/* ===================================
   AURASTYLE HOMES - Concept Page CSS
   Homeと完全統一版
   =================================== */

/* === CSS VARIABLES === */
:root {
    --color-bg: #0a0a0a;
    --color-text: #e8e8e8;
    --color-accent: #c9b896;
    --color-muted: #666;
    --font-serif-en: 'Cormorant Garamond', serif;
    --font-serif-ja: 'Noto Serif JP', serif;
    --font-sans: 'Inter', sans-serif;
}

/* === BASE RESET === */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: clamp(14px, 1.2vw, 18px);
}

body {
    background: var(--color-bg);
    color: var(--color-text);
    font-family: var(--font-serif-ja);
    line-height: 1.8;
    overflow-x: hidden;
    font-weight: 300;
}

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

/* === HEADER === */
header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: clamp(1.5rem, 3vw, 3rem) clamp(2rem, 5vw, 5rem);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: linear-gradient(to bottom, rgba(10, 10, 10, 0.95), transparent);
    transition: background 0.3s;
}

header.scrolled {
    background: rgba(10, 10, 10, 0.98);
    backdrop-filter: blur(10px);
}

.logo a {
    font-family: var(--font-serif-en);
    font-size: clamp(1.2rem, 2vw, 1.5rem);
    font-weight: 300;
    letter-spacing: 0.15em;
    color: var(--color-text);
    text-decoration: none;
}

nav {
    display: flex;
    gap: clamp(2rem, 4vw, 4rem);
    font-family: var(--font-sans);
    font-size: 0.75rem;
    letter-spacing: 0.1em;
}

nav a {
    color: var(--color-muted);
    text-decoration: none;
    transition: color 0.3s;
    position: relative;
}

nav a:hover,
nav a.active {
    color: var(--color-text);
}

nav a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--color-accent);
    transition: width 0.3s;
}

nav a:hover::after,
nav a.active::after {
    width: 100%;
}

/* === CONCEPT HERO === */
.concept-hero {
    height: 700px;
    position: relative;
    display: flex;
    align-items: center;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    overflow: hidden;
}

.hero-bg::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(rgba(0, 0, 0, 0.3), rgba(0, 0, 0, 0.5));
    z-index: 1;
}

.hero-bg img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    filter: grayscale(20%);
    animation: zoomIn 20s ease-out forwards;
}

@keyframes zoomIn {
    from {
        transform: scale(1.1);
    }
    to {
        transform: scale(1);
    }
}

.hero-content {
    position: relative;
    z-index: 10;
    padding-top: 10rem;
    padding-left: 4rem;
    max-width: 1200px;
}

.hero-title {
    font-size: 48px;
    font-weight: 300;
    letter-spacing: 0.08em;
    line-height: 1.4;
    margin-bottom: 3rem;
    opacity: 0;
    animation: fadeInUp 1.2s ease-out 0.5s forwards;
}

.hero-text {
    font-size: 14px;
    font-weight: 300;
    letter-spacing: 0.1em;
    line-height: 2;
    opacity: 0;
    animation: fadeInUp 1.2s ease-out 1s forwards;
}

.hero-text p {
    margin-bottom: 1.5rem;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* === CONCEPT SECTIONS === */
.concept-section {
    padding: 140px;
    padding-left: 120px;
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 1s, transform 1s;
}

.concept-section.visible {
    opacity: 1;
    transform: translateY(0);
}

#concept01 {
    background: linear-gradient(to bottom, var(--color-bg), #111);
}

#concept02 {
    background: #111;
}

#concept03 {
    background: var(--color-bg);
}

.concept-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
}

.concept-container.reverse {
    direction: rtl;
}

.concept-container.reverse > * {
    direction: ltr;
}

.concept-text {
    max-width: 600px;
}

.section-label {
    font-family: var(--font-sans);
    font-size: 0.7rem;
    letter-spacing: 0.3em;
    color: var(--color-accent);
    margin-bottom: 1rem;
    text-transform: uppercase;
}

.section-title {
    font-size: 32px;
    font-weight: 300;
    letter-spacing: 0.05em;
    margin-bottom: 3rem;
    line-height: 1.3;
}

.concept-lead {
    font-size: 18px;
    font-weight: 400;
    letter-spacing: 0.05em;
    margin-bottom: 2rem;
    line-height: 1.6;
}

.concept-body {
    font-size: 14px;
    line-height: 2;
    color: var(--color-muted);
}

.concept-body p {
    margin-bottom: 1.5rem;
}

.concept-image {
    width: 500px;
    height: 550px;
    position: relative;
    aspect-ratio: 3/4;
    overflow: hidden;
    border-radius: 4px;
}

.concept-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    filter: grayscale(30%);
    transition: transform 0.6s;
}

.concept-section:hover .concept-image img {
    transform: scale(1.05);
}

/* === CLOSING SECTION === */
.concept-closing {
    position: relative;
    min-height: 600px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.closing-bg {
    position: absolute;
    inset: 0;
}

