/* ===================================================================
   epsom salt × Dori Sakurada - Bathtime Music LP
   カラーパレット: #fff / #eee / #ccc / #0b73c1
   デザイン: モダン・スタイリッシュ・フラット（影なし・アイコンなし）
   =================================================================== */

/* ===================================================================
   Reset & Base
   =================================================================== */
* {
	margin: 0;
	padding: 0;
	box-sizing: border-box;
}

html {
	font-size: 16px;
	scroll-behavior: smooth;
}

body.bathtime-music-page {
	font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", 
	             "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
	color: #111;
	line-height: 1.7;
	-webkit-font-smoothing: antialiased;
	-moz-osx-font-smoothing: grayscale;
}

a {
	color: inherit;
	text-decoration: none;
	transition: color 0.3s ease;
}

a:hover {
	color: #0b73c1;
}

img {
	max-width: 100%;
	height: auto;
	display: block;
}

/* ===================================================================
   Header
   =================================================================== */
.btm-header {
	position: fixed;
	top: 0;
	left: 0;
	right: 0;
	z-index: 1000;
	background-color: #fff;
	border-bottom: 1px solid #0b73c1;
}

.btm-header__container {
	margin: 0 auto;
	padding: 0 24px;
	height: 64px;
	display: flex;
	align-items: center;
	justify-content: space-between;
}

.btm-header__logo a {
	display: flex;
	align-items: center;
	gap: 8px;
	transition: opacity 0.3s ease;
}

.btm-header__logo a:hover {
	opacity: 0.7;
}

.btm-header__logo-img {
	height: 22px;
	width: auto;
}

.btm-header__logo-main {
	font-size: 20px;
	font-weight: 600;
	letter-spacing: 0.05em;
	color: #0b73c1;
}

.btm-header__logo-separator {
	font-size: 14px;
	font-weight: 300;
	color: #999;
}

.btm-header__logo-sub {
	font-size: 20px;
	font-weight: 400;
	letter-spacing: 0.02em;
	color: #333;
}

/* Desktop Navigation */
.btm-nav {
	display: none;
}

.btm-nav__list {
	list-style: none;
	display: flex;
	gap: 32px;
	align-items: center;
}

.btm-nav__link {
	font-size: 13px;
	font-weight: 400;
	letter-spacing: 0.08em;
	text-transform: uppercase;
	color: #333;
	transition: color 0.3s ease;
	position: relative;
}

.btm-nav__link::after {
	content: '';
	position: absolute;
	bottom: -4px;
	left: 0;
	width: 0;
	height: 1px;
	background-color: #0b73c1;
	transition: width 0.3s ease;
}

.btm-nav__link:hover {
	color: #0b73c1;
}

.btm-nav__link:hover::after {
	width: 100%;
}

/* Mobile Menu Toggle */
.btm-header__menu-toggle {
	background: none;
	border: none;
	cursor: pointer;
	padding: 8px;
	display: flex;
	flex-direction: column;
	gap: 5px;
	width: 32px;
	height: 32px;
	justify-content: center;
}

.btm-header__menu-bar {
	display: block;
	width: 24px;
	height: 2px;
	background-color: #0b73c1;
	transition: all 0.3s ease;
	border-radius: 2px;
}

.btm-header__menu-toggle[aria-expanded="true"] .btm-header__menu-bar:nth-child(1) {
	transform: translateY(7px) rotate(45deg);
}

.btm-header__menu-toggle[aria-expanded="true"] .btm-header__menu-bar:nth-child(2) {
	opacity: 0;
}

.btm-header__menu-toggle[aria-expanded="true"] .btm-header__menu-bar:nth-child(3) {
	transform: translateY(-7px) rotate(-45deg);
}

/* Mobile Navigation */
.btm-nav-mobile {
	position: fixed;
	top: 57px;
	left: 0;
	right: 0;
	background-color: rgba(255, 255, 255, 0.98);
	backdrop-filter: blur(10px);
	max-height: 0;
	overflow: hidden;
	transition: max-height 0.4s ease;
	box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.btm-nav-mobile[aria-hidden="false"] {
	max-height: 400px;
}

