:root {
    --bg-color: #f4f7f6;
    --text-color: #2c3e50;
    --text-muted: #576574;
    --primary-color: #10ac84; 
    --primary-hover: #1dd1a1;
    --nav-bg: rgba(255, 255, 255, 0.85);
    --card-bg: rgba(255, 255, 255, 0.9);
    --border-color: rgba(0, 0, 0, 0.1);
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

[data-theme="dark"] {
    --bg-color: #0f141e;
    --text-color: #f1f2f6;
    --text-muted: #a4b0be;
    --primary-color: #1dd1a1;
    --primary-hover: #10ac84;
    --nav-bg: rgba(15, 20, 30, 0.85);
    --card-bg: rgba(30, 39, 51, 0.9);
    --border-color: rgba(255, 255, 255, 0.1);
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.5);
}

* { margin: 0; padding: 0; box-sizing: border-box; font-family: 'Inter', sans-serif; }

body {
    background-color: var(--bg-color); color: var(--text-color);
    transition: background-color 0.4s ease, color 0.4s ease;
    overflow-x: hidden;
    display: flex; flex-direction: column; min-height: 100vh;
}

/* --- NAVIGATION --- */
nav {
    display: grid;
    grid-template-columns: 1fr auto 1fr; 
    align-items: center;
    padding: 1rem 5%; background: var(--nav-bg);
    backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    position: sticky; top: 0; z-index: 1000;
}

.nav-left { display: flex; align-items: center; gap: 1.5rem; justify-self: start; }
.nav-controls { display: flex; justify-self: end; }


.logo img { height: 45px; transition: filter 0.3s ease; }
[data-theme="dark"] .logo img { 
    filter: drop-shadow(0px 0px 12px rgba(255, 255, 255, 0.6)); 
}

.nav-links { display: flex; gap: 3rem; list-style: none; justify-self: center; }
.nav-links a { color: var(--text-color); text-decoration: none; font-weight: 600; transition: color 0.3s; font-size: 1.05rem; }
.nav-links a:hover, .nav-links a.active { color: var(--primary-color); }

.theme-btn { background: transparent; border: none; color: var(--text-color); font-size: 1.5rem; cursor: pointer; transition: transform 0.3s; }
.theme-btn:hover { transform: rotate(30deg); color: var(--primary-color); }

/* Hamburger Menu */
.hamburger { display: none; flex-direction: column; justify-content: space-between; width: 30px; height: 21px; background: transparent; border: none; cursor: pointer; }
.hamburger span { width: 100%; height: 3px; background-color: var(--text-color); border-radius: 5px; transition: all 0.3s ease; }
.hamburger.active span:nth-child(1) { transform: translateY(9px) rotate(45deg); }
.hamburger.active span:nth-child(2) { opacity: 0; }
.hamburger.active span:nth-child(3) { transform: translateY(-9px) rotate(-45deg); }

/* Mobile Menu */
.mobile-menu { position: fixed; top: 70px; left: -100%; width: 250px; height: calc(100vh - 70px); background: var(--card-bg); backdrop-filter: blur(15px); display: flex; flex-direction: column; align-items: center; padding-top: 2rem; gap: 2rem; transition: left 0.4s cubic-bezier(0.68, -0.55, 0.265, 1.55); box-shadow: 5px 0 15px rgba(0,0,0,0.1); z-index: 999; }
.mobile-menu.open { left: 0; }
.mobile-menu a { font-size: 1.2rem; font-weight: 600; color: var(--text-color); text-decoration: none; }

/* Buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 0.5rem; padding: 12px 28px; background: linear-gradient(135deg, var(--primary-color), var(--primary-hover)); color: #fff; text-decoration: none; border-radius: 50px; font-weight: 600; border: none; transition: transform 0.2s, box-shadow 0.2s; cursor: pointer; box-shadow: 0 4px 15px rgba(16, 172, 132, 0.4); }
.btn:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(16, 172, 132, 0.6); }

/* Home Page Layout */
.hero { display: flex; align-items: center; justify-content: space-between; padding: 5% 10%; min-height: 70vh; gap: 4rem; }
.hero-text { flex: 1; }
.hero-image-container { flex: 1; display: flex; justify-content: flex-end; }
.hero-image-container img { width: 100%; max-width: 500px; border-radius: 24px; box-shadow: var(--shadow); object-fit: cover; }

/* Strict 3-Column Grid */
.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 2.5rem; padding: 5% 10%; }
.feature-card { background: var(--card-bg); backdrop-filter: blur(10px); border: 1px solid var(--border-color); border-radius: 24px; padding: 2.5rem 2rem; box-shadow: var(--shadow); transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease; text-align: center; }
.feature-card:hover { transform: translateY(-12px); box-shadow: 0 20px 40px rgba(16, 172, 132, 0.15); border-color: var(--primary-color); }

/* About Page: Green Trees Style */
.about-split { display: grid; grid-template-columns: 1fr 1fr; gap: 4rem; padding: 5% 10%; align-items: center; }
.about-img { width: 100%; aspect-ratio: 4/5; object-fit: cover; border-radius: 30px; box-shadow: var(--shadow); }
.mission-banner { background: var(--primary-color); padding: 5rem 10%; text-align: center; color: white; margin: 2rem 0; }

/* Marquee */
.marquee-container { overflow: hidden; background: var(--primary-color); color: white; padding: 12px 0; white-space: nowrap; display: flex; width: 100%; }
.marquee-track { display: flex; animation: smoothMarquee 25s linear infinite; }
.marquee-track span { font-weight: 600; letter-spacing: 2px; padding: 0 20px; font-size: 1.1rem; }
@keyframes smoothMarquee { 0% { transform: translate3d(0, 0, 0); } 100% { transform: translate3d(-50%, 0, 0); } }

/* Footer */
footer { background: var(--card-bg); border-top: 1px solid var(--border-color); padding: 3rem 5% 2rem; margin-top: auto; text-align: center; }
.social-links { display: flex; justify-content: center; gap: 3rem; margin-bottom: 2rem; }
.social-links a { color: var(--text-muted); font-size: 1.8rem; transition: color 0.3s, transform 0.3s; }
.social-links a:hover { color: var(--primary-color); transform: translateY(-5px); }

/* Mobile Formatting */
@media (max-width: 900px) {
    nav { grid-template-columns: auto 1fr auto; }
    .nav-links { display: none; }
    .hamburger { display: flex; }
    .hero, .about-split { flex-direction: column; text-align: center; padding: 8% 5%; }
    .hero-image-container { justify-content: center; margin-top: 2rem; }
    .features-grid { grid-template-columns: 1fr; gap: 1.5rem; }
}