/* =========================================
   1. THEME VARIABLES & COLORS
   ========================================= */
:root {
    /* LIGHT MODE (Blue & Cyan Theme) */
    --bg-main: #f0f8ff;       /* Alice Blue (Very light blue tint) */
    --text-main: #0f172a;     /* Deep Navy Text */
    --text-muted: #334155;    /* Slate Text */
    --primary-blue: #0284c7;  /* Sky Blue */
    --accent-cyan: #06b6d4;   /* Cyan Accent */
    
    /* Glass Effect */
    --glass-bg: rgba(255, 255, 255, 0.5);
    --glass-border: rgba(255, 255, 255, 0.9);
    --glass-shadow: 0 8px 32px rgba(2, 132, 199, 0.1); /* Blue tinted shadow */
    
    /* LIQUID BLOBS (Strictly Blue/Cyan/Teal) */
    --blob-1: linear-gradient(135deg, #0ea5e9, #3b82f6); /* Sky to Royal Blue */
    --blob-2: linear-gradient(135deg, #06b6d4, #22d3ee); /* Cyan to Light Blue */
    --blob-3: linear-gradient(135deg, #0369a1, #0c4a6e); /* Deep Ocean */
    
    /* Background Text Visibility Settings */
    /* INCREASED OPACITY FOR VISIBILITY */
    --bg-text-opacity: 0.15; 
    --bg-text-color: #0284c7; /* Blue tint */
}

/* DARK MODE OVERRIDES */
body.dark-mode {
    --bg-main: #0b1120;       /* Very Dark Navy */
    --text-main: #f0f9ff;     /* Lightest Blue/White */
    --text-muted: #94a3b8;    /* Blue-Grey */
    
    /* Glass Effect (Dark) */
    --glass-bg: rgba(15, 23, 42, 0.4);
    --glass-border: rgba(56, 189, 248, 0.1); /* Subtle Cyan border */
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.5);

    /* Dark Mode Blobs (Neon Blue/Cyan) */
    --blob-1: linear-gradient(135deg, #1d4ed8, #1e40af); /* Deep Blue */
    --blob-2: linear-gradient(135deg, #0891b2, #0e7490); /* Teal */
    --blob-3: linear-gradient(135deg, #0c4a6e, #075985); /* Navy */
    
    --bg-text-opacity: 0.08; /* Slightly lower in dark mode to avoid being too distracting */
    --bg-text-color: #fff;
}

/* =========================================
   2. GLOBAL RESET & BASE STYLES
   ========================================= */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html, body {
    width: 100%;
    overflow-x: hidden;
    scroll-behavior: smooth;
}

body {
    font-family: 'Montserrat', sans-serif;
    color: var(--text-main);
    background-color: var(--bg-main);
    transition: background-color 0.5s ease, color 0.5s ease;
}

/* =========================================
   3. PARALLAX BACKGROUND
   ========================================= */
.parallax-wrapper {
    position: fixed; 
    top: 0; 
    left: 0; 
    width: 100%; 
    height: 100%; 
    z-index: -1; 
    overflow: hidden;
    background: radial-gradient(circle at top, transparent, var(--bg-main));
}

.blob {
    position: absolute; 
    border-radius: 50%; 
    filter: blur(90px); 
    opacity: 0.7;
    animation: float 20s infinite ease-in-out alternate;
}

.blob-1 { top: -10%; left: -10%; width: 50vw; height: 50vw; background: var(--blob-1); }
.blob-2 { bottom: -10%; right: -10%; width: 60vw; height: 60vw; background: var(--blob-2); animation-delay: -5s; }
.blob-3 { top: 40%; left: 30%; width: 40vw; height: 40vw; background: var(--blob-3); animation-delay: -10s; }
.blob-4 { top: 10%; right: 10%; width: 25vw; height: 25vw; background: var(--blob-2); animation-delay: -15s; }

@keyframes float {
    0% { transform: translate(0, 0) scale(1); }
    100% { transform: translate(30px, 50px) scale(1.1); }
}

