/* ==========================================================================
   1. VARIABLES & RESET
   ========================================================================== */
:root {
    --primary-color: #0056b3; /* Trustworthy Blue */
    --primary-hover: #004494;
    --text-color: #333333;
    --text-light: #666666;
    --bg-light: #f8f9fa;
    --border-color: #e0e0e0;
    --success-bg: #d4edda;
    --success-text: #155724;
    --font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}

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

body {
    font-family: var(--font-family);
    color: var(--text-color);
    line-height: 1.6;
    background-color: #ffffff;
    display: flex;
    flex-direction: column;
    min-height: 100vh; /* Pushes the footer to the bottom of short pages */
}

main {
    flex-grow: 1; /* Ensures the main content expands to fill screen space */
}

/* Typography */
h1, h2, h3, h4 {
    margin-bottom: 15px;
    line-height: 1.2;
    color: #222;
}

p {
    margin-bottom: 15px;
}

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

/* ==========================================================================
   2. HEADER & NAVIGATION
   ========================================================================== */
header {
    background-color: #ffffff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 15px 20px;
    position: relative;
}

.logo {
    font-size: 1.8rem;
    font-weight: 900;
    color: var(--primary-color);
    text-decoration: none;
    letter-spacing: -0.5px;
}

.logo span {
    color: #333;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 25px;
    align-items: center;
}

nav ul li a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    font-size: 1rem;
    transition: color 0.3s ease;
}

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

/* ==========================================================================
   3. BUTTONS
   ========================================================================== */
.btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: #ffffff;
    padding: 10px 24px;
    text-decoration: none;
    border-radius: 6px;
    font-weight: 600;
    border: 2px solid var(--primary-color);
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
}

.btn:hover {
    background-color: var(--primary-hover);
    border-color: var(--primary-hover);
    color: #ffffff;
}

.btn-large {
    padding: 15px 35px;
    font-size: 1.1rem;
}

.btn-outline {
    background-color: transparent;
    color: var(--primary-color);
}

.btn-outline:hover {
    background-color: var(--primary-color);
    color: #ffffff;
}

.btn-outline-light {
    border-color: #ffffff;
    color: #ffffff;
    background-color: transparent;
}

.btn-outline-light:hover {
    background-color: #ffffff;
    color: var(--primary-color);
}

/* ==========================================================================
   4. LAYOUT & GRIDS
   ========================================================================== */
section {
    max-width: 1200px;
    margin: 0 auto;
    padding: 60px 20px;
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

/* Hero Section */
.hero {
    background: linear-gradient(rgba(0, 86, 179, 0.85), rgba(0, 86, 179, 0.95)), url('../images/hero-bg.jpg') center/cover;
    color: #ffffff;
    text-align: center;
    padding: 100px 20px;
    max-width: 100%;
}

.hero h1 {
    font-size: 3.5rem;
    color: #ffffff;
    margin-bottom: 20px;
}

.hero p {
    font-size: 1.3rem;
    max-width: 600px;
    margin: 0 auto 40px auto;
}

.hero-actions {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

/* Cards */
.card {
    background: #ffffff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    border: 1px solid var(--border-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

/* ==========================================================================
   5. FORMS
   ========================================================================== */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #444;
}

input[type="text"], 
input[type="email"], 
input[type="number"], 
input[type="date"], 
select, 
textarea {
    width: 100%;
    padding: 14px;
    border: 1px solid #ccc;
    border-radius: 6px;
    font-family: var(--font-family);
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

input:focus, select:focus, textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 86, 179, 0.1);
}

/* Inventory specific styling */
.inventory-row {
    display: flex;
    gap: 10px;
    align-items: center;
    margin-bottom: 15px;
    flex-wrap: wrap;
    background: #fff;
    padding: 15px;
    border-radius: 6px;
    border: 1px solid #ddd;
}

.remove-row {
    background: #dc3545;
    color: white;
    border: none;
    border-radius: 4px;
    padding: 10px 15px;
    cursor: pointer;
    font-weight: bold;
}

/* ==========================================================================
   6. FOOTER
   ========================================================================== */
footer {
    background-color: #1a1a1a;
    color: #ffffff;
    padding: 60px 20px 20px;
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.footer-col h3 {
    color: #ffffff;
    margin-bottom: 20px;
    font-size: 1.3rem;
}

.footer-col p, .footer-col a {
    color: #bbbbbb;
    text-decoration: none;
    margin-bottom: 10px;
    display: block;
}

.footer-col a:hover {
    color: #ffffff;
}

.footer-col ul {
    list-style: none;
}

.footer-copyright {
    border-top: 1px solid #333;
    padding-top: 20px;
    margin-top: 40px;
    text-align: center;
    color: #888;
    font-size: 0.9rem;
}

/* ==========================================================================
   7. MOBILE RESPONSIVENESS (MEDIA QUERIES)
   ========================================================================== */
@media (max-width: 900px) {
    .grid-3 {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    /* Collapse grids */
    .grid-3, .grid-2, .footer-container {
        grid-template-columns: 1fr;
    }
    
    /* Adjust hero text */
    .hero h1 {
        font-size: 2.5rem;
    }
    
    /* Mobile Menu Logic */
    .mobile-menu-toggle {
        display: block !important;
    }
    
    #main-nav {
        display: none; /* Hidden by default on mobile, toggled by JS */
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: #ffffff;
        box-shadow: 0 10px 15px rgba(0,0,0,0.1);
        padding: 20px;
        z-index: 999;
    }
    
    #main-nav ul {
        flex-direction: column;
        align-items: flex-start;
        gap: 15px;
    }
    
    #main-nav ul li {
        width: 100%;
    }
    
    #main-nav .btn {
        display: block;
        text-align: center;
        width: 100%;
    }

    /* Inventory Rows on Mobile */
    .inventory-row > div {
        flex: 1 1 100%; /* Force inputs to stack on small screens */
    }
}