/* ===========================================================
   EcoSand 微型生态沙盘 — 全局样式（静态版）
   主题：清新水下蓝绿色（fresh underwater blue-green）
   范围：设计令牌、基础重置、顶部导航、首页、模拟器、日志、原理、快照、预设、提示条、水下氛围层
   说明：纯 CSS，无预处理器；颜色集中为 CSS 变量，便于整体换肤。
   =========================================================== */

/* ---------- 1. 设计令牌（CSS 变量） ---------- */
:root {
  --bg-top: #e6fbfb;
  --bg-mid: #c7f0ef;
  --bg-bottom: #a7e3e0;

  --primary: #0e7490;
  --primary-light: #06b6d4;
  --accent: #14b8a6;
  --accent-soft: #5eead4;
  --danger: #b91c1c;

  --ink: #0f2e36;
  --ink-soft: #4a6570;

  --surface: rgba(255, 255, 255, 0.72);
  --surface-solid: #ffffff;
  --border: rgba(20, 184, 166, 0.28);
  --shadow: 0 10px 30px rgba(14, 116, 144, 0.15);

  --radius: 16px;
  --radius-sm: 10px;
  --gap: 24px;

  --font: "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

/* ---------- 2. 基础重置 ---------- */
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  color: var(--ink);
  min-height: 100vh;
  position: relative;
  /* 水下渐变背景：上浅下深 */
  background: linear-gradient(180deg, var(--bg-top) 0%, var(--bg-mid) 55%, var(--bg-bottom) 100%);
  overflow-x: hidden;
}

/* ---------- 3. 水下氛围层（光束 + 气泡，纯装饰，置于内容之下） ---------- */
body::before,
body::after {
  content: "";
  position: fixed;
  z-index: 0;
  pointer-events: none;
}
/* 顶部斜射光束 */
body::before {
  inset: 0;
  background:
    radial-gradient(60% 40% at 20% -10%, rgba(255, 255, 255, 0.5), transparent 60%),
    radial-gradient(50% 35% at 80% -5%, rgba(94, 234, 212, 0.35), transparent 60%);
  animation: beamDrift 14s ease-in-out infinite alternate;
}
/* 上浮气泡 */
body::after {
  inset: 0;
  background-image:
    radial-gradient(circle, rgba(255, 255, 255, 0.6) 1.5px, transparent 2px),
    radial-gradient(circle, rgba(255, 255, 255, 0.4) 1px, transparent 1.5px);
  background-size: 120px 120px, 80px 80px;
  background-position: 10% 100%, 70% 100%;
  opacity: 0.5;
  animation: bubbleRise 18s linear infinite;
}
@keyframes beamDrift { from { transform: translateX(-12px); } to { transform: translateX(12px); } }
@keyframes bubbleRise { from { background-position: 10% 100%, 70% 100%; } to { background-position: 10% -20%, 70% -20%; } }

/* 内容统一抬到氛围层之上 */
.topbar, main, .site-footer { position: relative; z-index: 1; }

/* ---------- 4. 顶部导航 ---------- */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 28px;
  background: rgba(255, 255, 255, 0.6);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 5;
}
.topbar__brand { font-size: 20px; font-weight: 800; color: var(--primary); }
.topbar__nav { display: flex; gap: 6px; flex-wrap: wrap; }
.nav-link {
  padding: 8px 14px;
  border-radius: 999px;
  color: var(--ink-soft);
  text-decoration: none;
  font-weight: 600;
  font-size: 14px;
  transition: background 0.2s, color 0.2s;
}
.nav-link:hover { background: rgba(20, 184, 166, 0.12); color: var(--primary); }
.nav-link.is-active { background: var(--accent); color: #fff; }