.btm-nav-mobile__list {
	list-style: none;
	padding: 16px 0;
}

.btm-nav-mobile__link {
	display: block;
	padding: 16px 32px;
	color: #333;
	font-size: 14px;
	font-weight: 400;
	letter-spacing: 0.05em;
	transition: all 0.3s ease;
	border-left: 3px solid transparent;
}

.btm-nav-mobile__link:hover {
	background-color: rgba(11, 115, 193, 0.05);
	color: #0b73c1;
	border-left-color: #0b73c1;
}

/* ===================================================================
   Main
   =================================================================== */
.btm-main {
	margin-top: 64px;
}

/* ===================================================================
   Hero Section
   =================================================================== */
.btm-hero {
	position: relative;
	min-height: calc(100vh - 64px);
	display: flex;
	flex-direction: column;
	align-items: center;
	justify-content: center;
	background-size: cover;
	background-position: center;
	background-repeat: no-repeat;
	padding: 80px 24px;
	text-align: center;
	overflow: hidden;
	--hero-blur: 0px;
	animation: heroFogClear 2.5s ease-out forwards;
}

.btm-hero::before,
.btm-hero::after {
	content: '';
	position: absolute;
	top: 0;
	left: 0;
	width: 100%;
	height: 100%;
	background-size: cover;
	background-position: center;
	background-repeat: no-repeat;
	opacity: 0;
	z-index: 0;
	filter: blur(var(--hero-blur, 0px));
	transition: filter 0.1s ease-out;
	will-change: filter;
}

.btm-hero::before {
	background-image: url('../img/hero_img_01.png');
	animation: heroSlide1 18s infinite;
}

.btm-hero::after {
	background-image: url('../img/hero_img_02.png');
	animation: heroSlide2 18s infinite;
}

.btm-hero__bg3 {
	position: absolute;
	top: 0;
	left: 0;
	width: 100%;
	height: 100%;
	background-image: url('../img/hero_img_03.png');
	background-size: cover;
	background-position: center;
	background-repeat: no-repeat;
	opacity: 0;
	z-index: 0;
	filter: blur(var(--hero-blur, 0px));
	transition: filter 0.1s ease-out;
	will-change: filter;
	animation: heroSlide3 18s infinite;
}

.btm-hero__content {
	max-width: 800px;
	margin: 0 auto;
	text-align: center;
	transition: filter 0.1s ease-out, opacity 0.1s ease-out, transform 0.1s ease-out;
	position: relative;
	z-index: 1;
	opacity: 0;
	animation: heroContentFadeIn 1.5s ease-out 1s forwards;
}

.btm-hero__title {
	font-size: 40px;
	font-weight: 300;
	letter-spacing: 0.05em;
	line-height: 1.4;
	margin-bottom: 24px;
	color: #fff;
}

.btm-hero__logo {
	max-width: 400px;
	width: 80%;
	height: auto;
	margin-bottom: 24px;
	margin-left: auto;
	margin-right: auto;
}

.btm-hero__tagline {
	font-size: 18px;
	font-weight: 300;
	letter-spacing: 0.05em;
	color: #fff;
}

.btm-hero__desc {
	font-size: 12px;
	font-weight: 300;
	letter-spacing: 0.04em;
	line-height: 2;
	color: rgba(255, 255, 255, 0.7);
	margin-top: 32px;
}

.btm-hero__scroll {
	position: absolute;
	bottom: 32px;
	left: 50%;
	transform: translateX(-50%);
	text-align: center;
	font-size: 12px;
	letter-spacing: 0.1em;
	color: #0b73c1;
	transition: filter 0.1s ease-out, opacity 0.1s ease-out;
}

