:root {
    --primary-color: #4CAF50;
    --secondary-color: #FFC107;
    --background-color: #ffffff;
    --text-color: #333333;
    --surface-color: #f9f9f9;
    --border-color: #e0e0e0;
    --header-height: 70px;
    --border-radius: 8px;
}

[data-theme="dark"] {
    --primary-color: #66bb6a;
    --secondary-color: #ffd54f;
    --background-color: #121212;
    --text-color: #ffffff;
    --surface-color: #1e1e1e;
    --border-color: #333333;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    line-height: 1.6;
    transition: background-color 0.3s, color 0.3s;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Header */
.site-header {
    background-color: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
    height: var(--header-height);
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

.brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
}

.nav {
    display: flex;
    gap: 1rem;
}

.nav a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 600;
    transition: color 0.3s;
}

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

.header-right {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.theme-toggle {
    background: none;
    border: none;
    color: var(--text-color);
    cursor: pointer;
    font-size: 1.2rem;
}

.hamburger {
    display: none;
    background: none;
    border: none;
    color: var(--text-color);
    font-size: 1.5rem;
    cursor: pointer;
}

/* Hero Section */
.hero {
    padding: 3rem 0;
    text-align: center;
}

.gradient-bg {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: #fff;
}

.hero-inner {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 3rem;
}

.hero-copy h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.hero-copy p {
    font-size: 1.2rem;
    max-width: 600px;
    margin: 0 auto 2rem;
}

.hero-ctas {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

.btn {
    padding: 0.8rem 1.5rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 600;
    transition: transform 0.3s, background-color 0.3s;
}

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

.btn.primary:hover {
    background-color: #3e8e41;
    transform: translateY(-3px);
}

.btn.secondary {
    border: 2px solid #fff;
    color: #fff;
}

.btn.secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-3px);
}

.hero-media img {
    max-width: 100%;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

/* Features Section */
.features {
    padding: 3rem 0;
    text-align: center;
}

.features h2 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.feature {
    background: var(--surface-color);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s, box-shadow 0.3s;
}

.feature:hover {
    transform: translateY(-10px);
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.1);
}

.feature-icon {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.feature h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

/* Screenshots Section */
.screenshots {
    padding: 3rem 0;
    text-align: center;
    background-color: var(--surface-color);
}

.screenshots h2 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
}

.screens-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0.25rem;
}

.screens-grid img {
    width: auto;
    max-width: 100%;
    max-height: 450px;
    border-radius: var(--border-radius);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s;
    border: 3px solid var(--border-color);
}

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

/* Testimonials Section */
.testimonials {
    padding: 3rem 0;
    text-align: center;
}

.testimonials h2 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
}

.testimonial-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.testimonial {
    background: var(--surface-color);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    border-left: 5px solid var(--primary-color);
}

.testimonial p {
    font-style: italic;
    margin-bottom: 1rem;
}

.testimonial cite {
    font-weight: 600;
}

/* Download Section */
.download {
    padding: 3rem 0;
    text-align: center;
}

.gradient-bg-2 {
    background: linear-gradient(135deg, var(--secondary-color), var(--primary-color));
    color: #fff;
}

.download h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.download p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
}

.btn.big {
    font-size: 1.2rem;
    padding: 1rem 2rem;
}

/* Contact Section */
.contact {
    padding: 3rem 0;
    text-align: center;
}

.contact h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.contact form {
    display: grid;
    gap: 1rem;
    max-width: 600px;
    margin: 2rem auto 0;
}

.contact input,
.contact textarea {
    padding: 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    background-color: var(--surface-color);
    color: var(--text-color);
}

/* Footer */
.site-footer {
    background-color: var(--surface-color);
    padding: 1.5rem 0;
    text-align: center;
    border-top: 1px solid var(--border-color);
}

.footer-inner {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.footer-social a {
    color: var(--text-color);
    font-size: 1.5rem;
    margin: 0 0.5rem;
    transition: color 0.3s;
}

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

#back-to-top {
  position: fixed;
  bottom: 20px;
  right: 20px;
  display: none;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  font-size: 1.5rem;
  line-height: 1;
  text-align: center;
  padding: 0;
}

/* Responsive */
@media (max-width: 768px) {
    .nav {
        display: none;
        flex-direction: column;
        position: absolute;
        top: var(--header-height);
        right: 0;
        background-color: var(--surface-color);
        width: 100%;
        text-align: center;
        padding: 1rem 0;
        border-bottom: 1px solid var(--border-color);
    }

    .nav.active {
        display: flex;
    }

    .hamburger {
        display: block;
    }

    .hero-inner {
        flex-direction: column-reverse;
    }

    .hero-copy h1 {
        font-size: 2.5rem;
    }
}