/* =========================================================
   GODOT 学习站 · 全局星空科技风样式
   适用于: 主站 index.html 与 100 节课程子站
   ========================================================= */

:root {
  --bg-deep: #030614;
  --bg-space: #070b1f;
  --panel: rgba(13, 20, 48, 0.72);
  --panel-2: rgba(18, 28, 66, 0.6);
  --line: rgba(90, 160, 255, 0.18);
  --line-strong: rgba(120, 190, 255, 0.5);
  --cyan: #22e0ff;
  --blue: #4d7cff;
  --purple: #9a6bff;
  --pink: #ff6bd6;
  --green: #2ff3b2;
  --yellow: #ffd166;
  --text: #e8f2ff;
  --text-dim: #9db4d6;
  --glow-cyan: 0 0 14px rgba(34, 224, 255, 0.55);
  --glow-blue: 0 0 16px rgba(77, 124, 255, 0.55);
  --radius: 16px;
  --font-mono: "JetBrains Mono", "Cascadia Code", Consolas, "Courier New", monospace;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: "Segoe UI", "Microsoft YaHei", "PingFang SC", sans-serif;
  background: radial-gradient(1200px 700px at 80% -10%, #12204a 0%, transparent 55%),
              radial-gradient(900px 600px at -10% 30%, #1a1040 0%, transparent 50%),
              var(--bg-deep);
  color: var(--text);
  min-height: 100vh;
  overflow-x: hidden;
  line-height: 1.75;
}

/* ---------- 星空画布（主站） ---------- */
#starfield {
  position: fixed; inset: 0;
  z-index: 0; pointer-events: none;
}
.star-canvas { position: fixed; inset: 0; z-index: 0; pointer-events: none; }
/* 课程页静态星空（无 canvas 时兜底） */
.stars-static {
  position: fixed; inset: 0; z-index: 0; pointer-events: none;
  background-image:
    radial-gradient(1px 1px at 20% 30%, rgba(255,255,255,.8), transparent),
    radial-gradient(1px 1px at 70% 60%, rgba(255,255,255,.6), transparent),
    radial-gradient(1.5px 1.5px at 40% 80%, rgba(160,220,255,.9), transparent),
    radial-gradient(1px 1px at 85% 20%, rgba(255,255,255,.7), transparent),
    radial-gradient(1.5px 1.5px at 10% 70%, rgba(180,200,255,.8), transparent),
    radial-gradient(1px 1px at 55% 15%, rgba(255,255,255,.5), transparent),
    radial-gradient(1px 1px at 90% 85%, rgba(255,255,255,.6), transparent),
    radial-gradient(1.5px 1.5px at 30% 50%, rgba(120,180,255,.7), transparent);
  background-size: 1200px 1200px, 900px 900px, 1100px 1100px, 800px 800px, 1000px 1000px, 700px 700px, 950px 950px, 850px 850px;
  animation: twinkle 6s ease-in-out infinite alternate;
}
@keyframes twinkle { from { opacity: .45; } to { opacity: 1; } }

