/* 1. Reset and Universal Box Sizing */
*, *::before, *::after {
    box-sizing: border-box;
}

/* 2. Global Variables */
:root {
    --primary: #2e7d32;
    --primary-hover: #236327;
    --secondary: #1a73e8;
    --secondary-hover: #1557b0;
    --bg: #f8f9fa;
    --text: #202124;
    --white: #ffffff;
    --border: #dddddd;
    --shadow: 0 4px 12px rgba(0,0,0,0.1);
}

/* 3. Body Layout */
body {
    font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg);
    color: var(--text);
    margin: 0;
    padding: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;    /* Horizontal centering */
    justify-content: center; /* Vertical centering */
    min-height: 100vh;      /* Ensures full screen height */
}

/* 4. Containers & Cards */
.container, .card {
    background: var(--white);
    width: 100%;
    max-width: 450px;
    padding: 30px;
    border-radius: 15px;
    box-shadow: var(--shadow);
    margin-bottom: 20px;
}

/* 5. Headings */
h1, h2, h3 {
    color: var(--primary);
    margin-top: 0;
    margin-bottom: 20px;
    text-align: center;
}

/* 6. Buttons */
.btn {
    display: block;
    width: 100%;
    padding: 14px;
    margin: 12px 0;
    border: 2px solid transparent; /* 2px matches outline border to prevent resizing */
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    text-align: center;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-primary { 
    background: var(--primary); 
    color: var(--white); 
}
.btn-primary:hover { 
    background: var(--primary-hover); 
}

.btn-secondary { 
    background: var(--secondary); 
    color: var(--white); 
}
.btn-secondary:hover { 
    background: var(--secondary-hover); 
}

.btn-outline { 
    background: transparent; 
    border: 2px solid var(--primary); 
    color: var(--primary); 
}
.btn-outline:hover { 
    background: #e8f5e9; 
}

.btn:active { 
    transform: scale(0.98); 
}

/* 7. Form Inputs */
input, select, textarea {
    width: 100%;
    padding: 12px;
    margin: 8px 0 18px 0;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 16px; /* Prevents auto-zoom on mobile */
    color: var(--text);
}

input:focus, select:focus, textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(46, 125, 50, 0.1);
}

/* 8. Status Badges */
.badge {
    display: inline-block;
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: bold;
    text-transform: uppercase;
}

.available { 
    background: #e8f5e9; 
    color: #2e7d32; 
}

.unavailable { 
    background: #ffebee; 
    color: #c62828; 
}

/* 9. Utility & Links */
.back-link {
    display: block;
    text-align: center;
    margin-top: 10px;
    color: #5f6368;
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    transition: color 0.2s;
}

.back-link:hover { 
    text-decoration: underline;
    color: var(--primary);
}

/* 10. Helper Classes */
.text-center { text-align: center; }
.mt-20 { margin-top: 20px; }