.btm-hero__arrow {
	font-size: 20px;
	animation: bounce 2s infinite;
}

@keyframes bounce {
	0%, 100% {
		transform: translateY(0);
	}
	50% {
		transform: translateY(8px);
	}
}

@keyframes heroFadeIn {
	0% {
		opacity: 0;
	}
	100% {
		opacity: 1;
	}
}

@keyframes contentFadeIn {
	0% {
		opacity: 0;
		transform: translateY(20px);
	}
	100% {
		opacity: 1;
		transform: translateY(0);
	}
}

@keyframes heroSlideLeft {
	0% {
		transform: translateX(0);
	}
	100% {
		transform: translateX(-50%);
	}
}

@keyframes heroResizeToHalf {
	0% {
		width: 100vw;
	}
	100% {
		width: calc(100vw - 540px);
	}
}

@keyframes contentSlideIn {
	0% {
		margin-left: -540px;
	}
	100% {
		margin-left: 0;
	}
}

@keyframes contentAppear {
	0% {
		visibility: hidden;
	}
	100% {
		visibility: visible;
	}
}

@keyframes heroSlide1 {
	0% {
		opacity: 1;
	}
	27% {
		opacity: 1;
	}
	33.33% {
		opacity: 0;
	}
	66.66% {
		opacity: 0;
	}
	94% {
		opacity: 0;
	}
	100% {
		opacity: 1;
	}
}

@keyframes heroSlide2 {
	0% {
		opacity: 0;
	}
	27% {
		opacity: 0;
	}
	33.33% {
		opacity: 1;
	}
	60.66% {
		opacity: 1;
	}
	66.66% {
		opacity: 0;
	}
	100% {
		opacity: 0;
	}
}

@keyframes heroSlide3 {
	0% {
		opacity: 0;
	}
	33.33% {
		opacity: 0;
	}
	60.66% {
		opacity: 0;
	}
	66.66% {
		opacity: 1;
	}
	94% {
		opacity: 1;
	}
	100% {
		opacity: 0;
	}
}

@keyframes heroFogClear {
	0% {
		filter: blur(30px) brightness(1.2);
		opacity: 0;
	}
	40% {
		filter: blur(15px) brightness(1.1);
		opacity: 0.7;
	}
	100% {
		filter: blur(0px) brightness(1);
		opacity: 1;
	}
}

@keyframes heroContentFadeIn {
	0% {
		opacity: 0;
		transform: translateY(20px);
	}
	100% {
		opacity: 1;
		transform: translateY(0);
	}
}

/* ===================================================================
   Part Section
   =================================================================== */
.btm-part {
	padding: 60px 24px;
	border-bottom: 1px solid #eee;
	background: rgba(255, 255, 255, 0.7);
}

#part1.btm-part {
	padding-top: 110px;
}

.btm-part:nth-child(even) {
	background-color: #fafafa;
}

.btm-part__container {
	max-width: 1200px;
	margin: 0 auto;
	padding: 0 20px;
	display: grid;
	grid-template-columns: 120px 1fr;
	gap: 48px;
	align-items: start;
}

.btm-part__number {
	font-size: 14px;
	font-weight: 400;
	letter-spacing: 0.08em;
	color: #0b73c1;
	opacity: 1;
	line-height: 1.4;
}

.btm-part__content {
	display: flex;
	flex-direction: column;
	gap: 24px;
}

.btm-part__title {
	font-size: 28px;
	font-weight: 400;
	line-height: 1.5;
	color: #111;
	display: flex;
	align-items: center;
	gap: 16px;
	flex-wrap: wrap;
	font-feature-settings: "palt";
}

.btm-part__description {
	font-size: 14px;
	line-height: 1.8;
	color: #333;
}

.btm-part__track {
	padding: 16px 0;
	border-top: 1px solid #eee;
	border-bottom: 1px solid #eee;
	display: flex;
	gap: 24px;
	align-items: baseline;
}

.btm-part__track-label {
	font-size: 12px;
	font-weight: 400;
	text-transform: uppercase;
	letter-spacing: 0.1em;
	color: #999;
}

