/* ============================================================
   小蛇学Python 🐍 — 小学生专属样式
   ============================================================ */

:root {
  --bg: #fff7e6;                 /* 奶油色背景 */
  --card: #ffffff;
  --ink: #4a3f35;                /* 深棕色文字，柔和不刺眼 */
  --orange: #ff8c42;
  --blue: #4aa3df;
  --green: #58c04d;
  --pink: #ff6fa5;
  --purple: #9b7ede;
  --yellow: #ffc93c;
  --radius: 22px;
  --shadow: 0 6px 18px rgba(74, 63, 53, 0.12);
}

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

html { font-size: 18px; }

body {
  font-family: "Comic Sans MS", "Comic Sans", "PingFang SC", "Microsoft YaHei",
    "Hiragino Sans GB", sans-serif;
  background:
    radial-gradient(circle at 12% 18%, #fff3c4 0, transparent 32%),
    radial-gradient(circle at 88% 12%, #ffe0ec 0, transparent 30%),
    radial-gradient(circle at 82% 85%, #dff3ff 0, transparent 34%),
    radial-gradient(circle at 15% 88%, #e4f7dd 0, transparent 32%),
    var(--bg);
  color: var(--ink);
  min-height: 100vh;
  line-height: 1.7;
}

/* ---------- 顶部栏 ---------- */
.topbar {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 22px;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(6px);
  box-shadow: 0 3px 12px rgba(74, 63, 53, 0.08);
  position: sticky;
  top: 0;
  z-index: 50;
}

.logo {
  font-size: 1.6rem;
  font-weight: 900;
  color: var(--orange);
  text-shadow: 2px 2px 0 rgba(255, 140, 66, 0.2);
  white-space: nowrap;
}

.logo span { color: var(--green); }

.topbar .spacer { flex: 1; }

.stars-badge {
  background: linear-gradient(135deg, #fff3c4, #ffe9a8);
  border: 3px dashed var(--yellow);
  border-radius: 999px;
  padding: 6px 18px;
  font-size: 1.05rem;
  font-weight: 800;
  color: #a57100;
  white-space: nowrap;
}

.btn-back {
  background: var(--blue);
  color: #fff;
  border: none;
  border-radius: 999px;
  padding: 8px 20px;
  font-size: 1rem;
  font-weight: 700;
  font-family: inherit;
  cursor: pointer;
  box-shadow: 0 4px 0 #2f7cb4;
  transition: transform 0.1s, box-shadow 0.1s;
}
.btn-back:hover { transform: translateY(-2px); }
.btn-back:active { transform: translateY(2px); box-shadow: 0 1px 0 #2f7cb4; }

/* ---------- 主容器 ---------- */
.container {
  max-width: 920px;
  margin: 0 auto;
  padding: 28px 20px 70px;
}

/* ---------- 首页英雄区 ---------- */
.hero {
  text-align: center;
  padding: 34px 16px 26px;
}

.hero .mascot { font-size: 4.6rem; display: block; margin-bottom: 6px; animation: bounce 2.4s infinite; }

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}

.hero h1 {
  font-size: 2.4rem;
  color: var(--orange);
  letter-spacing: 2px;
}
.hero h1 .s { color: var(--green); }

.hero p {
  font-size: 1.15rem;
  margin-top: 8px;
  color: #7a6a58;
}

.big-btn {
  display: inline-block;
  margin-top: 20px;
  background: linear-gradient(135deg, var(--orange), #ffb03c);
  color: #fff;
  font-size: 1.35rem;
  font-weight: 900;
  font-family: inherit;
  border: none;
  border-radius: 999px;
  padding: 16px 44px;
  cursor: pointer;
  box-shadow: 0 6px 0 #d96a1f;
  transition: transform 0.12s, box-shadow 0.12s;
  text-decoration: none;
}
.big-btn:hover { transform: translateY(-3px); }
.big-btn:active { transform: translateY(3px); box-shadow: 0 1px 0 #d96a1f; }

/* ---------- 卡片 ---------- */
.section-title {
  font-size: 1.5rem;
  margin: 30px 0 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.card {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 22px;
}

/* 课程卡片网格 */
.lesson-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 18px;
  margin-top: 8px;
}

