/* ===================================================
   楽器練習@千代田 — Main Stylesheet v1.0.0
   =================================================== */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
    --cream:        #f9f6f0;
    --warm-white:   #fdfbf8;
    --charcoal:     #1a1814;
    --charcoal-60:  rgba(26,24,20,0.6);
    --charcoal-30:  rgba(26,24,20,0.3);
    --charcoal-10:  rgba(26,24,20,0.08);
    --gold:         #b8975a;
    --gold-light:   #d4b87a;
    --gold-pale:    #f2ead8;
    --serif-en:     'Cormorant Garamond', serif;
    --serif-ja:     'Noto Serif JP', serif;
    --sans-ja:      'Noto Sans JP', sans-serif;
}

html { scroll-behavior: smooth; }

body {
    font-family: var(--serif-ja);
    background: var(--warm-white);
    color: var(--charcoal);
    font-weight: 300;
    line-height: 1.9;
    -webkit-font-smoothing: antialiased;
}

/* ─── HEADER ─── */
.site-header {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.5rem 4rem;
    background: rgba(253,251,248,0.92);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 0.5px solid var(--charcoal-10);
    transition: border-color 0.3s;
}
.site-header.scrolled { border-bottom-color: rgba(26,24,20,0.15); }

.logo {
    font-family: var(--serif-en);
    font-size: 1.05rem;
    font-weight: 400;
    letter-spacing: 0.12em;
    color: var(--charcoal);
    text-decoration: none;
    display: flex;
    flex-direction: column;
    gap: 1px;
}
.logo span {
    font-family: var(--serif-ja);
    font-size: 0.65rem;
    font-weight: 300;
    letter-spacing: 0.22em;
    color: var(--charcoal-60);
}

.site-nav {
    display: flex;
    gap: 2.5rem;
    align-items: center;
}
.site-nav ul { list-style: none; display: flex; gap: 2.5rem; align-items: center; }
.site-nav a {
    font-family: var(--sans-ja);
    font-size: 0.72rem;
    letter-spacing: 0.18em;
    color: var(--charcoal-60);
    text-decoration: none;
    transition: color 0.3s;
}
.site-nav a:hover { color: var(--charcoal); }
.site-nav .btn-join {
    font-family: var(--sans-ja);
    font-size: 0.7rem;
    letter-spacing: 0.18em;
    color: var(--gold);
    border: 0.5px solid var(--gold);
    padding: 0.55rem 1.4rem;
    transition: all 0.3s;
}
.site-nav .btn-join:hover { background: var(--gold); color: var(--warm-white); }

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}
.nav-toggle span {
    display: block;
    width: 22px;
    height: 0.5px;
    background: var(--charcoal);
    transition: transform 0.3s, opacity 0.3s;
}
.nav-toggle.active span:nth-child(1) { transform: translateY(5.5px) rotate(45deg); }
.nav-toggle.active span:nth-child(2) { opacity: 0; }
.nav-toggle.active span:nth-child(3) { transform: translateY(-5.5px) rotate(-45deg); }

/* ─── HERO ─── */
.hero {
    min-height: 100vh;
    display: grid;
    grid-template-columns: 1fr 1fr;
    align-items: center;
    overflow: hidden;
}
.hero-left {
    padding: 10rem 5rem 6rem 8rem;
    display: flex;
    flex-direction: column;
    gap: 2rem;
}
.hero-eyebrow {
    font-family: var(--sans-ja);
    font-size: 0.65rem;
    letter-spacing: 0.3em;
    color: var(--gold);
    font-weight: 300;
}
.hero-title {
    font-family: var(--serif-en);
    font-size: clamp(3.2rem, 5vw, 5rem);
    font-weight: 300;
    line-height: 1.1;
    letter-spacing: -0.01em;
}
.hero-title em { font-style: italic; color: var(--gold); }
.hero-subtitle {
    font-family: var(--serif-ja);
    font-size: 1.05rem;
    font-weight: 300;
    color: var(--charcoal-60);
    line-height: 2;
    max-width: 340px;
}
.hero-meta { display: flex; flex-direction: column; gap: 0.4rem; }
.hero-meta-item {
    font-family: var(--sans-ja);
    font-size: 0.7rem;
    letter-spacing: 0.15em;
    color: var(--charcoal-60);
    display: flex;
    align-items: center;
    gap: 0.7rem;
}
.hero-meta-item::before {
    content: '';
    display: inline-block;
    width: 18px;
    height: 0.5px;
    background: var(--gold);
}
.hero-cta { display: flex; gap: 1.2rem; align-items: center; margin-top: 0.5rem; }
.btn-primary {
    font-family: var(--sans-ja);
    font-size: 0.72rem;
    letter-spacing: 0.2em;
    color: var(--warm-white);
    background: var(--charcoal);
    padding: 1rem 2.2rem;
    text-decoration: none;
    transition: background 0.3s;
    display: inline-block;
}
.btn-primary:hover { background: var(--gold); }
.btn-secondary {
    font-family: var(--sans-ja);
    font-size: 0.7rem;
    letter-spacing: 0.18em;
    color: var(--charcoal-60);
    text-decoration: none;
    border-bottom: 0.5px solid var(--charcoal-30);
    padding-bottom: 2px;
    transition: color 0.3s, border-color 0.3s;
}
.btn-secondary:hover { color: var(--gold); border-color: var(--gold); }