.btm-part__track-title {
	font-size: 16px;
	font-weight: 500;
	color: #111;
	font-feature-settings: "palt";
}

.btm-part__video {
	margin-top: 16px;
}

.btm-part__video-placeholder {
	width: 100%;
	aspect-ratio: 16 / 9;
	background-color: #000;
	border: 1px solid #ccc;
}

/* Coming Soon State */
.btm-part--coming-soon {
	opacity: 0.8;
}

.btm-badge--coming-soon {
	display: inline-block;
	padding: 4px 12px;
	font-size: 11px;
	font-weight: 400;
	letter-spacing: 0.08em;
	color: #0b73c1;
	background-color: rgba(11, 115, 193, 0.1);
	border: 1px solid #0b73c1;
	vertical-align: middle;
}

.btm-part__notice {
	font-size: 14px;
	color: #999;
	font-style: italic;
}

.btm-part__link {
	margin-top: 8px;
}

.btm-part__link a {
	display: inline-flex;
	align-items: center;
	gap: 8px;
	padding: 0;
	font-size: 14px;
	font-weight: 400;
	letter-spacing: 0.02em;
	color: #111;
	background-color: transparent;
	transition: all 0.3s ease;
	position: relative;
}

.btm-part__link a::before {
	content: '↗';
	font-size: 14px;
	color: #0b73c1;
	transition: transform 0.3s ease;
}

.btm-part__link a:hover {
	color: #0b73c1;
}

.btm-part__link a:hover::before {
	transform: translate(2px, -2px);
}

/* ===================================================================
   Profile Section
   =================================================================== */
.btm-profile {
	padding: 80px 24px 0;
	background-color: rgba(255, 255, 255, 0.8);
}

.btm-profile__container {
	max-width: 1200px;
	margin: 0 auto;
	padding: 0 24px;
	display: grid;
	grid-template-columns: 40% 60%;
	gap: 64px;
	align-items: start;
}

.btm-profile__image-placeholder {
	width: 100%;
	aspect-ratio: 3 / 4;
	margin-bottom: 40px;
	background-image: url('../img/profile_img.png');
	background-size: cover;
	background-position: top;
	background-repeat: no-repeat;
}

.btm-profile__heading {
	font-size: 13px;
	font-weight: 400;
	letter-spacing: 0.12em;
	text-transform: uppercase;
	color: #0b73c1;
	margin-bottom: 32px;
	padding-bottom: 16px;
	border-bottom: 2px solid #0b73c1;
}

.btm-profile__name-ja {
	font-size: 18px;
	font-weight: 400;
	color: #111;
	letter-spacing: 0.02em;
}

.btm-profile__name-en {
	font-size: 14px;
	font-weight: 300;
	letter-spacing: 0.08em;
	color: #666;
	margin-bottom: 40px;
}

.btm-profile__basics {
	display: grid;
	grid-template-columns: repeat(2, 1fr);
	gap: 20px 40px;
	padding: 32px 0;
	border-top: 1px solid rgba(11, 115, 193, 0.2);
	border-bottom: 1px solid rgba(11, 115, 193, 0.2);
	margin-bottom: 40px;
}

.btm-profile__basic-item {
	display: flex;
	flex-direction: column;
	gap: 6px;
}

.btm-profile__basic-label {
	font-size: 11px;
	color: #0b73c1;
	font-weight: 400;
	letter-spacing: 0.05em;
}

.btm-profile__basic-value {
	font-size: 14px;
	color: #111;
	font-weight: 400;
}

.btm-profile__bio p {
	font-size: 14px;
	line-height: 1.85;
	color: #333;
	margin-bottom: 20px;
}

.btm-profile__bio p:last-child {
	margin-bottom: 0;
}

/* ===================================================================
   Social Media Section
   =================================================================== */
.btm-social {
	padding: 40px 0 0 0;
	background-color: transparent;
}

