/* ============================================
   MDEditor 官网 - 宇宙感首屏
   深空底 + 来源星球 → 转换器 → 交付成品
   ============================================ */

:root {
  /* 文字 */
  --text: #eef2fb;
  --text-2: #a8b3cc;
  --text-3: #6f7b96;

  /* 全站深空背景 */
  --bg: #020309;
  --bg-soft: #070a14;
  --bg-line: rgba(126, 148, 200, 0.16);

  /* 品牌／光效 */
  --brand: #4d7dff;
  --brand-lit: #7aa2ff;
  --cyan: #45e0e8;
  --violet: #9b6cff;

  /* 尺寸 */
  --wrap: 1180px;
  --radius: 10px;

  /* 字体 */
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC',
          'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

ul, ol {
  list-style: none;
}

.wrap {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 2rem;
}

/* ============================================
   顶栏
   ============================================ */

.topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(2, 3, 9, 0.76);
  backdrop-filter: saturate(160%) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s ease;
}

.topbar.is-stuck {
  border-bottom-color: var(--bg-line);
}

.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.brand {
  font-size: 1.0625rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.topbar-nav {
  display: flex;
  gap: 0.25rem;
}

.nav-tab {
  padding: 0.375rem 0.75rem;
  border-radius: 6px;
  font-size: 0.8125rem;
  color: var(--text-2);
  transition: background 0.15s, color 0.15s;
}

.nav-tab:hover {
  background: rgba(77, 125, 255, 0.08);
  color: var(--text);
}

.nav-tab.is-active {
  background: rgba(77, 125, 255, 0.12);
  color: var(--brand-lit);
}

/* ============================================
   按钮
   ============================================ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  font-size: 0.9375rem;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s ease, border-color 0.15s ease,
              box-shadow 0.2s ease, transform 0.15s ease;
  white-space: nowrap;
}

.btn svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
  flex-shrink: 0;
}

.btn-copy {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.125rem;
  line-height: 1.15;
}

.btn-copy small {
  font-size: 11px;
  font-weight: 400;
  opacity: 0.72;
}

.btn-primary {
  background: linear-gradient(135deg, var(--brand), var(--violet));
  color: #fff;
  box-shadow: 0 0 0 1px rgba(122, 162, 255, 0.35),
              0 8px 28px -8px rgba(77, 125, 255, 0.7);
}

.btn-primary:hover {
  box-shadow: 0 0 0 1px rgba(122, 162, 255, 0.55),
              0 10px 34px -8px rgba(77, 125, 255, 0.9);
}

.btn-ghost {
  background: rgba(126, 148, 200, 0.08);
  color: var(--text);
  border: 1px solid var(--bg-line);
}

.btn-ghost:hover {
  border-color: rgba(122, 162, 255, 0.5);
}

.btn-sm {
  padding: 0.4375rem 1rem;
  font-size: 0.8125rem;
  background: linear-gradient(135deg, var(--brand), var(--violet));
  color: #fff;
}

.btn:active {
  transform: translateY(1px);
}

.btn.is-off {
  opacity: 0.4;
  pointer-events: none;
}

/* ============================================
   首屏容器与深空背景
   ============================================ */

.hero {
  position: relative;
  padding: 4rem 0 5.5rem;
  text-align: center;
  background: var(--bg);
  overflow: hidden;
}

/* 星点：多层 radial-gradient，避免引图片 */
.starfield {
  position: absolute;
  inset: -10% 0 0;
  pointer-events: none;
}
.starfield canvas {
  display: block;
  width: 100%;
  height: 100%;
  opacity: 0.7;
  filter: blur(0.5px);
}

/* 星云：两团柔光，一冷一紫 */
.nebula {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  pointer-events: none;
}

.nebula-a {
  top: -14rem;
  left: 50%;
  width: 46rem;
  height: 32rem;
  margin-left: -23rem;
  background: radial-gradient(circle, rgba(77, 125, 255, 0.28), transparent 68%);
}

.nebula-b {
  bottom: -18rem;
  left: 50%;
  width: 38rem;
  height: 28rem;
  margin-left: -19rem;
  background: radial-gradient(circle, rgba(155, 108, 255, 0.2), transparent 70%);
}

.hero-inner {
  position: relative;
  z-index: 1;
}

.eyebrow {
  display: inline-block;
  padding: 0.25rem 0.875rem;
  border: 1px solid var(--bg-line);
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  color: var(--brand-lit);
  background: rgba(77, 125, 255, 0.08);
  margin-bottom: 1.25rem;
}

.hero-title {
  font-size: clamp(2.125rem, 4.4vw, 3.25rem);
  font-weight: 650;
  line-height: 1.22;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
  background: linear-gradient(180deg, #ffffff 30%, #a9bfef 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-lede {
  max-width: 34rem;
  margin: 0 auto 3.75rem;
  font-size: 1rem;
  color: #67c7ff;
  text-shadow: 0 0 12px rgba(103, 199, 255, 0.35);
}

.hero-cta {
  position: relative;
  z-index: 999;
  display: flex;
  gap: 0.875rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 3.75rem;
  scroll-margin-top: 80px;
}

.download-option {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.375rem;
}

.backup-download {
  margin-top: 5px;
  color: var(--text-3);
  font-size: 12px;
  line-height: 1.25;
  text-decoration: none;
  transition: color 0.15s ease;
}

.backup-download:hover {
  color: var(--text-2);
}

.backup-download.is-off {
  opacity: 0.4;
  pointer-events: none;
}

.hero-meta {
  margin-top: 1.25rem;
  font-size: 0.8125rem;
  color: var(--text-3);
}

/* ============================================
   宇宙链路：来源星球 → 转换器 → 交付成品
   ============================================ */

.cosmos {
  position: relative;
  display: grid;
  grid-template-columns: 14rem 1fr minmax(0, 14rem) 1fr 14rem;
  align-items: center;
  pointer-events: none;
}

.cosmos-beams {
  position: absolute;
  z-index: 1;
  inset: 0;
  width: 100%;
  height: 100%;
  overflow: visible;
  pointer-events: none;
}

.orbit {
  position: relative;
}

.orbit-cap {
  position: absolute;
  z-index: 3;
  top: 50%;
  width: 2rem;
  transform: translateY(-50%);
  font-size: 0.6875rem;
  font-weight: 600;
  line-height: 1.45;
  letter-spacing: 0.12em;
  text-align: center;
  color: var(--text-3);
  text-transform: uppercase;
}