.hero-right {
    position: relative;
    height: 100vh;
    background: var(--cream);
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}
.hero-illustration { width: 100%; height: 100%; display: flex; align-items: center; justify-content: center; }
.hero-right-label {
    position: absolute;
    bottom: 3rem; right: 3rem;
    font-family: var(--sans-ja);
    font-size: 0.6rem;
    letter-spacing: 0.28em;
    color: var(--charcoal-30);
    writing-mode: vertical-lr;
}

/* Piano visual */
.piano-visual { position: relative; width: 240px; height: 300px; }
.staff-lines { position: absolute; top: 22px; left: 18px; right: 18px; }
.staff-line { height: 0.5px; background: var(--charcoal-30); margin-bottom: 10px; }
.note-symbol {
    position: absolute;
    font-family: var(--serif-en);
    font-size: 2.8rem;
    font-weight: 300;
    color: var(--gold);
    opacity: 0.6;
    animation: float 6s ease-in-out infinite;
}
@keyframes float {
    0%, 100% { transform: translateY(0) rotate(0deg); opacity: 0.5; }
    50%       { transform: translateY(-8px) rotate(3deg); opacity: 0.85; }
}
.piano-keys {
    display: flex;
    gap: 3px;
    align-items: flex-start;
    position: absolute;
    bottom: 18px;
    left: 50%;
    transform: translateX(-50%);
}
.white-key {
    width: 28px; height: 120px;
    background: #f5f0e8;
    border: 0.5px solid var(--charcoal-30);
    border-radius: 0 0 3px 3px;
    flex-shrink: 0;
}
.white-key.pressed { background: var(--gold-pale); border-color: var(--gold); }


/* ─── SECTIONS COMMON ─── */
section { overflow: hidden; }

.section-label {
    font-family: var(--sans-ja);
    font-size: 0.6rem;
    letter-spacing: 0.35em;
    color: var(--gold);
    font-weight: 300;
    margin-bottom: 1.2rem;
}
.section-title {
    font-family: var(--serif-en);
    font-size: clamp(2rem, 3.5vw, 3rem);
    font-weight: 300;
    line-height: 1.15;
    letter-spacing: -0.01em;
    margin-bottom: 1.5rem;
}
.section-title em { font-style: italic; color: var(--gold); }
.section-text {
    font-family: var(--serif-ja);
    font-size: 0.92rem;
    font-weight: 300;
    color: var(--charcoal-60);
    line-height: 2.2;
    max-width: 480px;
}
.divider { width: 40px; height: 0.5px; background: var(--gold); margin: 2rem 0; }

/* ─── ABOUT ─── */
.about {
    padding: 9rem 8rem;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8rem;
    align-items: center;
}

/* ─── FEATURES ─── */
.features { background: var(--cream); padding: 9rem 8rem; }
.features-header {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8rem;
    align-items: end;
    margin-bottom: 6rem;
}
.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 3px; }
.feature-card {
    background: var(--warm-white);
    padding: 3rem 2.5rem;
    transition: background 0.3s;
}
.feature-card:hover { background: var(--charcoal); }
.feature-card:hover .feature-number,
.feature-card:hover .feature-title,
.feature-card:hover .feature-desc { color: var(--warm-white); }
.feature-card:hover .feature-number { color: var(--gold-light); }
.feature-number {
    font-family: var(--serif-en);
    font-size: 3.5rem;
    font-weight: 300;
    color: var(--charcoal-10);
    line-height: 1;
    margin-bottom: 1.5rem;
    transition: color 0.3s;
}
.feature-title {
    font-family: var(--serif-ja);
    font-size: 1rem;
    font-weight: 400;
    color: var(--charcoal);
    margin-bottom: 0.8rem;
    transition: color 0.3s;
}
.feature-desc {
    font-family: var(--sans-ja);
    font-size: 0.76rem;
    font-weight: 300;
    color: var(--charcoal-60);
    line-height: 2;
    transition: color 0.3s;
}

