/* Import Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=Space+Grotesk:wght@300;400;500;600;700&display=swap');

/* CSS Variables */
:root {
    /* Colors */
    --primary: #3b82f6;
    --primary-dark: #2563eb;
    --secondary: #10b981;
    --dark: #111827;
    --darker: #030712;
    --light: #f9fafb;
    --gray: #6b7280;
    --light-gray: #e5e7eb;
    
    /* Gradients */
    --gradient-primary: linear-gradient(90deg, var(--primary), var(--secondary));
    --gradient-dark: linear-gradient(135deg, #1e293b, #0f172a);
    
    /* Typography */
    --font-sans: 'Inter', sans-serif;
    --font-mono: 'Space Grotesk', monospace;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.1);
    --shadow: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
    --shadow-xl: 0 20px 25px rgba(0,0,0,0.1);
    
    /* Border Radius */
    --radius-sm: 0.25rem;
    --radius: 0.5rem;
    --radius-lg: 1rem;
    --radius-full: 9999px;
}

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

html {
    font-size: 62.5%;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    font-size: 1.6rem;
    line-height: 1.6;
    color: var(--light);
    background-color: var(--darker);
    overflow-x: hidden;
}

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

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    outline: none;
    background: none;
}

ul {
    list-style: none;
}

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

::selection {
    background: var(--primary);
    color: var(--light);
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--dark);
}

::-webkit-scrollbar-thumb {
    background: var(--primary);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-dark);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 1.2rem 2.4rem;
    border-radius: var(--radius-full);
    font-weight: 600;
    font-size: 1.6rem;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    gap: 1rem;
}

.btn i {
    transition: transform var(--transition);
}

.btn:hover i {
    transform: translateX(4px);
}

.btn-primary {
    background: var(--primary);
    color: var(--light);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-3px);
    box-shadow: var(--shadow);
}

.btn-outline {
    border: 2px solid var(--primary);
    color: var(--primary);
    background: transparent;
}

.btn-outline:hover {
    background: var(--primary);
    color: var(--light);
    transform: translateY(-3px);
    box-shadow: var(--shadow);
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: var(--transition-slow);
}

.btn:hover::before {
    left: 100%;
}

/* Header & Navigation */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: 2rem 5%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 1000;
    transition: var(--transition);
    backdrop-filter: blur(10px);
    background: rgba(3, 7, 18, 0.8);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

header.scrolled {
    padding: 1.2rem 5%;
    background: rgba(3, 7, 18, 0.95);
}

.logo {
    font-family: var(--font-mono);
    font-size: 3rem;
    font-weight: 700;
    color: var(--light);
    position: relative;
}

.nav-links {
    display: flex;
    gap: 3rem;
}

.nav-link {
    font-size: 1.6rem;
    font-weight: 500;
    color: var(--light);
    padding: 0.5rem 1rem;
    position: relative;
}

.nav-link::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: var(--transition);
}

.nav-link:hover::before,
.nav-link.active::before {
    width: 100%;
}

.nav-link.active {
    color: var(--primary);
}

.menu-btn {
    display: none;
    cursor: pointer;
    width: 30px;
    height: 20px;
    position: relative;
    z-index: 2;
}

.menu-btn__burger {
    position: absolute;
    top: 50%;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--light);
    transition: var(--transition);
    transform: translateY(-50%);
}

.menu-btn__burger::before,
.menu-btn__burger::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 2px;
    background: var(--light);
    transition: var(--transition);
}

.menu-btn__burger::before {
    transform: translateY(-10px);
}

.menu-btn__burger::after {
    transform: translateY(10px);
}

.menu-btn.open .menu-btn__burger {
    transform: translateX(-50px);
    background: transparent;
}

.menu-btn.open .menu-btn__burger::before {
    transform: rotate(45deg) translate(35px, -35px);
}

.menu-btn.open .menu-btn__burger::after {
    transform: rotate(-45deg) translate(35px, 35px);
}

/* Main Content */
main {
    padding-top: 8rem;
}

section {
    padding: 10rem 5%;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 6rem;
}

.section-title-container {
    max-width: 70%;
}

.section-title {
    font-size: 5rem;
    font-weight: 800;
    color: var(--light);
    margin-bottom: 1rem;
    position: relative;
}

.section-title::before {
    content: '';
    position: absolute;
    left: 0;
    bottom: -10px;
    width: 80px;
    height: 4px;
    background: var(--primary);
}

.section-subtitle {
    font-size: 2rem;
    color: var(--gray);
    margin-top: 2rem;
}

.section-number {
    font-family: var(--font-mono);
    font-size: 12rem;
    font-weight: 800;
    color: rgba(255, 255, 255, 0.03);
    line-height: 1;
}

/* Footer */
footer {
    padding: 3rem 5%;
    background: var(--dark);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-text {
    font-size: 1.4rem;
    color: var(--gray);
}

.footer-text span {
    color: var(--primary);
}

.back-to-top {
    width: 4rem;
    height: 4rem;
    border-radius: 50%;
    background: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--light);
    font-size: 1.8rem;
    transition: var(--transition);
}

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-5px);
}

/* Responsive Design */
@media screen and (max-width: 1200px) {
    html {
        font-size: 58%;
    }
}

@media screen and (max-width: 992px) {
    html {
        font-size: 56%;
    }
    .section-header {
        flex-direction: column;
        gap: 2rem;
    }
    .section-number {
        align-self: flex-start;
    }
    .section-title-container {
        max-width: 100%;
    }
}

@media screen and (max-width: 768px) {
    html {
        font-size: 54%;
    }
    .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 70%;
        height: 100vh;
        background: var(--dark);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        transition: var(--transition);
        z-index: 998;
    }
    .nav-links.active {
        right: 0;
        box-shadow: -5px 0 15px rgba(0, 0, 0, 0.2);
    }
    .menu-btn {
        display: block;
        z-index: 999;
    }
}

@media screen and (max-width: 576px) {
    html {
        font-size: 52%;
    }
    section {
        padding: 8rem 3%;
    }
    .section-title {
        font-size: 4rem;
    }
    .section-number {
        font-size: 7rem;
    }
}