*,
*::before,
*::after {
    box-sizing: border-box;
}

:root {
    --bg-color: #f0f2f5;
    --card-bg: #ffffff;
    --text-main: #1c1e21;
    --text-sub: #65676b;
    --accent: #007bff;
    --accent-hover: #0056b3;
    --border-radius: 16px;
    --shadow: 0 2px 4px rgba(0, 0, 0, 0.1), 0 8px 16px rgba(0, 0, 0, 0.1);
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #18191a;
        --card-bg: #242526;
        --text-main: #e4e6eb;
        --text-sub: #b0b3b8;
        --accent: #4599ff;
        --accent-hover: #70b1ff;
        --shadow: 0 2px 4px rgba(0, 0, 0, 0.3), 0 8px 16px rgba(0, 0, 0, 0.3);
    }
}

body {
    font-family: 'Inter', 'Noto Sans JP', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    margin: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 100vh;
    transition: background-color 0.3s ease;
}

.container {
    background: var(--card-bg);
    padding: 2.5rem 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    max-width: 400px;
    width: 90%;
    text-align: center;
    transition: background-color 0.3s ease;
    margin: auto 0;
}

.icon-container {
    margin-bottom: 1.5rem;
}

.icon {
    width: 120px;
    height: 120px;
    border-radius: 20px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    border: 4px solid var(--card-bg);
}

h1 {
    margin: 0;
    font-size: 1.8rem;
    font-weight: 700;
}

.subtitle {
    margin: 0.25rem 0 1rem;
    font-size: 1.1rem;
    color: var(--text-main);
    font-weight: 500;
}

.description {
    font-size: 0.95rem;
    color: var(--text-sub);
    margin-bottom: 2rem;
    line-height: 1.6;
    padding: 0 1rem;
}

.description p {
    margin: 0;
}

.links {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.link-item {
    display: flex;
    align-items: center;
    padding: 0.85rem 1.25rem;
    background-color: var(--bg-color);
    color: var(--text-main);
    text-decoration: none;
    border-radius: 12px;
    transition: all 0.2s ease;
    font-weight: 500;
    border: 1px solid transparent;
}

.link-item:hover {
    background-color: var(--card-bg);
    color: var(--accent);
    border-color: var(--accent);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.05);
}

.link-item i {
    font-size: 1.25rem;
    width: 1.5rem;
    margin-right: 1rem;
    text-align: center;
}

.link-item span {
    font-size: 0.95rem;
    word-break: break-all;
}

.footer {
    padding: 1.5rem 0;
    font-size: 0.8rem;
    color: var(--text-sub);
    opacity: 0.8;
    width: 100%;
    text-align: center;
}

.footer p {
    margin: 0;
}