/* ─── INSTRUMENTS ─── */
.instruments {
    padding: 9rem 8rem;
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 8rem;
    align-items: center;
}
.instrument-list { display: flex; flex-direction: column; margin-top: 3rem; }
.instrument-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.4rem 0;
    border-bottom: 0.5px solid var(--charcoal-10);
    transition: padding-left 0.3s;
}
.instrument-item:hover { padding-left: 0.5rem; }
.instrument-name { font-family: var(--serif-ja); font-size: 0.95rem; font-weight: 300; }
.instrument-en { font-family: var(--serif-en); font-size: 0.78rem; font-style: italic; color: var(--gold); letter-spacing: 0.05em; }
.violin-visual { position: relative; height: 500px; display: flex; align-items: center; justify-content: center; }

/* ─── SCHEDULE ─── */
.schedule { background: var(--charcoal); padding: 9rem 8rem; color: var(--warm-white); }
.schedule .section-label { color: var(--gold); }
.schedule .section-title { color: var(--warm-white); }
.schedule .section-text { color: rgba(253,251,248,0.55); }
.schedule .divider { background: var(--gold); }
.schedule-grid { margin-top: 5rem; display: grid; grid-template-columns: repeat(4, 1fr); gap: 3px; }
.schedule-card {
    background: rgba(253,251,248,0.04);
    padding: 2.5rem 2rem;
    border: 0.5px solid rgba(253,251,248,0.08);
    transition: background 0.3s, border-color 0.3s;
}
.schedule-card:hover { background: rgba(184,151,90,0.1); border-color: rgba(184,151,90,0.3); }
.schedule-day { font-family: var(--serif-en); font-size: 2rem; font-weight: 300; color: var(--gold-light); margin-bottom: 0.3rem; }
.schedule-day-ja { font-family: var(--sans-ja); font-size: 0.65rem; letter-spacing: 0.2em; color: rgba(253,251,248,0.35); margin-bottom: 1.5rem; }
.schedule-time { font-family: var(--serif-en); font-size: 1.05rem; color: var(--warm-white); font-weight: 300; margin-bottom: 0.3rem; }
.schedule-label { font-family: var(--sans-ja); font-size: 0.7rem; font-weight: 300; color: rgba(253,251,248,0.45); letter-spacing: 0.1em; }

/* ─── LOCATION ─── */
.location {
    padding: 9rem 8rem;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8rem;
    align-items: center;
}
.location-details { display: flex; flex-direction: column; gap: 2rem; margin-top: 3rem; }
.location-detail {
    display: flex;
    flex-direction: column;
    gap: 0.3rem;
    padding-left: 1.5rem;
    border-left: 0.5px solid var(--gold);
}
.location-detail-label { font-family: var(--sans-ja); font-size: 0.62rem; letter-spacing: 0.28em; color: var(--gold); font-weight: 300; }
.location-detail-value { font-family: var(--serif-ja); font-size: 0.9rem; font-weight: 300; line-height: 1.7; }
.map-placeholder { height: 380px; background: var(--cream); overflow: hidden; }

/* ─── CTA ─── */
.cta {
    background: var(--gold-pale);
    padding: 9rem 8rem;
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2rem;
}
.cta .section-title { font-size: clamp(2.5rem, 4vw, 3.8rem); }
.cta-sub { font-family: var(--serif-ja); font-size: 0.95rem; font-weight: 300; color: var(--charcoal-60); line-height: 2.2; max-width: 500px; }
.cta-form { display: flex; gap: 0; width: 100%; max-width: 540px; }
.cta-input {
    flex: 1;
    padding: 1rem 1.5rem;
    border: 0.5px solid var(--charcoal-30);
    background: var(--warm-white);
    font-family: var(--sans-ja);
    font-size: 0.78rem;
    font-weight: 300;
    color: var(--charcoal);
    outline: none;
    letter-spacing: 0.05em;
}
.cta-input::placeholder { color: var(--charcoal-30); }
.cta-input:focus { border-color: var(--gold); }
.cta-submit {
    background: var(--charcoal);
    color: var(--warm-white);
    border: none;
    padding: 1rem 2rem;
    font-family: var(--sans-ja);
    font-size: 0.72rem;
    letter-spacing: 0.18em;
    cursor: pointer;
    transition: background 0.3s;
    white-space: nowrap;
}
.cta-submit:hover { background: var(--gold); }
.cta-submit:disabled { opacity: 0.5; cursor: not-allowed; }
.form-message {
    font-family: var(--sans-ja);
    font-size: 0.78rem;
    letter-spacing: 0.08em;
    min-height: 1.2em;
    transition: color 0.3s;
}
.form-message.success { color: #3b6d11; }
.form-message.error   { color: #a32d2d; }
.cta-note { font-family: var(--sans-ja); font-size: 0.65rem; color: var(--charcoal-30); letter-spacing: 0.12em; }

