/* --- 基本設定 --- */
:root {
    --primary-color: #007BFF; /* メインカラー (青) */
    --primary-hover-color: #0056b3;
    --text-color: #333; /* 基本テキストカラー */
    --background-color: #f8f9fa; /* 背景色 */
    --white-color: #fff;
    --border-color: #ddd;
    --header-height: 70px;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans JP', sans-serif;
    line-height: 1.7;
    color: var(--text-color);
    background-color: var(--white-color);
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

a {
    text-decoration: none;
    color: var(--primary-color);
}

h1, h2, h3 {
    margin-bottom: 20px;
    font-weight: 700;
}

span.block {
  display: inline-block;
}

.section-title {
    text-align: center;
    font-size: 1.75rem;
}

/* --- ヘッダー --- */
.header {
    background-color: var(--white-color);
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
    height: var(--header-height);
    width: 100%;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

.site-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-color);
}

.nav ul {
    list-style: none;
    display: flex;
}

.nav ul li {
    margin-left: 20px;
}

.nav ul li a {
    color: var(--text-color);
    font-weight: 700;
    transition: color 0.3s;
}

.nav ul li a:hover {
    color: var(--primary-color);
}

/* --- ヒーローセクション --- */
#hero {
    background-color: var(--background-color);
    height: 220px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
}

#hero h1 {
    font-size: 1.75rem;
}

#hero p {
    font-size: 1rem;
    color: #555;
}

/* --- 各セクションの共通スタイル --- */
#tools {
    padding: 30px 0 0;
}

#about {
    padding: 20px 0;
    background-color: var(--background-color);
}

#about .container {
    max-width: 640px
}

#about .container p {
    margin-bottom: 10px;
    text-align: left
}

/* --- ツール一覧セクション --- */
.tool-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.tool-card {
    background-color: var(--white-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 30px;
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
    color: var(--text-color);
    display: block;
}

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

.tool-icon {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.tool-title {
    font-size: 1.4rem;
    margin-bottom: 10px;
}

.tool-description {
    font-size: 0.9rem;
    color: #666;
    line-height: 1.6;
}

/* --- このサイトについてセクション --- */
#about .container {
    max-width: 640px;
}
#about .container p {
    margin-bottom: 10px;
    text-align: left;
}

/* --- フッター --- */
.footer {
    background-color: #333;
    color: var(--white-color);
    text-align: center;
    padding: 20px 0;
}

/* --- スマートフォン・タブレット対応 (レスポンシブ) --- */
.sp-only { display: none; }
.hamburger-menu { display: none; }

@media (max-width: 768px) {
    .nav {
        display: none;
        position: absolute;
        top: var(--header-height);
        left: 0;
        width: 100%;
        background-color: var(--white-color);
        border-bottom: 1px solid var(--border-color);
    }
    .nav.active {
        display: block;
    }
    .nav ul {
        flex-direction: column;
    }
    .nav ul li {
        margin: 0;
        text-align: center;
        border-top: 1px solid #eee;
    }
    .nav ul li a {
        display: block;
        padding: 15px;
    }
    
    .hamburger-menu {
        display: block;
        cursor: pointer;
        background: none;
        border: none;
        width: 30px;
        height: 22px;
        position: relative;
    }
    .hamburger-menu span {
        display: block;
        position: absolute;
        width: 100%;
        height: 3px;
        background-color: var(--text-color);
        border-radius: 2px;
        transition: transform 0.3s, opacity 0.3s;
    }
    .hamburger-menu span:nth-child(1) { top: 0; }
    .hamburger-menu span:nth-child(2) { top: 9px; }
    .hamburger-menu span:nth-child(3) { bottom: 0; }

    .hamburger-menu.active span:nth-child(1) {
        transform: translateY(9px) rotate(45deg);
    }
    .hamburger-menu.active span:nth-child(2) {
        opacity: 0;
    }
    .hamburger-menu.active span:nth-child(3) {
        transform: translateY(-9px) rotate(-45deg);
    }

    .sp-only {
        display: block;
    }
}


/* --- ツールページ共通スタイル --- */
main .container {
    padding-top: calc(var(--header-height) - 40px);
    padding-bottom: 50px;
}

.page-header {
    text-align: center;
    margin-bottom: 20px;
}

.page-title {
    font-size: 1.5rem;
    margin-bottom: 10px;
}

.page-description {
    font-size: 1rem;
    color: #555;
}

.tool-wrapper {
    max-width: 800px;
    margin: 0 auto;
    background-color: #fff;
    padding: 0;
}
@media (min-width: 768px) {
    .tool-wrapper {
        padding: 20px;
        border: 1px solid var(--border-color);
        border-radius: 8px;
        box-shadow: 0 4px 10px rgba(0,0,0,0.05);
    }
}

.input-label {
    display: block;
    font-weight: 700;
    margin-bottom: 8px;
}

.button {
    padding: 10px 20px;
    font-size: 1rem;
    font-weight: 700;
    color: #fff;
    background-color: var(--primary-color);
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
    white-space: nowrap;
}

.button:hover:not(:disabled) {
    background-color: var(--primary-hover-color);
}

.button:disabled {
    background-color: #a0cfff;
    cursor: not-allowed;
}

.button-secondary {
    background-color: #6c757d;
}
.button-secondary:hover:not(:disabled) {
    background-color: #5a6268;
}

.tool-controls {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin: 15px 0;
    flex-wrap: wrap;
}

.error-message {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
    border-radius: 5px;
    padding: 15px;
    font-family: 'Courier New', Courier, monospace;
    margin-bottom: 20px;
}
.info-message {
    background-color: #d9edf7;
    color: #31708f;
    border: 1px solid #bce8f1;
    border-radius: 5px;
    padding: 15px;
    margin-top: 20px;
    text-align: center;
}


/* ======== ▼選択ボックスのカスタムスタイル▼ ======== */

.select-wrapper {
    position: relative;
    display: inline-block;
}

.select-wrapper::after {
    content: '';
    position: absolute;
    top: 50%;
    right: 12px;
    transform: translateY(-50%);
    width: 0;
    height: 0;
    border-left: 5px solid transparent;
    border-right: 5px solid transparent;
    border-top: 6px solid #555;
    pointer-events: none;
}

.select-wrapper select {
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    padding: 8px 30px 8px 12px;
    font-size: 1rem;
    border: 1px solid #ccc;
    border-radius: 5px;
    background-color: var(--white-color);
    cursor: pointer;
}

.select-wrapper select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(0, 123, 255, 0.25);
}