@charset "UTF-8";

/* ==================================================
   How It Works - Page Specific Styles
   ================================================== */

/* 背景設定（index.cssの変数を前提） */
body {
    background-color: var(--color-black);
    color: var(--color-white);
}

.how-main {
    position: relative;
    width: 100%;
    min-height: 100vh;
    padding-top: calc(var(--header-height) + 40px);
    padding-bottom: 80px;
    padding-left: 24px;
    padding-right: 24px;
    display: flex;
    flex-direction: column;
    align-items: center;
    z-index: 10;
}

/* --- Hero Section --- */
.how-title {
    font-family: var(--font-sans);
    font-size: 2.5rem;
    font-weight: 900;
    text-align: center;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-white);
    margin-bottom: 8px;
    text-shadow: 0 0 20px rgba(168, 85, 247, 0.3); /* Neon glow */
}

.how-subtitle {
    font-family: var(--font-jp);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-gray-500);
    text-align: center;
    margin-bottom: 48px;
    letter-spacing: 0.05em;
}

/* --- Tabs Navigation --- */
.how-tabs {
    display: flex;
    justify-content: center;
    gap: 24px; /* スマホでの間隔 */
    width: 100%;
    max-width: 600px;
    margin-bottom: 56px;
    position: relative;
}

.how-tab-btn {
    background: transparent;
    border: none;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    opacity: 0.5;
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    width: 80px;
}

.how-tab-btn:hover {
    opacity: 0.8;
}

.how-tab-btn.active {
    opacity: 1;
    transform: translateY(-5px);
}

/* Icon Circle */
.tab-icon-box {
    width: 64px;
    height: 64px;
    border-radius: 50%;
    
    /* 未選択時はダークなガラス */
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(4px);
    
    display: flex;
    justify-content: center;
    align-items: center;
    transition: all 0.3s ease;
}

.tab-icon-img {
    width: 28px;
    height: 28px;
    object-fit: contain;
    /* 黒アイコンを白く反転 */
    filter: invert(1);
    transition: all 0.3s ease;
}

/* Active State: Neon Glow */
.how-tab-btn.active .tab-icon-box {
    background: var(--color-neon);
    border-color: var(--color-neon);
    box-shadow: 0 0 20px rgba(168, 85, 247, 0.4);
}

.how-tab-btn.active .tab-icon-img {
    /* ネオン背景の上なので白のまま */
    filter: invert(1) brightness(10);
}

.tab-label {
    font-family: var(--font-sans);
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-white);
}

/* --- Content Area --- */
.how-content-wrapper {
    width: 100%;
    max-width: 500px;
    position: relative;
    min-height: 400px; /* ガタつき防止 */
}

.how-content-item {
    display: none;
    text-align: center;
    flex-direction: column;
    align-items: center;
    /* アニメーション */
    animation: fadeInUp 0.5s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.how-content-item.active {
    display: flex;
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Content Image */
.content-image {
    width: 100%;
    aspect-ratio: 16 / 9;
    object-fit: cover;
    border-radius: 12px;
    margin-bottom: 32px;
    
    /* ガラス風の枠 */
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    opacity: 0.9;
}

/* Content Text */
.content-headline {
    font-family: var(--font-jp);
    font-size: 1.5rem;
    font-weight: 900;
    line-height: 1.4;
    color: var(--color-white);
    margin-bottom: 24px;
}

.content-desc {
    font-family: var(--font-jp);
    font-size: 0.9rem;
    font-weight: 500;
    line-height: 1.8;
    color: var(--color-gray-300);
    margin-bottom: 32px;
}

/* Buttons in Content (override generic btn styles if needed) */
.how-content-item .btn {
    width: 100%;
    max-width: 280px;
}

/* ==================================================
   Responsive (Tablet/Desktop)
   ================================================== */
@media (min-width: 768px) {
    .how-main { padding-top: calc(var(--header-height) + 60px); }
    
    .how-title { font-size: 3.5rem; }
    .how-subtitle { font-size: 1rem; }
    
    .how-tabs { gap: 60px; margin-bottom: 64px; }
    
    .tab-icon-box { width: 80px; height: 80px; }
    .tab-icon-img { width: 32px; height: 32px; }
    .tab-label { font-size: 0.875rem; margin-top: 4px; }
    
    .how-content-wrapper { max-width: 600px; }
    .content-headline { font-size: 2rem; }
    .content-desc { font-size: 1rem; }
}