.btm-social__container {
	max-width: 100%;
	margin-top: 32px;
	padding: 0;
}

.btm-social__heading {
	font-size: 13px;
	font-weight: 400;
	letter-spacing: 0.12em;
	text-transform: uppercase;
	color: #0b73c1;
	margin-bottom: 24px;
	padding-bottom: 16px;
	border-bottom: 2px solid #0b73c1;
}

.btm-social__links {
	display: flex;
	flex-direction: column;
	gap: 0;
	align-items: flex-start;
}

.btm-social__link {
	display: flex;
	align-items: center;
	gap: 8px;
	padding: 4px 0;
	font-size: 14px;
	font-weight: 400;
	letter-spacing: 0.02em;
	color: #111;
	background-color: transparent;
	transition: all 0.3s ease;
	position: relative;
	width: 100%;
}

.btm-social__link::before {
	content: '\2197';
	font-size: 14px;
	color: #0b73c1;
	transition: transform 0.3s ease;
}

.btm-social__link:hover {
	color: #0b73c1;
}

.btm-social__link:hover::before {
	transform: translate(2px, -2px);
}

.btm-social__link span {
	position: relative;
}

.btm-interview {
	padding: 80px 24px;
	background-color: rgba(250, 250, 250, 0.7);
}

.btm-interview__container {
	max-width: 1200px;
	margin: 0 auto;
	padding: 48px 0;
	border-top: 1px solid #eee;
}

.btm-interview__image-placeholder {
	width: 100%;
	aspect-ratio: 3 / 4;
	background-image: url('../img/profile-sakurada.jpg');
	background-size: cover;
	background-position: top;
	background-repeat: no-repeat;
}

.btm-interview__caption {
	font-size: 12px;
	color: #999;
	margin-top: 8px;
}

.btm-interview__content {
	display: flex;
	flex-direction: column;
	gap: 24px;
}

.btm-interview__heading {
	font-size: 13px;
	font-weight: 400;
	letter-spacing: 0.12em;
	text-transform: uppercase;
	color: #0b73c1;
	margin-bottom: 32px;
	padding-bottom: 16px;
	border-bottom: 2px solid #0b73c1;
}

.btm-interview__lead {
	font-size: 14px;
	line-height: 1.8;
	color: #333;
}

.btm-interview__qa {
	list-style: none;
	display: flex;
	flex-direction: column;
	gap: 16px;
}

.btm-interview__item {
	padding-top: 16px;
	border-top: 1px solid #eee;
}

.btm-interview__photo {
	width: 100%;
	aspect-ratio: 16 / 9;
	background-size: cover;
	background-position: center;
	background-repeat: no-repeat;
	margin-bottom: 12px;
}

.btm-interview__photo--01 { background-image: url('../img/hero_img_01.png'); }
.btm-interview__photo--02 { background-image: url('../img/hero_img_02.png'); }
.btm-interview__photo--03 { background-image: url('../img/hero_img_03.png'); }

.btm-interview__q,
.btm-interview__a {
	font-size: 14px;
	line-height: 1.8;
	color: #333;
}

.btm-interview__q {
	color: #111;
	font-weight: 500;
}

.btm-interview__role {
	font-size: 11px;
	letter-spacing: 0.08em;
	text-transform: uppercase;
	display: inline-block;
	margin-right: 8px;
}

.btm-interview__role--interviewer {
	color: #999;
}

.btm-interview__role--sakurada {
	color: #0b73c1;
}

/* ===================================================================
   About Section
   =================================================================== */
.btm-about {
	padding: 80px 24px;
	background-color: rgba(250, 250, 250, 0.7);
}

.btm-about__container {
	max-width: 800px;
	margin: 0 auto;
	padding: 48px 0;
	border-top: 1px solid #eee;
}

.btm-about__image-placeholder {
	width: 100%;
	aspect-ratio: 3 / 4;
	margin-bottom: 40px;
	background-image: url('../img/epsomsalt_product.png');
	background-size: cover;
	background-position: top;
	background-repeat: no-repeat;
}