.lesson-card {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px;
  cursor: pointer;
  border: 5px solid transparent;
  transition: transform 0.15s, border-color 0.15s;
  display: flex;
  flex-direction: column;
  gap: 6px;
  text-decoration: none;
  color: var(--ink);
  position: relative;
}
.lesson-card:hover { transform: translateY(-5px) rotate(-0.5deg); }

.lesson-card .num {
  font-size: 0.85rem;
  font-weight: 800;
  color: #fff;
  border-radius: 999px;
  padding: 2px 12px;
  align-self: flex-start;
}

.lesson-card .icon { font-size: 2.6rem; }

.lesson-card .title { font-size: 1.25rem; font-weight: 900; }
.lesson-card .sub { font-size: 0.95rem; color: #8a7a68; }

.lesson-card .stars {
  margin-top: auto;
  font-size: 1.1rem;
  letter-spacing: 3px;
  color: #e8d9b0;
}
.lesson-card .stars .got { color: #f7b500; }

.lesson-card .done-flag {
  position: absolute;
  top: 12px;
  right: 12px;
  font-size: 1.3rem;
}

/* 每课一个主题色 */
.c1 { border-color: #ffd9b8; } .c1 .num { background: var(--orange); }
.c2 { border-color: #c9e6fb; } .c2 .num { background: var(--blue); }
.c3 { border-color: #d0f2cb; } .c3 .num { background: var(--green); }
.c4 { border-color: #ffd3e4; } .c4 .num { background: var(--pink); }
.c5 { border-color: #e2d8fb; } .c5 .num { background: var(--purple); }
.c6 { border-color: #fff0bf; } .c6 .num { background: #e0a800; }
.c7 { border-color: #d3f0f2; } .c7 .num { background: #2ba8a8; }

/* 阶段卡片配色 */
.l1 { border-color: #ffd9b8; } .l1 .num { background: var(--orange); }
.l2 { border-color: #d0f2cb; } .l2 .num { background: var(--green); }
.l3 { border-color: #e2d8fb; } .l3 .num { background: var(--purple); }

.lesson-card .progress {
  margin-top: auto;
  font-size: 0.95rem;
  font-weight: 700;
  color: #7a6a58;
  background: #f6f0e4;
  border-radius: 999px;
  padding: 4px 14px;
  align-self: flex-start;
}

/* ---------- 课程页 ---------- */
.lesson-head {
  text-align: center;
  margin-bottom: 18px;
}
.lesson-head .icon { font-size: 3.4rem; }
.lesson-head h2 { font-size: 1.9rem; }
.lesson-head .sub { color: #8a7a68; }

.block { margin-bottom: 22px; }

.block-text { font-size: 1.1rem; }

.block-tip {
  background: #fff8e1;
  border-left: 8px solid var(--yellow);
  border-radius: 14px;
  padding: 14px 18px;
  font-size: 1.05rem;
}

.code-box {
  background: #2d2a3d;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: var(--shadow);
}

.code-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 16px;
  background: #3a3650;
  color: #cfc9e6;
  font-size: 0.9rem;
  font-weight: 700;
}

.run-btn {
  background: var(--green);
  color: #fff;
  border: none;
  border-radius: 999px;
  padding: 6px 16px;
  font-size: 0.9rem;
  font-weight: 800;
  font-family: inherit;
  cursor: pointer;
  box-shadow: 0 3px 0 #3c8f33;
  transition: transform 0.1s, box-shadow 0.1s;
}
.run-btn:hover { transform: translateY(-1px); }
.run-btn:active { transform: translateY(2px); box-shadow: 0 0 0 #3c8f33; }

.code-box pre {
  padding: 16px 18px;
  overflow-x: auto;
  color: #ffe9a8;
  font-family: "SF Mono", "Cascadia Code", Consolas, Menlo, monospace;
  font-size: 1.02rem;
  line-height: 1.6;
}

/* ---------- 测验 ---------- */
.quiz-card { margin-top: 26px; }

.quiz-card h3 { font-size: 1.4rem; margin-bottom: 6px; }
.quiz-q { font-size: 1.2rem; font-weight: 800; margin-bottom: 14px; }