.orbit-in .orbit-cap { right: -1.25rem; }
.orbit-out .orbit-cap { left: -1.25rem; }

/* 对象层和光束层重叠，星球可以占用整段线路空间 */
.orbit-in { grid-column: 1 / 3; grid-row: 1; z-index: 2; }
.beam-in-space { grid-column: 1 / 3; grid-row: 1; }
.core { grid-column: 3; grid-row: 1; z-index: 3; }
.beam-out-space { grid-column: 4 / 6; grid-row: 1; }
.orbit-out { grid-column: 4 / 6; grid-row: 1; z-index: 2; }

/* 星球散布：绝对定位，坐标和大小由行内 --x/--y/--s 给 */
.planets {
  position: relative;
  height: 21rem;
}

.planet {
  position: absolute;
  left: var(--x);
  top: var(--y);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.4375rem;
  transform: translate(-50%, -50%);
}

/* 星球本体：球面渐变 + 外发光，尺寸跟随 --s */
.planet-body {
  position: relative;
  display: grid;
  place-items: center;
  width: calc(var(--s) * var(--k, 1));
  height: calc(var(--s) * var(--k, 1));
  border-radius: 50%;
  background:
    radial-gradient(circle at 32% 28%,
      rgba(180, 205, 255, 0.28) 0%,
      rgba(40, 58, 110, 0.55) 55%,
      rgba(10, 14, 28, 0.9) 100%);
  box-shadow:
    inset -6px -8px 14px rgba(0, 0, 0, 0.55),
    0 0 18px -4px rgba(77, 125, 255, 0.45);
  transition: box-shadow 0.25s ease, transform 0.25s ease;
}

.planet-body::before {
  position: absolute;
  inset: 0;
  padding: 1px;
  border-radius: inherit;
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.16) 0%,
    rgba(255, 255, 255, 0.05) 100%
  );
  content: '';
  pointer-events: none;
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
}

/* 漂浮加在外层，避免和 hover 的 transform 打架；相位由 --d 错开 */
.planet {
  animation: drift 7s ease-in-out infinite;
  animation-delay: var(--d, 0s);
}

/* 位移必须带上居中的 -50%，否则会顶掉定位 */
@keyframes drift {
  0%, 100% { transform: translate(-50%, -50%); }
  50%      { transform: translate(-50%, calc(-50% - 7px)); }
}

.planet-body svg {
  width: calc(var(--s) * var(--k, 1) * 0.36);
  height: calc(var(--s) * var(--k, 1) * 0.36);
  fill: none;
  stroke: var(--brand-lit);
  stroke-width: 1.6;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.planet-body .icon-solid {
  width: calc(var(--s) * var(--k, 1) * 0.42);
  height: calc(var(--s) * var(--k, 1) * 0.42);
  stroke: #fff;
  stroke-width: 1.35;
}

.icon-solid > :first-child { fill: var(--icon-color); stroke: none; }
.icon-solid > :not(:first-child) { fill: #fff; stroke: none; }
.icon-word { --icon-color: #2b72d6; }
.icon-ppt { --icon-color: #d85b32; }
.icon-pdf { --icon-color: #e5484d; }
.icon-ai { --icon-color: #7567f8; }
.icon-idea { --icon-color: #f5b942; }
.icon-markdown { --icon-color: #3978d4; }
.icon-html { --icon-color: #e55b2d; }

.planet:hover .planet-body {
  transform: translateY(-3px) scale(1.06);
  box-shadow:
    inset -6px -8px 14px rgba(0, 0, 0, 0.5),
    0 0 26px -2px rgba(122, 162, 255, 0.7);
}

.planet-name {
  font-size: 0.75rem;
  color: var(--text-2);
  text-align: center;
  line-height: 1.35;
  white-space: nowrap;
}

/* 可编辑 PPTX 高亮：青色区分 */
.planet-hl .planet-body {
  background:
    radial-gradient(circle at 32% 28%,
      rgba(160, 245, 250, 0.3) 0%,
      rgba(20, 80, 95, 0.6) 55%,
      rgba(8, 18, 26, 0.92) 100%);
  box-shadow:
    inset -6px -8px 14px rgba(0, 0, 0, 0.5),
    0 0 22px -3px rgba(69, 224, 232, 0.5);
}

.planet-hl .planet-body svg {
  stroke: var(--cyan);
}

.planet-hl .planet-name {
  color: var(--cyan);
}

/* ============================================
   光束
   ============================================ */

.beam {
  position: relative;
  height: 21rem;
  min-width: 3rem;
}

.cosmos-beams {
  display: block;
}

.cosmos-beams .beam-in,
.cosmos-beams .beam-out {
  display: block;
}

.beam-line path {
  fill: none;
  stroke: rgba(126, 148, 200, 0.2);
  stroke-width: 1;
  vector-effect: non-scaling-stroke;
}

/* 流星效果：单层高亮 dash + 强发光 + 快速缓动 */
.beam-meteor path {
  fill: none;
  stroke: var(--meteor-color, #7aa2ff);
  stroke-width: 1;
  stroke-linecap: round;
  stroke-dasharray: 18 508;
  vector-effect: non-scaling-stroke;
  filter: drop-shadow(0 0 4px var(--meteor-color, #7aa2ff))
          drop-shadow(0 0 10px var(--meteor-color, #7aa2ff));
  animation: meteor 7.5s linear infinite;
}

/* 入口多色 */
.beam-in .beam-meteor path:nth-child(1) { --meteor-color: #ff6b6b; }
.beam-in .beam-meteor path:nth-child(2) { --meteor-color: #8affc1; }
.beam-in .beam-meteor path:nth-child(3) { --meteor-color: #f1dd9b; }
.beam-in .beam-meteor path:nth-child(4) { --meteor-color: #d7c5ff; }
.beam-in .beam-meteor path:nth-child(5) { --meteor-color: #9fe9ff; }
.beam-in .beam-meteor path:nth-child(6) { --meteor-color: #7aa2ff; }

/* 出口多色 */
.beam-out .beam-meteor path:nth-child(1) { --meteor-color: #45e0e8; }
.beam-out .beam-meteor path:nth-child(2) { --meteor-color: #8affc1; }
.beam-out .beam-meteor path:nth-child(3) { --meteor-color: #d7c5ff; }
.beam-out .beam-meteor path:nth-child(4) { --meteor-color: #f1dd9b; }
.beam-out .beam-meteor path:nth-child(5) { --meteor-color: #ff6b6b; }
.beam-out .beam-meteor path:nth-child(6) { --meteor-color: #9fe9ff; }

