/* 瑞物里家居美学馆 — Poliform 意式极简质感
 * 设计原则：
 * 1. 极致留白（section padding 140px+）
 * 2. 大图沉浸（hero 全屏、案例全幅）
 * 3. 方角无阴影（仅 hairline border）
 * 4. 暖米白底 + 深炭灰文字 + 木色点缀
 * 5. 衬线编号 01/02/03 作为章节锚点
 * 6. 超宽字间距细标签
 */

:root {
  /* RWL × Poliform — 纯黑白灰 + 深木色点缀（品牌绿已移除） */
  --color-brand: #2A2A2A;          /* 深炭灰（替代原品牌绿） */
  --color-brand-light: #8A8780;     /* 暖中灰（深色背景上的 label 用） */
  --color-brand-deep: #0A0A0A;     /* 纯黑（按钮悬停） */
  --color-accent: #6B4A2F;         /* 深胡桃木色（细小点缀） */
  --color-accent-light: #8A6A4A;   /* 浅一档木色 */

  --color-bg: #F4F1EC;            /* 暖米白（Poliform 经典底色） */
  --color-bg-alt: #EAE5DD;        /* 微深一档 */
  --color-bg-warm: #E8E2D6;
  --color-bg-dark: #1A1A1A;
  --color-bg-darker: #0E0E0E;

  --color-text: #1A1A1A;
  --color-text-secondary: #5A5853;
  --color-text-muted: #8A8780;
  --color-light: #F4F1EC;

  --color-border: rgba(26, 26, 26, 0.08);
  --color-border-strong: rgba(26, 26, 26, 0.18);

  --font-sans: -apple-system, BlinkMacSystemFont, "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-serif: "Cormorant Garamond", Georgia, "Times New Roman", "Songti SC", "SimSun", serif;
  --container: 1320px;
  --container-narrow: 980px;
  --radius: 0;                    /* Poliform 风格：全部方角 */
  --radius-lg: 0;
  --shadow: none;
  --shadow-sm: none;
  --transition: all 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

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

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

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  font-weight: 300;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; transition: var(--transition); }
ul { list-style: none; }

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 40px;
}
.container.narrow { max-width: var(--container-narrow); }

/* ====== Typography ====== */
.h1, .h2, .h3, .h4 { font-weight: 300; line-height: 1.25; letter-spacing: -0.01em; }
.h1 { font-size: clamp(2.75rem, 7vw, 5.5rem); letter-spacing: -0.02em; }
.h2 { font-size: clamp(2rem, 4.5vw, 3.5rem); letter-spacing: -0.015em; }
.h3 { font-size: 1.5rem; }
.h4 { font-size: 1.15rem; font-weight: 400; }

.text-serif { font-family: var(--font-serif); font-style: italic; font-weight: 400; }
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-light { color: var(--color-light); }
.text-secondary { color: var(--color-text-secondary); }
.text-muted { color: var(--color-text-muted); }

/* Poliform 风格：超宽字间距小标签 */
.label {
  display: inline-block;
  font-size: 0.7rem;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--color-text-secondary);
  margin-bottom: 1.5rem;
  font-weight: 400;
}

/* 章节衬线编号：01 / 02 / 03 */
.section-num {
  font-family: var(--font-serif);
  font-size: 1rem;
  letter-spacing: 0.4em;
  color: var(--color-text-muted);
  display: block;
  margin-bottom: 2rem;
  font-style: italic;
}
.section-dark .section-num { color: rgba(244, 241, 236, 0.5); }

/* ====== Buttons ====== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 18px 44px;
  font-size: 0.75rem;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  border-radius: var(--radius);
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid transparent;
  font-family: var(--font-sans);
  font-weight: 400;
}
.btn-primary {
  background: var(--color-bg-dark);
  color: var(--color-light);
  border-color: var(--color-bg-dark);
}
.btn-primary:hover {
  background: var(--color-brand-deep);
  border-color: var(--color-brand-deep);
}
.btn-outline {
  background: transparent;
  color: var(--color-text);
  border-color: var(--color-border-strong);
}
.btn-outline:hover {
  background: var(--color-text);
  color: var(--color-light);
  border-color: var(--color-text);
}
.btn-outline-light {
  background: transparent;
  color: var(--color-light);
  border-color: rgba(244, 241, 236, 0.4);
}
.btn-outline-light:hover {
  background: var(--color-light);
  color: var(--color-bg-dark);
  border-color: var(--color-light);
}

