/* ==========================================================================
   copher 宣传页
   方向：一份产品说明书配一台安静的仪器。白底黑字、系统字体、单一强调色；
   截图装在带阴影的窗口里，是页面上唯一的"实物"。
   间距一律取 4 的倍数；圆角 12，阴影只有两个配方。
   ========================================================================== */

:root {
  --bg: #ffffff;
  --bg-alt: #f5f5f7;
  --fg: #1d1d1f;
  --dim: #6e6e73;
  --faint: #86868b;
  --line: #d2d2d7;
  --line-soft: rgba(0, 0, 0, 0.06);
  --accent: #0a6b4d;
  --accent-hover: #0d7d5a;
  --on-accent: #ffffff;
  --term-bg: #1d1d1f;
  --term-fg: #e8e8ea;
  --term-line: rgba(255, 255, 255, 0.14);
  --term-dim: #9a9aa0;
  --term-comment: #6b6b70;
  --ok: #22863a;
  --danger: #d93a35;
  --shadow-window:
    0 50px 100px -30px rgba(0, 0, 0, 0.28),
    0 30px 60px -40px rgba(0, 0, 0, 0.3),
    0 0 0 0.5px rgba(0, 0, 0, 0.12);
  --shadow-soft: 0 1px 2px rgba(0, 0, 0, 0.06), 0 12px 32px rgba(0, 0, 0, 0.08);
  --radius: 12px;
  --nav-h: 52px;
  --wrap: 1080px;
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC",
    "Segoe UI Variable", "Segoe UI", "Helvetica Neue", "Microsoft YaHei", sans-serif;
  --mono: ui-monospace, "SFMono-Regular", "Cascadia Code", "JetBrains Mono",
    Consolas, "PingFang SC", monospace;
}

[data-theme="dark"] {
  --bg: #101013;
  --bg-alt: #17171b;
  --fg: #f5f5f7;
  --dim: #a1a1a8;
  --faint: #85858c;
  --line: #3a3a40;
  --line-soft: rgba(255, 255, 255, 0.08);
  --accent: #2ea883;
  --accent-hover: #37bd93;
  --on-accent: #0c1512;
  --term-bg: #1c1c20;
  --term-fg: #e8e8ea;
  --term-line: rgba(255, 255, 255, 0.12);
  --term-dim: #9a9aa0;
  --term-comment: #6f6f76;
  --shadow-window:
    0 50px 100px -30px rgba(0, 0, 0, 0.7),
    0 30px 60px -40px rgba(0, 0, 0, 0.6),
    0 0 0 0.5px rgba(255, 255, 255, 0.14);
  --shadow-soft: 0 1px 2px rgba(0, 0, 0, 0.4), 0 12px 32px rgba(0, 0, 0, 0.45);
}

/* ---------- 基底 ---------- */

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.7;
  color: var(--fg);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 24px; }
.wrap-narrow { max-width: 720px; }

h1, h2, h3 { font-weight: 650; letter-spacing: -0.015em; line-height: 1.25; }

h2 {
  font-size: clamp(28px, 4.5vw, 40px);
  margin: 0 0 12px;
}
.h2-dim { color: var(--dim); }

p { margin: 0 0 16px; }
p:last-child { margin-bottom: 0; }

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); }

code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: var(--line-soft);
  border-radius: 5px;
  padding: 1.5px 6px;
}

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

figure { margin: 0; }

/* 线条图标：统一描边画法，颜色随容器的 color 走（深浅色都成立） */
.nav-icon svg, .quad-list svg, .cap-grid svg, .col-icon,
.copy-btn svg, .to-top svg {
  fill: none;
  stroke: currentColor;
  stroke-width: 1.7;
  stroke-linecap: round;
  stroke-linejoin: round;
}

section { position: relative; }

/* 锚点定位留出导航高度 */
[id] { scroll-margin-top: calc(var(--nav-h) + 16px); }

::selection { background: rgba(10, 107, 77, 0.22); }

/* ---------- 顶部导航 ---------- */

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--bg) 78%, transparent);
  backdrop-filter: saturate(1.6) blur(16px);
  -webkit-backdrop-filter: saturate(1.6) blur(16px);
  border-bottom: 1px solid var(--line-soft);
}