/* ---------- 顶部导航 ---------- */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 30px;
  background: rgba(4, 8, 24, 0.55);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
  transition: background .4s, box-shadow .4s;
}
.nav.scrolled { background: rgba(4, 8, 24, 0.85); box-shadow: 0 8px 30px rgba(0,0,0,.5); }
.nav .logo {
  display: flex; align-items: center; gap: 10px;
  font-weight: 800; font-size: 1.15rem; letter-spacing: 1px;
  color: var(--text); text-decoration: none;
}
.nav .logo .cube {
  width: 26px; height: 26px; border-radius: 7px;
  background: linear-gradient(135deg, var(--cyan), var(--blue), var(--purple));
  box-shadow: var(--glow-cyan);
  animation: spinCube 6s linear infinite;
}
@keyframes spinCube {
  0% { transform: rotateX(0) rotateY(0); }
  50% { transform: rotateX(180deg) rotateY(90deg); }
  100% { transform: rotateX(360deg) rotateY(360deg); }
}
.nav .links { display: flex; gap: 6px; align-items: center; flex-wrap: wrap; }
.nav .links a {
  color: var(--text-dim); text-decoration: none;
  padding: 7px 14px; border-radius: 9px; font-size: .92rem;
  transition: color .25s, background .25s, box-shadow .25s;
  position: relative;
}
.nav .links a:hover { color: var(--cyan); background: rgba(34,224,255,.08); box-shadow: inset 0 0 0 1px var(--line-strong); }
.progress-chip {
  font-size: .8rem; color: var(--green);
  border: 1px solid rgba(47,243,178,.4);
  padding: 6px 12px; border-radius: 999px;
  background: rgba(47,243,178,.06);
}
/* 课程目录下拉 */
.cur-nav {
  max-width: 240px; padding: 8px 12px; border-radius: 10px;
  background: rgba(6,12,34,.85); border: 1px solid var(--line-strong);
  color: var(--text); font-size: .88rem; cursor: pointer;
  outline: none; transition: box-shadow .25s, border-color .25s;
}
.cur-nav:hover, .cur-nav:focus { border-color: var(--cyan); box-shadow: 0 0 14px rgba(34,224,255,.35); }
.cur-nav option { background: #0a1230; color: var(--text); }
.menu-btn { display: none; background: none; border: 1px solid var(--line); color: var(--text); border-radius: 9px; padding: 6px 12px; cursor: pointer; font-size: 1.1rem; }

/* ---------- 主站 Hero ---------- */
.hero {
  position: relative; z-index: 2;
  min-height: 100vh;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  text-align: center; padding: 90px 24px 60px;
}
.hero .badge {
  display: inline-flex; gap: 8px; align-items: center;
  border: 1px solid var(--line-strong); border-radius: 999px;
  padding: 8px 18px; margin-bottom: 26px; font-size: .88rem;
  color: var(--cyan); background: rgba(34,224,255,.06);
  box-shadow: var(--glow-cyan); animation: pulse 2.6s ease-in-out infinite;
}
@keyframes pulse { 0%,100% { box-shadow: 0 0 8px rgba(34,224,255,.35);} 50% { box-shadow: 0 0 22px rgba(34,224,255,.8);} }
.hero h1 {
  font-size: clamp(2.4rem, 6vw, 4.6rem);
  font-weight: 900; letter-spacing: 2px; line-height: 1.15;
  background: linear-gradient(120deg, #ffffff 0%, var(--cyan) 35%, var(--purple) 70%, var(--pink) 100%);
  background-size: 200% auto;
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
  animation: shine 5s linear infinite;
}
@keyframes shine { to { background-position: 200% center; } }
.typing { font-size: clamp(1.05rem, 2.4vw, 1.5rem); color: var(--text-dim); margin: 18px 0 12px; min-height: 2.2em; }
.typing .cursor { color: var(--cyan); animation: blink .8s step-end infinite; }
@keyframes blink { 50% { opacity: 0; } }
.hero .sub { color: var(--text-dim); max-width: 720px; margin-bottom: 34px; font-size: 1.02rem; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 13px 30px; border-radius: 12px; text-decoration: none; font-weight: 700;
  border: 1px solid var(--line-strong); color: var(--cyan);
  background: linear-gradient(120deg, rgba(34,224,255,.14), rgba(77,124,255,.1));
  transition: transform .25s, box-shadow .25s, background .25s;
  cursor: pointer;
}
.btn:hover { transform: translateY(-3px); box-shadow: var(--glow-cyan); }
.btn.primary {
  background: linear-gradient(120deg, var(--cyan), var(--blue));
  color: #02101d; border: none; box-shadow: var(--glow-cyan);
}
.btn.primary:hover { box-shadow: 0 0 28px rgba(34,224,255,.9); }
.btn.ghost { background: transparent; }
.hero-cta { display: flex; gap: 16px; flex-wrap: wrap; justify-content: center; }
.scroll-hint { position: absolute; bottom: 26px; left: 50%; transform: translateX(-50%); color: var(--text-dim); font-size: .85rem; animation: float 2.2s ease-in-out infinite; }
@keyframes float { 0%,100%{ transform: translate(-50%,0);} 50%{ transform: translate(-50%,12px);} }

