@import url('https://fonts.googleapis.com/css2?family=Montserrat:wght@300;400;600;700;800&display=swap');

:root {
    --primary-color: #000000;
    --primary-light: #333333;
    --secondary-color: #f6f6f6;
    --dark-bg: #111111;
    --text-color: #333333;
    --light-text: #ffffff;
    --muted-text: #666666;
    --container-width: 1200px;
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Montserrat', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

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

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

.section-padding {
    padding: 80px 0;
}

.bg-light {
    background-color: var(--secondary-color);
}

.bg-dark {
    background-color: var(--dark-bg);
    color: var(--light-text);
}

h1,
h2,
h3,
h4 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 20px;
}

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

.btn {
    display: inline-block;
    padding: 12px 30px;
    border: 2px solid var(--primary-color);
    background: transparent;
    color: var(--primary-color);
    font-weight: 700;
    text-transform: uppercase;
    font-size: 14px;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

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

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

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

/* Header */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 20px 0;
    transition: var(--transition);
}

header.scrolled {
    background: rgba(255, 255, 255, 0.95);
    padding: 15px 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

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

.logo {
    font-size: 24px;
    font-weight: 800;
    color: var(--light-text);
    text-transform: uppercase;
}

header.scrolled .logo {
    color: var(--primary-color);
}

nav ul {
    display: flex;
    gap: 30px;
}

nav ul li a {
    font-weight: 600;
    font-size: 14px;
    text-transform: uppercase;
    color: var(--light-text);
}

header.scrolled nav ul li a {
    color: var(--text-color);
}

header.scrolled nav ul li a:hover {
    color: var(--primary-color);
}

#header {
    background-color: #ffffff;
}

#header img {
    width: 160px;
}

#header ul li {
    display: flex;
    align-items: center;
}

#header a {
    color: black;
}

/* Hero Section */
.hero {
    height: 100vh;
    background: linear-gradient(rgba(0, 0, 0, 0.5), rgba(0, 0, 0, 0.5)), url('digital_survey_hero.png') center/cover no-repeat;
    display: flex;
    align-items: center;
    color: var(--light-text);
    text-align: left;
}

.hero-content {
    max-width: 700px;
}

.hero h1 {
    font-size: 48px;
    margin-bottom: 20px;
}

.hero p {
    font-size: 18px;
    margin-bottom: 30px;
    font-weight: 300;
}

/* Overview Section */
.overview-grid {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 60px;
    align-items: center;
}

.overview-title {
    text-align: center;
    margin-bottom: 50px;
    color: var(--primary-color);
    font-size: 42px;
    text-transform: uppercase;
}

@media (max-width: 992px) {
    .overview-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .overview-title {
        font-size: 32px;
    }
}

/* Sub-nav */
.sub-nav {
    background: var(--light-text);
    padding: 15px 0;
    position: sticky;
    top: 0;
    z-index: 900;
    border-bottom: 1px solid #eee;
}

.sub-nav ul {
    display: flex;
    justify-content: center;
    gap: 40px;
}

.sub-nav ul li a {
    font-size: 12px;
    font-weight: 700;
    text-transform: uppercase;
    color: var(--muted-text);
}

.sub-nav ul li a:hover,
.sub-nav ul li a.active {
    color: var(--primary-color);
}

/* Success Stories Section */
.success-title {
    text-align: center;
    margin-bottom: 60px;
    font-size: 48px;
    color: var(--light-text);
    font-weight: 300;
}

.success-title span {
    font-weight: 800;
}

.success-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
}

.success-card {
    position: relative;
    height: 500px;
    border-radius: 8px;
    overflow: hidden;
    color: var(--light-text);
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    padding: 40px;
    transition: var(--transition);
}

.success-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom, rgba(0, 0, 0, 0.1), rgba(0, 0, 0, 0.9));
    z-index: 1;
}

.success-card img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    z-index: 0;
}

.success-card-content {
    position: relative;
    z-index: 2;
}

.success-card h4 {
    font-size: 24px;
    margin-bottom: 15px;
    color: var(--light-text);
}

.success-card p {
    font-size: 14px;
    line-height: 1.5;
    opacity: 0.9;
}

@media (max-width: 768px) {
    .success-grid {
        grid-template-columns: 1fr;
    }
}

/* Footer */
footer {
    padding: 60px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-col h3 {
    font-size: 18px;
    margin-bottom: 25px;
    position: relative;
    padding-bottom: 10px;
}

.footer-col h3::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 40px;
    height: 2px;
    background: var(--primary-color);
}

.footer-col p,
.footer-col ul li {
    font-size: 14px;
    color: var(--muted-text);
    margin-bottom: 15px;
}

.footer-bottom {
    border-top: 1px solid #eee;
    padding-top: 30px;
    text-align: center;
    font-size: 12px;
    color: var(--muted-text);
}

@media (max-width: 768px) {
    .hero h1 {
        font-size: 36px;
    }

    nav {
        display: none;
        /* Add menu toggle later */
    }

    .sub-nav ul {
        gap: 20px;
        overflow-x: auto;
        justify-content: flex-start;
        padding: 5px 20px;
    }
}