:root {
    --bg-color: linear-gradient(135deg, #f0f4f8, #d9e2ec); /* Исходный цвет фона */
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--bg-color);
    margin: 0;
    padding: 0;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    color: #2b3e50;
    transition: background 0.3s ease; /* Плавный переход при смене фона */
}

.container {
    background-color: white;
    padding: 40px;
    border-radius: 16px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
    text-align: center;
    max-width: 500px;
    width: 90%;
    transition: transform 0.3s ease;
}

.container:hover {
    transform: translateY(-5px);
}

h1 {
    color: #3366cc;
    font-size: 28px;
    margin-bottom: 20px;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.1);
}

hr {
    width: 50%;
    margin: 20px auto;
    border: 0;
    border-top: 1px solid #e0e0e0;
}

.link {
    display: inline-block;
    padding: 12px 24px;
    text-decoration: none;
    border-radius: 50px;
    font-size: 16px;
    transition: all 0.3s ease;
    cursor: pointer;
}

.link-pdf {
    background: linear-gradient(to right, #e74c3c, #c0392b);
    color: white;
    box-shadow: 0 4px 10px rgba(231, 76, 60, 0.4);
}

.link-pdf:hover {
    background: linear-gradient(to right, #c0392b, #a53023);
    transform: translateY(-3px);
    box-shadow: 0 6px 15px rgba(231, 76, 60, 0.5);
}

.link-bg {
    background: linear-gradient(to right, #3498db, #2980b9);
    color: white;
    box-shadow: 0 4px 10px rgba(52, 152, 219, 0.4);
}

.link-bg:hover {
    background: linear-gradient(to right, #2980b9, #2573a7);
    transform: translateY(-3px);
    box-shadow: 0 6px 15px rgba(52, 152, 219, 0.5);
}

.back-button-container {
    text-align: center;
    padding: 20px;
    margin: 0;
}

.back-button {
    display: inline-flex;
    align-items: center;
    padding: 8px 16px;
    background: transparent;
    color: rgba(25, 101, 152, 0.4); 
    text-decoration: none;
    font-size: 16px;
    font-weight: 500;
    color: rgba(25, 101, 152, 0.4);
    border-radius: 8px;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
    gap: 6px;
}

.back-button::before {
    content: "←";
    font-size: 16px;
    transition: transform 0.2s ease;
}

.back-button:hover::before {
    transform: translateX(-2px);
}

.back-button::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background:rgba(52, 152, 219, 0.6);
    transition: width 0.3s ease;
}

.back-button:hover::after {
    width: 100%;
}

.back-button:hover {
    background: rgba(59, 130, 246, 0.05);
    box-shadow: 0 8px 20px rgba(25, 101, 152, 0.4);
    transform: translateY(-1px);
}

.back-button:active {
    transform: translateY(0);
}