/* ---------- 通用 section ---------- */
.section { position: relative; z-index: 2; padding: 84px 5vw; max-width: 1400px; margin: 0 auto; }
.section-title { text-align: center; margin-bottom: 46px; }
.section-title .kicker {
  color: var(--cyan); font-size: .9rem; letter-spacing: 4px; text-transform: uppercase;
}
.section-title h2 {
  font-size: clamp(1.6rem, 3.6vw, 2.6rem); font-weight: 800; margin-top: 6px;
}
.section-title .bar {
  width: 90px; height: 4px; margin: 16px auto 0; border-radius: 4px;
  background: linear-gradient(90deg, var(--cyan), var(--purple));
  box-shadow: var(--glow-cyan);
}

/* ---------- 卡片 / 网格 ---------- */
.grid { display: grid; gap: 22px; }
.grid.cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid.cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid.cols-4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 1000px) { .grid.cols-4, .grid.cols-3 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 640px) { .grid.cols-2, .grid.cols-3, .grid.cols-4 { grid-template-columns: 1fr; } }

.card {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  overflow: hidden;
  transition: transform .3s, box-shadow .3s, border-color .3s;
}
.card::before {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(140deg, rgba(34,224,255,.14), transparent 40%, transparent 70%, rgba(154,107,255,.14));
  opacity: 0; transition: opacity .35s;
}
.card:hover { transform: translateY(-6px); border-color: var(--line-strong); box-shadow: 0 14px 44px rgba(34,120,255,.18); }
.card:hover::before { opacity: 1; }
.card h3 { font-size: 1.14rem; margin-bottom: 8px; position: relative; }
.card p { color: var(--text-dim); font-size: .94rem; position: relative; }

/* 章节卡 */
.part-card .num {
  font-family: var(--font-mono); color: var(--cyan); font-size: 1.5rem; font-weight: 800;
  margin-bottom: 6px; text-shadow: var(--glow-cyan);
}
.part-card .lessons { margin-top: 12px; font-size: .86rem; color: var(--green); }

/* 课程卡 */
.lesson-card { cursor: pointer; text-decoration: none; color: inherit; display: block; }
.lesson-card .lno {
  font-family: var(--font-mono); font-size: .8rem; color: var(--purple);
  letter-spacing: 1px; margin-bottom: 6px;
}
.lesson-card .meta { display: flex; justify-content: space-between; font-size: .8rem; color: var(--text-dim); margin-top: 10px; }
.lesson-card.done { border-color: rgba(47,243,178,.5); }
.lesson-card.done .lno::after { content: " ✓"; color: var(--green); }

/* ---------- 功能面板 ---------- */
.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}
.stat-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; margin-bottom: 40px; }
@media (max-width: 800px) { .stat-row { grid-template-columns: repeat(2, 1fr); } }
.stat { text-align: center; padding: 22px 10px; }
.stat .v { font-family: var(--font-mono); font-size: 2.2rem; font-weight: 800; color: var(--cyan); text-shadow: var(--glow-cyan); }
.stat .l { color: var(--text-dim); font-size: .9rem; margin-top: 4px; }

/* 搜索框 */
.search-box {
  display: flex; gap: 10px; max-width: 640px; margin: 0 auto 30px;
}
.search-box input {
  flex: 1; padding: 14px 18px; border-radius: 12px;
  background: rgba(6,12,34,.7); border: 1px solid var(--line);
  color: var(--text); font-size: 1rem; outline: none;
  transition: border-color .3s, box-shadow .3s;
}
.search-box input:focus { border-color: var(--cyan); box-shadow: var(--glow-cyan); }

