/* --- Global Styles & Fonts --- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;700;800;900&display=swap');

/* --- CSS Variables --- */
:root {
    --primary-color: #22d3ee; /* cyan-400 */
    --primary-hover: #67e8f9; /* cyan-300 */
    --dark-bg: #111827; /* gray-900 */
    --medium-bg: #1f2937; /* gray-800 */
    --light-bg: #374151; /* gray-700 */
    --text-light: #d1d5db; /* gray-300 */
    --text-white: #ffffff;
    --border-color: #4b5563; /* gray-600 */
}

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

html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--dark-bg);
    font-family: 'Inter', sans-serif;
    color: var(--text-light);
    line-height: 1.6;
    font-size: 16px;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
    color: var(--text-white);
    font-weight: 700;
}

h2.section-title {
    text-shadow: 0 0 10px rgba(34, 211, 238, 0.3);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: var(--primary-hover);
}

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

/* --- Layout --- */
.section {
    padding: 6rem 0;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 800;
    text-align: center;
    margin-bottom: 3rem;
}

.section-subtitle {
    text-align: center;
    max-width: 600px;
    margin: -2rem auto 3rem;
    font-size: 1.125rem;
    color: var(--text-light);
}

/* --- Header & Navigation --- */
.main-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background-color: rgba(17, 24, 39, 0.8);
    backdrop-filter: blur(10px);
    box-shadow: 0 4px 30px rgba(34, 211, 238, 0.1);
    border-bottom: 1px solid rgba(34, 211, 238, 0.1);
}

.main-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 5rem;
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-white);
}

.logo span {
    color: var(--primary-color);
    font-weight: 400;
}

.main-nav { display: none; }
.main-nav a {
    color: var(--text-light);
    font-size: 1rem;
    font-weight: 500;
    padding: 0.5rem 1rem;
    position: relative;
    transition: color 0.3s ease;
}
.main-nav a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: width 0.3s ease;
}
.main-nav a:hover, .main-nav a.active { color: var(--text-white); }
.main-nav a:hover::after, .main-nav a.active::after { width: 60%; }

.header-cta { display: none; }
.mobile-nav-toggle { display: block; background: none; border: none; color: var(--text-white); cursor: pointer; z-index: 1001; }
.mobile-nav { display: none; position: absolute; top: 5rem; left: 0; right: 0; background-color: rgba(17, 24, 39, 0.98); padding: 2rem 0; text-align: center; }
.mobile-nav.open { display: block; }
.mobile-nav a { display: block; color: var(--text-light); font-size: 1.25rem; padding: 1rem 0; }
.mobile-nav .btn { margin-top: 1rem; width: calc(100% - 4rem); }

/* --- Buttons --- */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    font-weight: 700;
    text-align: center;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}
.btn-primary {
    background-color: var(--primary-color);
    color: var(--dark-bg);
    box-shadow: 0 4px 20px rgba(34, 211, 238, 0.3);
}
.btn-primary:hover {
    background-color: var(--primary-hover);
    color: var(--dark-bg);
    transform: translateY(-2px);
}
.btn-secondary { background-color: var(--light-bg); color: var(--text-white); }
.btn-secondary:hover { background-color: #4b5563; transform: translateY(-2px); }


/* --- Footer --- */
.main-footer {
    background-color: var(--dark-bg);
    border-top: 1px solid rgba(34, 211, 238, 0.1);
    padding: 2rem 0;
    text-align: center;
    color: #9ca3af;
}
.footer-social { margin-bottom: 1rem; }
.footer-social a { color: var(--text-light); transition: color 0.3s ease; }
.footer-social a:hover { color: var(--primary-color); }
.main-footer p:last-child { font-size: 0.875rem; margin-top: 0.5rem; }

/* --- Responsive Design (Global) --- */
@media (min-width: 768px) {
    .main-nav { display: flex; gap: 1rem; }
    .header-cta { display: block; }
    .mobile-nav-toggle { display: none; }
    .section { padding: 8rem 0; }
    .section-title { font-size: 3rem; margin-bottom: 4rem; }
}