/* 入口侧错落 */
.beam-in .beam-meteor path:nth-child(1) { animation-delay: 0s; }
.beam-in .beam-meteor path:nth-child(2) { animation-delay: 0.4s; }
.beam-in .beam-meteor path:nth-child(3) { animation-delay: 0.8s; }
.beam-in .beam-meteor path:nth-child(4) { animation-delay: 1.2s; }
.beam-in .beam-meteor path:nth-child(5) { animation-delay: 1.6s; }
.beam-in .beam-meteor path:nth-child(6) { animation-delay: 2.0s; }

/* 出口侧延迟 */
.beam-out .beam-meteor path:nth-child(1) { animation-delay: 1.2s; }
.beam-out .beam-meteor path:nth-child(2) { animation-delay: 1.55s; }
.beam-out .beam-meteor path:nth-child(3) { animation-delay: 1.9s; }
.beam-out .beam-meteor path:nth-child(4) { animation-delay: 2.25s; }
.beam-out .beam-meteor path:nth-child(5) { animation-delay: 2.6s; }
.beam-out .beam-meteor path:nth-child(6) { animation-delay: 2.95s; }

@keyframes meteor {
  from { stroke-dashoffset: 526; }
  to   { stroke-dashoffset: 0; }
}

/* ============================================
   中央转换器
   ============================================ */

.core {
  position: relative;
  display: grid;
  place-items: center;
  height: 19rem;
}

/* 底层光晕 */
.core-halo {
  position: absolute;
  width: 15rem;
  height: 15rem;
  border-radius: 50%;
  background: radial-gradient(circle,
    rgba(77, 125, 255, 0.35) 0%,
    rgba(155, 108, 255, 0.14) 45%,
    transparent 70%);
  filter: blur(18px);
  animation: breathe 4s ease-in-out infinite;
}

@keyframes breathe {
  0%, 100% { opacity: 0.7; transform: scale(1); }
  50%      { opacity: 1;   transform: scale(1.08); }
}

/* 两圈旋转光环，做「过滤转换」的机械感 */
.core-ring {
  position: absolute;
  border-radius: 50%;
  border: 1px solid transparent;
}

.core-ring-1 {
  width: 11.5rem;
  height: 11.5rem;
  border-color: rgba(122, 162, 255, 0.18);
  border-top-color: rgba(122, 162, 255, 0.55);
  animation: spin 12s linear infinite;
}

.core-ring-2 {
  width: 13.5rem;
  height: 13.5rem;
  border-color: rgba(69, 224, 232, 0.14);
  border-bottom-color: rgba(69, 224, 232, 0.45);
  animation: spin 18s linear infinite reverse;
}

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

.core-label {
  position: relative;
  z-index: 1;
  display: grid;
  place-content: center;
  width: 8.5rem;
  height: 8.5rem;
  border: 2px solid rgba(122, 162, 255, 0.18);
  border-radius: 50%;
  background: radial-gradient(circle at 42% 35%, rgba(77, 125, 255, 0.18), rgba(10, 14, 28, 0.88) 68%);
  box-shadow: inset 0 0 1.75rem rgba(77, 125, 255, 0.1), 0 0 2rem rgba(77, 125, 255, 0.12);
  text-align: center;
}

.core-brand {
  font-size: 1rem;
  font-weight: 650;
  letter-spacing: 0;
  margin-bottom: 0.1875rem;
  text-shadow: 0 0 18px rgba(122, 162, 255, 0.55);
}

.core-fn {
  font-size: 1rem;
  color: #67c7ff;
  letter-spacing: 0.08em;
  text-shadow: 0 0 12px rgba(103, 199, 255, 0.7);
}

/* ============================================
   第二屏：AI 生成成果展廊
   ============================================ */

.showcase-section {
  position: relative;
  height: 100vh;
  min-height: 42rem;
  max-height: 56rem;
  padding: 5rem 0 3rem;
  color: #f2f3f5;
  background: var(--bg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.showcase-section::before {
  position: absolute;
  top: -10rem;
  left: 18%;
  width: 42rem;
  height: 18rem;
  border-radius: 50%;
  background: rgba(93, 112, 166, 0.08);
  filter: blur(80px);
  content: '';
  pointer-events: none;
}

.showcase-header {
  position: relative;
  margin-bottom: 1.25rem;
}

.showcase-heading { max-width: 42rem; }

.showcase-kicker,
.skill-label {
  display: inline-block;
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 4px;
  color: #9aa3b8;
  background: rgba(255, 255, 255, 0.035);
  font-size: 0.6875rem;
  font-weight: 700;
  line-height: 1.7;
}

.showcase-kicker {
  margin-bottom: 0.85rem;
  padding: 0.1rem 0.45rem;
}

.skill-label {
  padding: 0 0.35rem;
  vertical-align: 0.08em;
}

.showcase-heading h2 {
  margin-bottom: 0.9rem;
  font-size: clamp(2.125rem, 4.4vw, 3.25rem);
  font-weight: 650;
  line-height: 1.22;
  letter-spacing: -0.02em;
  background: linear-gradient(180deg, #fff 0%, rgba(255, 255, 255, 0.75) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.showcase-summary {
  max-width: 38rem;
  font-size: 1rem;
  color: #67c7ff;
  text-shadow: 0 0 12px rgba(103, 199, 255, 0.35);
  line-height: 1.8;
}

.showcase-mode-row {
  position: relative;
  z-index: 3;
  display: flex;
  justify-content: flex-end;
  margin-bottom: 1rem;
  transform: translateY(35px);
}

.showcase-modes {
  position: relative;
  isolation: isolate;
  display: flex;
  align-items: stretch;
  gap: 0.2rem;
  padding: 1px;
  border-radius: 999px;
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.16) 0%,
    rgba(255, 255, 255, 0.05) 100%
  );
  box-shadow: none;
  overflow: hidden;
}

.showcase-modes::before {
  position: absolute;
  inset: 1px;
  border-radius: inherit;
  background: rgba(2, 3, 9, 0.9);
  backdrop-filter: blur(14px) saturate(130%);
  content: '';
  pointer-events: none;
}