/* ---------- 课程页专属 ---------- */
.lesson-body { position: relative; z-index: 2; max-width: 960px; margin: 0 auto; padding: 110px 24px 60px; }
.lesson-head { text-align: center; margin-bottom: 40px; }
.lesson-head .crumb { color: var(--text-dim); font-size: .88rem; letter-spacing: 2px; }
.lesson-head h1 { font-size: clamp(1.8rem, 4.5vw, 2.9rem); font-weight: 900; margin: 12px 0; background: linear-gradient(120deg, var(--text), var(--cyan)); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.lesson-head .part-tag {
  display: inline-block; padding: 5px 14px; border-radius: 999px;
  border: 1px solid var(--purple); color: var(--purple); font-size: .8rem;
  background: rgba(154,107,255,.08); margin-bottom: 10px;
}
.lesson-head .meta { display: flex; gap: 18px; justify-content: center; flex-wrap: wrap; color: var(--text-dim); font-size: .9rem; }
.lesson-head .meta span b { color: var(--cyan); }

/* 目标框 */
.objectives {
  background: linear-gradient(120deg, rgba(34,224,255,.1), rgba(77,124,255,.06));
  border: 1px solid var(--line-strong);
  border-radius: var(--radius); padding: 22px 26px; margin-bottom: 34px;
}
.objectives h2 { font-size: 1.1rem; color: var(--cyan); margin-bottom: 12px; display: flex; align-items: center; gap: 8px; }
.objectives ul { list-style: none; }
.objectives li { padding-left: 26px; position: relative; margin: 7px 0; color: var(--text); }
.objectives li::before {
  content: "▸"; position: absolute; left: 0; color: var(--green);
  text-shadow: 0 0 8px var(--green);
}

/* 步骤 */
.step {
  position: relative; margin: 34px 0; padding: 26px 26px 26px 60px;
  background: var(--panel-2); border: 1px solid var(--line);
  border-radius: var(--radius); backdrop-filter: blur(8px);
}
.step::before {
  content: attr(data-no);
  position: absolute; left: -6px; top: -6px;
  width: 44px; height: 44px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-mono); font-weight: 800; font-size: 1.05rem;
  background: linear-gradient(135deg, var(--cyan), var(--blue));
  color: #02101d; box-shadow: var(--glow-cyan);
}
.step h3 { font-size: 1.18rem; margin-bottom: 12px; color: var(--text); }
.step h3 .step-tag {
  font-size: .72rem; color: var(--cyan); border: 1px solid var(--line-strong);
  border-radius: 6px; padding: 2px 8px; margin-left: 8px; vertical-align: middle;
  letter-spacing: 1px;
}
.step p, .step li { color: var(--text-dim); }
.step ul, .step ol { padding-left: 22px; }
.step ul { list-style: none; }
.step ul li { position: relative; padding-left: 16px; margin: 5px 0; }
.step ul li::before { content: "•"; color: var(--cyan); position: absolute; left: 0; }

/* 代码块 */
pre {
  position: relative;
  background: #050a1c; border: 1px solid var(--line);
  border-radius: 12px; padding: 18px 20px; margin: 16px 0;
  overflow-x: auto; font-family: var(--font-mono); font-size: .9rem;
  line-height: 1.7; color: #cfe8ff;
}
pre .lang-tag {
  position: absolute; top: -11px; right: 14px;
  font-size: .7rem; color: var(--green); letter-spacing: 1px;
  background: #050a1c; padding: 0 8px; border: 1px solid var(--line); border-radius: 6px;
}
code { font-family: var(--font-mono); }
p code, li code, td code {
  background: rgba(34,224,255,.1); border: 1px solid rgba(34,224,255,.25);
  border-radius: 5px; padding: 1px 7px; font-size: .88em; color: var(--cyan);
}
/* 行内代码语法高亮（生成时用类） */
.tok-kw { color: #ff7de9; font-weight: 700; }
.tok-str { color: #7be77b; }
.tok-num { color: #ffd166; }
.tok-cm { color: #6f87ad; font-style: italic; }
.tok-fn { color: #5ad1ff; }
.tok-type { color: #c7a4ff; }

