:root {
    --sea-deep: #0f172a;
    --sea-mid: #075985;
    --sea-light: #0ea5e9;
    --glass-bg: rgba(255, 255, 255, 0.1);
    --glass-border: rgba(255, 255, 255, 0.2);
    --text-bright: #f0f9ff;
    --accent-cyan: #7dd3fc;
}
main{ 
    background: linear-gradient(135deg, #2c5364, #203a43, #2c5364);
    background-attachment: fixed;
    color: var(--text-bright);
    padding: 20px;
    line-height: 1.5;
}

.box { 
    width: 100%; 
    margin: 0 auto; 
}

.upper { 
    text-align: center; 
}

.upper h1 { 
    font-size: 2.5rem; 
    background: linear-gradient(to right, var(--accent-cyan), var(--sea-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 10px 20px rgba(0,0,0,0.2);
}

.upper p {
    color: var(--accent-cyan);
    opacity: 0.8;
    margin-top: 8px;
    letter-spacing: 1px;
}

.selection-container {
    background: var(--glass-bg);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 20px;
    margin-bottom: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
}

.selection-container label {
    font-weight: bold;
    color: var(--accent-cyan);
}

.class-dropdown {
    padding: 12px 20px;
    background: rgba(15, 23, 42, 0.8); /* Darker background for readability */
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    color: var(--text-bright);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    outline: none;
    min-width: 200px;
    transition: all 0.3s ease;
}

.class-dropdown:hover, .class-dropdown:focus {
    border-color: var(--accent-cyan);
    box-shadow: 0 0 15px rgba(14, 165, 233, 0.3);
}

/* Style the options inside (Note: standard HTML select options have limited styling) */
.class-dropdown option {
    background-color: var(--sea-deep);
    color: white;
}


/* --- BOOK LIST CARD --- */
.book-card {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    padding: clamp(15px, 5vw, 35px);
    box-shadow: 0 15px 45px rgba(0, 0, 0, 0.4);
    animation: fadeIn 0.6s ease-out;
}

.list-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--glass-border);
    padding-bottom: 20px;
    margin-bottom: 25px;
    flex-wrap: wrap;
    gap: 15px;
}

.print-btn {
    background: #10b981;
    color: white;
    border: none;
    padding: 10px 24px;
    border-radius: 12px;
    font-weight: bold;
    cursor: pointer;
    transition: 0.3s;
    box-shadow: 0 4px 10px rgba(16, 185, 129, 0.3);
}

.print-btn:hover {
    background: #059669;
    transform: scale(1.05);
}

/* --- TABLE FIXES (Long names wrapped) --- */
.table-wrapper {
    width: 100%;
    overflow: hidden; /* Stops horizontal scroll */
}

table { 
    width: 100%; 
    border-collapse: collapse; 
    table-layout: fixed; /* CRITICAL: Forces text wrap */
}

th { 
    text-align: left; 
    padding: 15px 10px; 
    color: var(--accent-cyan); 
    font-size: 0.8rem; 
    text-transform: uppercase; 
    border-bottom: 2px solid var(--glass-border);
}

td { 
    padding: 18px 10px; 
    border-bottom: 1px solid rgba(255,255,255,0.05); 
    font-size: 1rem;
    word-wrap: break-word; /* Wrap long book names */
    overflow-wrap: break-word;
    word-break: break-word;
}

/* Specific Column Widths */
th:nth-child(1), td:nth-child(1) { width: 50px; }
th:nth-child(2), td:nth-child(2) { width: 25%; }
th:nth-child(3), td:nth-child(3) { width: 45%; } /* Give book name more space */
th:nth-child(4), td:nth-child(4) { width: 25%; }

tr:hover td {
    background: rgba(255, 255, 255, 0.03);
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(15px); }
    to { opacity: 1; transform: translateY(0); }
}

/* --- MOBILE RESPONSIVE CARDS --- */
@media (max-width: 480px) {
    header h1 { font-size: 1.8rem; }
    
    table thead { display: none; }
    
    table, tbody, tr, td { display: block; width: 100%; }
    
    tr { 
        background: rgba(255,255,255,0.03); 
        border-radius: 18px; 
        margin-bottom: 20px; 
        padding: 15px; 
        border: 1px solid var(--glass-border);
    }
    
    td { 
        display: flex; 
        justify-content: space-between; 
        align-items: flex-start; /* Keeps multi-line book names neat */
        text-align: right; 
        border: none; 
        padding: 10px 5px;
        width: 100% !important; /* Override desktop width */
    }
    
    td::before { 
        content: attr(data-label); 
        font-weight: bold; 
        color: var(--accent-cyan); 
        font-size: 0.7rem; 
        text-transform: uppercase; 
        padding-right: 20px;
        min-width: 80px;
        text-align: left;
    }

    /* Wrap the actual text in the card */
    td strong, td em, td span {
        max-width: 65%; 
        word-wrap: break-word;
    }
}

@media print {
    body { background: white; color: black; }
    .nav-grid, .print-btn { display: none !important; }
    .book-card { border: 1px solid #000; box-shadow: none; background: white; color: black; backdrop-filter: none; }
    th { color: black; border-bottom: 2px solid #000; }
    td { color: black; border-bottom: 1px solid #ddd; }
}