/* ============================================================
   星动纪元 · 高端 MCN 内容机构 — 纯静态版样式
   黑金质感 / 极简留白 / 移动端自适应
   ============================================================ */

:root {
  --black: #0b0b0b;
  --white: #ffffff;
  --paper: #f4f4f5;
  --grey: #666666;
  --line: #1a1a1a;
  color-scheme: light dark;
}

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

html {
  -webkit-font-smoothing: antialiased;
  scroll-behavior: smooth;
}

body {
  font-family: "Helvetica Neue", "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", sans-serif;
  background: var(--white);
  color: #000;
  overflow-x: hidden;
}

::selection {
  background: #000;
  color: #fff;
}

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

button {
  font-family: inherit;
}

/* ---------- 加载动画 ---------- */
#preloader {
  position: fixed;
  inset: 0;
  z-index: 100;
  background: var(--black);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity 0.9s ease, visibility 0.9s;
}

#preloader.done {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.preloader-word {
  color: #fff;
  font-size: clamp(28px, 5vw, 56px);
  letter-spacing: 0.4em;
  animation: breathe 1.6s ease-in-out infinite;
}

@keyframes breathe {
  0%, 100% { opacity: 0.25; }
  50% { opacity: 1; }
}

/* ---------- 顶部导航 ---------- */
#site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 64px;
  padding: 0 clamp(20px, 4vw, 60px);
  color: #fff;
  transition: background 0.4s ease, color 0.4s ease,
    border-color 0.4s ease;
  border-bottom: 1px solid transparent;
}

#site-header.solid {
  background: #fff;
  color: #000;
  border-bottom-color: #e5e5e5;
}

.site-logo {
  font-size: 18px;
  font-weight: 500;
  letter-spacing: 0.22em;
  white-space: nowrap;
  cursor: pointer;
}

#site-header nav {
  display: flex;
  align-items: center;
}

.site-nav-item {
  background: none;
  border: none;
  color: inherit;
  font-size: 14px;
  letter-spacing: 0.1em;
  padding: 8px 20px;
  cursor: pointer;
  position: relative;
}

.site-nav-item::after {
  content: "";
  position: absolute;
  left: 20px;
  right: 20px;
  bottom: 4px;
  height: 1px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}

.site-nav-item:hover::after {
  transform: scaleX(1);
}

/* ---------- 首屏主视觉 ---------- */
#hero {
  position: relative;
  height: 100vh;
  min-height: 640px;
  overflow: hidden;
  background: var(--black);
}

.hero-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  animation: slow-zoom 18s ease-in-out infinite alternate;
}

@keyframes slow-zoom {
  from { transform: scale(1.1); }
  to { transform: scale(1); }
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    rgba(0, 0, 0, 0.55) 0%,
    rgba(0, 0, 0, 0.28) 35%,
    rgba(0, 0, 0, 0.6) 100%
  );
}

.hero-content {
  position: relative;
  z-index: 2;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 28px;
  padding: 0 clamp(32px, 4.5vw, 72px);
}

.hero-content h1 {
  font-size: clamp(44px, 7vw, 108px);
  font-weight: 400;
  letter-spacing: -0.03em;
  line-height: 1.08;
  color: #fff;
  max-width: 980px;
  text-shadow: 0 2px 24px rgba(0, 0, 0, 0.35);
}

.hero-content p {
  font-size: clamp(15px, 1.2vw, 18px);
  font-weight: 300;
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.88);
  max-width: 560px;
}

.btn-outline {
  align-self: flex-start;
  margin-top: 12px;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.14em;
  color: #fff;
  background: transparent;
  border: 1px solid #fff;
  padding: 16px 36px;
  cursor: pointer;
  transition: all 0.3s ease;
}

.btn-outline:hover {
  background: #fff;
  color: var(--black);
}

/* ---------- 品牌理念 ---------- */
#philosophy {
  background: var(--white);
  padding: clamp(100px, 14vw, 180px) clamp(24px, 6vw, 96px);
}

