/* ==========================================================================
   千岛出海 · 基础层 v2
   Reset · 黑体排版 · 12 栏网格 · 玻璃 · 焦点 · 平滑动效
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. Reset
   -------------------------------------------------------------------------- */
*,
*::before,
*::after { box-sizing: border-box; }

* { margin: 0; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  touch-action: manipulation;
}

body {
  min-height: 100dvh;
  background-color: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  font-weight: var(--fw-regular);
  line-height: var(--lh-body);
  letter-spacing: var(--ls-body);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  -webkit-tap-highlight-color: rgba(225, 27, 44, 0.12);
  transition: background-color var(--dur-base) var(--ease-out),
              color var(--dur-base) var(--ease-out);
}

img, picture, svg, video { display: block; max-width: 100%; }
img { height: auto; }

input, button, textarea, select { font: inherit; color: inherit; }
button { background: none; border: none; cursor: pointer; }
ul, ol { list-style: none; padding: 0; }
a { color: inherit; text-decoration: none; }

/* --------------------------------------------------------------------------
   2. 排版：黑体
   -------------------------------------------------------------------------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: var(--fw-bold);
  line-height: var(--lh-heading);
  letter-spacing: var(--ls-heading);
  text-wrap: balance;
}

p { text-wrap: pretty; }

:target,
[id] { scroll-margin-top: calc(var(--header-h) + var(--space-6)); }

.tnum,
.stat-value,
.coord-deg,
time { font-variant-numeric: tabular-nums; }

/* --------------------------------------------------------------------------
   3. 12 栏网格（沿用）
   注意：列跨度用 grid-column-end，不要用 `grid-column: span N` 简写 ——
   简写会把 span 写进 grid-column-start，之后再设起始线就会把它覆盖掉。
   -------------------------------------------------------------------------- */
.grid {
  display: grid;
  grid-template-columns: repeat(var(--grid-cols), minmax(0, 1fr));
  column-gap: var(--gutter);
  row-gap: var(--gutter);
  width: 100%;
  max-width: var(--content-max);
  margin-inline: auto;
  padding-inline: max(var(--page-margin), env(safe-area-inset-left));
}

@media (min-width: 640px) {
  .grid {
    padding-inline: max(var(--page-margin), env(safe-area-inset-left), env(safe-area-inset-right));
  }
}

.section { padding-block: var(--section-y); }
.section--tight { padding-block: clamp(3rem, 6vw, 5rem); }

.col-1  { grid-column-end: span 1; }
.col-2  { grid-column-end: span 2; }
.col-3  { grid-column-end: span 3; }
.col-4  { grid-column-end: span 4; }
.col-5  { grid-column-end: span 5; }
.col-6  { grid-column-end: span 6; }
.col-7  { grid-column-end: span 7; }
.col-8  { grid-column-end: span 8; }
.col-9  { grid-column-end: span 9; }
.col-10 { grid-column-end: span 10; }
.col-11 { grid-column-end: span 11; }
.col-12 { grid-column-end: span 12; }

.col-start-1 { grid-column-start: 1; }
.col-start-6 { grid-column-start: 6; }
.col-start-7 { grid-column-start: 7; }

@media (max-width: 639px) {
  [class*="col-"] { grid-column-end: span 12; }
  .col-start-1, .col-start-6, .col-start-7 { grid-column-start: auto; }
}

/* --------------------------------------------------------------------------
   4. 玻璃表面
   只用于需要「浮起」的少数表面，不是所有容器都上玻璃
   -------------------------------------------------------------------------- */
.glass {
  position: relative;
  background-color: var(--glass-bg);
  backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-sat));
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-sat));
  border: 1px solid var(--glass-brd);
  box-shadow: var(--sh-md), var(--sh-inner);
}

/* 顶部高光描边：玻璃质感的关键一笔 */
.glass::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(160deg, var(--glass-hi), transparent 42%);
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
  mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  mask-composite: exclude;
  pointer-events: none;
}

/* 不支持 backdrop-filter 时提高不透明度，保证可读 */
@supports not ((backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px))) {
  .glass { background-color: var(--glass-bg-strong); }
}