/* ─── FAQ ─── */
.faq { padding: 9rem 8rem; max-width: 980px; margin: 0 auto; }
.faq-header { margin-bottom: 4rem; }
.faq-item { border-top: 0.5px solid var(--charcoal-10); padding: 2rem 0; }
.faq-item:last-child { border-bottom: 0.5px solid var(--charcoal-10); }
.faq-q {
    font-family: var(--serif-ja);
    font-size: 0.95rem;
    font-weight: 400;
    color: var(--charcoal);
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    cursor: pointer;
    gap: 2rem;
    line-height: 1.7;
    user-select: none;
}
.faq-q::after {
    content: '+';
    font-family: var(--serif-en);
    font-size: 1.4rem;
    font-weight: 300;
    color: var(--gold);
    flex-shrink: 0;
    line-height: 1.2;
    transition: transform 0.3s;
}
.faq-item.open .faq-q::after { transform: rotate(45deg); }
.faq-a {
    font-family: var(--sans-ja);
    font-size: 0.8rem;
    font-weight: 300;
    color: var(--charcoal-60);
    line-height: 2.2;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding-top 0.4s ease;
}
.faq-item.open .faq-a { max-height: 400px; padding-top: 1.2rem; }

/* ─── FOOTER ─── */
.site-footer { background: var(--charcoal); padding: 5rem 8rem 3rem; }
.footer-top {
    display: grid;
    grid-template-columns: 1.4fr 1fr 1fr;
    gap: 4rem;
    padding-bottom: 4rem;
    border-bottom: 0.5px solid rgba(253,251,248,0.1);
    margin-bottom: 2rem;
}
.footer-logo { font-family: var(--serif-en); font-size: 1.1rem; font-weight: 300; color: var(--warm-white); margin-bottom: 1rem; letter-spacing: 0.05em; }
.footer-logo span { display: block; font-family: var(--sans-ja); font-size: 0.62rem; letter-spacing: 0.22em; color: var(--gold); margin-top: 3px; }
.footer-desc { font-family: var(--sans-ja); font-size: 0.72rem; font-weight: 300; line-height: 2; color: rgba(253,251,248,0.35); }
.footer-col-title { font-family: var(--sans-ja); font-size: 0.62rem; letter-spacing: 0.25em; color: var(--gold); margin-bottom: 1.5rem; }
.footer-links, .footer-links ul { list-style: none; display: flex; flex-direction: column; gap: 0.8rem; }
.footer-links a, .footer-links li a {
    font-family: var(--sans-ja);
    font-size: 0.75rem;
    font-weight: 300;
    color: rgba(253,251,248,0.4);
    text-decoration: none;
    letter-spacing: 0.05em;
    transition: color 0.3s;
}
.footer-links a:hover, .footer-links li a:hover { color: var(--gold); }
.footer-bottom { display: flex; justify-content: space-between; align-items: center; }
.footer-copy { font-family: var(--sans-ja); font-size: 0.62rem; letter-spacing: 0.12em; color: rgba(253,251,248,0.2); }

/* ─── SCROLL REVEAL ─── */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.8s ease, transform 0.8s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ─── RESPONSIVE ─── */
@media (max-width: 1200px) {
    .about, .instruments, .location { gap: 5rem; padding: 7rem 5rem; }
    .features { padding: 7rem 5rem; }
    .schedule { padding: 7rem 5rem; }
    .cta { padding: 7rem 5rem; }
    .faq { padding: 7rem 5rem; }
    .site-footer { padding: 5rem 5rem 3rem; }
}

