/* static/css/start.css */

:root {
    --primary-color: #00BFFF;
    --dark-bg: #1a1a1a;
    --text-color: #333;
    --font-jp: 'Zen Kaku Gothic New', sans-serif;
}

body {
    margin: 0;
    font-family: var(--font-jp);
    color: var(--text-color);
    line-height: 1.8;
    overflow-x: hidden;
    background-color: #ffffff;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
}

/* メインコンテンツ（白紙部分）の最低限のエリア確保 */
.main-content {
    flex: 1;
    padding: 60px 0;
}

/* =========================================
   ヘッダーのスタイル
   ========================================= */
.site-header {
    background-color: #ffffff;
    padding: 20px 40px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 100;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--text-color);
    letter-spacing: 1px;
}

.sub-logo {
    font-size: 0.9rem;
    color: #888;
    font-weight: normal;
    margin-left: 5px;
}

.site-header nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    gap: 30px;
    align-items: center;
}

.site-header nav a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s;
}

.site-header nav a:hover {
    color: var(--primary-color);
}

.site-header nav .btn-login {
    background-color: var(--primary-color);
    color: white;
    padding: 8px 20px;
    border-radius: 20px;
    transition: background-color 0.3s;
}

.site-header nav .btn-login:hover {
    background-color: #009ACD;
    color: white;
}

/* =========================================
   フッターのスタイル
   ========================================= */
.site-footer {
    background-color: var(--dark-bg);
    color: #fff;
    padding: 40px 0;
    text-align: center;
    margin-top: auto;
}

.footer-social-icons {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 20px;
}

.footer-social-icons .social-icon {
    width: 30px;
    height: 30px;
    object-fit: contain;
    transition: transform 0.3s, opacity 0.3s;
    filter: invert(1); /* 黒アイコンを白反転させてダーク背景に合わせる */
}

.footer-social-icons .social-icon:hover {
    transform: scale(1.1);
    opacity: 0.8;
}

.copyright {
    color: #666;
    font-size: 0.85rem;
    margin: 0;
}

/* =========================================
   ヒーローセクション（トップ説明部分）
   ========================================= */
.hero-section {
    text-align: center;
    padding: 20px 0;
}

.hero-section h2 {
    color: var(--primary-color);
    margin-bottom: 20px;
    font-size: 1.8rem;
}

.hero-description {
    margin-bottom: 2.5em;
    font-size: 1.1rem;
}

/* 機能説明リスト */
.feature-list {
    list-style: none;
    padding: 0;
    max-width: 500px;
    margin: 0 auto 40px auto;
    text-align: left;
}

.feature-list li {
    background-color: #f8f9fa;
    border-left: 5px solid var(--primary-color);
    padding: 20px;
    margin-bottom: 15px;
    border-radius: 5px;
    display: flex;
    align-items: flex-start;
    gap: 15px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.02);
}

.feature-icon {
    font-size: 1.5rem;
    line-height: 1;
}

.feature-text strong {
    display: block;
    margin-bottom: 5px;
    font-size: 1.1rem;
    color: var(--text-color);
}

.feature-text span {
    font-size: 0.9rem;
    color: #666;
    line-height: 1.5;
    display: block;
}

/* アクションボタン */
.action-area {
    margin-top: 40px;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    padding: 15px 40px;
    text-decoration: none;
    border-radius: 30px;
    font-weight: bold;
    font-size: 1.1rem;
    transition: background-color 0.3s, transform 0.2s;
    display: inline-block;
    box-shadow: 0 4px 10px rgba(0, 191, 255, 0.3);
}

.btn-primary:hover {
    background-color: #009ACD;
    transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(0, 191, 255, 0.4);
}

/* =========================================
   レスポンシブ設定
   ========================================= */
@media (max-width: 768px) {
    .site-header {
        padding: 15px 20px;
        flex-direction: column;
        gap: 10px;
    }
    
    .site-header nav ul {
        gap: 15px;
        font-size: 0.85rem;
    }
}