.btm-about__heading {
	font-size: 13px;
	font-weight: 400;
	letter-spacing: 0.12em;
	text-transform: uppercase;
	color: #0b73c1;
	margin-bottom: 32px;
	padding-bottom: 16px;
	border-bottom: 2px solid #0b73c1;
}

.btm-about__content {
	margin-bottom: 32px;
}

.btm-about__content p {
	font-size: 14px;
	line-height: 1.8;
	color: #333;
	margin: 0;
}

.btm-about__links {
	display: flex;
	flex-direction: column;
	gap: 0;
	align-items: flex-start;
}

.btm-about__link {
	display: flex;
	align-items: center;
	gap: 8px;
	padding: 4px 0;
	font-size: 14px;
	font-weight: 400;
	letter-spacing: 0.02em;
	color: #111;
	background-color: transparent;
	transition: all 0.3s ease;
	position: relative;
	width: 100%;
}

.btm-about__link::before {
	content: '↗';
	font-size: 14px;
	color: #0b73c1;
	transition: transform 0.3s ease;
}

.btm-about__link:hover {
	color: #0b73c1;
}

.btm-about__link:hover::before {
	transform: translate(2px, -2px);
}

.btm-about__link span {
	position: relative;
}

/* ===================================================================
   FAQ Section
   =================================================================== */
.btm-faq {
	padding: 80px 24px;
	background-color: rgba(250, 250, 250, 0.8);
}

.btm-faq__container {
	margin: 0 auto;
}

.btm-faq__heading {
	font-size: 13px;
	font-weight: 400;
	letter-spacing: 0.12em;
	text-transform: uppercase;
	color: #0b73c1;
	margin-bottom: 48px;
	padding-bottom: 16px;
	border-bottom: 2px solid #0b73c1;
	text-align: left;
}

.btm-faq__list {
	display: flex;
	flex-direction: column;
	gap: 16px;
}

.btm-faq__item {
	border: 1px solid rgba(11, 115, 193, 0.2);
	border-radius: 4px;
	overflow: hidden;
	transition: all 0.3s ease;
}

.btm-faq__item:hover {
	border-color: #0b73c1;
	box-shadow: 0 2px 8px rgba(11, 115, 193, 0.1);
}

.btm-faq__question {
	width: 100%;
	display: flex;
	justify-content: space-between;
	align-items: center;
	padding: 20px 24px;
	background: none;
	border: none;
	cursor: pointer;
	text-align: left;
	transition: all 0.3s ease;
}

.btm-faq__question:hover {
	background-color: rgba(11, 115, 193, 0.05);
}

.btm-faq__question[aria-expanded="true"] {
	background-color: rgba(11, 115, 193, 0.1);
}

.btm-faq__question-text {
	font-size: 14px;
	font-weight: 500;
	letter-spacing: 0.03em;
	color: #111;
	flex: 1;
}

.btm-faq__icon {
	font-size: 24px;
	color: #0b73c1;
	font-weight: 300;
	transition: transform 0.3s ease;
	flex-shrink: 0;
	margin-left: 16px;
}

.btm-faq__question[aria-expanded="true"] .btm-faq__icon {
	transform: rotate(45deg);
}

.btm-faq__answer {
	max-height: 0;
	overflow: hidden;
	transition: max-height 0.4s ease, padding 0.4s ease;
	padding: 0 24px;
}

.btm-faq__question[aria-expanded="true"] + .btm-faq__answer {
	max-height: 500px;
	padding: 24px;
}

.btm-faq__answer p {
	font-size: 14px;
	line-height: 1.8;
	color: #666;
}

.btm-faq__answer a {
	color: #0b73c1;
	text-decoration: underline;
	transition: opacity 0.3s ease;
}

.btm-faq__answer a:hover {
	opacity: 0.7;
}

/* ===================================================================
   Footer
   =================================================================== */
.btm-footer {
	padding: 48px 0;
	background-color: #0b73c1;
	color: #fff;
	position: relative;
	z-index: 3;
}

