/* ==========================================================================
   Design System & Variables
   ========================================================================== */
:root {
    /* Color Palette */
    --color-bg-primary: #F9F7F5;   /* 米白 */
    --color-bg-secondary: #F0EEEC; /* 浅灰 */
    --color-accent-dark: #2A2826;  /* 深炭灰 */
    --color-accent-soft: #E8D3C9;  /* 柔和裸粉 */
    --color-accent-oat: #D8C4B6;   /* 燕麦色 */
    
    /* Typography Colors */
    --color-text-primary: #333333; /* 深灰 */
    --color-text-secondary: #666666; /* 浅灰 */
    --color-text-light: #FFFFFF;     /* 纯白 */

    /* Typography Fonts */
    --font-family-en: 'Montserrat', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    --font-family-cn: 'PingFang SC', 'Source Han Sans CN', 'Microsoft YaHei', sans-serif;
    
    /* Spacing & Layout */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 8rem;
    
    /* Transitions */
    --transition-fast: 0.3s ease;
    --transition-smooth: 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ==========================================================================
   Reset & Base Styles
   ========================================================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

body {
    font-family: var(--font-family-en), var(--font-family-cn);
    background-color: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition-fast);
}

ul {
    list-style: none;
}

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

/* ==========================================================================
   Typography
   ========================================================================== */
h1, h2, h3, h4 {
    font-weight: 400;
    color: var(--color-accent-dark);
    letter-spacing: 0.05em;
}

h1 {
    font-size: clamp(2rem, 5vw, 3.5rem);
    line-height: 1.2;
    margin-bottom: var(--spacing-sm);
}

h2 {
    font-size: 2rem;
    margin-bottom: var(--spacing-md);
    text-align: center;
    position: relative;
}

h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-xs);
}

p {
    color: var(--color-text-secondary);
    font-size: 1rem;
    margin-bottom: var(--spacing-sm);
}

.text-center { text-align: center; }
.text-uppercase { text-transform: uppercase; }
.text-light { color: var(--color-text-light); }

/* ==========================================================================
   Layout Components
   ========================================================================== */
.container {
    width: 90%;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
}

.section {
    padding: var(--spacing-xl) 0;
}

.section-title {
    margin-bottom: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.section-title span {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.2em;
    margin-top: var(--spacing-xs);
}

/* ==========================================================================
   Navigation
   ========================================================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: rgba(249, 247, 245, 0.9);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid rgba(0,0,0,0.05);
    transition: var(--transition-fast);
}

.nav-brand {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    color: var(--color-accent-dark);
}

.nav-links {
    display: flex;
    gap: var(--spacing-md);
}

.nav-link {
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    position: relative;
    padding-bottom: 4px;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background-color: var(--color-accent-dark);
    transition: width var(--transition-fast);
}

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

/* Mobile Menu Toggle */
.mobile-toggle {
    display: none;
    cursor: pointer;
    font-size: 1.5rem;
}

/* ==========================================================================
   Hero Slider (Homepage)
   ========================================================================== */
.hero {
    position: relative;
    height: 100vh;
    width: 100%;
    overflow: hidden;
}

.hero-slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 1.5s ease-in-out;
    z-index: 1;
}

.hero-slide.active {
    opacity: 1;
    z-index: 2;
}

.hero-slide img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    filter: brightness(0.85); /* Slightly darken for text readability */
}

.hero-content {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 3;
    text-align: center;
    color: var(--color-text-light);
    width: 80%;
}

.hero-content h1 {
    color: var(--color-text-light);
    font-weight: 300;
    text-shadow: 0 2px 10px rgba(0,0,0,0.1);
    opacity: 0;
    transform: translateY(20px);
    transition: all 1s ease 0.5s;
}

.hero-slide.active .hero-content h1 {
    opacity: 1;
    transform: translateY(0);
}

/* Slider Controls */
.slider-dots {
    position: absolute;
    bottom: var(--spacing-md);
    left: 50%;
    transform: translateX(-50%);
    z-index: 10;
    display: flex;
    gap: var(--spacing-sm);
}

