/* --- 共通変数定義 --- */
:root {
    --primary: #1fc7d4;
    --secondary: #7645d9;
    --bg: #08060b;
    --card: #27262c;
    --text: #f4eeff;
    --text-sub: #b8add2;
    --warning: #ff4444;
    --gradient: linear-gradient(135deg, #1fc7d4 0%, #7645d9 100%);
    --shadow: 0 4px 0 #130f1a;
}

/* --- ベーススタイル --- */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Kanit', 'Segoe UI', sans-serif;
    background-color: var(--bg);
    color: var(--text);
    line-height: 1.6;
    position: relative;
    overflow-x: hidden;
}

/* --- コイン背景 --- */
#coin-field {
    position: fixed;
    inset: 0;
    z-index: 0;
    pointer-events: none;
    overflow: hidden;
}

.coin {
    position: absolute;
    border-radius: 50%;
    --coin-rot: 0deg;
    background:
        radial-gradient(circle at 35% 35%, #fff2bf 0%, #ffd369 35%, #ffb237 60%, #c77b1f 100%);
    box-shadow:
        inset 0 0 10px rgba(255, 255, 255, 0.35),
        inset -6px -8px 12px rgba(143, 82, 10, 0.45),
        0 10px 18px rgba(0, 0, 0, 0.45);
    opacity: 0.55;
    transform: translate3d(0, 0, 0) rotate(var(--coin-rot));
    animation-timing-function: ease-in-out;
    will-change: transform, opacity;
}

.coin::after {
    content: "";
    position: absolute;
    inset: 18%;
    border-radius: 50%;
    border: 2px solid rgba(255, 255, 255, 0.35);
    box-shadow: inset 0 0 6px rgba(255, 231, 163, 0.6);
}

@keyframes coin-float-a {
    0% { transform: translate3d(0, 0, 0) rotate(calc(var(--coin-rot) + 0deg)); opacity: 0.35; }
    50% { transform: translate3d(12px, -18px, 0) rotate(calc(var(--coin-rot) + 20deg)); opacity: 0.65; }
    100% { transform: translate3d(-10px, 14px, 0) rotate(calc(var(--coin-rot) - 12deg)); opacity: 0.45; }
}

@keyframes coin-float-b {
    0% { transform: translate3d(0, 0, 0) rotate(calc(var(--coin-rot) + 0deg)); opacity: 0.3; }
    50% { transform: translate3d(-16px, 10px, 0) rotate(calc(var(--coin-rot) - 18deg)); opacity: 0.6; }
    100% { transform: translate3d(8px, -12px, 0) rotate(calc(var(--coin-rot) + 14deg)); opacity: 0.4; }
}

header,
.hero,
.container,
footer,
#backToTop {
    position: relative;
    z-index: 1;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 1rem;
}

/* --- ヘッダー --- */
header {
    background: rgba(39, 38, 44, 0.95);
    padding: 0.8rem 0;
    border-bottom: 1px solid #383241;
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
}

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

.logo-container {
    display: flex;
    align-items: center;
    gap: 12px;
    transition: opacity 0.2s;
}

.logo-container:hover {
    opacity: 0.8;
}

.logo-img {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 1px solid var(--primary);
}

.logo-text {
    font-weight: 800;
    font-size: 1.5rem;
    color: var(--primary);
    letter-spacing: 0.5px;
}

/* --- ヒーローセクション --- */
.hero {
    text-align: center;
    padding: 4rem 1rem;
    background: radial-gradient(circle at center, #201335 0%, #08060b 100%);
}

.hero-img {
    max-width: 100%;
    width: 500px;
    border-radius: 20px;
    box-shadow: 0 0 30px rgba(31, 199, 212, 0.3);
    margin-bottom: 2rem;
    transition: transform 0.3s;
}

.hero-img:hover {
    transform: translateY(-5px);
}

h1 {
    font-size: 2.8rem;
    margin-bottom: 1rem;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: 800;
}

.hero-desc {
    color: var(--text-sub);
    font-size: 1.1rem;
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* --- カード & セクション --- */
.card {
    background: var(--card);
    border-radius: 24px;
    padding: 2.5rem;
    margin-bottom: 2rem;
    border: 1px solid #383241;
    box-shadow: var(--shadow);
}

.section-title {
    color: var(--primary);
    margin-top: 0;
    margin-bottom: 1.5rem;
    font-size: 1.6rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* --- ボタン --- */
.btn-primary {
    background: var(--gradient);
    color: white;
    padding: 14px 32px;
    border-radius: 16px;
    text-decoration: none;
    font-weight: bold;
    display: inline-block;
    transition: all 0.2s;
    border: none;
    cursor: pointer;
    box-shadow: 0 4px 0 rgba(0,0,0,0.2);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(118,69,217,0.4);
}

/* --- カウントダウン施策エリア --- */
.countdown-box {
    background: #3c3742;
    padding: 1.5rem;
    border-radius: 16px;
    text-align: center;
    margin-top: 1.5rem;
    border: 1px solid rgba(31, 199, 212, 0.2);
}

#timer {
    font-size: 2.2rem;
    font-weight: 900;
    color: var(--primary);
    font-family: monospace;
    -webkit-text-stroke: 2px var(--primary);
    text-stroke: 2px var(--primary);
}

