:root {
    /* Palette: Calm & Natural (Ghibli-esque) */
    --bg-main: #fcfbf9;      /* 優しい生成り色 */
    --bg-card: #ffffff;
    --text-primary: #2d3436;
    --text-secondary: #636e72;
    --accent-blue: #74b9ff;  /* 彩度を抑えた空色 */
    --accent-red: #ff7675;   /* 攻撃的すぎない赤 */
    --accent-green: #55efc4; /* 柔らかい緑 */
    --border-soft: #dfe6e9;
    
    /* Spacing & Layout */
    --radius-lg: 24px;
    --radius-md: 12px;
    --shadow-soft: 0 10px 40px -10px rgba(0,0,0,0.05);
    --font-sans: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", sans-serif;
}

body {
    background-color: var(--bg-main);
    color: var(--text-primary);
    font-family: var(--font-sans);
    margin: 0;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* Container */
.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 2rem;
}

/* Header Styling */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 2rem 0 4rem;
}

.brand {
    font-size: 1.2rem;
    font-weight: 700;
    letter-spacing: -0.5px;
    color: var(--text-primary);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 8px;
}

/* Status Indicator */
.status-pill {
    background: rgba(85, 239, 196, 0.1);
    color: #00b894;
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 6px;
}
.status-dot {
    width: 8px;
    height: 8px;
    background: #00b894;
    border-radius: 50%;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% { opacity: 1; }
    50% { opacity: 0.5; }
    100% { opacity: 1; }
}

/* Cards & Grid */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 2rem;
    text-decoration: none;
    color: inherit;
    transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
    box-shadow: 0 4px 6px rgba(0,0,0,0.01);
    border: 1px solid var(--border-soft);
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    min-height: 180px;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-soft);
    border-color: transparent;
}

.card h2 {
    font-size: 1.2rem;
    margin: 0 0 0.5rem 0;
}

.card p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin: 0;
}

.card-icon {
    font-size: 2rem;
    margin-bottom: 1.5rem;
}
/* Mermaidの図をコンテナ幅に合わせて拡大 */
.mermaid svg {
    width: 100% !important;
    max-width: 900px; /* 横に広がりすぎないように制限 */
    height: auto;
}