;
    /* Increased padding for breathing room */
    border-radius: 12px;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    flex: 1 1 300px;
    max-width: 400px;
    width: 100%;
}

.service-card:hover {
    transform: translateY(-5px);
    border-color: var(--accent-color);
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

.service-card h4 {
    color: #1e3a8a;
    margin-bottom: 1rem;
    font-size: 1.25rem;
    /* Larger heading */
    font-weight: 600;
    letter-spacing: -0.02em;
}

.service-card p {
    color: var(--text-secondary);
    font-size: 1.05rem;
    /* Larger body text */
    line-height: 1.7;
}

/* About Section */
#about {
    padding: 60px 0;
    text-align: center;
    background-color: var(--bg-color);
    border-top: 1px solid var(--border-color);
}

#about .container {
    max-width: 1000px;
    margin: 0 auto;
}

.about-layout {
    display: flex;
    align-items: flex-start;
    justify-content: center;
    gap: 60px;
    text-align: left;
}

.about-photo {
    width: 280px;
    height: auto;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    box-shadow: 0 20px 40px -20px rgba(0, 0, 0, 0.5);
    object-fit: cover;
    flex-shrink: 0;
}

.about-text {
    flex: 1;
    color: var(--text-secondary);
}

.about-text strong {
    color: var(--text-primary);
}

.profile-photo {
    width: 320px;
    height: 320px;
    border-radius: 50%;
    object-fit: cover;
    border: 1px solid var(--border-color);
    box-shadow: 0 20px 40px -20px rgba(0, 0, 0, 0.5);
    margin-bottom: 0;
    flex-shrink: 0;
    transition: all 0.5s ease;
}

.profile-photo:hover {
    transform: scale(1.02);
}

/* Speaking Section */
#speaking {
    padding: 100px 0;
    background-color: var(--surface-color);
    color: var(--text-primary);
    border-top: 1px solid var(--border-color);
}

.talks-list {
    max-width: 800px;
    margin: 0 auto;
}

.talks-list li {
    margin-bottom: 15px;
    padding-bottom: 15px;
    border-bottom: 1px solid var(--border-color);
}

/* Contact Section */
#contact {
    padding: 60px 0;
    text-align: center;
    background-color: var(--surface-color);
    border-top: 1px solid var(--border-color);
    color: var(--text-primary);
}

#contact h2 {
    color: var(--text-primary);
    margin-bottom: 2rem;
}

.contact-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
    margin-top: 3rem;
}

.contact-btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 28px;
    background-color: var(--accent-color);
    color: white;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 500;
    transition: all 0.3s ease;
    border: none;
}

.contact-btn:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 10px 20px -10px rgba(37, 99, 235, 0.3);
    color: white;
}

/* Footer */
footer {
    padding: 40px 0;
    text-align: center;
    background-color: var(--bg-color);
    color: var(--text-secondary);
    font-size: 0.9rem;
    border-top: 1px solid var(--border-color);
}

/* Scroll Animation */
.section-hidden {
    opacity: 0;
    transform: translateX(-50px);
    /* Slide from left */
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.section-visible {
    opacity: 1;
    transform: translateX(0);
}

/* Responsive */
@media (max-width: 768px) {
    h1 {
        font-size: 2rem;
    }

    .hero-layout {
        flex-direction: column-reverse;
        text-align: center;
    }

    .hero-content {
        text-align: center;
    }

    .menu-toggle {
        display: block;
    }

    .nav-links {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--surface-color);
        border-bottom: 1px solid var(--border-color);
        flex-direction: column;
        padding: 20px;
        box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
        clip-path: polygon(0 0, 100% 0, 100% 0, 0 0);
        /* Hidden by default */
        transition: clip-path 0.4s ease-in-out;
    }

    .nav-links.active {
        clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
    }

    .nav-links li {
        margin: 10px 0;
        width: 100%;
        text-align: center;
    }

    .btn-nav {
        display: block;
        width: 100%;
    }

    .about-layout {
        flex-direction: column;
        text-align: center;
    }

    .about-photo {
        width: 100%;
        max-width: 400px;
    }

    /* Mobile Collapsible Sections */
    .mobile-toggle {
        cursor: pointer;
        display: flex;
        align-items: center;
        justify-content: center;
        gap: 10px;
        user-select: none;
    }

    .toggle-icon::after {
        content: '+';
        font-size: 1.5rem;
        font-weight: bold;
        color: var(--accent-color);
        transition: transform 0.3s ease;
        display: inline-block;
    }

    .mobile-toggle.active .toggle-icon::after {
        content: '-';
        transform: rotate(180deg);
    }

    .services-wrapper,
    .about-wrapper {
        max-height: 0;
        opacity: 0;
        overflow: hidden;
        transform: translateX(-20px);
        transition: max-height 0.5s ease-in-out, opacity 0.5s ease-in-out, transform 0.5s ease-in-out;
    }

    .services-wrapper.active,
    .about-wrapper.active {
        max-height: 3000px;
        /* Large enough to fit content */
        opacity: 1;
        transform: translateX(0);
    }
}