/* commonstyle.css */
:root {
    /* カラーパレット */
    --accent: #0ea5a4; /* teal-ish accent */
    --accent-strong: #06b6d4;
    --primary: #2563eb;
    --primary-hover: #1e40af;

    /* surfaces */
    --bg-body: #0f172a; /* dark background for better contrast */
    --bg-card: #0b1220;
    --surface: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.00));
    --muted-surface: rgba(255,255,255,0.02);

    /* text */
    --text-main: #e6eef8;
    --text-muted: #94a3b8;
    --muted-text: #9aa8bd;

    /* borders & shadows */
    --border: rgba(255,255,255,0.04);
    --shadow-sm: 0 6px 18px rgba(2,6,23,0.6);
    --shadow-lg: 0 20px 60px rgba(2,6,23,0.7);

    /* UI */
    --radius: 12px;
    --header-h: 72px;

    /* gradients */
    --gradient-primary: linear-gradient(90deg, var(--primary), #7c3aed);
    --gradient-secondary: linear-gradient(90deg, rgba(37,99,235,0.12), rgba(6,182,212,0.08));
    --gradient-accent: linear-gradient(90deg, var(--accent), var(--accent-strong));
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html,body{height:100%}
body {
    font-family: 'Noto Sans JP', system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial;
    background-color: var(--bg-body);
    color: var(--text-main);
    line-height: 1.6;
    -webkit-font-smoothing:antialiased;
    -moz-osx-font-smoothing:grayscale;
}

.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

/* ナビゲーション */
.site-header {
    height: var(--header-h);
    background: rgba(4,6,11,0.35);
    border-bottom: 1px solid rgba(255,255,255,0.02);
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(6px);
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

.logo {
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--accent);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 10px;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 18px;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-main);
    font-weight: 600;
    padding: 8px 10px;
    border-radius: 8px;
    transition: all 0.18s ease;
}

/* prevent awkward mid-character breaks for CJK and improve wrapping behavior */
.nav-links a, .mobile-nav ul li a {
    white-space: normal;
    word-break: keep-all; /* prefer breaking between words for CJK */
    overflow-wrap: break-word;
}

.nav-links a:hover, .nav-links a.active {
    color: #fff;
    background: var(--gradient-secondary);
    transform: translateY(-2px);
}

/* ユーティリティ: ボタン */
.btn { display:inline-flex; align-items:center; gap:8px; padding:10px 14px; border-radius:8px; cursor:pointer; border:1px solid transparent; font-weight:600; white-space:normal; overflow-wrap:break-word; }
.btn-primary { background: var(--gradient-primary); color:#fff; box-shadow: var(--shadow-sm); }
.btn-ghost { background: transparent; color:var(--text-main); border:1px solid var(--border); }

/* カード */
.card { background: var(--bg-card); border-radius: var(--radius); padding:16px; border:1px solid var(--border); box-shadow: var(--shadow-sm); }

/* フォーム要素共通 */
input, select, textarea, button { font-family: inherit }

/* 公開用小サイズユーティリティ */
.sr-only{position:absolute!important;height:1px;width:1px;padding:0;border:0;overflow:hidden;clip:rect(1px,1px,1px,1px);white-space:nowrap}

/* main-nav (desktop) and mobile navigation styles */
.main-nav { display:block; }
.main-nav ul { list-style:none; display:flex; gap:18px; align-items:center; }
.main-nav ul li a { color:var(--text-main); text-decoration:none; padding:8px 10px; border-radius:8px; display:inline-block; }

.hamburger { display:none; width:40px; height:32px; cursor:pointer; flex-direction:column; justify-content:space-around; align-items:center; }
.hamburger span { display:block; width:24px; height:3px; background:var(--text-main); border-radius:3px; transition: transform 0.18s ease, opacity 0.18s ease; }
.hamburger.active span:nth-child(1) { transform: translateY(8px) rotate(45deg); }
.hamburger.active span:nth-child(2) { opacity:0; }
.hamburger.active span:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }

.mobile-nav { display:none; }
.mobile-nav.show { display:block; position:fixed; inset:var(--header-h) 0 0 0; background:var(--bg-card); z-index:1200; padding:16px; overflow:auto; box-shadow:var(--shadow-lg); }
.mobile-nav ul { list-style:none; padding:12px 0; }
.mobile-nav ul li { padding:8px 0; border-bottom:1px solid rgba(255,255,255,0.02); }
.mobile-nav ul li a { color:var(--text-main); display:block; padding:8px 6px; }

/* Responsive breakpoint */
@media (max-width: 900px) {
    .main-nav { display:none; }
    .hamburger { display:flex; }
}

/* global mobile adjustments */
@media (max-width: 900px) {
    .container { padding: 0 12px; }
    .header-inner { flex-wrap: wrap; gap:8px; align-items:center; }
    .logo { font-size: 1rem; }
    .nav-links { display:none; }
    .site-header { height: auto; padding: 8px 0; }
    /* reduce base font slightly on very small screens */
    html, body { font-size: 15px; }
}