/* ====== Sections — 极致留白 ====== */
.section { padding: 140px 0; }
.section.section-sm { padding: 100px 0; }
.section.section-lg { padding: 180px 0; }
.section-dark { background: var(--color-bg-dark); color: var(--color-light); }
.section-alt { background: var(--color-bg-alt); }
.section-warm { background: var(--color-bg-warm); }

.section-header { max-width: 760px; margin-bottom: 80px; }
.section-header.center { margin-left: auto; margin-right: auto; text-align: center; }
.section-subtitle { font-size: 1.1rem; color: var(--color-text-secondary); line-height: 1.85; font-weight: 300; }
.section-dark .section-subtitle { color: rgba(244, 241, 236, 0.65); }

/* ====== Grid ====== */
.grid { display: grid; gap: 0; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-5 { grid-template-columns: repeat(5, 1fr); }
.grid-gap-sm { gap: 16px; }
.grid-gap-md { gap: 32px; }
.grid-gap-lg { gap: 60px; }

/* ====== Card — Poliform 风格：无圆角、无阴影、方框 ====== */
.card {
  background: transparent;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: none;
  transition: var(--transition);
  position: relative;
}
.card:hover { transform: none; box-shadow: none; }
.card-img {
  width: 100%;
  height: 480px;
  object-fit: cover;
  transition: var(--transition);
}
.card:hover .card-img { transform: scale(1.04); }
.card-body { padding: 32px 0 0; background: transparent; }
.card-title { font-size: 1.35rem; margin-bottom: 0.75rem; font-weight: 400; letter-spacing: 0.01em; }
.card-text { color: var(--color-text-secondary); font-size: 0.95rem; line-height: 1.8; font-weight: 300; }

/* ====== Header & Nav ====== */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  transition: var(--transition);
  padding: 32px 0;
}
.header.scrolled {
  background: rgba(244, 241, 236, 0.92);
  backdrop-filter: blur(12px);
  box-shadow: 0 1px 0 var(--color-border);
  padding: 18px 0;
}
.header.dark { background: transparent; }
.header.dark.scrolled {
  background: rgba(14, 14, 14, 0.92);
  backdrop-filter: blur(12px);
  box-shadow: 0 1px 0 rgba(244, 241, 236, 0.06);
}
.header .container { display: flex; align-items: center; justify-content: space-between; }

.logo { display: flex; align-items: center; gap: 14px; text-decoration: none; }
.logo img { height: 38px; width: auto; display: block; }
.logo .logo-light { display: block; }
.logo .logo-dark { display: none; }
.header.scrolled:not(.dark) .logo .logo-light { display: none; }
.header.scrolled:not(.dark) .logo .logo-dark { display: block; }
.header.dark .logo .logo-light { display: block; }
.header.dark .logo .logo-dark { display: none; }

.logo-text {
  font-size: 1.25rem;
  letter-spacing: 0.18em;
  font-weight: 400;
  color: var(--color-text);
  text-transform: uppercase;
}
.header.dark .logo-text,
.header:not(.scrolled) .logo-text { color: var(--color-light); }
.header.scrolled .logo-text { color: var(--color-text); }

.nav { display: flex; align-items: center; gap: 48px; }
.nav-link {
  font-size: 0.78rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-text);
  position: relative;
  padding: 6px 0;
  font-weight: 400;
}
.header:not(.scrolled) .nav-link,
.header.dark .nav-link { color: var(--color-light); }
.header.scrolled .nav-link { color: var(--color-text); }
.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0;
  width: 0; height: 1px;
  background: currentColor;
  transition: var(--transition);
}
.nav-link:hover::after,
.nav-link.active::after { width: 100%; }
.nav-link:hover, .nav-link.active { color: var(--color-text); }
.header.dark .nav-link:hover,
.header.dark .nav-link.active { color: var(--color-light); }

.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 8px;
  background: none;
  border: none;
}
.mobile-menu-toggle span {
  display: block;
  width: 24px;
  height: 1px;
  background: var(--color-text);
  transition: var(--transition);
}
.header:not(.scrolled) .mobile-menu-toggle span,
.header.dark .mobile-menu-toggle span { background: var(--color-light); }
.header.scrolled .mobile-menu-toggle span { background: var(--color-text); }