.deadline-label {
    font-size: 0.85rem;
    color: var(--text-sub);
    margin-bottom: 5px;
    text-transform: uppercase;
}

/* --- インフォメーション & タブ --- */
.tabs {
    display: flex;
    gap: 12px;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid #383241;
    padding-bottom: 12px;
}

.tab-btn {
    background: transparent;
    border: 2px solid var(--secondary);
    color: var(--text);
    padding: 8px 20px;
    border-radius: 12px;
    cursor: pointer;
    font-weight: 600;
    transition: 0.2s;
}

.tab-btn:hover {
    background: rgba(118, 69, 217, 0.1);
}

.tab-btn.active {
    background: var(--secondary);
    color: white;
}

/* --- Information --- */
.info-list {
    list-style: none;
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem 1.5rem;
}

.info-item {
    border-bottom: 1px solid #383241;
    padding-bottom: 0.5rem;
}

.info-date {
    color: var(--text-sub);
    font-size: 0.8rem;
    display: block;
    margin-bottom: 0.35rem;
}

.info-text {
    display: block;
}

.info-event-card {
    background: rgba(31, 199, 212, 0.1);
    padding: 1rem;
    border-radius: 12px;
    border: 1px solid transparent;
    margin-bottom: 1rem;
}

.info-event-card:last-child {
    margin-bottom: 0;
}

.info-event-card--upcoming {
    background: rgba(118, 69, 217, 0.12);
    border-style: dashed;
}

.info-event-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1rem 1.5rem;
    align-items: start;
}

.info-note {
    font-size: 0.9rem;
    color: var(--text-sub);
    margin-top: 0.5rem;
}

.info-status {
    color: #4cd964;
}

.info-status--upcoming {
    color: #f7c948;
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.5rem;
}

.info-heading {
    font-size: 1rem;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    color: var(--text-sub);
    margin-bottom: 0.75rem;
}

.info-panel {
    background: rgba(15, 13, 20, 0.55);
    border: 1px solid #383241;
    border-radius: 16px;
    padding: 1rem;
}

/* --- 利用規約・サポート用詳細スタイル --- */
.legal-section h3, .support-section h3 {
    color: var(--text);
    margin: 1.5rem 0 0.5rem;
    font-size: 1.2rem;
}

.sub-text {
    font-size: 0.9rem;
    color: var(--text-sub);
}

.warning-box {
    background: rgba(255, 68, 68, 0.1);
    padding: 1.5rem;
    border-radius: 16px;
    border: 1px solid var(--warning);
    margin: 2rem 0;
}

.warning-box h4 {
    color: var(--warning);
    margin-top: 0;
    margin-bottom: 10px;
}

.warning-box ul {
    padding-left: 20px;
}

.qa-item {
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid #383241;
}

.qa-item:last-child {
    border-bottom: none;
}

.qa-item h4 {
    color: var(--primary);
    font-size: 1.1rem;
    margin-bottom: 8px;
}

/* --- リンク --- */
.text-link {
    color: var(--primary);
    text-decoration: none;
    font-weight: bold;
    border-bottom: 1px solid transparent;
    transition: 0.2s;
}

.text-link:hover {
    border-bottom: 1px solid var(--primary);
}

.highlight {
    color: #ffb237;
    font-weight: 800;
}

/* --- フッター --- */
footer {
    text-align: center;
    padding: 5rem 1rem;
    border-top: 1px solid #383241;
    background: #130f1a;
}

.footer-links {
    margin-bottom: 2.5rem;
    display: flex;
    justify-content: center;
    gap: 25px;
    flex-wrap: wrap;
}

.footer-links a {
    color: var(--text-sub);
    text-decoration: none;
    font-size: 0.95rem;
    transition: color 0.2s;
}

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

.copyright {
    font-size: 0.8rem;
    opacity: 0.6;
}

/* --- トップへ戻るボタン --- */
#backToTop {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background: var(--secondary);
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s;
    color: white;
    box-shadow: 0 4px 15px rgba(0,0,0,0.4);
    z-index: 1001;
}

#backToTop.show {
    opacity: 1;
    visibility: visible;
}

#backToTop:hover {
    transform: scale(1.1);
    background: #8a59f2;
}

/* --- レスポンシブ調整 --- */
@media (max-width: 768px) {
    h1 { font-size: 2.2rem; }
    .hero { padding: 3rem 1rem; }
    .card { padding: 1.5rem; }
    #timer { font-size: 1.6rem; }
    .footer-links { gap: 15px; }
    .info-list { grid-template-columns: 1fr; }
    .info-event-grid { grid-template-columns: 1fr; }
    .info-grid { grid-template-columns: 1fr; }
}

/* --- フォームスタイル (新規追加) --- */
.form-group {
    margin-bottom: 1rem;
    text-align: left;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-sub);
    font-size: 0.9rem;
}

.form-group input {
    width: 100%;
    padding: 12px;
    background: #130f1a;
    border: 1px solid #383241;
    border-radius: 12px;
    color: var(--text);
    font-family: inherit;
    font-size: 1rem;
    transition: 0.3s;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 10px rgba(31, 199, 212, 0.2);
}

/* スマホでの入力しやすさ調整 */
@media (max-width: 600px) {
    .form-group input {
        font-size: 16px; /* iOSでのズーム防止 */
    }
}