.showcase-modes .mode-indicator {
  position: absolute;
  z-index: 1;
  top: 1px;
  left: 4px;
  height: calc(100% - 2px);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.07);
  box-shadow: 0 0 0 0.5px rgba(255, 255, 255, 0.1);
  transition: transform 0.32s cubic-bezier(0.4, 0, 0.2, 1), width 0.32s cubic-bezier(0.4, 0, 0.2, 1);
  pointer-events: none;
}

.mode-tab {
  position: relative;
  z-index: 2;
  display: grid;
  min-width: 6.25rem;
  min-height: 2.4rem;
  padding: 0 1rem;
  place-items: center;
  border: 0;
  border-radius: 999px;
  color: #8f99ad;
  background: transparent;
  font: inherit;
  font-size: 0.8125rem;
  font-weight: 650;
  cursor: pointer;
  transition: color 0.18s ease, background 0.18s ease, box-shadow 0.18s ease;
}

.mode-tab.is-active {
  color: #f7f9ff;
}

.showcase-gallery-wrap {
  position: relative;
  flex: 1;
  display: grid;
  align-items: center;
  width: 100%;
  overflow: hidden;
}

.showcase-gallery {
  --gallery-gap: 1.125rem;
  display: flex;
  gap: var(--gallery-gap);
  padding: 0.8rem 0;
  overflow: hidden;
  width: 100%;
  grid-area: 1 / 1;
  -webkit-mask-image: linear-gradient(
    90deg,
    transparent 0%,
    #000 12%,
    #000 88%,
    transparent 100%
  );
  mask-image: linear-gradient(
    90deg,
    transparent 0%,
    #000 12%,
    #000 88%,
    transparent 100%
  );
  opacity: 1;
  visibility: visible;
  transition: opacity 0.45s cubic-bezier(0.4, 0, 0.2, 1), visibility 0.45s;
}

.showcase-gallery--ppt {
  flex-direction: column;
  gap: 0.75rem;
}

.showcase-gallery--ppt .showcase-track {
  gap: 0.75rem;
}

.showcase-gallery--ppt .showcase-card {
  flex: 0 0 clamp(16rem, 22vw, 22rem);
}

.showcase-gallery--ppt .showcase-track--reverse {
  animation-name: marquee-reverse;
}

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

.showcase-gallery.is-hidden {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.35s cubic-bezier(0.4, 0, 0.2, 1), visibility 0s 0.35s;
}

.showcase-track {
  display: flex;
  flex-shrink: 0;
  width: max-content;
  gap: var(--gallery-gap);
  animation: marquee var(--marquee-duration, 30s) linear infinite;
  will-change: transform;
}

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

.showcase-card {
  flex: 0 0 clamp(19rem, 28.5vw, 27rem);
  min-width: 0;
  margin: 0;
  padding: 1px;
  border-radius: 8px;
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.13) 0%,
    rgba(255, 255, 255, 0.04) 100%
  );
  box-shadow:
    0 8px 24px rgba(0, 0, 0, 0.32),
    0 2px 6px rgba(0, 0, 0, 0.2);
  overflow: hidden;
  transition: transform 0.22s ease, box-shadow 0.22s ease;
}

.showcase-card:hover {
  transform: translateY(-3px) scale(1.005);
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.17) 0%,
    rgba(255, 255, 255, 0.05) 100%
  );
  box-shadow:
    0 16px 40px rgba(0, 0, 0, 0.38),
    0 4px 12px rgba(0, 0, 0, 0.24);
}

.showcase-card img {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: 6px;
  object-fit: cover;
  background: #08090c;
  pointer-events: none;
}

.showcase-gallery--page .showcase-card {
  flex: 0 0 clamp(12rem, 18vw, 17rem);
}

.showcase-gallery--page .showcase-card img {
  aspect-ratio: 9 / 16;
}

.showcase-gallery-status {
  display: grid;
  flex: 1 0 calc(100% - 2rem);
  min-height: 15rem;
  place-items: center;
  border: 1px solid rgba(126, 148, 200, 0.16);
  border-radius: 8px;
  color: #858da0;
  background: rgba(8, 10, 16, 0.68);
  text-align: center;
}

.showcase-page-empty {
  display: grid;
  place-items: center;
  align-content: center;
  grid-area: 1 / 1;
  min-height: 23rem;
  margin: 0 max(2rem, calc((100vw - var(--wrap)) / 2 + 2rem)) 0 0;
  padding: 2rem;
  border: 1px solid rgba(190, 196, 211, 0.14);
  border-radius: 7px;
  color: #8e94a1;
  background: linear-gradient(145deg, #0b0d12, #090a0d);
  text-align: center;
  opacity: 1;
  visibility: visible;
  transition: opacity 0.45s cubic-bezier(0.4, 0, 0.2, 1), visibility 0.45s;
}

.showcase-page-empty.is-hidden {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.35s cubic-bezier(0.4, 0, 0.2, 1), visibility 0s 0.35s;
}

.empty-state-mark {
  margin-bottom: 1rem;
  padding: 0.2rem 0.55rem;
  border: 1px solid rgba(182, 190, 209, 0.18);
  border-radius: 4px;
  color: #727988;
  font-size: 0.6875rem;
  font-weight: 700;
}

.showcase-page-empty strong {
  margin-bottom: 0.4rem;
  color: #e8eaf0;
  font-size: 1.3rem;
}

.showcase-page-empty p {
  max-width: 27rem;
  color: #858b98;
  font-size: 0.875rem;
}


.mode-tab:focus-visible,
.showcase-page-empty:focus-visible {
  outline: 2px solid #8ea8e8;
  outline-offset: 3px;
}

@media (max-width: 760px) {
  .showcase-section { height: auto; min-height: auto; max-height: none; padding: 4rem 0 2.5rem; }
  .showcase-header { margin-bottom: 1.25rem; }
  .showcase-modes { width: 100%; }
  .mode-tab { flex: 1; min-width: 0; min-height: 2.75rem; }
  .showcase-gallery-wrap { width: 100%; flex: none; display: grid; }
  .showcase-gallery {
    padding: 0.8rem 0 1.2rem;
    overflow: hidden;
    -webkit-mask-image: none;
    mask-image: none;
  }
  .showcase-card { flex-basis: min(84vw, 24rem); }
  .showcase-page-empty { min-height: 19rem; margin-right: 1.25rem; }
}

@media (max-width: 520px) {
  .showcase-heading h2 { font-size: 2rem; }
  .showcase-summary { font-size: 0.9375rem; }
}