.closing-bg::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(rgba(0, 0, 0, 0.4), rgba(0, 0, 0, 0.6));
    z-index: 1;
}

.closing-bg img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    filter: grayscale(30%);
}

.closing-content {
    position: relative;
    z-index: 10;
    max-width: 900px;
    text-align: center;
    padding: 0 2rem;
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 1s, transform 1s;
}

.concept-closing.visible .closing-content {
    opacity: 1;
    transform: translateY(0);
}

.closing-title {
    font-size: 38px;
    font-weight: 300;
    letter-spacing: 0.08em;
    line-height: 1.5;
    margin-bottom: 3rem;
}

.closing-text {
    font-size: 16px;
    line-height: 2.2;
    letter-spacing: 0.05em;
}

/* === CTA SECTION === */

.cta-inner {
    text-align: center;
    max-width: 700px;
    margin: 0 auto;
    padding-top: 5rem;
    padding-bottom: 3rem;
}

.cta-heading {
    font-family: var(--font-serif-en);
    font-size: 38px;
    font-weight: 300;
    letter-spacing: 0.1em;
    margin-bottom: 1rem;
}

.cta-description {
    font-size: 14px;
    line-height: 2;
    color: var(--color-muted);
    margin-bottom: 3rem;
}

.cta-button {
    display: inline-block;
    padding: 1.2rem 3rem;
    border: 1px solid var(--color-accent);
    color: var(--color-text);
    text-decoration: none;
    font-family: var(--font-sans);
    font-size: 20px;
    letter-spacing: 0.15em;
    transition: all 0.3s;
    position: relative;
    overflow: hidden;
    background: transparent;
}

.cta-button::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--color-accent);
    transform: translateX(-100%);
    transition: transform 0.3s;
    z-index: -1;
}

.cta-button:hover {
    color: var(--color-bg);
}

.cta-button:hover::before {
    transform: translateX(0);
}

/* === FOOTER === */
footer {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding: 4rem clamp(2rem, 5vw, 5rem);
    background: #0a0a0a;
}

.footer-content {
    margin-bottom: 3rem;
}

.footer-nav {
    display: flex;
    justify-content: center;
    gap: clamp(2rem, 4vw, 4rem);
    font-family: var(--font-sans);
    font-size: 0.85rem;
    flex-wrap: wrap;
}

.footer-nav a {
    color: var(--color-muted);
    text-decoration: none;
    transition: color 0.3s;
}

.footer-nav a:hover {
    color: var(--color-accent);
}

.copyright {
    text-align: center;
    font-family: var(--font-sans);
    font-size: 0.7rem;
    letter-spacing: 0.2em;
    color: var(--color-muted);
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

/* === PAGE TOP BUTTON === */
.page-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    border: 1px solid var(--color-accent);
    background: rgba(10, 10, 10, 0.9);
    color: var(--color-accent);
    font-family: var(--font-sans);
    font-size: 0.7rem;
    letter-spacing: 0.1em;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s;
    z-index: 999;
    backdrop-filter: blur(10px);
}

.page-top.is-active {
    opacity: 1;
    visibility: visible;
}

.page-top:hover {
    background: var(--color-accent);
    color: var(--color-bg);
    transform: translateY(-3px);
}

/* === RESPONSIVE DESIGN === */
@media (max-width: 1024px) {
    nav {
        display: none;
    }

    .hero-content {
        padding: 8rem 2rem 0;
    }

    .concept-section {
        padding: 100px 2rem;
    }

    .concept-container,
    .concept-container.reverse {
        grid-template-columns: 1fr;
        gap: 3rem;
        direction: ltr;
    }

    .concept-text {
        max-width: 100%;
    }

    .concept-image {
        width: 100%;
        height: 400px;
    }

    .concept-cta {
        padding: 100px 2rem;
    }
}

@media (max-width: 640px) {
    header {
        padding: 1.5rem;
    }

    .hero-content {
        padding: 6rem 1.5rem 0;
    }

    .hero-title {
        font-size: 32px;
        margin-bottom: 2rem;
    }

    .hero-text {
        font-size: 13px;
    }

    .concept-section {
        padding: 80px 1.5rem;
    }

    .section-title {
        font-size: 28px;
    }

    .concept-lead {
        font-size: 16px;
    }

    .concept-body {
        font-size: 13px;
    }

    .concept-image {
        height: 350px;
    }

    .closing-title {
        font-size: 32px;
    }

    .closing-text {
        font-size: 14px;
    }

    .concept-cta {
        padding: 80px 1.5rem;
    }

    .cta-heading {
        font-size: 36px;
    }

    .footer-nav {
        flex-direction: column;
        align-items: center;
        gap: 1rem;
    }

    .page-top {
        width: 45px;
        height: 45px;
        bottom: 1.5rem;
        right: 1.5rem;
    }
}