.btm-footer__container {
	max-width: 1200px;
	margin: 0 auto;
	padding: 0 24px;
	text-align: center;
}

.btm-footer__copyright {
	font-size: 14px;
	font-weight: 300;
	margin-bottom: 16px;
}

.btm-footer__links {
	display: flex;
	justify-content: center;
	align-items: center;
	gap: 16px;
	flex-wrap: wrap;
	font-size: 13px;
}

.btm-footer__link {
	color: #fff;
	font-size: 14px;
	transition: all 0.3s ease;
	border-bottom: 1px solid transparent;
}

.btm-footer__link:hover {
	border-bottom-color: #fff;
	color: #fff;
}

.btm-footer__separator {
	color: rgba(255, 255, 255, 0.5);
}

/* ===================================================================
   Responsive - Tablet (768px - 1023px)
   =================================================================== */
@media screen and (max-width: 1023px) {
	.btm-main {
		display: block;
	}

	.btm-hero {
		position: relative;
		width: 100%;
	}

	.btm-content-wrapper {
		width: 100%;
	}

	.btm-hero__title {
		font-size: 32px;
	}

	.btm-part__container {
		grid-template-columns: 80px 1fr;
		gap: 32px;
	}

	.btm-part__number {
		font-size: 14px;
	}

	.btm-part__title {
		font-size: 24px;
	}

	.btm-profile__container {
		grid-template-columns: 1fr;
		gap: 48px;
	}

	.btm-profile__image {
		max-width: 400px;
		margin: 0 auto;
	}

	.btm-profile__basics {
		grid-template-columns: repeat(2, 1fr);
	}

	.btm-interview__container {
		grid-template-columns: 1fr;
		gap: 48px;
	}
}

/* ===================================================================
   Responsive - Mobile (≤767px)
   =================================================================== */
@media screen and (max-width: 767px) {
	.btm-header__container {
		height: 56px;
	}

	.btm-header__logo-main {
		font-size: 3.5vw;
	}

	.btm-header__logo-separator {
		font-size: 2.5vw;
	}

	.btm-header__logo-sub {
		font-size: 3.5vw;
	}

	.btm-main {
		margin-top: 56px;
		display: block;
	}

	.btm-nav {
		top: 56px;
	}

	.btm-hero {
		position: fixed;
		top: 56px;
		left: 0;
		right: 0;
		width: 100%;
		height: calc(100vh - 56px);
		padding: 64px 24px;
		z-index: 1;
	}

	.btm-content-wrapper {
		width: 94%;
        margin-left: auto;
        margin-right: auto;
        margin-bottom: 4%;
		position: relative;
		z-index: 2;
		margin-top: calc(100vh - 56px);
	}

	.btm-hero__title {
		font-size: 28px;
	}

	.btm-hero__tagline {
		font-size: 16px;
	}

	.btm-part {
		padding: 64px 0;
	}

	.btm-part__container {
		grid-template-columns: 1fr;
		gap: 24px;
	}

	.btm-part__number {
		font-size: 13px;
	}

	.btm-part__title {
		font-size: 16px;
		flex-direction: column-reverse;
        align-items: self-start;
	}

	#part1.btm-part {
		padding-top: 60px;
	}

	.btm-part__description {
		font-size: 14px;
	}

	.btm-part__track {
		flex-direction: column;
		gap: 8px;
	}

	.btm-part__track-title {
		font-size: 14px;
	}

	.btm-part__audio {
		margin-top: 16px;
	}

	.btm-part__video {
		margin-top: 24px;
		width: 100%;
		overflow: hidden;
	}

	.btm-part__video .instagram-media {
		min-width: auto !important;
		width: 100% !important;
		margin: 0 !important;
	}

	.btm-profile {
		padding: 64px 0;
	}

	.btm-profile__container {
		grid-template-columns: 1fr;
		gap: 40px;
	}

	.btm-profile__heading {
		font-size: 12px;
		margin-bottom: 24px;
		padding-bottom: 12px;
	}