@media (prefers-reduced-motion: reduce) {
  .mode-tab,
  .showcase-card { transition: none; }
  .showcase-track { animation: none; }
  .mode-indicator { transition: none; }
  .showcase-gallery,
  .showcase-page-empty { transition: none; }
}

/* ============================================
   第三屏：自然语言 AI 设计
   ============================================ */

.ai-design-section {
  position: relative;
  min-height: 100vh;
  padding: 6rem 0;
  color: var(--text);
  background: var(--bg);
  overflow: hidden;
}

.ai-design-section::before {
  position: absolute;
  top: 14%;
  right: 8%;
  width: 34rem;
  height: 24rem;
  border-radius: 50%;
  background: rgba(38, 111, 163, 0.08);
  filter: blur(90px);
  content: '';
  pointer-events: none;
}

.ai-design-inner {
  position: relative;
}

.ai-design-header {
  max-width: 45rem;
  margin-bottom: 3rem;
}

.ai-design-header h2 {
  margin-bottom: 0.9rem;
  font-size: clamp(2.125rem, 4.4vw, 3.25rem);
  font-weight: 650;
  line-height: 1.22;
  letter-spacing: -0.02em;
  background: linear-gradient(180deg, #fff 0%, rgba(255, 255, 255, 0.75) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.ai-design-header p {
  color: #67c7ff;
  font-size: 1rem;
  line-height: 1.8;
  text-shadow: 0 0 12px rgba(103, 199, 255, 0.35);
}

.ai-design-stage {
  display: grid;
  grid-template-columns: minmax(17rem, 0.72fr) minmax(30rem, 1.45fr);
  gap: clamp(2rem, 5vw, 5rem);
  align-items: center;
}

.ai-chat,
.ai-result {
  position: relative;
  overflow: hidden;
  border-radius: 8px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.09), rgba(255, 255, 255, 0.015));
  padding: 1px;
}

.ai-chat::before,
.ai-result::before {
  position: absolute;
  inset: 1px;
  border-radius: 7px;
  background: rgba(4, 8, 15, 0.94);
  content: '';
}

.ai-chat {
  align-self: stretch;
  min-height: 25rem;
  opacity: 0.7;
  box-shadow: 0 18px 50px rgba(0, 0, 0, 0.22);
}

.ai-chat-bar,
.ai-result-bar {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  min-height: 2.75rem;
  padding: 0 1rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.055);
  color: #7f899e;
  font-size: 0.75rem;
  font-weight: 650;
}

.ai-chat-bar {
  gap: 0.55rem;
}

.ai-chat-status {
  width: 0.45rem;
  height: 0.45rem;
  border-radius: 50%;
  background: #45e0e8;
  box-shadow: 0 0 10px rgba(69, 224, 232, 0.65);
}

.ai-chat-body {
  position: relative;
  z-index: 1;
  padding: 1.5rem 1.25rem;
}

.ai-chat-intro {
  margin-bottom: 1.5rem;
  color: #667086;
  font-size: 0.8125rem;
  line-height: 1.65;
}

.ai-command {
  position: relative;
  display: flex;
  min-height: 3.2rem;
  margin-top: 1rem;
  padding: 0.85rem 0.9rem;
  border: 1px solid rgba(255, 255, 255, 0.055);
  border-radius: 6px;
  color: #d6dce9;
  background: rgba(255, 255, 255, 0.025);
  font-size: 0.875rem;
  line-height: 1.55;
  opacity: 0.24;
  transition: opacity 0.3s ease, border-color 0.3s ease, background 0.3s ease;
}

.ai-command.is-active,
.ai-command.is-complete {
  opacity: 1;
}

.ai-command.is-active {
  border-color: rgba(69, 224, 232, 0.16);
  background: rgba(69, 224, 232, 0.035);
}

.ai-command-mark {
  flex: none;
  margin-right: 0.55rem;
  color: #45e0e8;
}

.ai-command-caret {
  display: none;
  width: 1px;
  height: 1.05em;
  margin: 0.18em 0 0 0.16rem;
  background: #67c7ff;
  animation: ai-caret 0.75s step-end infinite;
}

.ai-command.is-active .ai-command-caret {
  display: inline-block;
}

@keyframes ai-caret {
  50% { opacity: 0; }
}

.ai-result {
  box-shadow: 0 28px 70px rgba(0, 0, 0, 0.34);
}

.ai-result-bar {
  justify-content: space-between;
}

.ai-result-state {
  color: #45e0e8;
}

.ai-result-canvas {
  position: relative;
  z-index: 1;
  aspect-ratio: 860 / 420;
  overflow: hidden;
  border-radius: 0 0 7px 7px;
  background: #061522;
  isolation: isolate;
}

.ai-result-image {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0;
  clip-path: inset(0 0 100% 0);
  transition: opacity 0.12s linear;
  pointer-events: none;
}

.ai-result-image.is-base {
  position: relative;
  opacity: 1;
  clip-path: inset(0);
}

.ai-result-image.is-revealing {
  opacity: 1;
  animation: ai-image-reveal 1.45s cubic-bezier(0.42, 0, 0.2, 1) forwards;
}

.ai-result-image.is-visible {
  opacity: 1;
  clip-path: inset(0);
}

.ai-scan-line {
  position: absolute;
  z-index: 5;
  top: -10%;
  left: 2.5%;
  width: 95%;
  height: 1px;
  opacity: 0;
  background: linear-gradient(90deg, transparent, rgba(69, 224, 232, 0.52) 20%, #b7f8ff 50%, rgba(69, 224, 232, 0.52) 80%, transparent);
  box-shadow: 0 0 12px rgba(69, 224, 232, 0.52), 0 6px 24px rgba(69, 224, 232, 0.18);
  pointer-events: none;
}

.ai-scan-line.is-scanning {
  animation: ai-scan 1.45s cubic-bezier(0.42, 0, 0.2, 1) forwards;
}

@keyframes ai-scan {
  0% { top: -2%; opacity: 0; }
  8% { opacity: 1; }
  92% { opacity: 1; }
  100% { top: 102%; opacity: 0; }
}

@keyframes ai-image-reveal {
  from { clip-path: inset(0 0 100% 0); }
  to { clip-path: inset(0); }
}

@media (max-width: 860px) {
  .ai-design-section { min-height: auto; padding: 5rem 0; }
  .ai-design-header { margin-bottom: 2rem; }
  .ai-design-stage { grid-template-columns: 1fr; gap: 1.5rem; }
  .ai-chat { min-height: 15rem; }
  .ai-result { order: -1; }
}

