/* =========================================
   1. VARIABLES & RESET
   ========================================= */
:root {
    --bg-gradient: linear-gradient(135deg, #000000, #1a0000, #2b0000);
    --glass-bg: rgba(0, 0, 0, 0.7);
    --glass-border: rgba(255, 0, 0, 0.3);
    --text-color: #ffffff;
    --text-muted: #dadada;
    --accent-color: #ff0000;
    --accent-gradient: linear-gradient(90deg, #ff0000, #b30000);
    --danger-color: #ffffff;
    --danger-gradient: linear-gradient(90deg, #ffffff, #dcdcdc);
    /* White button for contrast */
    --input-bg: rgba(255, 255, 255, 0.1);
    --shadow-light: 0 8px 32px 0 rgba(0, 0, 0, 0.8);
    --card-radius: 20px;
    --font-main: 'Poppins', sans-serif;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: var(--font-main);
}

body {
    background: var(--bg-gradient);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 40px 20px;
    color: var(--text-color);
    overflow-x: hidden;
    position: relative;
}

/* =========================================
   2. DYNAMIC BACKGROUND
   ========================================= */
.background-shapes .shape {
    position: absolute;
    filter: blur(100px);
    z-index: -1;
    animation: float 10s infinite alternate;
}

.shape-1 {
    top: -10%;
    left: -10%;
    width: 600px;
    height: 600px;
    background: #ff0000;
    opacity: 0.2;
}

.shape-2 {
    bottom: -10%;
    right: -10%;
    width: 500px;
    height: 500px;
    background: #ffffff;
    opacity: 0.1;
    animation-delay: -5s;
}

.shape-3 {
    top: 40%;
    left: 40%;
    width: 300px;
    height: 300px;
    background: #800000;
    opacity: 0.3;
    animation-delay: -2s;
}

@keyframes float {
    0% {
        transform: translate(0, 0) rotate(0deg);
    }

    100% {
        transform: translate(30px, 30px) rotate(10deg);
    }
}

/* =========================================
   3. GLASS CONTAINER
   ========================================= */
.container {
    width: 100%;
    max-width: 900px;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: var(--card-radius);
    padding: 40px;
    box-shadow: var(--shadow-light);
    animation: slideUp 0.8s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(50px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* =========================================
   4. HEADER
   ========================================= */
header {
    text-align: center;
    margin-bottom: 40px;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 600;
    margin-bottom: 10px;
    background: linear-gradient(to right, #ffffff, #b3b3b3);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

header .subtitle {
    font-size: 1rem;
    color: var(--text-muted);
    font-weight: 300;
}

/* =========================================
   5. SECTIONS & CARDS
   ========================================= */
main {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.card {
    background: rgba(255, 255, 255, 0.03);
    padding: 25px;
    border-radius: 15px;
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: transform 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    border-color: rgba(255, 255, 255, 0.1);
}

h2 {
    font-size: 1.2rem;
    margin-bottom: 20px;
    color: var(--accent-color);
    display: flex;
    align-items: center;
    gap: 10px;
}

/* =========================================
   6. FORMS & INPUTS
   ========================================= */
.form-group {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    align-items: center;
}

.input-wrapper {
    position: relative;
    width: 100%;
}

.input-wrapper i {
    position: absolute;
    left: 15px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    font-size: 0.9rem;
    transition: color 0.3s;
}

input {
    width: 100%;
    padding: 12px 15px 12px 40px;
    background: var(--input-bg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    outline: none;
    color: white;
    font-size: 0.95rem;
    transition: all 0.3s;
}

input:focus {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(255, 0, 0, 0.2);
}

input:focus+i,
.input-wrapper:focus-within i {
    color: var(--accent-color);
}

input::placeholder {
    color: rgba(255, 255, 255, 0.3);
}

/* =========================================
   7. BUTTONS
   ========================================= */
.btn {
    padding: 12px 25px;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    color: white;
}

.btn-primary {
    background: var(--accent-gradient);
    box-shadow: 0 4px 15px rgba(255, 0, 0, 0.3);
}

.btn-primary:hover {
    box-shadow: 0 6px 20px rgba(255, 0, 0, 0.5);
    transform: scale(1.02);
}

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

.delete-btn {
    background: var(--danger-gradient);
    padding: 8px 15px;
    font-size: 0.85rem;
    color: black;
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(255, 255, 255, 0.1);
}

.delete-btn:hover {
    box-shadow: 0 6px 20px rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

/* =========================================
   8. LISTS & RESULTS
   ========================================= */
ul {
    list-style: none;
}

.book-list li,
.result-item {
    background: rgba(255, 255, 255, 0.05);
    margin-bottom: 12px;
    padding: 15px 20px;
    border-radius: 12px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all 0.3s ease;
    border: 1px solid transparent;
}

.book-list li:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateX(5px);
    border-color: rgba(255, 255, 255, 0.2);
}

.book-info strong {
    font-size: 1.1rem;
    color: white;
    display: block;
}

.book-info small {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.empty-state {
    text-align: center;
    padding: 40px;
    color: var(--text-muted);
    opacity: 0.7;
}

.empty-state i {
    font-size: 2rem;
    margin-bottom: 10px;
    display: block;
}

/* =========================================
   9. SEARCH RESULTS AREA
   ========================================= */
.results-container {
    margin-top: 20px;
}

.result-item {
    background: linear-gradient(135deg, rgba(255, 0, 0, 0.1), rgba(100, 0, 0, 0.1));
    border: 1px solid rgba(255, 0, 0, 0.2);
    margin-top: 10px;
    flex-direction: column;
    align-items: flex-start;
    animation: fadeIn 0.4s ease forwards;
}

.result-item h3 {
    font-size: 1.1rem;
    color: var(--accent-color);
}

.result-item p {
    font-size: 0.9rem;
    color: var(--text-muted);
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive adjustments */
@media (max-width: 600px) {
    .container {
        padding: 20px;
    }

    .form-group {
        grid-template-columns: 1fr;
    }

    header h1 {
        font-size: 1.8rem;
    }
}