/* ====== Hero — Poliform 大图沉浸 ====== */
.hero {
  position: relative;
  height: 100vh;
  min-height: 700px;
  display: flex;
  align-items: flex-end;
  overflow: hidden;
  background: var(--color-bg-dark);
}
.hero-bg { position: absolute; inset: 0; z-index: 1; }
.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 1;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(0,0,0,0.65) 0%, rgba(0,0,0,0.15) 50%, rgba(0,0,0,0.25) 100%);
  z-index: 2;
}
.hero-content {
  position: relative;
  z-index: 3;
  max-width: var(--container);
  margin: 0 auto;
  width: 100%;
  padding: 0 40px 100px;
  color: var(--color-light);
}
.hero-label {
  font-size: 0.7rem;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  margin-bottom: 2rem;
  opacity: 0.85;
  font-weight: 400;
}
.hero-title {
  font-size: clamp(2.25rem, 6vw, 4.5rem);
  line-height: 1.15;
  margin-bottom: 1.5rem;
  font-weight: 300;
  letter-spacing: -0.015em;
  max-width: 720px;
}
.hero-subtitle {
  font-size: 1.1rem;
  max-width: 540px;
  opacity: 0.85;
  line-height: 1.8;
  font-weight: 300;
  margin-bottom: 3rem;
}
.hero-buttons { display: flex; gap: 16px; flex-wrap: wrap; }

.scroll-hint {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 3;
  color: var(--color-light);
  opacity: 0.6;
  font-size: 0.7rem;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  animation: bounce 2.5s infinite;
}
@keyframes bounce {
  0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
  40% { transform: translateX(-50%) translateY(-8px); }
  60% { transform: translateX(-50%) translateY(-4px); }
}

/* ====== Page Header ====== */
.page-header {
  padding: 220px 0 120px;
  background: var(--color-bg-dark);
  color: var(--color-light);
  text-align: center;
  position: relative;
  overflow: hidden;
}
.page-header-title {
  font-size: clamp(2.25rem, 6vw, 4rem);
  margin-bottom: 1.5rem;
  letter-spacing: -0.015em;
  font-weight: 300;
}
.page-header-desc {
  max-width: 560px;
  margin: 0 auto;
  opacity: 0.7;
  font-size: 1.05rem;
  font-weight: 300;
  line-height: 1.85;
}

/* ====== Feature / Value blocks ====== */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  border-top: 1px solid var(--color-border);
  border-left: 1px solid var(--color-border);
}
.feature-item {
  padding: 56px 40px;
  background: transparent;
  border-radius: 0;
  box-shadow: none;
  transition: var(--transition);
  border-right: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}
.feature-item:hover { background: var(--color-bg-alt); transform: none; box-shadow: none; }
.feature-number {
  font-family: var(--font-serif);
  font-size: 2.25rem;
  color: var(--color-text-muted);
  margin-bottom: 1.5rem;
  line-height: 1;
  font-style: italic;
  letter-spacing: 0.05em;
}
.feature-title {
  font-size: 1.25rem;
  margin-bottom: 1rem;
  font-weight: 400;
  letter-spacing: 0.01em;
}
.feature-desc {
  color: var(--color-text-secondary);
  font-size: 0.92rem;
  line-height: 1.85;
  font-weight: 300;
}

/* ====== Process timeline ====== */
.timeline { position: relative; padding-left: 40px; }
.timeline::before {
  content: '';
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--color-border-strong);
}
.timeline-item { position: relative; padding-bottom: 56px; }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-dot {
  position: absolute;
  left: -40px;
  top: 6px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--color-text);
  border: 3px solid var(--color-bg);
  box-shadow: 0 0 0 1px var(--color-border-strong);
}
.timeline-year {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  color: var(--color-text-muted);
  margin-bottom: 0.5rem;
  font-style: italic;
  letter-spacing: 0.05em;
}
.timeline-title { font-size: 1.35rem; margin-bottom: 0.75rem; font-weight: 400; }
.timeline-desc { color: var(--color-text-secondary); font-size: 0.95rem; line-height: 1.85; font-weight: 300; }

/* ====== Image showcase — Poliform 大幅全幅展示 ====== */
.showcase {
  position: relative;
  border-radius: 0;
  overflow: hidden;
}
.showcase img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 1.2s cubic-bezier(0.16, 1, 0.3, 1);
}
.showcase:hover img { transform: scale(1.04); }
.showcase-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(0,0,0,0.75) 0%, transparent 55%);
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: 48px;
  color: var(--color-light);
}
.showcase-title { font-size: 1.6rem; margin-bottom: 0.5rem; font-weight: 400; }
.showcase-meta { font-size: 0.78rem; opacity: 0.8; letter-spacing: 0.16em; text-transform: uppercase; }