	.btm-profile__name-ja {
		font-size: 30px;
	}

	.btm-profile__name-en {
		font-size: 14px;
		margin-bottom: 32px;
	}

	.btm-profile__basics {
		grid-template-columns: 1fr;
		gap: 16px;
		padding: 24px 0;
		margin-bottom: 32px;
	}

	.btm-profile__bio p {
		font-size: 14px;
		line-height: 1.8;
		margin-bottom: 16px;
	}

	.btm-social {
		padding: 32px 0 0 0;
	}

	.btm-social__heading {
		font-size: 12px;
		margin-bottom: 20px;
		padding-bottom: 12px;
	}

	.btm-about {
		padding: 64px 0;
	}

	.btm-about__heading {
		font-size: 12px;
		margin-bottom: 24px;
		padding-bottom: 12px;
	}

	.btm-about__content p {
		font-size: 14px;
	}

	.btm-interview {
		padding: 64px 0;
	}

	.btm-interview__container {
		grid-template-columns: 1fr;
		gap: 40px;
	}

	.btm-interview__heading {
		font-size: 12px;
		margin-bottom: 24px;
		padding-bottom: 12px;
	}

	.btm-footer {
		padding: 40px 0;
	}

	.btm-footer__links {
		flex-direction: column;
		gap: 8px;
	}

	.btm-footer__separator {
		display: none;
	}
}

/* ===================================================================
   Responsive - Desktop (1024px+)
   =================================================================== */
@media screen and (min-width: 1024px) {
	.btm-nav {
		display: block;
	}

	.btm-header__menu-toggle {
		display: none;
	}

	.btm-nav-mobile {
		display: none;
	}

	.btm-main {
		display: flex;
		margin-top: 0;
	}

	.btm-hero {
		position: sticky;
		top: 64px;
		flex: 1;
		min-height: calc(100vh - 64px);
		height: calc(100vh - 64px);
		flex-shrink: 0;
	}

	.btm-content-wrapper {
		width: 540px;
		max-width: 540px;
		flex-shrink: 0;
		padding: 0;
	}

	/* コンテンツ内のセクションは最大幅を制限 */
	.btm-part__container,
	.btm-profile__container,
	.btm-social__container,
	.btm-faq__container {
		max-width: 100%;
		padding: 0;
	}

	.btm-interview__container,
	.btm-about__container {
		max-width: 100%;
		padding: 48px 0;
		border-top: 1px solid #eee;
	}

	.btm-interview__heading {
		font-size: 12px;
		margin-bottom: 24px;
		padding-bottom: 12px;
	}

	/* Part セクションをモバイルレイアウトに */
	.btm-part__container {
		grid-template-columns: 1fr;
		gap: 24px;
	}

	.btm-part__number {
		font-size: 13px;
	}

	.btm-part__title {
		font-size: 16px;
	}

	.btm-part__description {
		font-size: 14px;
	}

	.btm-part__track {
		flex-direction: column;
		gap: 8px;
	}

	.btm-part__track-title {
		font-size: 14px;
	}

	/* Profile セクションをモバイルレイアウトに */
	.btm-profile__container {
		grid-template-columns: 1fr;
		gap: 40px;
	}

	.btm-profile__heading {
		font-size: 12px;
		margin-bottom: 24px;
		padding-bottom: 12px;
	}

	.btm-profile__name-ja {
		font-size: 20px;
	}

	.btm-profile__name-en {
		font-size: 14px;
		margin-bottom: 32px;
	}

	.btm-profile__basics {
		grid-template-columns: 1fr;
		gap: 16px;
		padding: 24px 0;
		margin-bottom: 32px;
	}

	.btm-profile__bio p {
		font-size: 14px;
		line-height: 1.8;
		margin-bottom: 16px;
	}
}

.post-password-form {
	padding: 100px 0;
}