/* =========================================
   4. GLASS UI UTILITIES
   ========================================= */
.glass-nav, .glass-card {
    background: var(--glass-bg);
    backdrop-filter: blur(16px); 
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    box-shadow: var(--glass-shadow);
    transition: all 0.3s ease;
}

/* =========================================
   5. NAVIGATION
   ========================================= */
nav {
    display: flex; 
    justify-content: space-between; 
    align-items: center; 
    padding: 15px 5%;
    position: fixed; 
    width: 100%; 
    top: 0; 
    z-index: 1000;
}

.logo-container { height: 40px; }
.logo-container img { height: 100%; object-fit: contain; transition: filter 0.3s ease; }
body.dark-mode .logo-container img { filter: invert(1) brightness(2); }

.nav-right { display: flex; align-items: center; gap: 30px; }
.nav-links { list-style: none; display: flex; gap: 30px; }
.nav-links a {
    text-decoration: none; 
    color: var(--text-main); 
    font-weight: 600; 
    font-size: 0.9rem;
    transition: 0.3s; 
    text-transform: uppercase; 
    letter-spacing: 1px;
}
.nav-links a:hover { color: var(--accent-cyan); }

.theme-btn {
    background: transparent; 
    border: 2px solid var(--text-main); 
    color: var(--text-main);
    width: 35px; height: 35px; border-radius: 50%; cursor: pointer; font-size: 1rem;
    display: flex; align-items: center; justify-content: center; transition: 0.3s;
}
.theme-btn:hover { background: var(--text-main); color: var(--bg-main); }

.hamburger { 
    display: none; 
    font-size: 1.5rem; 
    cursor: pointer; 
    color: var(--text-main); 
    margin-left: 15px; 
}

/* =========================================
   6. HERO SECTION
   ========================================= */
.hero { 
    min-height: 100vh; 
    display: flex; 
    justify-content: center; 
    align-items: center; 
    text-align: center; 
    padding: 100px 20px 0; 
}

.hero-card { 
    padding: 60px 40px; 
    border-radius: 20px; 
    max-width: 700px; 
    width: 100%; 
}

.hero h1 {
    font-size: 3.5rem; margin-bottom: 20px;
    background: -webkit-linear-gradient(45deg, var(--primary-blue), var(--accent-cyan));
    -webkit-background-clip: text; -webkit-text-fill-color: transparent; line-height: 1.2;
}

.hero p { font-size: 1.2rem; color: var(--text-muted); margin-bottom: 40px; }

.btn-glow {
    padding: 15px 40px; 
    background: linear-gradient(90deg, var(--primary-blue), var(--accent-cyan));
    color: white; 
    text-decoration: none; 
    border-radius: 50px; 
    font-weight: 700;
    box-shadow: 0 5px 20px rgba(6, 182, 212, 0.3); 
    transition: 0.3s; 
    display: inline-block;
}
.btn-glow:hover { transform: translateY(-3px); box-shadow: 0 8px 25px rgba(6, 182, 212, 0.5); }

/* =========================================
   7. ABOUT SECTION
   ========================================= */
.about-section { padding: 80px 5%; display: flex; justify-content: center; }

.about-card { 
    padding: 50px; 
    border-radius: 20px; 
    max-width: 900px; 
    width: 100%; 
    text-align: center; 
}

.about-card p { font-size: 1.4rem; font-weight: 400; line-height: 1.6; }
.highlight { color: var(--accent-cyan); font-weight: 700; }

/* =========================================
   8. SERVICES TRACK
   ========================================= */
.service-track { position: relative; width: 100%; overflow: hidden; }

.service-level {
    flex-direction: column; 
    justify-content: flex-start; 
    min-height: 80vh; 
    display: flex;
    align-items: center;
    padding: 0 10%;
    position: relative;
    border-bottom: 1px solid rgba(0,0,0,0.05);
}
body.dark-mode .service-level { border-bottom: 1px solid rgba(255,255,255,0.05); }

