:root {
    --primary-color: #36474F;
    --secondary-color: #009788;
    --background-color: #f4f6f8;
    --text-color: #333;
    --card-bg-color: #ffffff;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.7;
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
}

.container {
    max-width: 800px;
    width: 100%;
    padding: 20px;
    box-sizing: border-box;
}

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

header .logo {
    width: 100px;
    height: 100px;
    border-radius: 24px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

header h1 {
    font-size: 2.5em;
    color: var(--primary-color);
    margin: 20px 0 10px;
}

header p {
    font-size: 1.1em;
    color: #555;
}

.section {
    background-color: var(--card-bg-color);
    border-radius: 12px;
    padding: 30px;
    margin-bottom: 30px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

h2 {
    font-size: 1.8em;
    color: var(--primary-color);
    border-bottom: 2px solid var(--secondary-color);
    padding-bottom: 10px;
    margin-top: 0;
}

.screenshot-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin: 20px 0;
}

.screenshot-placeholder {
    width: 100%;
    height: 450px;
    background-color: #e0e0e0;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #999;
    font-size: 1.2em;
    font-style: italic;
}

.gallery-container {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
}

.gallery-container::-webkit-scrollbar {
    display: none;
}

.screenshot-gallery {
    display: flex;
    flex-wrap: nowrap;
    gap: 20px;
    margin: 20px 0;
    padding-bottom: 20px;

    scroll-snap-type: x mandatory;
}

.screenshot-item {
    flex: 0 0 80%;
    max-width: 300px;
    scroll-snap-align: center;
    scroll-snap-stop: always;
}

.screenshot-placeholder {
    width: 100%;
    height: auto;
    aspect-ratio: 9 / 16;
    background-color: #e0e0e0;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #999;
    font-size: 1.2em;
    font-style: italic;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

.button-container {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin-top: 30px;
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
}

.button {
    display: block;
    text-decoration: none;
    color: white;
    padding: 15px 20px;
    border-radius: 8px;
    text-align: center;
    font-size: 1.1em;
    font-weight: bold;
    transition: transform 0.2s, box-shadow 0.2s;
}

.button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.15);
}

.button.primary {
    background-color: var(--secondary-color);
}

.button.secondary {
    background-color: var(--primary-color);
}

.pro-distinction {
    margin-top: 20px;
    padding: 20px;
    background-color: #e8f5e9;
    border-left: 5px solid var(--secondary-color);
    border-radius: 4px;
}

.pro-distinction p {
    margin: 0;
}

footer {
    text-align: center;
    padding: 20px;
    font-size: 0.9em;
    color: #777;
}

.gallery-wrapper {
    position: relative;
}

.gallery-container {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    cursor: grab;
}

.gallery-container:active {
    cursor: grabbing;
}

.gallery-container::-webkit-scrollbar {
    display: none;
}

.gallery-nav {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background-color: rgba(255, 255, 255, 0.8);
    border: 1px solid #ddd;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    font-size: 20px;
    font-weight: bold;
    color: #333;
    cursor: pointer;
    z-index: 10;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    transition: background-color 0.2s, transform 0.2s;
    user-select: none;
}

.gallery-nav:hover {
    background-color: white;
    transform: translateY(-50%) scale(1.1);
}

.gallery-nav.prev {
    left: -20px;
}

.gallery-nav.next {
    right: -20px;
}

@media (max-width: 768px) {
    .gallery-nav {
        display: none;
    }
}

.payment-section-wrapper {
    margin-top: 40px;
    padding: 30px;
    background-color: var(--card-bg-color);
    border-radius: 12px;
    border: 1px solid #e0e0e0;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    text-align: center;
}

.payment-title {
    font-size: 1.6em;
    font-weight: bold;
    color: var(--primary-color);
    margin: 0 0 8px 0;
}

.payment-subtitle {
    font-size: 1em;
    color: #555;
    margin-top: 0;
    margin-bottom: 30px;
}

.payment-tabs {
    display: flex;
    justify-content: center;
    border-bottom: 1px solid #ddd;
    margin-bottom: 20px;
}

.payment-tab {
    padding: 10px 20px;
    cursor: pointer;
    color: #555;
    margin-bottom: -1px;
    border-bottom: 3px solid transparent;
    transition: color 0.3s, border-bottom-color 0.3s;
}

.payment-tab:hover {
    color: var(--primary-color);
}

.payment-tab.active {
    color: var(--secondary-color);
    font-weight: bold;
    border-bottom-color: var(--secondary-color);
}

.payment-content {
    display: none;
    text-align: left;
}

.payment-content.active {
    display: block;
}

.qr-code {
    max-width: 200px;
    width: 100%;
    display: block;
    margin: 15px auto;
}

.download-section, .section-bottom-margin {
    margin-bottom: 1.5rem;
}

.language-switcher {
    position: absolute;
    top: 15px;
    right: 20px;
    text-decoration: none;
    color: var(--primary-color);
    font-weight: bold;
    padding: 8px 12px;
    border-radius: 6px;
    background-color: rgba(255, 255, 255, 0.7);
    transition: background-color 0.3s;
    z-index: 100;
}

.language-switcher:hover {
    background-color: white;
}

@media (max-width: 840px) {

    .language-switcher {
        top: 10px;
        right: 10px;
    }
}

.version-section .version-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: #eef1f3;
    padding: 10px 20px;
    border-radius: 8px;
    margin-bottom: 20px;
}

.version-section .version-info p {
    margin: 0;
}

.version-section .version-number {
    font-weight: bold;
    color: var(--secondary-color);
    background-color: white;
    padding: 4px 8px;
    border-radius: 4px;
}

.changelog-container {
    overflow-y: auto;
    padding-right: 15px;
    border: 1px solid #eee;
    border-radius: 8px;
    padding: 10px 20px;
    background-color: #eef1f3;
}

.changelog-item {
    margin-bottom: 20px;
    padding-bottom: 20px;
    border-bottom: 1px dashed #ddd;
}

.changelog-item:last-child {
    border-bottom: none;
    margin-bottom: 0;
}

.changelog-item h3 {
    margin-bottom: 5px;
    color: var(--primary-color);
}

.changelog-item .release-date {
    font-size: 0.9em;
    color: #777;
    margin-top: 0;
    font-style: italic;
}

.changelog-item ul {
    padding-left: 20px;
    margin-top: 10px;
}