#philosophy blockquote {
  font-size: clamp(26px, 4vw, 56px);
  font-weight: 400;
  letter-spacing: -0.02em;
  line-height: 1.4;
  max-width: 1080px;
}

#philosophy .tags {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 48px;
}

#philosophy .tags li {
  font-size: 12px;
  letter-spacing: 0.18em;
  border: 1px solid #000;
  padding: 10px 22px;
}

/* ---------- 全链路内容服务 ---------- */
#capabilities {
  position: relative;
  background: var(--black);
  color: #fff;
  overflow: hidden;
}

.cap-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.cap-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
}

.cap-inner {
  position: relative;
  z-index: 2;
  max-width: 1400px;
  margin: 0 auto;
  padding: clamp(90px, 10vw, 140px) clamp(24px, 4vw, 60px);
}

.cap-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 40px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.35);
  padding-bottom: 56px;
  margin-bottom: 0;
}

.cap-eyebrow {
  font-size: 12px;
  letter-spacing: 0.22em;
  color: rgba(255, 255, 255, 0.6);
  margin-bottom: 20px;
}

.cap-head h2 {
  font-size: clamp(40px, 6vw, 80px);
  font-weight: 400;
  letter-spacing: -0.03em;
  line-height: 1;
  margin-bottom: 24px;
}

.cap-desc {
  font-size: clamp(15px, 1.2vw, 18px);
  font-weight: 300;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.78);
  max-width: 640px;
}

.orbital {
  width: 170px;
  height: 170px;
  flex-shrink: 0;
  animation: spin 24s linear infinite;
}

.orbital text {
  fill: rgba(255, 255, 255, 0.7);
  font-size: 12.5px;
  letter-spacing: 3px;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.cap-grid {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-left: 1px solid rgba(255, 255, 255, 0.25);
}

.cap-grid li {
  border-right: 1px solid rgba(255, 255, 255, 0.25);
  border-bottom: 1px solid rgba(255, 255, 255, 0.25);
  padding: 32px 28px 40px;
  transition: background 0.35s ease;
}

.cap-grid li:hover {
  background: rgba(255, 255, 255, 0.06);
}

.cap-num {
  display: block;
  font-size: 12px;
  color: rgba(255, 255, 255, 0.5);
  margin-bottom: 20px;
}

.cap-grid h3 {
  font-size: 20px;
  font-weight: 500;
  letter-spacing: 0.02em;
  margin-bottom: 14px;
}

.cap-grid p {
  font-size: 14px;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.65);
}

/* ---------- 商务合作表单 ---------- */
#contact {
  display: grid;
  grid-template-columns: 1fr 1fr;
  min-height: 100vh;
}

.contact-left {
  position: relative;
  background: var(--black);
  overflow: hidden;
  min-height: 420px;
}

#shader-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.contact-left-text {
  position: absolute;
  left: clamp(28px, 4vw, 60px);
  bottom: clamp(32px, 5vw, 64px);
  z-index: 2;
}

.contact-big {
  font-size: clamp(34px, 4vw, 64px);
  font-weight: 400;
  letter-spacing: -0.02em;
  line-height: 1.15;
  color: #fff;
  margin-bottom: 18px;
}

.contact-small {
  font-size: 12px;
  letter-spacing: 0.2em;
  color: rgba(255, 255, 255, 0.7);
}

.contact-right {
  background: #111111;
  color: #fff;
  padding: clamp(64px, 8vw, 120px) clamp(28px, 5vw, 80px);
}

.form-eyebrow {
  font-size: 12px;
  letter-spacing: 0.22em;
  color: rgba(255, 255, 255, 0.55);
  margin-bottom: 20px;
}

.form-title {
  font-size: clamp(30px, 3.4vw, 52px);
  font-weight: 400;
  letter-spacing: -0.02em;
  margin-bottom: 48px;
}

#inquiry-form label {
  display: block;
  margin-bottom: 24px;
}

#inquiry-form label span {
  display: block;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: rgba(255, 255, 255, 0.55);
  margin-bottom: 10px;
}

