/* ==========================================================================
   Variable & Base
   ========================================================================== */
:root {
    --bg-main: #fdfcfb;
    --nail-color: #8c705f;      /* ネイル：ブランドカラー（グレージュ） */
    --coaching-color: #5d4a3e;  /* コーチング：落ち着いたディープブラウン */
    --text-color: #444444;
    --text-muted: #777777;
    --white: #ffffff;
    --transition: 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

body {
    font-family: 'Noto Serif JP', serif;
    background-color: var(--bg-main);
    color: var(--text-color);
    line-height: 1.8;
    overflow-x: hidden;
}

/* ==========================================================================
   Hero Section (ファーストビューの強化)
   ========================================================================== */
.hero {
    padding: 100px 0;
    background: linear-gradient(to bottom, #ffffff, #fdfcfb);
}

.hero-logo {
    max-width: 280px;
    margin-bottom: 40px;
    height: auto;
    animation: fadeIn 1.5s ease forwards; /* ふわっと表示 */
}

.hero-title {
    font-size: 1.8rem;
    font-weight: 700;
    letter-spacing: 0.15em; /* 文字間隔を広げて高級感を出す */
    color: #333;
    margin-bottom: 2rem;
    text-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

.hero-sub {
    font-size: 1.1rem;
    color: var(--text-muted);
    line-height: 2;
    margin-bottom: 3rem;
}

/* ヒーロー専用ボタンのデザイン */
.btn-hero {
    display: inline-block;
    padding: 12px 20px; /* PCは少し広め */
    border-radius: 50px;
    text-decoration: none !important;
    color: var(--white) !important;
    font-weight: bold;
    transition: all 0.4s ease;
    min-width: 140px; /* iPhone SEに合わせて少し小さめに設定 */
    line-height: 1.2;
    border: none;
    flex: 1; /* 親のd-flex内で均等に広がるように設定 */
    max-width: 200px; /* 広がりすぎ防止 */
}

/* スマホ・iPhone SE対策 (幅767px以下) */
@media (max-width: 767px) {
    .hero-btns {
        gap: 10px !important; /* ボタン同士の隙間を狭くする */
        padding: 0 10px;      /* 画面端との余白を確保 */
    }

    .btn-hero {
        min-width: 0;        /* 最小幅の制限を解除 */
        padding: 10px 5px;   /* 左右の余白を最小限に */
        font-size: 0.9rem;   /* メイン文字を少し小さく */
    }

    .btn-hero .small {
        font-size: 0.6rem;   /* 英語表記をさらに小さく */
        /*margin-bottom: 2px;*/
    }
}

/* PC・タブレット以上のサイズ (幅768px以上) */
@media (min-width: 768px) {
    .btn-hero {
        min-width: 220px;
        padding: 15px 35px;
        font-size: 1rem;
    }
}

.btn-nail-hero { background-color: var(--nail-color); }
.btn-coaching-hero { background-color: var(--coaching-color); }

.btn-hero:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.1) !important;
    filter: brightness(1.1);
}

.btn-hero .small {
    font-size: 0.7rem;
    font-weight: normal;
    opacity: 0.9;
    margin-bottom: 4px;
    letter-spacing: 0.05em;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

@media (min-width: 768px) {
    .hero-title { font-size: 2.8rem; }
    .btn-hero { min-width: 220px; }
}

/* ==========================================================================
   Navigation (PC & Mobile)
   ========================================================================== */

/* PC Floating Sidebar */
.floating-sidebar {
    position: fixed;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    z-index: 1050;
    flex-direction: column;
    display: flex;
}

.sidebar-btn {
    writing-mode: vertical-rl;
    padding: 30px 20px 30px 10px;
    color: var(--white) !important;
    text-decoration: none;
    font-size: 0.85rem;
    border-radius: 10px 0 0 10px;
    transition: var(--transition);
    letter-spacing: 0.1em;
    margin-bottom: 2px;
    transform: translateX(12px);
}

.btn-nail { background-color: var(--nail-color); }
.btn-coaching { background-color: var(--coaching-color); }

.sidebar-btn:hover {
    transform: translateX(0);
    filter: brightness(1.2);
    box-shadow: -5px 0 15px rgba(0,0,0,0.1);
}

/* Mobile Bottom Nav */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    display: flex;
    z-index: 1050;
    box-shadow: 0 -3px 15px rgba(0,0,0,0.08);
}

.bottom-nav-btn {
    flex: 1;
    padding: 20px 10px;
    text-align: center;
    color: var(--white) !important;
    text-decoration: none;
    font-size: 0.85rem;
    font-weight: bold;
}

.sp-nail { background-color: var(--nail-color); }
.sp-coaching { background-color: var(--coaching-color); }
.btn-left { border-right: 1px solid rgba(255, 255, 255, 0.1); }

/* ==========================================================================
   Gallery (Image Expandable)
   ========================================================================== */
.img-expandable {
    cursor: pointer;
    width: 100%;
    height: 250px;
    object-fit: cover;
    transition: var(--transition);
}

.img-expandable:hover {
    transform: translateY(-5px);
    filter: brightness(0.9);
    box-shadow: 0 10px 20px rgba(0,0,0,0.1) !important;
}

@media (max-width: 767px) {
    .img-expandable { height: 160px; }
}

/* ==========================================================================
   Buttons (CTA) - 各セクション用
   ========================================================================== */
.btn-cta {
    color: var(--white) !important;
    padding: 14px 45px;
    border-radius: 50px;
    text-decoration: none;
    display: inline-block;
    transition: var(--transition);
    font-size: 0.95rem;
    font-weight: bold;
    border: none;
}

#nail .btn-cta { background-color: var(--nail-color); }
#coaching .btn-cta { background-color: var(--coaching-color); }

.btn-cta:hover {
    filter: brightness(1.1);
    transform: scale(1.05);
}

/* ==========================================================================
   Back to Top
   ========================================================================== */
.back-to-top {
    position: fixed;
    right: 20px;
    width: 48px;
    height: 48px;
    background: var(--white);
    border: 1px solid var(--nail-color);
    color: var(--nail-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 1000;
    font-size: 1.5rem;
    bottom: 90px;
}

@media (min-width: 992px) {
    .back-to-top { bottom: 30px; }
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

/* ==========================================================================
   Other UI Elements
   ========================================================================== */
section { padding: 100px 0; }
.section-title { font-weight: 700; margin-bottom: 50px; position: relative; }
.section-title::after {
    content: ''; position: absolute; left: 50%; bottom: -15px;
    transform: translateX(-50%); width: 40px; height: 1px; background: var(--nail-color);
}
.card-custom { background: var(--white); border-radius: 15px; padding: 50px 30px; }
.price-focus { font-size: 1.7rem; color: var(--nail-color); font-weight: 700; }
#coaching .price-focus { color: var(--coaching-color); }
.btn-modal-close { top: 5px; right: 5px; font-size: 2.5em; }

@media (max-width: 991px) {
    body { padding-bottom: 70px; }
    .btn-modal-close { top: 0; right: 0; font-size: 2.0em; }
}