.nav-inner {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 24px;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 650;
  font-size: 16px;
  color: var(--fg);
}
.brand:hover { color: var(--fg); }
.brand-mark {
  width: 20px;
  height: 20px;
  border-radius: 5px;
  background: var(--bg);
  box-shadow: 0 0 0 0.5px var(--line);
}
[data-theme="dark"] .brand-mark { background: #e8e8ea; }

.nav-links {
  display: flex;
  gap: 4px;
  margin-left: auto;
}
.nav-links a {
  color: var(--dim);
  padding: 6px 12px;
  border-radius: 8px;
  font-size: 14px;
  transition: color 0.18s, background 0.18s;
}
.nav-links a:hover { color: var(--fg); background: var(--line-soft); }

.nav-actions { display: flex; align-items: center; gap: 12px; margin-left: 8px; }

.nav-icon {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--dim);
  cursor: pointer;
  transition: color 0.18s, background 0.18s;
}
.nav-icon:hover { color: var(--fg); background: var(--line-soft); }
.nav-icon svg { width: 18px; height: 18px; }

.lang-toggle {
  height: 32px;
  padding: 0 10px;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--dim);
  font: inherit;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: color 0.18s, background 0.18s;
}
.lang-toggle:hover { color: var(--fg); background: var(--line-soft); }

.icon-sun { display: none; }
[data-theme="dark"] .icon-sun { display: block; }
[data-theme="dark"] .icon-moon { display: none; }
@media (prefers-color-scheme: dark) {
  html:not([data-theme]) .icon-sun { display: block; }
  html:not([data-theme]) .icon-moon { display: none; }
}

.nav-cta {
  font-size: 14px;
  font-weight: 500;
  color: var(--on-accent);
  background: var(--accent);
  padding: 7px 16px;
  border-radius: 999px;
  transition: background 0.18s, transform 0.18s;
}
.nav-cta:hover { background: var(--accent-hover); color: var(--on-accent); }

/* ---------- Hero ---------- */

.hero { padding: 96px 24px 72px; max-width: var(--wrap); }

.eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 500;
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 9%, transparent);
  border: 1px solid color-mix(in srgb, var(--accent) 24%, transparent);
  border-radius: 999px;
  padding: 4px 14px;
  margin: 0 0 24px;
}

.hero h1 {
  font-size: clamp(40px, 7vw, 64px);
  line-height: 1.12;
  letter-spacing: -0.022em;
  margin: 0 0 24px;
}

.hero-sub {
  font-size: 19px;
  line-height: 1.65;
  color: var(--dim);
  max-width: 640px;
  margin: 0 0 32px;
}

.hero-cta { display: flex; gap: 16px; flex-wrap: wrap; align-items: center; }

.hero-meta {
  margin-top: 24px;
  font-size: 13.5px;
  color: var(--faint);
}

/* ---------- 按钮 ---------- */

.btn {
  display: inline-block;
  font-size: 16px;
  font-weight: 500;
  padding: 12px 24px;
  border-radius: 999px;
  transition: background 0.18s, transform 0.18s, box-shadow 0.18s;
}
.btn:active { transform: translateY(1px); }

.btn-primary {
  color: var(--on-accent);
  background: var(--accent);
}
.btn-primary:hover {
  background: var(--accent-hover);
  color: var(--on-accent);
  box-shadow: var(--shadow-soft);
}

.btn-ghost {
  color: var(--fg);
  border: 1px solid var(--line);
}
.btn-ghost:hover { background: var(--line-soft); color: var(--fg); }

/* ---------- 截图窗口 ---------- */

.shot {
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-window);
  background: var(--term-bg);
  line-height: 0;
}

.shot img { width: 100%; }

.shot figcaption {
  line-height: 1.6;
  padding: 12px 20px;
  font-size: 13.5px;
  color: var(--dim);
  background: var(--bg);
  text-align: center;
  border-top: 1px solid var(--line-soft);
}