/* ====== Stats ====== */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  border-top: 1px solid var(--color-border-strong);
}
.stat-item {
  text-align: left;
  padding: 56px 32px;
  border-right: 1px solid var(--color-border);
}
.stat-item:last-child { border-right: none; }
.stat-number {
  font-family: var(--font-serif);
  font-size: 3.5rem;
  color: var(--color-text);
  line-height: 1;
  margin-bottom: 1rem;
  font-style: italic;
  letter-spacing: -0.01em;
}
.stat-label {
  font-size: 0.78rem;
  color: var(--color-text-secondary);
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

/* ====== Footer ====== */
.footer {
  background: var(--color-bg-darker);
  color: var(--color-light);
  padding: 120px 0 40px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 60px;
  margin-bottom: 100px;
}
.footer-brand {
  font-size: 1.25rem;
  letter-spacing: 0.18em;
  margin-bottom: 1.5rem;
  text-transform: uppercase;
}
.footer-brand .footer-logo { height: 36px; width: auto; display: block; }
.footer-desc {
  color: rgba(244, 241, 236, 0.5);
  font-size: 0.92rem;
  line-height: 1.9;
  max-width: 320px;
  font-weight: 300;
}
.footer-title {
  font-size: 0.72rem;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  margin-bottom: 1.5rem;
  color: rgba(244, 241, 236, 0.5);
  font-weight: 400;
}
.footer-links li { margin-bottom: 0.9rem; }
.footer-links a {
  color: rgba(244, 241, 236, 0.65);
  font-size: 0.92rem;
  font-weight: 300;
}
.footer-links a:hover { color: var(--color-light); }
.footer-bottom {
  border-top: 1px solid rgba(244, 241, 236, 0.08);
  padding-top: 32px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.78rem;
  color: rgba(244, 241, 236, 0.4);
  letter-spacing: 0.06em;
}

/* ====== Forms ====== */
.form-group { margin-bottom: 32px; }
.form-label {
  display: block;
  font-size: 0.72rem;
  margin-bottom: 12px;
  color: var(--color-text);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  font-weight: 400;
}
.form-input, .form-textarea {
  width: 100%;
  padding: 16px 0;
  border: none;
  border-bottom: 1px solid var(--color-border-strong);
  background: transparent;
  font-family: var(--font-sans);
  font-size: 1rem;
  color: var(--color-text);
  border-radius: 0;
  transition: var(--transition);
  font-weight: 300;
}
.form-input:focus, .form-textarea:focus {
  outline: none;
  border-color: var(--color-text);
  border-bottom-width: 1px;
}
.form-textarea { min-height: 120px; resize: vertical; }

/* ====== Utility ====== */
.mt-1 { margin-top: 1rem; }
.mt-2 { margin-top: 2rem; }
.mt-3 { margin-top: 3rem; }
.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 2rem; }
.mb-3 { margin-bottom: 3rem; }

/* ====== Responsive ====== */
@media (max-width: 992px) {
  .grid-3, .grid-4, .grid-5, .feature-grid, .stat-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
  .section { padding: 100px 0; }
  .hero-content { padding: 0 32px 80px; }
  .container { padding: 0 32px; }
}

@media (max-width: 768px) {
  .section { padding: 80px 0; }
  .grid-2, .grid-3, .grid-4, .grid-5, .feature-grid, .stat-grid { grid-template-columns: 1fr; }
  .feature-grid, .stat-grid { border-left: none; }
  .feature-item, .stat-item { border-right: none; }

  .nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0; right: 0;
    flex-direction: column;
    background: rgba(244, 241, 236, 0.98);
    backdrop-filter: blur(12px);
    padding: 24px 32px;
    gap: 24px;
    box-shadow: 0 1px 0 var(--color-border);
  }
  .nav.active { display: flex; }
  .header:not(.scrolled) .nav,
  .header.dark .nav { background: rgba(14, 14, 14, 0.98); }
  .header:not(.scrolled) .nav-link,
  .header.dark .nav-link,
  .nav-link { color: var(--color-text); }
  .header:not(.scrolled) .nav.active .nav-link,
  .header.dark .nav.active .nav-link { color: var(--color-light); }

  .mobile-menu-toggle { display: flex; }
  .footer-grid { grid-template-columns: 1fr; gap: 40px; }
  .footer-bottom { flex-direction: column; gap: 12px; text-align: center; }
  .hero-buttons { flex-direction: column; align-items: stretch; }
  .hero-content { padding: 0 24px 60px; }
  .card-img { height: 320px; }
  .page-header { padding: 160px 0 80px; }
}

@media (max-width: 480px) {
  .container { padding: 0 24px; }
  .hero-title { font-size: 2.25rem; }
  .card-img { height: 240px; }
}