@media (max-width: 520px) {
  .ai-design-section { padding: 4rem 0; }
  .ai-design-header h2 { font-size: 2rem; }
  .ai-design-header p { font-size: 0.9375rem; }
}

@media (prefers-reduced-motion: reduce) {
  .ai-command-caret,
  .ai-scan-line,
  .ai-result-image { animation: none !important; }
}

/* 第三屏叠层舞台覆写 */
.ai-design-section {
  min-height: 100vh;
  padding: 6rem 0 7rem;
}

.ai-design-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 4rem;
  max-width: none;
  margin-bottom: 2rem;
}

.ai-design-header h2 { max-width: 31rem; }
.ai-design-header p { max-width: 22rem; margin-bottom: 0.35rem; }

.ai-design-stage {
  position: relative;
  display: block;
  min-height: 31rem;
}

.ai-canvas {
  position: relative;
  width: min(73%, 52rem);
  min-height: calc(25rem + 30px);
  margin: 1rem 0 0 auto;
  padding: 1.2rem 1.35rem;
  opacity: 0.7;
  transform: rotate(-1.2deg);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.ai-canvas::before {
  position: absolute;
  inset: 0;
  border-top: 1px solid rgba(255, 255, 255, 0.09);
  border-left: 1px solid rgba(255, 255, 255, 0.035);
  background: linear-gradient(135deg, rgba(255,255,255,0.035), transparent 45%);
  content: '';
  pointer-events: none;
}

.ai-canvas-meta {
  position: relative;
  display: flex;
  justify-content: space-between;
  margin-bottom: 2rem;
  color: #596477;
  font-size: 0.625rem;
  letter-spacing: 0.16em;
}

.ai-canvas-meta .ai-result-state { color: #45e0e8; letter-spacing: 0; }
.ai-raw-content,
.ai-design-grid { position: relative; }

.ai-raw-content {
  max-width: 40rem;
  padding: 1rem 1.2rem 1.5rem;
  color: #b4bdcc;
  font-size: clamp(0.85rem, 1.25vw, 1.05rem);
  line-height: 1.8;
  transition: opacity 0.55s ease, transform 0.7s cubic-bezier(0.2, 0.8, 0.2, 1), filter 0.7s ease;
}

.ai-raw-kicker,
.ai-card-label {
  display: block;
  margin-bottom: 0.65rem;
  color: #5ac8d7;
  font-size: 0.6rem;
  letter-spacing: 0.16em;
}

.ai-raw-content p { margin-bottom: 0.85rem; }
.ai-raw-content.is-leaving { opacity: 0; transform: translateY(-1rem); filter: blur(5px); }

.ai-design-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.8rem;
  opacity: 0;
  transform: translateY(1.5rem) scale(0.98);
  filter: blur(7px);
  transition: opacity 0.85s ease, transform 0.85s cubic-bezier(0.2, 0.8, 0.2, 1), filter 0.85s ease;
}

.ai-design-grid.is-visible { opacity: 1; transform: none; filter: none; }
.ai-design-card {
  position: relative;
  min-height: 8.3rem;
  padding: 1.15rem 1.2rem;
  border-top: 1px solid rgba(94, 210, 226, 0.23);
  border-left: 1px solid rgba(255, 255, 255, 0.06);
  background: linear-gradient(135deg, rgba(16, 36, 54, 0.5), rgba(5, 15, 26, 0.16));
  box-shadow: 0 1.5rem 3rem rgba(0,0,0,0.12);
}

.ai-design-card p { max-width: 18rem; color: #c3ccd9; font-size: 0.8rem; line-height: 1.55; }
.ai-design-card strong { color: #45e0e8; font-size: 0.8rem; }
.ai-icon-grid { position: absolute; inset: 4.1rem 0 auto; }
.ai-icon-grid.is-visible .ai-svg-icon { opacity: 1; transform: scale(1); }
.ai-svg-icon {
  display: block;
  width: 1.3rem;
  height: 1.3rem;
  margin-bottom: 0.8rem;
  color: #45e0e8;
  font-size: 1.3rem;
  line-height: 1;
  opacity: 0;
  transform: scale(0.4) rotate(-12deg);
  transition: opacity 0.45s ease 0.35s, transform 0.55s cubic-bezier(0.2, 1.5, 0.4, 1) 0.35s;
}

.ai-chat {
  position: absolute;
  z-index: 3;
  left: 2%;
  bottom: 0;
  width: min(34rem, 48%);
  min-height: 18rem;
  padding: 0;
  overflow: visible;
  border: 0;
  border-radius: 0;
  background: transparent;
  opacity: 1;
  box-shadow: 0 2rem 5rem rgba(0,0,0,0.3);
}

.ai-chat::before { display: none; }
.ai-chat-bar { padding: 0 0 0.8rem; border: 0; color: #7d8799; }
.ai-chat-body { padding: 0; }
.ai-chat-intro { margin-bottom: 1rem; color: #596477; }
.ai-command { min-height: 2.7rem; margin-top: 0.65rem; padding: 0.65rem 0.8rem; border: 0; border-left: 1px solid rgba(69,224,232,0.28); border-radius: 0; background: transparent; }
.ai-command.is-active { background: linear-gradient(90deg, rgba(69,224,232,0.06), transparent 75%); }
.ai-command.is-complete { color: #e0e6f0; }
.ai-send-row { display: flex; align-items: center; justify-content: space-between; margin-top: 1.2rem; padding-top: 0.8rem; border-top: 1px solid rgba(255,255,255,0.06); color: #596477; font-size: 0.7rem; }
.ai-send-button { display: grid; place-items: center; width: 1.7rem; height: 1.7rem; border-radius: 0.45rem; color: #08121d; background: #45e0e8; box-shadow: 0 0 1.5rem rgba(69,224,232,0.32); font-size: 1rem; font-weight: 700; opacity: 0.85; }
.ai-send-button.is-sending { animation: ai-send-pulse 0.55s ease; }

@keyframes ai-send-pulse { 50% { transform: translateY(-3px) scale(1.08); box-shadow: 0 0 2rem rgba(69,224,232,0.55); } }