@media (max-width: 1024px) {
    .site-header { padding: 1.5rem 2.5rem; }

    .hero { grid-template-columns: 1fr; min-height: auto; }
    .hero-left { padding: 8rem 2.5rem 4rem; }
    .hero-right { height: 50vh; }

    .about, .instruments, .location { grid-template-columns: 1fr; gap: 3rem; padding: 6rem 2.5rem; }
    .features { padding: 6rem 2.5rem; }
    .features-header { grid-template-columns: 1fr; gap: 2rem; margin-bottom: 3rem; }
    .features-grid { grid-template-columns: 1fr 1fr; }
    .schedule { padding: 6rem 2.5rem; }
    .schedule-grid { grid-template-columns: 1fr 1fr; }
    .cta { padding: 6rem 2.5rem; }
    .faq { padding: 6rem 2.5rem; }
    .site-footer { padding: 4rem 2.5rem 2rem; }
    .footer-top { grid-template-columns: 1fr 1fr; gap: 2.5rem; }
    .footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 768px) {
    .site-nav ul { display: none; }
    .site-nav ul.open {
        display: flex;
        flex-direction: column;
        position: fixed;
        top: 60px; left: 0; right: 0;
        background: rgba(253,251,248,0.97);
        backdrop-filter: blur(12px);
        padding: 2rem;
        gap: 1.5rem;
        border-bottom: 0.5px solid var(--charcoal-10);
    }
    .nav-toggle { display: flex; }
    .features-grid { grid-template-columns: 1fr; }
    .schedule-grid { grid-template-columns: 1fr 1fr; }
    .footer-top { grid-template-columns: 1fr; }
}

@media (max-width: 600px) {
    .site-header { padding: 1.2rem 1.5rem; }
    .hero-left { padding: 7rem 1.5rem 3rem; }
    .hero-cta { flex-direction: column; align-items: flex-start; }
    .schedule-grid { grid-template-columns: 1fr; }
    .cta-form { flex-direction: column; }
    .footer-bottom { flex-direction: column; gap: 0.8rem; text-align: center; }
}

/* ─── SECTION SCROLL NAV ─── */
.scroll-nav {
    position: fixed;
    right: 2rem;
    bottom: 2rem;
    z-index: 90;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    opacity: 0;
    transform: translateX(12px);
    transition: opacity 0.4s ease, transform 0.4s ease;
    pointer-events: none;
}
.scroll-nav.visible {
    opacity: 1;
    transform: translateX(0);
    pointer-events: auto;
}
.scroll-nav-btn {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--warm-white);
    border: 0.5px solid var(--charcoal-30);
    color: var(--charcoal-60);
    cursor: pointer;
    transition: background 0.25s, color 0.25s, border-color 0.25s;
}
.scroll-nav-btn:hover {
    background: var(--charcoal);
    border-color: var(--charcoal);
    color: var(--warm-white);
}
.scroll-nav-btn:disabled {
    opacity: 0.25;
    cursor: default;
    pointer-events: none;
}
.scroll-nav-index {
    font-family: var(--serif-en);
    font-size: 0.65rem;
    font-weight: 300;
    letter-spacing: 0.1em;
    color: var(--charcoal-30);
    line-height: 1;
    padding: 2px 0;
    min-width: 36px;
    text-align: center;
}

/* schedule セクション内では白で表示 */
.scroll-nav.on-dark .scroll-nav-btn {
    background: rgba(253,251,248,0.08);
    border-color: rgba(253,251,248,0.2);
    color: rgba(253,251,248,0.6);
}
.scroll-nav.on-dark .scroll-nav-btn:hover {
    background: var(--gold);
    border-color: var(--gold);
    color: var(--warm-white);
}
.scroll-nav.on-dark .scroll-nav-index {
    color: rgba(253,251,248,0.3);
}

@media (max-width: 600px) {
    .scroll-nav { right: 1rem; bottom: 1rem; }
}

/* ─── VIOLIN / ENSEMBLE IMAGE ─── */
.violin-img-wrap {
    width: 100%;
    max-width: 460px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}
.violin-img-bg {
    width: 100%;
}
.violin-ensemble-img {
    width: 100%;
    height: auto;
    display: block;
}
.violin-label {
    font-family: 'Noto Sans JP', sans-serif;
    font-size: 0.62rem;
    letter-spacing: 0.32em;
    color: rgba(26,24,20,0.25);
    font-weight: 300;
    margin: 0;
}