/* --------------------------------------------------------------------------
   5. 焦点：可见且只在键盘导航时出现
   -------------------------------------------------------------------------- */
:focus { outline: none; }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: var(--r-xs);
}

.field:focus-within .field__label { color: var(--accent-deep); }

/* --------------------------------------------------------------------------
   6. 跳至内容 / 屏幕阅读器
   -------------------------------------------------------------------------- */
.skip-link {
  position: absolute;
  top: var(--space-3);
  left: var(--space-3);
  z-index: var(--z-skip);
  padding: var(--space-3) var(--space-5);
  background-color: var(--surface);
  color: var(--ink);
  border-radius: var(--r-pill);
  box-shadow: var(--sh-md);
  font-weight: var(--fw-semi);
  transform: translateY(calc(-100% - var(--space-6)));
  transition: transform var(--dur-fast) var(--ease-out);
}

.skip-link:focus-visible { transform: translateY(0); }

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

/* --------------------------------------------------------------------------
   7. 滚动揭示：平滑翻页的主要手段
   -------------------------------------------------------------------------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--dur-reveal) var(--ease-out),
              transform var(--dur-reveal) var(--ease-out);
  transition-delay: var(--reveal-delay, 0ms);
  will-change: opacity, transform;
}

[data-reveal].is-visible {
  opacity: 1;
  transform: none;
  will-change: auto;
}

/* 用户显式关闭动效：不依赖系统设置也能降级 */
html[data-motion="off"] { scroll-behavior: auto; }

html[data-motion="off"] [data-reveal] {
  opacity: 1 !important;
  transform: none !important;
  transition: none !important;
}

html[data-motion="off"] *,
html[data-motion="off"] *::before,
html[data-motion="off"] *::after {
  animation-duration: 0.01ms !important;
  animation-iteration-count: 1 !important;
  transition-duration: 0.01ms !important;
  scroll-behavior: auto !important;
}

/* 跟随系统：html[data-motion="on"] 时整体绕过（默认地址就是这个状态） */
@media (prefers-reduced-motion: reduce) {
  html:not([data-motion="on"]) { scroll-behavior: auto; }

  html:not([data-motion="on"]) [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }

  html:not([data-motion="on"]) *,
  html:not([data-motion="on"]) *::before,
  html:not([data-motion="on"]) *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* --------------------------------------------------------------------------
   8. 小工具
   -------------------------------------------------------------------------- */
.text-muted { color: var(--ink-2); }
.measure { max-width: var(--measure); }
.flex { display: flex; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.min-w-0 { min-width: 0; }

/* --------------------------------------------------------------------------
   9. 开发用网格参考层（?grid=1）
   -------------------------------------------------------------------------- */
.grid-overlay {
  position: fixed;
  inset: 0;
  z-index: var(--z-overlay);
  pointer-events: none;
  display: none;
}

[data-grid="on"] .grid-overlay {
  display: grid;
  grid-template-columns: repeat(var(--grid-cols), minmax(0, 1fr));
  column-gap: var(--gutter);
  max-width: var(--content-max);
  margin-inline: auto;
  padding-inline: max(var(--page-margin), env(safe-area-inset-left));
}

.grid-overlay__col {
  background-color: rgba(225, 27, 44, 0.07);
  border-inline: 1px solid rgba(225, 27, 44, 0.18);
  border-radius: var(--r-xs);
}

/* --------------------------------------------------------------------------
   10. Expensive UI 底座：品牌环境光 + 极细高光边框
   纪律：只用现有变量（--accent / currentColor）调透明度，不引入新色相。
   color-mix 让暗色主题自动跟随 --accent；不支持的旧浏览器整条声明丢弃，
   效果静默缺席，不影响布局与可读。
   -------------------------------------------------------------------------- */
/* 品牌色文本选中态：只动背景透明度，不动文字色（对比度由原文字色保证） */
::selection {
  background-color: var(--accent-soft);
  background-color: color-mix(in srgb, var(--accent) 24%, transparent);
}