:root { 
    --primary: #2563eb; 
    --bg: #f1f5f9; 
    --text: #1e293b; 
    --card-bg: #ffffff;
}

body { 
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; 
    background: var(--bg); 
    color: var(--text); 
    max-width: 500px; 
    margin: 0 auto; 
    padding: 16px; 
    line-height: 1.5;
}

.container { 
    background: var(--card-bg); 
    padding: 28px 20px; 
    border-radius: 16px; 
    box-shadow: 0 4px 20px rgba(0,0,0,0.08); 
}

h1 { 
    font-size: 1.8rem; 
    margin: 0; 
    font-weight: 800; 
    text-align: center;
}

h1 span { color: var(--primary); }

.hidden { display: none !important; }

.subtitle { 
    text-align: center; 
    font-size: 0.75rem; 
    color: #64748b; 
    margin-bottom: 24px; 
    text-transform: uppercase; 
    letter-spacing: 0.1em; 
}

label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    margin-top: 16px;
    color: #475569;
}

input, textarea { 
    width: 100%; 
    padding: 12px; 
    margin-top: 8px; 
    border: 1px solid #cbd5e1; 
    border-radius: 10px; 
    box-sizing: border-box; 
    font-size: 16px; 
}

button { 
    width: 100%; 
    padding: 16px; 
    margin-top: 24px; 
    background: var(--primary); 
    color: white; 
    border: none; 
    border-radius: 10px; 
    font-weight: 700; 
    font-size: 1rem;
    cursor: pointer; 
}

button:active { transform: scale(0.98); background: #1d4ed8; }

.btn-copy {
    background: #64748b; /* 少し落ち着いたグレーブルー */
    margin-top: 10px;
}
.btn-copy:active {
    background: #475569;
}
.result-box { 
    margin-top: 28px; 
    padding: 20px; 
    background: #f8fafc; 
    border-radius: 12px; 
    border: 2px dashed #e2e8f0; 
}

.code-display { 
    font-size: 2.5rem; 
    font-family: 'Courier New', monospace; 
    font-weight: 900; 
    color: var(--primary); 
    text-align: center; 
    margin: 16px 0; 
}

.checker-link {
    display: block; 
    text-align: center; 
    margin-top: 20px; 
    font-size: 0.85rem; 
    color: #64748b; 
    text-decoration: none;
}

.help-text { font-size: 0.7rem; color: #64748b; margin-top: 8px; }
.res-label { text-align: center; margin: 0; font-size: 0.8rem; font-weight: 600; color: #475569; }
.btn-x { background: #0f172a; margin-top: 10px; }

/* ガイド用スタイル */
.guide-section { margin-top: 40px; border-top: 1px solid #e2e8f0; padding-top: 20px; }
.guide-title { font-size: 0.9rem; color: #475569; margin-bottom: 12px; }
.guide-model { background: #f8fafc; padding: 15px; border-radius: 10px; margin-bottom: 15px; border: 1px solid #e2e8f0; }
.guide-model strong { color: var(--primary); display: block; margin-bottom: 8px; font-size: 0.85rem; }
.guide-model ol { font-size: 0.75rem; color: #475569; padding-left: 18px; line-height: 1.6; margin: 0; }
.guide-section ul { font-size: 0.8rem; color: #64748b; padding-left: 20px; line-height: 1.6; margin: 0; }