/* レター招待ページ CSS - Figmaデザイン準拠 */

/* 全体のレイアウト */
body {
    font-family: "SF Pro", -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: #FFF;
    margin: 0;
    padding: 0;
    min-height: 100vh;
    font-size: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.main {
    padding: 40px 0 80px;
    display: flex;
    justify-content: center;
}

.container {
    width: 355px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

/* 上部のレター画像 */
.hero-image img {
    width: 240px;
    height: 96px;
    filter: drop-shadow(0px 3px 7px rgba(0, 0, 0, 0.10)) drop-shadow(0px 14px 14px rgba(0, 0, 0, 0.09)) drop-shadow(0px 30px 18px rgba(0, 0, 0, 0.05)) drop-shadow(0px 54px 22px rgba(0, 0, 0, 0.01)) drop-shadow(0px 84px 24px rgba(0, 0, 0, 0.00));
}

/* メインカード */
.main-card {
    width: 100%;
    position: relative;
    background: linear-gradient(-45deg, #FEB7B4, #F0A8A5, #E78681, #F2AAA7, #FFB8B5, #F1A9A6);
    background-size: 400% 400%;
    animation: gradientFlow 12s ease-in-out infinite;
    border-radius: 20px;
    padding: 30px 10px 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 24px;
    overflow: hidden;
}

/* スムーズなグラデーションアニメーション */
@keyframes gradientFlow {
    0% {
        background-position: 0% 50%;
        filter: brightness(1) saturate(1);
    }
    20% {
        background-position: 50% 25%;
        filter: brightness(1.02) saturate(1.03);
    }
    40% {
        background-position: 100% 50%;
        filter: brightness(1.04) saturate(1.05);
    }
    60% {
        background-position: 75% 100%;
        filter: brightness(1.02) saturate(1.03);
    }
    80% {
        background-position: 25% 75%;
        filter: brightness(1.01) saturate(1.02);
    }
    100% {
        background-position: 0% 50%;
        filter: brightness(1) saturate(1);
    }
}

/* 微細な輝き効果 */
.main-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(45deg,
        rgba(255, 255, 255, 0.04) 0%,
        rgba(255, 255, 255, 0.02) 25%,
        transparent 50%,
        rgba(255, 255, 255, 0.02) 75%,
        rgba(255, 255, 255, 0.04) 100%);
    background-size: 300% 300%;
    animation: shimmer 16s ease-in-out infinite;
    border-radius: 20px;
    pointer-events: none;
}

@keyframes shimmer {
    0% {
        background-position: -100% -100%;
        opacity: 0.2;
    }
    50% {
        background-position: 100% 100%;
        opacity: 0.4;
    }
    100% {
        background-position: -100% -100%;
        opacity: 0.2;
    }
}

/* カードヘッダー */

.logo-image {
    width: 160px;
}

/* ステップセクション */
.step-section {
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

.step-content {
    width: 335px;
    position: relative;
}

.step-number {
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 40px;
    height: 40px;
    background-color: #F19A96;
    border: 4px solid #FFF;
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: "Avenir Next", sans-serif;
    font-size: 20px;
    font-weight: 600;
    color: #FFF;
    z-index: 2;
}

.step-card {
    background-color: #FFF;
    border-radius: 16px;
    padding: 30px 20px 20px;
    margin-top: 18px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.step-info {
    display: flex;
    align-items: center;
    gap: 15px;
}

.app-icon {
    width: 48px;
    height: 48px;
    border-radius: 8px;
    flex-shrink: 0;
}

.step-description {
    line-height: 1.6em;
    letter-spacing: 0.033em;
    color: #000;
    margin: 0;
    flex: 1;
}

/* 招待コード */
.invite-code {
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: center;
    gap: 18px;
    width: 100%;
}

.invite-label {
    font-size: 12px;
    font-weight: bold;
    line-height: 1.4em;
    letter-spacing: 0.042em;
    color: #000;
}

.invite-code-text {
    font-size: 32px;
    font-weight: bold;
    line-height: 1.4em;
    letter-spacing: 0.016em;
    color: #F19A96;
}

/* ボタン */
.download-btn, .start-btn {
    background-color: #000;
    color: #FFF;
    border: none;
    border-radius: 22px;
    padding: 10px;
    font-size: 16px;
    font-weight: bold;
    line-height: 1em;
    letter-spacing: 0.031em;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
    width: 100%;
    min-height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.download-btn:hover, .start-btn:hover {
    background-color: #666;
    transform: translateY(-2px);
}

.download-btn:active, .start-btn:active {
    transform: translateY(0);
}

/* 注意事項 */
.notice {
    font-size: 12px;
    line-height: 1.6em;
    letter-spacing: 0.042em;
    color: #FFF;
    text-align: center;
    margin: 0;
}

/* 招待特典セクション */
.benefits-section {
    width: 375px;
    margin-top: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 24px;
    background-color: #FFF;
    padding: 30px 20px;
    border-radius: 20px;
}

.benefits-content {
    width: 100%;
    display: flex;
    gap: 30px;
}

.benefit-item {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 14px;
}

.benefit-icon {
    width: 70px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.benefit-image {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
}

.benefit-title {
    font-size: 16px;
    font-weight: bold;
    line-height: 1.4em;
    letter-spacing: 0.031em;
    color: #F19A96;
    text-align: center;
    margin: 0;
}

.benefit-description {
    line-height: 1.6em;
    letter-spacing: 0.033em;
    color: #000;
    text-align: left;
    margin: 0;
}

/* フッター */
.footer {
    width: 192px;
    margin-top: 80px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

.copyright {
    line-height: 1.6em;
    letter-spacing: 0.033em;
    color: #000;
    text-align: center;
    margin: 0;
}