/* 同位结果切换与完整会话输入 */
.ai-result-stack { position: relative; min-height: 20rem; }
.ai-result-stack > [data-result] {
  position: absolute;
  inset: 0;
  opacity: 0;
  visibility: hidden;
  transform: translateY(0.7rem);
  filter: blur(4px);
  transition: opacity 0.65s ease, visibility 0s linear 0.65s, transform 0.65s cubic-bezier(0.2,0.8,0.2,1), filter 0.65s ease;
}
.ai-result-stack > [data-result].is-visible {
  opacity: 1;
  visibility: visible;
  transform: none;
  filter: none;
  transition-delay: 0s;
}
.ai-raw-content.is-leaving { opacity: 0; transform: none; filter: blur(4px); }
.ai-design-grid { gap: 0.65rem; }
.ai-design-card {
  min-height: 9.1rem;
  padding: 1.1rem 1.15rem 1rem 3.9rem;
  overflow: hidden;
  border: 0;
  border-radius: 0.4rem;
  background:
    linear-gradient(180deg, rgba(255,255,255,0.055), rgba(255,255,255,0.012)) padding-box,
    linear-gradient(180deg, rgba(255,255,255,0.14), rgba(95,209,226,0.035)) border-box;
  border: 1px solid transparent;
  box-shadow: inset 0 1px rgba(255,255,255,0.025), 0 1.5rem 3rem rgba(0,0,0,0.16);
}
.ai-design-card::after {
  position: absolute;
  inset: auto 1.1rem 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(69,224,232,0.18), transparent);
  content: '';
}
.ai-design-card h3 { margin: 0 0 0.35rem; color: #edf5fa; font-size: 0.92rem; font-weight: 560; letter-spacing: 0; }
.ai-design-card p { min-height: 2.5em; margin: 0 0 0.35rem; color: #8996a8; }
.ai-design-card strong { font-size: 0.68rem; font-weight: 520; }
.ai-card-icon {
  position: absolute;
  top: 1.15rem;
  left: 1.15rem;
  display: grid;
  place-items: center;
  width: 2rem;
  height: 2rem;
  border: 1px solid rgba(84,209,222,0.16);
  border-radius: 0.42rem;
  color: #54d1de;
  background: rgba(69,224,232,0.055);
  opacity: 0;
  transform: scale(0.72);
  transition: opacity 0.5s ease, transform 0.6s cubic-bezier(0.2,1.3,0.4,1);
}
.ai-design-grid.has-icons .ai-card-icon { opacity: 1; transform: none; }
.ai-card-icon svg { width: 1rem; height: 1rem; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }
.ai-card-label { margin-bottom: 0.35rem; color: #477d87; font-size: 0.52rem; }

.ai-chat {
  width: min(25rem, 41%);
  min-height: 20rem;
  padding: 0.85rem;
  border: 1px solid rgba(255,255,255,0.075);
  border-radius: 0.65rem;
  background: linear-gradient(180deg, rgba(11,16,25,0.88), rgba(5,9,16,0.72));
  box-shadow: 0 2.5rem 6rem rgba(0,0,0,0.36), inset 0 1px rgba(255,255,255,0.025);
  backdrop-filter: blur(18px);
}
.ai-chat-bar { display: flex; align-items: center; gap: 0.5rem; padding: 0.15rem 0.1rem 0.8rem; border-bottom: 1px solid rgba(255,255,255,0.055); }
.ai-chat-model { margin-left: auto; color: #465164; font-size: 0.52rem; letter-spacing: 0.12em; }
.ai-chat-body { padding: 1rem 0.15rem 0.1rem; }
.ai-chat-history { display: grid; align-content: end; gap: 0.6rem; min-height: 6.4rem; margin: 0.5rem 0 0.8rem; }
.ai-chat-message {
  justify-self: end;
  max-width: 88%;
  padding: 0.65rem 0.75rem;
  border: 1px solid rgba(255,255,255,0.065);
  border-radius: 0.55rem 0.55rem 0.15rem 0.55rem;
  color: #cbd4e0;
  background: rgba(255,255,255,0.035);
  font-size: 0.76rem;
  opacity: 0;
  transform: translateY(0.5rem) scale(0.98);
  transition: opacity 0.4s ease, transform 0.45s ease;
}
.ai-chat-message.is-visible { opacity: 1; transform: none; }
.ai-chat-message small { display: block; margin-top: 0.25rem; color: #4faebb; font-size: 0.55rem; text-align: right; }
.ai-composer {
  position: relative;
  display: flex;
  align-items: center;
  min-height: 3.25rem;
  padding: 0.75rem 3.1rem 0.75rem 0.85rem;
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 0.6rem;
  color: #e3e9f1;
  background: rgba(255,255,255,0.026);
  box-shadow: inset 0 1px rgba(255,255,255,0.025);
  font-size: 0.78rem;
}
.ai-send-button { position: absolute; right: 0.55rem; bottom: 0.55rem; width: 2rem; height: 2rem; }
.ai-send-button svg { width: 1rem; height: 1rem; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.ai-send-row { margin-top: 0.55rem; padding: 0 0.15rem; border: 0; color: #465164; font-size: 0.58rem; }

/* 第三屏标题区精修 */
.ai-design-header {
  display: block;
  margin-bottom: 3.25rem;
}
.ai-design-header .showcase-kicker {
  display: block;
  width: fit-content;
  margin: 0 0 1rem;
}
.ai-design-header h2 {
  max-width: none;
  margin: 0 0 0.85rem;
  white-space: nowrap;
}
.ai-design-header p {
  max-width: 30rem;
  margin: 0;
}

