/* --- Reset & Base --- */
:root {
    --primary-color: #3498db;
    --secondary-color: #2c3e50;
    --background-color: #f8f9fa;
    --text-color: #343a40;
    --light-gray: #ecf0f1;
}

body {
    font-family: 'Noto Sans JP', sans-serif;
    line-height: 1.8;
    color: var(--text-color);
    background-color: var(--background-color);
    margin: 0;
    padding: 0;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* --- Layout --- */
.container {
    max-width: 800px;
    margin: 60px auto;
    padding: 40px;
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.07);
}

/* --- Typography --- */
h1, h2 {
    color: var(--secondary-color);
    font-weight: 700;
    line-height: 1.4;
}

h1 {
    font-size: 2.2rem;
    text-align: center;
    margin-bottom: 2em;
}

h2 {
    font-size: 1.6rem;
    margin-top: 3em;
    margin-bottom: 1.5em;
    border-bottom: 2px solid var(--primary-color);
    padding-bottom: 0.5em;
}

p {
    margin-bottom: 1.5em;
}

strong {
    color: #e74c3c;
    font-weight: 700;
}

strong.quote-blue {
    color: var(--primary-color);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: all 0.2s ease-in-out;
}

a:hover {
    opacity: 0.8;
    text-decoration: underline;
}

hr {
    border: none;
    border-top: 1px solid #e9ecef;
    margin: 3em 0;
}

/* --- Components --- */
img {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 2.5em auto;
    border-radius: 8px;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
}

.image-row {
    display: flex;
    gap: 1em;
    margin: 2.5em auto;
    justify-content: center;
    align-items: flex-start;
}

.image-row img {
    flex: 1;
    max-width: calc(50% - 0.5em);
    margin: 0;
}

/* 3枚の画像の場合の特別なレイアウト */
.image-row.three-images {
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-template-rows: auto auto;
    gap: 1em;
}

.image-row.three-images img:nth-child(1) {
    grid-row: 1 / 3;
    max-width: 100%;
}

.image-row.three-images img:nth-child(2),
.image-row.three-images img:nth-child(3) {
    max-width: 100%;
}

ul {
    list-style: none;
    padding-left: 0;
    margin-bottom: 1.5em;
}

ul li {
    position: relative;
    padding-left: 1.8em;
    margin-bottom: 0.8em;
}

ul li::before {
    content: '✓';
    position: absolute;
    left: 0;
    top: 0;
    color: var(--primary-color);
    font-weight: 700;
}

blockquote {
    border-left: 4px solid var(--primary-color);
    padding: 1em 1.5em;
    margin: 2.5em 0;
    background-color: #f1f8ff;
    border-radius: 0 8px 8px 0;
}

aside {
    background-color: var(--light-gray);
    border-radius: 8px;
    padding: 1.5em 2em;
    margin: 2.5em 0;
    border-left: 4px solid #bdc3c7;
}

.cta form {
    margin: 0;
}

.cta a,
.cta button {
    display: block;
    width: 80%;
    margin: 3em auto;
    padding: 20px;
    background: linear-gradient(45deg, var(--primary-color), #2980b9);
    color: #fff;
    text-align: center;
    font-size: 1.4rem;
    font-weight: 700;
    border-radius: 50px;
    text-decoration: none;
    box-shadow: 0 10px 20px rgba(52, 152, 219, 0.3);
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-family: 'Noto Sans JP', sans-serif;
}

.cta a:hover,
.cta button:hover {
    transform: translateY(-3px);
    box-shadow: 0 14px 28px rgba(52, 152, 219, 0.4);
    text-decoration: none;
    opacity: 1;
}

/* --- Responsive Design for Smartphones --- */
@media (max-width: 768px) {
    body {
        line-height: 1.7;
        font-size: 14px;
    }

    .container {
        margin: 0;
        padding: 30px 20px;
        border-radius: 0;
        box-shadow: none;
    }

    h1 {
        font-size: 1.3rem;
        text-align: left;
        margin-bottom: 1.5em;
    }

    a strong {
        color: #e74c3c;
    }

    h2 {
        font-size: 1.4rem;
        margin-top: 2.5em;
    }

    .cta a,
    .cta button {
        width: 100%;
        font-size: 1.2rem;
        padding: 18px;
    }

    .image-row {
        flex-direction: column;
    }

    .image-row img {
        max-width: 100%;
        margin-bottom: 1em;
    }

    .image-row img:last-child {
        margin-bottom: 0;
    }

    .image-row.three-images {
        display: flex;
        flex-direction: column;
    }

    .image-row.three-images img:nth-child(1) {
        grid-row: auto;
    }
}