#inquiry-form input,
#inquiry-form select,
#inquiry-form textarea {
  width: 100%;
  background: transparent;
  border: none;
  border-bottom: 1px solid rgba(255, 255, 255, 0.35);
  color: #fff;
  font-size: 16px;
  font-family: inherit;
  padding: 10px 0;
  outline: none;
  transition: border-color 0.3s ease;
  border-radius: 0;
}

#inquiry-form select option {
  color: #000;
}

#inquiry-form input:focus,
#inquiry-form select:focus,
#inquiry-form textarea:focus {
  border-bottom-color: #fff;
}

#inquiry-form textarea {
  resize: vertical;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.btn-solid {
  width: 100%;
  margin-top: 12px;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.16em;
  background: #fff;
  color: #000;
  border: 1px solid #fff;
  padding: 18px 24px;
  cursor: pointer;
  transition: all 0.25s ease;
}

.btn-solid:hover {
  background: transparent;
  color: #fff;
}

.btn-solid[disabled] {
  opacity: 0.5;
  cursor: wait;
}

.form-error {
  font-size: 13px;
  color: #ff8a80;
  margin-top: 8px;
}

.form-success {
  font-size: 14px;
  line-height: 1.7;
  color: #9fd8ab;
  border: 1px solid #2e6b3a;
  background: rgba(46, 107, 58, 0.15);
  padding: 20px 24px;
  margin-bottom: 32px;
}

/* ---------- 页脚 ---------- */
footer {
  background: #fff;
  border-top: 1px solid #000;
  padding: 80px clamp(20px, 4vw, 60px) 0;
  overflow: hidden;
}

.footer-top {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 24px;
  padding-bottom: 80px;
}

.footer-tagline {
  font-size: clamp(18px, 2vw, 28px);
  line-height: 1.5;
  letter-spacing: -0.01em;
  max-width: 560px;
}

.footer-copy {
  font-size: 11px;
  letter-spacing: 0.22em;
  color: var(--grey);
  white-space: nowrap;
}

.footer-wordmark {
  font-size: clamp(64px, 21vw, 320px);
  line-height: 0.85;
  font-weight: 400;
  letter-spacing: -0.04em;
  text-align: center;
  white-space: nowrap;
  user-select: none;
  transform: translateY(15%);
}

/* ---------- 滚动显现动画 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(48px);
  transition: opacity 0.9s ease, transform 0.9s cubic-bezier(0.22, 1, 0.36, 1);
}

.reveal.in {
  opacity: 1;
  transform: none;
}

/* ---------- 深色模式：跟随系统（手机/桌面通用，自动判断） ---------- */
@media (prefers-color-scheme: dark) {
  body {
    background: var(--black);
    color: #fff;
  }

  ::selection {
    background: #fff;
    color: #000;
  }

  #site-header.solid {
    background: var(--black);
    color: #fff;
    border-bottom-color: #2a2a2a;
  }

  #philosophy {
    background: var(--black);
    color: #fff;
  }

  #philosophy .tags li {
    border-color: rgba(255, 255, 255, 0.6);
  }

  footer {
    background: var(--black);
    color: #fff;
    border-top-color: #2a2a2a;
  }

  .footer-copy {
    color: #888;
  }
}

/* ---------- 移动端 ---------- */
@media (max-width: 960px) {
  #contact {
    grid-template-columns: 1fr;
  }
  .cap-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  #site-header {
    padding: 0 16px;
  }
  .site-logo {
    font-size: 15px;
    letter-spacing: 0.12em;
  }
  .site-nav-item {
    padding: 8px 10px;
    font-size: 12px;
    letter-spacing: 0.04em;
  }
  .site-nav-item::after {
    left: 10px;
    right: 10px;
  }
  .cap-grid {
    grid-template-columns: 1fr;
  }
  .orbital {
    display: none;
  }
  .form-row {
    grid-template-columns: 1fr;
  }
  .footer-wordmark {
    font-size: 16.5vw;
    letter-spacing: -0.02em;
  }
}