.hero-shot { margin-top: 56px; }

/* ---------- 分区 ---------- */

.section { padding: 88px 0; }
.section-alt { background: var(--bg-alt); }

.section-sub {
  font-size: 17px;
  color: var(--dim);
  max-width: 640px;
  margin: 0 0 48px;
}

.section-note {
  margin-top: 24px;
  font-size: 14.5px;
  color: var(--dim);
}

/* 图文行 */
.media-row {
  display: grid;
  grid-template-columns: minmax(0, 7fr) minmax(0, 3fr);
  gap: 40px;
  align-items: center;
  margin-bottom: 64px;
}
.row-flip { grid-template-columns: minmax(0, 3fr) minmax(0, 7fr); }
.row-flip .shot { order: 0; }
.row-flip .media-copy { order: 1; }

.media-row:last-child { margin-bottom: 0; }

.media-copy h3 { font-size: 20px; margin: 0 0 8px; }
.media-copy p { font-size: 15.5px; color: var(--dim); margin: 0; }

/* ---------- 标签页（会话 / 终端演示） ---------- */

.tabs { margin-top: 8px; }

.tab-list {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 4px;
  padding: 4px;
  background: var(--line-soft);
  border-radius: 10px;
  margin-bottom: 32px;
}

.tab-list button {
  border: 0;
  background: transparent;
  color: var(--dim);
  font-family: inherit;
  font-size: 14px;
  font-weight: 500;
  padding: 8px 18px;
  border-radius: 7px;
  cursor: pointer;
  transition: color 0.18s, background 0.18s;
}

.tab-list button:hover { color: var(--fg); }

.tab-list button[aria-selected="true"] {
  color: var(--fg);
  background: var(--bg);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.tab-panels { position: relative; }

.tab-panel { width: 100%; }
.tab-panel[hidden] { display: none; }

.tab-panel.is-anim {
  animation: panel-in 0.32s cubic-bezier(0.2, 0.7, 0.2, 1);
}

@keyframes panel-in {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: none; }
}

/* ---------- 四宫格（离开电脑） ---------- */

.quad-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 24px;
}

.quad-list li {
  display: flex;
  gap: 16px;
  background: var(--bg);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: 0 0 0 1px var(--line-soft);
}

.quad-list svg {
  width: 22px;
  height: 22px;
  flex: none;
  color: var(--accent);
  margin-top: 2px;
}

.quad-list h3 { font-size: 17px; margin: 0 0 6px; }
.quad-list p { font-size: 14.5px; color: var(--dim); margin: 0; }

/* ---------- 能力九宫格 ---------- */

.cap-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 36px 32px;
}

.cap-grid svg {
  width: 22px;
  height: 22px;
  color: var(--accent);
  margin-bottom: 12px;
}

.cap-grid h3 { font-size: 16.5px; margin: 0 0 6px; }
.cap-grid p { font-size: 14.5px; color: var(--dim); margin: 0; }

/* ---------- 隐私两栏 ---------- */

.privacy-cols {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 40px;
}

.privacy-cols h3 {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 18px;
  margin: 0 0 16px;
}

.col-icon { width: 20px; height: 20px; }
.col-icon:first-of-type { color: var(--ok); }
.privacy-cols div:nth-child(2) .col-icon { color: var(--danger); }

.privacy-cols ul { list-style: none; margin: 0; padding: 0; }
.privacy-cols li {
  padding: 12px 0;
  border-top: 1px solid var(--line-soft);
  font-size: 15px;
  color: var(--dim);
}

/* ---------- 终端窗口（快速开始） ---------- */

.term-window {
  background: var(--term-bg);
  border-radius: var(--radius);
  box-shadow: var(--shadow-window);
  overflow: hidden;
}

.term-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--term-line);
}

.term-bar span {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--term-line);
}

.term-bar em {
  font-style: normal;
  font-size: 12.5px;
  color: var(--term-dim);
  margin-left: 8px;
  font-family: var(--mono);
}

