/* ============================================================
   common.css - Rhyn.jp Shared Design System
   All pages share these base styles, variables, and components.
   ============================================================ */

/* --- Design System / CSS Variables --- */
:root {
    /* Core Colors */
    --color-gold: #d4af37;
    --color-gold-light: #f8e47b;
    --color-gold-hover: #e0c055;
    --color-primary-text: #4a3728;
    --color-secondary-text: #6a5543;
    --color-heading-text: #3b2a1e;
    --color-alias-text: #8b7355;

    /* Backgrounds */
    --bg-body: #fdfaf6;
    --bg-section-alt: #f8f4e6;
    --bg-header: rgba(253, 250, 246, 0.95);
    --bg-card: #fff;
    --bg-overlay: rgba(0, 0, 0, 0.85);

    /* UI Elements */
    --border-color: #f0e9dd;
    --border-color-gold: #e8dcc6;

    /* Gradients */
    --gradient-gold: linear-gradient(45deg, #ffd700, #f8e47b, #d4af37);
    --gradient-gold-text: linear-gradient(135deg, #3b2a1e, #6a5543, #d4af37);
    --gradient-gold-button: linear-gradient(135deg, #d4af37, #f8e47b, #d4af37);
    --gradient-btn-green: linear-gradient(135deg, #2e7d3a, #4caf50);
    --gradient-btn-orange: linear-gradient(135deg, #ff6b6b, #ff8e53);
    --gradient-btn-blue: linear-gradient(135deg, #3498db, #5dade2);
    --gradient-btn-purple: linear-gradient(135deg, #9c27b0, #e91e63);
    --gradient-btn-brown: linear-gradient(135deg, #6a5543, #8b7355);
    --gradient-btn-dark: linear-gradient(45deg, #3b2a1e, #5a4538);
    --gradient-line: linear-gradient(90deg, transparent, #d4af37, transparent);

    /* Typography */
    --font-serif-jp: 'Noto Serif JP', serif;
    --font-serif-en: 'Playfair Display', serif;
    --font-cinzel: 'Cinzel', serif;

    /* Shadows */
    --shadow-sm: 0 4px 15px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 5px 20px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.1);
}

/* --- Base Styles --- */
body {
    margin: 0;
    font-family: var(--font-serif-jp);
    background-color: var(--bg-body);
    color: var(--color-primary-text);
    overflow-x: hidden;
    scroll-behavior: smooth;
    line-height: 1.7;
}

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

a {
    text-decoration: none;
    color: inherit;
}

a:focus, button:focus {
    outline: 2px solid var(--color-gold);
    outline-offset: 2px;
}

/* --- Header & Navigation --- */
.main-header {
    padding: 15px 0;
    text-align: center;
    position: sticky;
    top: 0;
    background-color: var(--bg-header);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    z-index: 100;
    border-bottom: 1px solid var(--border-color);
}

nav a {
    margin: 0 10px;
    padding: 8px 12px;
    font-weight: 700;
    font-size: 0.9rem;
    transition: all 0.3s;
    border-radius: 5px;
}

nav a:hover {
    color: var(--color-gold);
    background-color: rgba(212, 175, 55, 0.1);
}

nav a.active {
    color: var(--color-gold);
    background-color: rgba(212, 175, 55, 0.15);
}

/* --- Footer --- */
.footer {
    padding: 50px 20px;
    font-size: 0.9rem;
    color: #aaa;
    text-align: center;
}

/* --- Responsive: Mobile Navigation --- */
@media (max-width: 768px) {
    nav a {
        margin: 0 5px;
        font-size: 0.8rem;
        padding: 6px 8px;
    }
}