:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --bg-color: #f3f4f6;
    --card-bg: #ffffff;
    --text-main: #1f2937;
    --text-secondary: #6b7280;
    --accent-green: #10b981;
    --accent-red: #ef4444;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    padding-bottom: 50px;
}

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

header {
    text-align: center;
    margin-bottom: 40px;
    padding: 20px 0;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    color: var(--text-main);
}

header p {
    color: var(--text-secondary);
}

.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 25px;
    margin-bottom: 60px;
}

.product-card {
    background: var(--card-bg);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    display: flex;
    flex-direction: column;
}

.product-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

.card-image {
    height: 200px;
    width: 100%;
    object-fit: cover;
    background-color: #e5e7eb;
}

.card-body {
    padding: 20px;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.card-category {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 5px;
}

.card-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--text-main);
}

.card-desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 15px;
    line-height: 1.5;
    flex-grow: 1;
}

.card-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 1px solid #f3f4f6;
    padding-top: 15px;
}

.card-price {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-main);
}

.card-rating {
    font-size: 0.9rem;
    color: #f59e0b;
    font-weight: 600;
}

.discount-section {
    background: var(--card-bg);
    max-width: 600px;
    margin: 0 auto;
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1);
    border: 1px solid #e5e7eb;
}

.discount-header {
    text-align: center;
    margin-bottom: 25px;
}

.discount-header h2 {
    font-size: 1.8rem;
    margin-bottom: 5px;
}

.form-group {
    margin-bottom: 20px;
}

.form-label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--text-main);
}

.form-input {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.2s;
}

.form-input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.btn-calculate {
    width: 100%;
    padding: 14px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s;
}

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

.result-box {
    margin-top: 25px;
    padding: 20px;
    background-color: #f0fdf4;
    border: 1px solid #bbf7d0;
    border-radius: 8px;
    text-align: center;
    display: none;/
}

.result-box.error {
    background-color: #fef2f2;
    border-color: #fecaca;
}

.result-text {
    font-size: 1.1rem;
    color: var(--text-secondary);
}

.final-price {
    font-size: 2rem;
    font-weight: 800;
    color: var(--text-main);
    margin-top: 5px;
    display: block;
}

.saved-amount {
    display: inline-block;
    margin-top: 5px;
    padding: 4px 10px;
    background-color: var(--accent-green);
    color: white;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

.error-text {
    color: var(--accent-red);
    font-weight: 600;
}

.hint {
    margin-top: 20px;
    font-size: 0.8rem;
    color: #9ca3af;
    text-align: center;
}

hr {
    border: 0;
    border-top: 1px solid #e5e7eb;
    margin: 60px 0;
}