/* ==========================================================================
   1. CROSS-BROWSER RESET & GLOBAL SETTINGS
   ========================================================================== */
* {
    margin: 0;
    padding: 0;
    -webkit-box-sizing: border-box; /* Safari/Chrome */
    -moz-box-sizing: border-box;    /* Firefox */
    box-sizing: border-box;         /* Standard */
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

:root {
    --brand-red: #dc3545;    /* Air Cargo / Urgency */
    --brand-yellow: #ffc107; /* Navigation Highlights */
    --brand-green: #28a745;  /* Sea Cargo / Success / Tracking */
    --primary-dark: #1e293b; /* Deep Navy Blue for Airsell Cargo */
    --light-bg: #f8fafc;
    --text-dark: #1e293b;
    --white: #ffffff;
    --card-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

html, body {
    width: 100%;
    overflow-x: hidden; /* Prevents shaking on mobile Safari/Firefox */
    background-color: var(--light-bg);
    color: var(--text-dark);
    line-height: 1.6;
    /* Uses the best font available on the user's specific system */
    font-family: 'Segoe UI', system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    width: 100%;
}

/* =========================================
   2. HEADER & NAVIGATION
   ========================================= */
header {
    background: var(--primary-dark);
    padding: 1rem 0;
    position: -webkit-sticky; /* Safari Support */
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 4px solid var(--brand-yellow);
}

.header-flex {
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-pack: justify;
    -ms-flex-pack: justify;
    justify-content: space-between;
    -webkit-box-align: center;
    -ms-flex-align: center;
    align-items: center;
}

nav ul {
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    list-style: none;
    gap: 32px;
}

nav ul li a {
    color: white;
    text-decoration: none;
    font-weight: 600;
    -webkit-transition: 0.3s;
    transition: 0.3s;
}

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

.logo {
    font-size: 1.6rem;
    font-weight: 800;
    color: white;
}

.brand-red { color: var(--brand-red); }
.brand-green { color: var(--brand-green); }

/* =========================================
   3. HERO & SERVICE CARDS
   ========================================= */
.services-hero {
    background: var(--primary-dark);
    padding: 80px 0;
    color: white;
    text-align: center;
}

.services-grid {
    display: -ms-grid;
    display: grid;
    /* Grid support for Safari and Firefox */
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.service-card {
    background: var(--white);
    padding: 40px;
    border-radius: 16px;
    box-shadow: var(--card-shadow);
    text-align: center;
    border-top: 6px solid transparent;
    -webkit-transition: -webkit-transform 0.3s ease;
    transition: transform 0.3s ease;
}

.service-card:hover {
    -webkit-transform: translateY(-5px);
    transform: translateY(-5px);
}

.service-card:nth-child(1) { border-top-color: var(--brand-red); }
.service-card:nth-child(2) { border-top-color: var(--brand-yellow); }
.service-card:nth-child(3) { border-top-color: var(--brand-green); }

/* =========================================
   4. TRACKING RESULTS STYLING
   ========================================= */
.tracking-result-card {
    background: white;
    border-radius: 12px;
    padding: 30px;
    max-width: 600px;
    margin: 40px auto;
    box-shadow: var(--card-shadow);
    border-left: 8px solid var(--brand-green);
}

.status-step {
    padding: 10px 0 10px 20px;
    border-left: 2px solid #e2e8f0;
    margin-left: 10px;
    color: #94a3b8;
}

.status-step.completed {
    border-left-color: var(--brand-green);
    color: var(--text-dark);
}

/* =========================================
   5. CONTACT & FORMS
   ========================================= */
.contact-wrapper {
    display: -ms-grid;
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 50px;
    margin-top: 40px;
}

/* Form inputs styling for all browsers */
input[type="text"], input[type="email"], textarea {
    width: 100%;
    padding: 14px;
    margin: 10px 0;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 1rem;
    -webkit-appearance: none; /* Removes Safari default inner shadow */
}

.btn-primary {
    background: var(--brand-green);
    color: white;
    padding: 14px 28px;
    border: none;
    border-radius: 8px;
    font-weight: 700;
    cursor: pointer;
    -webkit-transition: 0.3s;
    transition: 0.3s;
}

.btn-primary:hover {
    background: var(--brand-red);
}

/* =========================================
   6. RESPONSIVENESS (Universal Mobile)
   ========================================= */
@media (max-width: 768px) {
    .header-flex {
        flex-direction: column;
        gap: 15px;
    }
    
    nav ul {
        gap: 15px;
    }
    
    .contact-wrapper {
        grid-template-columns: 1fr;
    }

    .services-grid {
        grid-template-columns: 1fr;
    }
}

/* =========================================
   7. FOOTER
   ========================================= */
footer {
    background: var(--primary-dark);
    color: white;
    padding: 60px 0 20px;
    border-top: 4px solid var(--brand-green);
    margin-top: 80px;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    margin-top: 40px;
    border-top: 1px solid #334155;
    color: #94a3b8;
    font-size: 0.85rem;
}