/* 第三屏最终精修 */
.ai-canvas {
  overflow: hidden;
  border-radius: 0.75rem;
  opacity: 0.82;
  transform: translateY(-30px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}
.ai-canvas::before {
  border: 1px solid transparent;
  border-radius: inherit;
  background:
    linear-gradient(rgba(2,3,9,0.82), rgba(2,3,9,0.82)) padding-box,
    linear-gradient(180deg, rgba(255,255,255,0.16), rgba(255,255,255,0.05)) border-box;
}
.ai-chat {
  bottom: -2rem;
  width: min(21.25rem, 35%);
  min-height: 14.5rem;
  padding: 0.65rem;
  border-color: rgba(255,255,255,0.12);
  background: rgba(2,3,9,0.76);
  box-shadow: none;
  backdrop-filter: blur(10px);
}
.ai-chat-body { display: flex; flex-direction: column; min-height: 11.9rem; padding: 0.5rem 0.1rem 0; }
.ai-chat-history { min-height: 0; margin: 0.2rem 0 0.45rem; gap: 0.4rem; }
.ai-composer { margin-top: auto; }
.ai-chat-message { padding: 0.5rem 0.65rem; border-color: rgba(255,255,255,0.08); background: rgba(255,255,255,0.025); }
.ai-composer { min-height: 2.55rem; padding: 0.5rem 2.35rem 0.5rem 0.7rem; border-color: rgba(255,255,255,0.1); background: rgba(255,255,255,0.018); }
.ai-send-button {
  right: 0.5rem;
  bottom: 0.5rem;
  width: 1.55rem;
  height: 1.55rem;
  border-radius: 0.35rem;
  box-shadow: none;
}
.ai-send-button svg { width: 0.78rem; height: 0.78rem; }
.ai-send-button.is-sending { animation: ai-send-press 0.35s ease; }
@keyframes ai-send-press { 50% { transform: translateY(-1px) scale(1.04); } }
.ai-design-card {
  min-height: 10.25rem;
  border-radius: 0.55rem;
  background:
    linear-gradient(rgba(2,3,9,0.56), rgba(2,3,9,0.56)) padding-box,
    linear-gradient(180deg, rgba(255,255,255,0.2), rgba(255,255,255,0.065)) border-box;
  box-shadow: inset 0 1px rgba(255,255,255,0.028);
}
.ai-design-card:hover { transform: translateY(-2px); box-shadow: inset 0 1px rgba(255,255,255,0.035); }
.ai-design-card h3 { letter-spacing: -0.01em; }
.ai-design-card p { color: #9daabd; }
.ai-card-icon { border-color: rgba(255,255,255,0.14); background: rgba(69,224,232,0.07); box-shadow: none; }

@media (max-width: 860px) {
  .ai-design-section { min-height: auto; padding: 5rem 0; }
  .ai-design-header { display: block; }
  .ai-design-header h2 { white-space: normal; }
  .ai-design-header p { margin-top: 1rem; }
  .ai-design-stage { display: flex; min-height: 0; flex-direction: column; gap: 1.5rem; }
  .ai-canvas { width: 100%; margin: 0; transform: none; }
  .ai-chat { position: relative; left: auto; bottom: auto; width: 100%; min-height: 0; order: 2; }
}

@media (max-width: 520px) {
  .ai-design-section { padding: 4rem 0; }
  .ai-design-header { margin-bottom: 2rem; }
  .ai-design-header h2 { font-size: 2rem; overflow-wrap: anywhere; }
  .ai-design-stage { gap: 1rem; }
  .ai-canvas { min-height: 0; padding: 1rem 0.75rem; }
  .ai-canvas-meta { margin-bottom: 1.25rem; }
  .ai-result-stack { min-height: 31rem; }
  .ai-design-grid { grid-template-columns: 1fr; }
  .ai-design-card { min-height: 7rem; padding: 0.9rem 0.9rem 0.9rem 3.8rem; }
  .ai-card-icon { top: 0.9rem; left: 0.9rem; width: 2rem; height: 2rem; }
  .ai-design-card p { min-height: 0; font-size: 0.75rem; }
  .ai-chat { padding: 0.75rem; }
  .ai-send-button { width: 2.25rem; height: 2.25rem; }
  .ai-composer { min-height: 3.25rem; padding-right: 3.25rem; }
}

/* ============================================
   页脚
   ============================================ */

.site-footer {
  padding: 3rem 0;
  border-top: 1px solid var(--bg-line);
  background: var(--bg);
  text-align: center;
  font-size: 0.8125rem;
  color: var(--text-3);
}

.footer-brand {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 0.75rem;
}

.footer-copy {
  margin-bottom: 0.375rem;
}

.footer-beian a {
  color: var(--text-3);
  transition: color 0.15s ease;
}

.footer-beian a:hover {
  color: var(--brand-lit);
}

/* ============================================
   响应式
   ============================================ */

@media (max-width: 1080px) {
  .cosmos {
    grid-template-columns: 12rem 1fr minmax(0, 12rem) 1fr 12rem;
  }

  .beam { min-width: 2rem; }

  /* 整体等比缩一档，尺寸差异保持不变 */
  .planet { --k: 0.88; }
}

/* 窄屏：链路转 90 度，来源在上、成品在下 */
@media (max-width: 900px) {
  .cosmos {
    grid-template-columns: 1fr;
    justify-items: center;
    gap: 0;
  }

  .orbit,
  .beam,
  .core {
    grid-column: auto;
    grid-row: auto;
  }

  .orbit {
    width: 100%;
    max-width: 24rem;
  }

  .orbit-cap,
  .orbit-in .orbit-cap,
  .orbit-out .orbit-cap {
    position: static;
    width: auto;
    transform: none;
    margin-bottom: 1.25rem;
    text-align: center;
  }

  .orbit-cap br { display: none; }

  /* 窄屏放弃散布坐标，改成平铺，尺寸分级仍然保留 */
  .planets {
    position: static;
    height: auto;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: flex-end;
    gap: 1.25rem 1rem;
  }

  .planet {
    position: static;
    transform: none;
    animation-name: drift-flat;
  }

  @keyframes drift-flat {
    0%, 100% { transform: translateY(0); }
    50%      { transform: translateY(-7px); }
  }

  .beam {
    width: 100%;
    max-width: 17rem;
    height: 4.5rem;
    min-width: 0;
    transform: rotate(90deg);
    margin: -6rem 0;
  }

  .core {
    height: auto;
    padding: 3rem 0;
  }

  .core-halo {
    width: 12rem;
    height: 12rem;
  }

  .core-ring-1 { width: 9.5rem; height: 9.5rem; }
  .core-ring-2 { width: 11rem; height: 11rem; }
}

@media (max-width: 560px) {
  .wrap { padding: 0 1.25rem; }

  .topbar-inner { height: 56px; }
  .btn-sm { min-height: 2.75rem; padding-inline: 1.1rem; }
  .hero { padding: 3rem 0 4rem; }
  .hero-title { font-size: 2.25rem; }

  .planet { --k: 0.72; }

  .planet-name { font-size: 0.6875rem; }

  .download-option {
    width: 100%;
  }

  .hero-cta .btn {
    width: 100%;
    min-height: 3rem;
  }
}

/* 尊重系统减少动效偏好 */
@media (prefers-reduced-motion: reduce) {
  .starfield,
  .beam-meteor,
  .core-halo,
  .core-ring {
    animation: none;
  }

  .beam-meteor { display: none; }

  .planet {
    animation: none;
  }

  html { scroll-behavior: auto; }
}