.quiz-options { display: flex; flex-direction: column; gap: 12px; }

.quiz-opt {
  display: block;
  width: 100%;
  text-align: left;
  background: #f4efe6;
  border: 3px solid #e5dccb;
  border-radius: 16px;
  padding: 14px 18px;
  font-size: 1.1rem;
  font-family: inherit;
  color: var(--ink);
  cursor: pointer;
  transition: transform 0.1s, border-color 0.15s, background 0.15s;
}
.quiz-opt:hover { transform: translateX(6px); border-color: var(--orange); }
.quiz-opt.correct {
  background: #e6f7e2;
  border-color: var(--green);
  font-weight: 800;
}
.quiz-opt.wrong {
  background: #ffe3e3;
  border-color: #ff6b6b;
  animation: shake 0.35s;
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-8px); }
  75% { transform: translateX(8px); }
}

.quiz-feedback {
  margin-top: 14px;
  font-size: 1.15rem;
  font-weight: 800;
  min-height: 1.8rem;
}
.quiz-feedback .ok { color: var(--green); }
.quiz-feedback .no { color: #ff6b6b; }

/* 完成庆祝 */
.celebrate {
  margin-top: 26px;
  text-align: center;
  background: linear-gradient(135deg, #fff3c4, #ffe9a8);
  border: 4px dashed var(--yellow);
  border-radius: var(--radius);
  padding: 26px;
  display: none;
}
.celebrate.show { display: block; animation: pop 0.4s; }

@keyframes pop {
  0% { transform: scale(0.7); opacity: 0; }
  100% { transform: scale(1); opacity: 1; }
}

.celebrate .big { font-size: 2.6rem; }
.celebrate h3 { font-size: 1.6rem; color: #a57100; margin: 6px 0; }
.celebrate p { font-size: 1.1rem; }

/* ---------- 游乐场 ---------- */
.play-area { display: flex; flex-direction: column; gap: 16px; }

.play-toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}

.play-btn {
  background: var(--green);
  color: #fff;
  border: none;
  border-radius: 999px;
  padding: 10px 26px;
  font-size: 1.1rem;
  font-weight: 800;
  font-family: inherit;
  cursor: pointer;
  box-shadow: 0 4px 0 #3c8f33;
  transition: transform 0.1s, box-shadow 0.1s;
}
.play-btn:hover { transform: translateY(-2px); }
.play-btn:active { transform: translateY(2px); box-shadow: 0 1px 0 #3c8f33; }
.play-btn.ghost {
  background: #eee7db;
  color: var(--ink);
  box-shadow: 0 4px 0 #cbbfa9;
}
.play-btn.ghost:active { box-shadow: 0 1px 0 #cbbfa9; }

.sample-select {
  font-family: inherit;
  font-size: 1rem;
  padding: 8px 14px;
  border-radius: 999px;
  border: 3px solid #e5dccb;
  background: #fff;
  color: var(--ink);
  cursor: pointer;
}

#code {
  width: 100%;
  min-height: 260px;
  resize: vertical;
  background: #2d2a3d;
  color: #ffe9a8;
  border: none;
  border-radius: 16px;
  padding: 18px;
  font-family: "SF Mono", "Cascadia Code", Consolas, Menlo, monospace;
  font-size: 1.05rem;
  line-height: 1.7;
  outline: 2px solid transparent;
}
#code:focus { outline: 2px solid var(--purple); }

.status-line {
  font-size: 0.95rem;
  color: #8a7a68;
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 1.6rem;
}
.status-line .dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #ccc;
  display: inline-block;
}
.status-line.ready .dot { background: var(--green); animation: blink 1.4s infinite; }
.status-line.loading .dot { background: var(--yellow); animation: blink 0.8s infinite; }
.status-line.error .dot { background: #ff6b6b; }

@keyframes blink { 50% { opacity: 0.25; } }

#output {
  background: #1c1a28;
  border-radius: 16px;
  padding: 18px;
  min-height: 140px;
  max-height: 320px;
  overflow-y: auto;
  color: #d8f3dc;
  font-family: "SF Mono", "Cascadia Code", Consolas, Menlo, monospace;
  font-size: 1.05rem;
  line-height: 1.7;
  white-space: pre-wrap;
  word-break: break-word;
}
#output .err { color: #ff9d9d; }

/* ---------- 页脚 ---------- */
footer {
  text-align: center;
  padding: 30px 20px 40px;
  color: #a3927d;
  font-size: 0.95rem;
}

/* ---------- 小工具 ---------- */
.hidden { display: none !important; }

@media (max-width: 600px) {
  html { font-size: 16px; }
  .hero h1 { font-size: 1.9rem; }
  .lesson-grid { grid-template-columns: 1fr; }
}