/* ---------- 5. 页面通用标题 ---------- */
.page-title { color: var(--primary); font-size: 28px; margin: 28px 0 6px; }
.page-sub { color: var(--ink-soft); margin-bottom: 22px; max-width: 720px; }

main { max-width: 1080px; margin: 0 auto; padding: 0 24px 60px; }

/* ---------- 6. 首页落地 ---------- */
.landing { padding-top: 36px; }
.landing__hero { text-align: center; padding: 24px 0 36px; }
.landing__title { color: var(--primary); font-size: 34px; margin-bottom: 14px; }
.landing__sub { color: var(--ink-soft); font-size: 16px; max-width: 620px; margin: 0 auto 22px; line-height: 1.7; }
.landing__cta { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.landing__cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--gap); margin-top: 12px; }
.landing__card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  text-decoration: none;
  color: var(--ink);
  box-shadow: var(--shadow);
  transition: transform 0.2s, box-shadow 0.2s;
}
.landing__card:hover { transform: translateY(-4px); box-shadow: 0 16px 36px rgba(14, 116, 144, 0.22); }
.landing__card-icon { font-size: 30px; margin-bottom: 10px; }
.landing__card h3 { color: var(--primary); margin-bottom: 8px; }
.landing__card p { color: var(--ink-soft); font-size: 14px; line-height: 1.6; }

/* ---------- 7. 模拟器布局 ---------- */
.simulator {
  display: grid;
  grid-template-columns: 1fr 360px;
  gap: var(--gap);
  align-items: start;
}
.simulator__stage { min-width: 0; }
.canvas-frame {
  position: relative;
  width: 100%;
  min-height: 460px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  background: rgba(186, 230, 253, 0.25);
}
.eco-canvas { display: block; width: 100%; height: 100%; cursor: crosshair; }
.canvas-tip { color: var(--ink-soft); font-size: 13px; margin-top: 10px; }

/* 右侧控制面板 */
.simulator__panel {
  display: flex;
  flex-direction: column;
  gap: 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow);
}
.control-group { display: flex; flex-direction: column; gap: 10px; }
.control-group__title {
  font-size: 13px;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: 0.04em;
  border-left: 3px solid var(--accent);
  padding-left: 8px;
}

/* ---------- 8. 通用按钮 ---------- */
.control-btn {
  appearance: none;
  border: none;
  cursor: pointer;
  padding: 11px 14px;
  border-radius: var(--radius-sm);
  background: var(--accent);
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  font-family: inherit;
  transition: transform 0.15s, background 0.2s, box-shadow 0.2s;
}
.control-btn:hover { background: var(--primary); transform: translateY(-1px); }
.control-btn:active { transform: scale(0.98); }
.control-btn--ghost { background: rgba(20, 184, 166, 0.14); color: var(--primary); }
.control-btn--ghost:hover { background: rgba(20, 184, 166, 0.24); }

/* 滑块 */
.slider { display: flex; flex-direction: column; gap: 6px; }
.slider__label { font-size: 13px; color: var(--ink-soft); display: flex; justify-content: space-between; }
.slider__label b { color: var(--ink); }
.slider input[type="range"] { width: 100%; accent-color: var(--accent); cursor: pointer; }

/* 实时数据 */
.stats {
  list-style: none;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}
.stats li {
  background: rgba(20, 184, 166, 0.1);
  border-radius: var(--radius-sm);
  padding: 8px 10px;
  font-size: 13px;
  color: var(--ink-soft);
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.stats li b { color: var(--primary); font-size: 16px; font-variant-numeric: tabular-nums; }

/* 投放工具 */
.pop-btn {
  appearance: none;
  cursor: pointer;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.6);
  color: var(--ink);
  border-radius: var(--radius-sm);
  padding: 9px 10px;
  font-size: 13px;
  font-family: inherit;
  transition: background 0.2s, border-color 0.2s, transform 0.15s;
}
.pop-btn:hover { background: rgba(94, 234, 212, 0.25); }
.pop-btn:active { transform: scale(0.98); }
.pop-btn.is-active { background: var(--accent); color: #fff; border-color: var(--accent); }