.dot {
    width: 40px;
    height: 2px;
    background-color: rgba(255,255,255,0.4);
    cursor: pointer;
    transition: var(--transition-fast);
}

.dot.active {
    background-color: #fff;
}

/* ==========================================================================
   Grid Systems (Features / Collections)
   ========================================================================== */
.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
}

.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
}

.feature-card {
    position: relative;
    overflow: hidden;
    aspect-ratio: 3/4;
    cursor: default;
}

.feature-card img {
    width: 100%;
    height: 100%;
    transition: transform var(--transition-smooth);
}

.feature-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.3);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    opacity: 0;
    transition: opacity var(--transition-fast);
    color: white;
}

.feature-card:hover img {
    transform: scale(1.05);
}

.feature-card:hover .feature-overlay {
    opacity: 1;
}

/* ==========================================================================
   Collections Page Specifics
   ========================================================================== */
.filter-bar {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-sm) 0;
    border-top: 1px solid var(--color-bg-secondary);
    border-bottom: 1px solid var(--color-bg-secondary);
}

.filter-btn {
    background: none;
    border: none;
    cursor: pointer;
    font-family: inherit;
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 5px;
    transition: var(--transition-fast);
}

.filter-btn:hover, .filter-btn.active {
    color: var(--color-accent-dark);
}

.collection-item {
    margin-bottom: var(--spacing-md);
}

.collection-img-wrapper {
    overflow: hidden;
    margin-bottom: var(--spacing-xs);
    box-shadow: 0 4px 20px rgba(0,0,0,0.05);
}

.collection-img-wrapper img {
    transition: transform var(--transition-smooth);
}

.collection-item:hover img {
    transform: scale(1.03);
}

.collection-info {
    text-align: center;
}

.collection-title {
    font-size: 1rem;
    color: var(--color-accent-dark);
    margin-bottom: 4px;
}

.collection-desc {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    font-style: italic;
}

/* ==========================================================================
   Style Guide Page
   ========================================================================== */
.style-section {
    margin-bottom: var(--spacing-xl);
}

.style-row {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
}

.style-row.reverse {
    flex-direction: row-reverse;
}

.style-content {
    flex: 1;
    padding: var(--spacing-md);
}

.style-image {
    flex: 1.2;
    overflow: hidden;
}

.detail-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-sm);
}

/* ==========================================================================
   Quote Section
   ========================================================================== */
.quote-section {
    background-color: var(--color-bg-secondary);
    text-align: center;
    padding: var(--spacing-xl) var(--spacing-md);
}

blockquote {
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-family: serif;
    font-style: italic;
    color: var(--color-accent-dark);
    max-width: 800px;
    margin: 0 auto;
}

/* ==========================================================================
   Footer
   ========================================================================== */
footer {
    background-color: var(--color-accent-dark);
    color: var(--color-bg-primary);
    text-align: center;
    padding: var(--spacing-md);
    font-size: 0.9rem;
    letter-spacing: 0.1em;
}

/* ==========================================================================
   Animations
   ========================================================================== */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.fade-in-up {
    animation: fadeIn 1s ease forwards;
}

/* ==========================================================================
   Responsive Design
   ========================================================================== */
@media (max-width: 1024px) {
    .grid-3 {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .navbar {
        padding: var(--spacing-sm);
    }

    .mobile-toggle {
        display: block;
    }

    .nav-links {
        position: fixed;
        top: 60px;
        right: -100%;
        width: 100%;
        height: calc(100vh - 60px);
        background: var(--color-bg-primary);
        flex-direction: column;
        align-items: center;
        justify-content: center;
        transition: right var(--transition-fast);
        box-shadow: -5px 0 15px rgba(0,0,0,0.1);
    }

    .nav-links.active {
        right: 0;
    }

    .grid-3, .grid-2 {
        grid-template-columns: 1fr;
    }

    .style-row, .style-row.reverse {
        flex-direction: column;
    }

    .detail-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .hero-content {
        width: 90%;
    }
}