.term-window pre {
  margin: 0;
  padding: 24px 28px;
  overflow-x: auto;
}

.term-window code {
  display: block;
  background: transparent;
  padding: 0;
  font-family: var(--mono);
  font-size: 14px;
  line-height: 1.9;
  color: var(--term-fg);
  white-space: pre;
}

.term-window .c { color: var(--term-comment); }
.term-window .s { color: #7ec9ae; }

.copy-btn {
  position: absolute;
  top: 56px;
  right: 14px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  border: 1px solid var(--term-line);
  background: rgba(255, 255, 255, 0.06);
  color: var(--term-dim);
  font-family: var(--font);
  font-size: 12.5px;
  padding: 5px 10px;
  border-radius: 7px;
  cursor: pointer;
  transition: color 0.18s, background 0.18s;
}
.copy-btn svg { width: 14px; height: 14px; }
.copy-btn:hover { color: var(--term-fg); background: rgba(255, 255, 255, 0.12); }
.copy-btn.is-copied { color: #7ec9ae; }

/* term-window 自身要作为 copy-btn 的定位父级 */
.term-window { position: relative; }

/* ---------- FAQ ---------- */

details {
  border-top: 1px solid var(--line-soft);
}
details:last-of-type { border-bottom: 1px solid var(--line-soft); }

summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 0;
  font-size: 17px;
  font-weight: 550;
}
summary::-webkit-details-marker { display: none; }
summary::after {
  content: "+";
  font-size: 22px;
  font-weight: 400;
  color: var(--faint);
  transition: transform 0.25s;
  flex: none;
}
details[open] summary::after { transform: rotate(45deg); }
details p {
  margin: 0;
  padding: 0 40px 20px 0;
  font-size: 15px;
  color: var(--dim);
}

/* ---------- 结尾与页脚 ---------- */

.final { padding: 96px 0 104px; text-align: center; }
.final h2 { font-size: clamp(32px, 5vw, 48px); }

.final-cta {
  display: flex;
  gap: 20px;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  margin: 32px 0 20px;
}

.final-cmd {
  font-family: var(--mono);
  font-size: 14.5px;
  color: var(--dim);
  background: var(--line-soft);
  padding: 10px 16px;
  border-radius: 9px;
}

.final-meta { font-size: 13.5px; color: var(--faint); }

.footer {
  border-top: 1px solid var(--line-soft);
  padding: 32px 0;
}
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 13.5px;
  color: var(--faint);
}
.footer-inner p { margin: 0; }
.footer nav { display: flex; gap: 20px; }
.footer a { color: var(--dim); }
.footer a:hover { color: var(--fg); }

/* ---------- 渐显 ---------- */

.js .reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.js .reveal.is-in {
  opacity: 1;
  transform: none;
}

/* ---------- 返回顶部 ---------- */

.to-top {
  position: fixed;
  right: 20px;
  bottom: 20px;
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: var(--bg);
  color: var(--dim);
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s, color 0.18s;
  z-index: 40;
}
.to-top.is-on { opacity: 1; pointer-events: auto; }
.to-top:hover { color: var(--fg); }
.to-top svg { width: 18px; height: 18px; }

/* ---------- 响应式 ---------- */

@media (max-width: 960px) {
  .media-row, .row-flip { grid-template-columns: 1fr; gap: 24px; }
  .row-flip .media-copy { order: 0; }
  .row-flip .shot { order: 1; }
  .cap-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 760px) {
  .nav-links { display: none; }
  .hero { padding: 64px 24px 48px; }
  .hero-sub { font-size: 17px; }
  .section { padding: 56px 0; }
  .quad-list, .privacy-cols { grid-template-columns: 1fr; }
  .cap-grid { grid-template-columns: 1fr; gap: 24px; }
  .final-cmd { font-size: 12.5px; }
  .copy-btn span { display: none; }
  .copy-btn { top: 52px; }
}

/* 打印时不显示交互元素 */
@media print {
  .nav, .to-top, .copy-btn { display: none; }
}