/* 预设实验 */
.preset-grid { display: flex; flex-direction: column; gap: 8px; }
.preset-btn {
  appearance: none;
  cursor: pointer;
  text-align: left;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.6);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  font-family: inherit;
  color: var(--primary);
  font-weight: 700;
  font-size: 14px;
  transition: background 0.2s, transform 0.15s;
}
.preset-btn small { display: block; margin-top: 4px; font-weight: 400; font-size: 12px; color: var(--ink-soft); }
.preset-btn:hover { background: rgba(94, 234, 212, 0.22); transform: translateY(-1px); }

/* 提示条 */
.eco-toast {
  position: fixed;
  left: 50%;
  bottom: 32px;
  transform: transl(-50%, 20px);
  transform: translateX(-50%) translateY(20px);
  background: var(--ink);
  color: #e6fffb;
  padding: 12px 20px;
  border-radius: 999px;
  font-size: 14px;
  box-shadow: var(--shadow);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s, transform 0.25s;
  z-index: 50;
}
.eco-toast.is-show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ---------- 9. 观测日志 + 快照 ---------- */
.log-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--gap); }
.log-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
}
.log-card__date { font-size: 12px; color: var(--ink-soft); }
.log-card__title { color: var(--primary); font-size: 20px; margin: 4px 0 10px; }
.log-card__meta { font-size: 13px; color: var(--ink-soft); margin-bottom: 8px; }
.log-card__meta b { color: var(--ink); }
.log-card__body { font-size: 13px; color: var(--ink-soft); line-height: 1.6; flex: 1; }

/* 快照结论标签（稳定绿 / 崩溃红 / 波动黄） */
.log-card__tag {
  align-self: flex-start;
  font-size: 12px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 999px;
  margin-bottom: 8px;
}
.log-card__tag--ok { background: rgba(14, 116, 144, 0.16); color: var(--primary); }
.log-card__tag--bad { background: rgba(185, 28, 28, 0.16); color: var(--danger); }
.log-card__tag--warn { background: rgba(202, 138, 4, 0.18); color: #92600a; }

.snapshot-section { margin-top: 36px; }
.snapshot-section__head { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.snapshot-section__title { color: var(--primary); font-size: 20px; }
.snapshot-clear {
  appearance: none; cursor: pointer;
  border: 1px solid rgba(185, 28, 28, 0.3);
  background: transparent; color: var(--danger);
  border-radius: var(--radius-sm); padding: 8px 14px;
  font-size: 13px; font-family: inherit; font-weight: 600;
  transition: background 0.2s;
}
.snapshot-clear:hover { background: rgba(185, 28, 28, 0.16); }
.snapshot-clear:disabled { opacity: 0.4; cursor: not-allowed; }
.snapshot-empty { color: var(--ink-soft); font-size: 14px; }

/* ---------- 10. 原理说明 ---------- */
.guide__section {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius-sm);
  padding: 22px 26px;
  margin-bottom: 20px;
  box-shadow: var(--shadow);
}
.guide__section h2 { color: var(--primary); font-size: 20px; margin-bottom: 10px; }
.guide__section p { color: var(--ink-soft); margin-bottom: 10px; line-height: 1.7; }
.guide__section ul { color: var(--ink-soft); padding-left: 20px; }
.guide__section li { margin-bottom: 6px; }
.guide__section code { background: rgba(20, 184, 166, 0.14); padding: 1px 6px; border-radius: 6px; font-size: 13px; }
.guide__chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 8px; }
.guide__chip { padding: 6px 14px; border-radius: 999px; background: rgba(94, 234, 212, 0.16); color: var(--primary); font-size: 13px; font-weight: 600; }

/* ---------- 11. 页脚 ---------- */
.site-footer { text-align: center; color: var(--ink-soft); font-size: 13px; padding: 28px 16px 40px; }

/* ---------- 12. 响应式 + 动效偏好 ---------- */
@media (max-width: 860px) {
  .simulator { grid-template-columns: 1fr; }
  .canvas-frame { min-height: 360px; }
  .landing__cards { grid-template-columns: 1fr; }
  .log-grid { grid-template-columns: 1fr; }
}
@media (prefers-reduced-motion: reduce) {
  body::before, body::after { animation: none; }
}