/* ==========================================
 * ベーススタイル - 改善＆変数導入版
 * ========================================== */

/* CSS Variables (カスタムプロパティ) の定義 */
:root {
    /* カラーパレット */
    --color-primary: #60a5fa; /* Blue-400 */
    --color-secondary: #a78bfa; /* Violet-400 */
    --color-accent: #ec4899; /* Pink-500 */
    --color-text-light: #e0e7ff; /* Indigo-100 */
    --color-text-subtle: #cbd5e1; /* Slate-300 */
    --color-text-muted: #94a3b8; /* Slate-400 */
    --color-bg-dark: #0f0c29; /* Primary Gradient Start */
    --color-bg-medium: #1e293b; /* Slate-800 Semi-opaque */
    --color-border-subtle: rgba(148, 163, 184, 0.3); /* Slate-400 30% */
    --color-bg-blur: rgba(15, 23, 42, 0.9); /* Dark Blue Semi-opaque */
    --color-success: #10b981; /* Emerald-500 */

    /* その他の設定 */
    --radius-large: 20px;
    --radius-medium: 12px;
}

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

body {
    font-family: 'Inter', 'Noto Sans JP', sans-serif;
    background: linear-gradient(135deg, var(--color-bg-dark) 0%, #302b63 50%, #24243e 100%);
    color: var(--color-text-light);
    min-height: 100vh;
    padding: 0;
    position: relative;
    overflow-x: hidden;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 20% 50%, rgba(59, 130, 246, 0.1) 0%, transparent 50%),
                radial-gradient(circle at 80% 80%, rgba(99, 102, 241, 0.1) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 40px 20px;
    position: relative;
    z-index: 1;
}

/* ==========================================
 * ヘッダー
 * ========================================== */
header {
    text-align: center;
    margin-bottom: 50px;
    animation: fadeInDown 0.8s ease;
}

h1 {
    font-size: 48px;
    font-weight: 900;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 50%, var(--color-accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 12px;
    letter-spacing: -1px;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.3));
}

.subtitle {
    color: var(--color-text-subtle);
    font-size: 17px;
    font-weight: 500;
    letter-spacing: 1.5px;
}

/* ==========================================
 * コンテンツリンク
 * ========================================== */
.content-links {
    text-align: center;
    margin-top: 30px;
    margin-bottom: 50px;
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.link-button {
    display: inline-block;
    background: rgba(148, 163, 184, 0.15);
    color: var(--color-text-subtle);
    text-decoration: none;
    padding: 12px 24px;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.3s;
    border: 1px solid var(--color-border-subtle);
}

.link-button:hover {
    background: rgba(148, 163, 184, 0.25);
    color: #f1f5f9;
    border-color: var(--color-primary);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.2);
}

/* ==========================================
 * サイトフッター
 * ========================================== */
.site-footer {
    margin-top: 80px;
    padding: 30px 20px;
    border-top: 1px solid var(--color-border-subtle);
    text-align: center;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 15px;
    flex-wrap: wrap;
}

.footer-links a {
    color: var(--color-text-subtle);
    text-decoration: none;
    font-size: 14px;
    transition: color 0.2s;
}

.footer-links a:hover {
    color: var(--color-primary);
}

.copyright {
    color: var(--color-text-muted);
    font-size: 13px;
}

/* ==========================================
 * アニメーション
 * ========================================== */
@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}