/* 提示框 */
.tipbox {
  display: flex; gap: 14px; padding: 18px 22px; border-radius: 12px;
  margin: 18px 0; border: 1px solid;
}
.tipbox .icon { font-size: 1.4rem; }
.tipbox.info { background: rgba(34,224,255,.07); border-color: rgba(34,224,255,.4); }
.tipbox.warn { background: rgba(255,209,102,.07); border-color: rgba(255,209,102,.45); }
.tipbox.danger { background: rgba(255,107,120,.07); border-color: rgba(255,107,120,.5); }
.tipbox.success { background: rgba(47,243,178,.07); border-color: rgba(47,243,178,.4); }
.tipbox b { color: var(--text); }
.tipbox p { color: var(--text-dim); font-size: .95rem; }

/* 练习区 */
.exercise { border: 1px dashed var(--line-strong); border-radius: var(--radius); padding: 24px; margin: 30px 0; background: rgba(154,107,255,.05); }
.exercise h2 { color: var(--purple); margin-bottom: 10px; display: flex; align-items: center; gap: 8px; }

/* 表格 */
table { width: 100%; border-collapse: collapse; margin: 16px 0; font-size: .92rem; }
th, td { border: 1px solid var(--line); padding: 10px 14px; text-align: left; }
th { background: rgba(34,224,255,.08); color: var(--cyan); font-weight: 700; }
tr:nth-child(even) td { background: rgba(255,255,255,.02); }

/* 上一页/下一页 */
.pager { display: flex; justify-content: space-between; gap: 14px; margin-top: 50px; }
.pager a {
  flex: 1; text-decoration: none; color: var(--text);
  background: var(--panel); border: 1px solid var(--line);
  border-radius: 14px; padding: 18px 22px;
  transition: border-color .3s, box-shadow .3s, transform .3s;
}
.pager a:hover { border-color: var(--line-strong); box-shadow: var(--glow-cyan); transform: translateY(-3px); }
.pager .dir { display: block; font-size: .78rem; color: var(--cyan); letter-spacing: 2px; text-transform: uppercase; }
.pager .ttl { font-weight: 700; margin-top: 4px; }
.pager .next { text-align: right; }

/* 完成按钮 */
.done-btn {
  display: block; width: 100%; margin: 26px 0 10px; padding: 16px;
  border-radius: 12px; border: 1px solid rgba(47,243,178,.5);
  background: rgba(47,243,178,.1); color: var(--green); font-size: 1.05rem; font-weight: 700;
  cursor: pointer; transition: box-shadow .3s, transform .3s;
}
.done-btn:hover { box-shadow: 0 0 20px rgba(47,243,178,.4); transform: translateY(-2px); }
.done-btn.marked { background: rgba(47,243,178,.22); }

/* 返回顶部 */
#toTop {
  position: fixed; right: 26px; bottom: 26px; z-index: 99;
  width: 48px; height: 48px; border-radius: 50%;
  background: linear-gradient(135deg, var(--cyan), var(--blue));
  color: #02101d; border: none; font-size: 1.3rem; cursor: pointer;
  box-shadow: var(--glow-cyan); opacity: 0; pointer-events: none;
  transition: opacity .3s, transform .3s;
}
#toTop.show { opacity: 1; pointer-events: auto; }
#toTop:hover { transform: translateY(-4px); }

/* 页脚 */
footer {
  position: relative; z-index: 2;
  border-top: 1px solid var(--line); padding: 36px 24px;
  text-align: center; color: var(--text-dim); font-size: .88rem;
  background: rgba(4,8,24,.5);
}
footer a { color: var(--cyan); text-decoration: none; }

/* 滚动条 */
::-webkit-scrollbar { width: 10px; }
::-webkit-scrollbar-track { background: #04081a; }
::-webkit-scrollbar-thumb { background: linear-gradient(var(--blue), var(--purple)); border-radius: 6px; }
::selection { background: rgba(34,224,255,.3); }

/* 响应式 */
@media (max-width: 700px) {
  .nav .links { display: none; position: absolute; top: 62px; left: 0; right: 0; flex-direction: column; background: rgba(4,8,24,.96); padding: 14px; border-bottom: 1px solid var(--line); }
  .nav .links.open { display: flex; }
  .menu-btn { display: block; }
  .step { padding-left: 24px; padding-top: 56px; }
  .step::before { left: 12px; top: 12px; }
}