.service-level:nth-child(even) { flex-direction: column; }

/* Content Card */
.service-content {
    z-index: 5; /* Increased Z-Index to stay above BG Text */
    padding: 50px;
    border-radius: 20px;
    max-width: 800px;
    width: 100%;
    text-align: center;
    margin-top: 250px; 
    margin-bottom: 50px;
}

.service-content h2 { font-size: 3rem; margin-bottom: 20px; color: var(--primary-blue); }
body.dark-mode .service-content h2 { color: var(--accent-cyan); }
.service-content p { color: var(--text-muted); line-height: 1.8; font-size: 1.1rem; }

/* BIG BACKGROUND TEXT (SKY, OCEAN, ETC)
   Fixed Visibility: Positioned centrally behind content
*/
.service-bg-text {
    position: absolute; 
    font-size: 12vw; 
    color: var(--bg-text-color); 
    opacity: var(--bg-text-opacity);
    font-weight: 800; 
    
    /* Center it vertically approx where the text card is */
    top: 65%; 
    left: 50%; 
    transform: translate(-50%, -50%);
    
    white-space: nowrap; 
    z-index: 1; /* Low Z-Index, but above background */
    pointer-events: none;
    user-select: none;
}

/* =========================================
   9. VEHICLES
   ========================================= */
.vehicle-wrapper {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 300px; 
    pointer-events: none; 
    z-index: 10; /* Highest Z-Index */
    display: flex;
    align-items: center; 
}

.vehicle {
    color: var(--primary-blue); 
    opacity: 1; 
    filter: drop-shadow(5px 5px 15px rgba(2, 132, 199, 0.4));
    transition: color 0.3s ease;
}
body.dark-mode .vehicle {
    color: var(--accent-cyan); 
    filter: drop-shadow(0 0 15px rgba(6, 182, 212, 0.6));
}

#plane-icon { font-size: 7rem; }
#ship-icon  { font-size: 7rem; margin-top: 20px; }
#truck-icon { font-size: 6rem; }
#human-icon { font-size: 5rem; }

/* =========================================
   10. FOOTER
   ========================================= */
footer { background: #0f172a; color: white; padding: 60px 5% 20px; }
.footer-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 30px; margin-bottom: 40px; }
.footer-col h3 { color: var(--accent-cyan); margin-bottom: 20px; }
.footer-col p, .footer-col a { color: #94a3b8; text-decoration: none; margin-bottom: 10px; display: block;}
.footer-col a:hover { color: var(--accent-cyan); }
.copyright { text-align: center; color: #64748b; font-size: 0.8rem; padding-top: 20px; border-top: 1px solid rgba(255,255,255,0.1); }

/* =========================================
   11. MOBILE RESPONSIVENESS
   ========================================= */
@media (max-width: 900px) {
    
    .hamburger { display: block; }
    
    .nav-links {
        position: fixed; background: var(--bg-main); height: 100vh; width: 100%;
        top: 0; right: -100%; flex-direction: column; align-items: center; justify-content: center;
        transition: right 0.4s ease; z-index: 998;
    }
    .nav-links.active { right: 0; }
    .nav-links a { font-size: 1.5rem; margin: 20px 0; }

    .hero { padding-top: 120px; min-height: 100vh; height: auto; }
    .hero-card { width: 90%; margin: 0 auto; padding: 40px 20px; }
    .hero h1 { font-size: 2.5rem; }
    .about-card { width: 90%; padding: 30px; }
    .about-card p { font-size: 1.1rem; }

    .service-level { min-height: 60vh; padding: 20px 5%; }

    .vehicle-wrapper { height: 180px; }

    #plane-icon, #ship-icon, #truck-icon, #human-icon { font-size: 4rem; margin-top: 0; }

    .service-content {
        margin-top: 150px; 
        padding: 30px 20px;
        width: 100%;
    }
    
    .service-content h2 { font-size: 2rem; }
    
    /* Adjust BG text for mobile to be visible */
    .service-bg-text { 
        font-size: 5rem; 
        top: 75%; 
    }

    .footer-grid { text-align: center; }
}