/* ===== SwiftLab · 看得见的 App ===== */
* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --bg-top: #0d0a1c;
  --bg-bottom: #050409;
  --accent-a: #8c5cf6;
  --accent-b: #ed4899;
  --mint: #4ddfae;
  --amber: #ffb84d;
  --text-1: rgba(255, 255, 255, 0.92);
  --text-2: rgba(255, 255, 255, 0.55);
  --glass: rgba(255, 255, 255, 0.05);
  --glass-line: rgba(255, 255, 255, 0.12);
  --grad: linear-gradient(120deg, var(--accent-a), var(--accent-b));
  --radius: 18px;
  --font: -apple-system, BlinkMacSystemFont, "PingFang SC", "Helvetica Neue", sans-serif;
  --mono: "SF Mono", ui-monospace, Menlo, monospace;
}

html, body { height: 100%; }
body {
  font-family: var(--font);
  color: var(--text-1);
  background: linear-gradient(180deg, var(--bg-top), var(--bg-bottom));
  min-height: 100vh;
  overflow-x: hidden;
}

/* ---- 极光背景 ---- */
.aurora { position: fixed; inset: 0; z-index: 0; pointer-events: none; overflow: hidden; }
.blob { position: absolute; border-radius: 50%; filter: blur(90px); opacity: 0.55; }
.b1 { width: 560px; height: 560px; background: rgba(140, 92, 246, 0.5); top: -180px; left: -140px; animation: drift1 26s ease-in-out infinite alternate; }
.b2 { width: 520px; height: 520px; background: rgba(237, 72, 153, 0.34); bottom: -160px; right: -120px; animation: drift2 32s ease-in-out infinite alternate; }
.b3 { width: 460px; height: 460px; background: rgba(51, 115, 242, 0.3); bottom: -220px; left: 30%; animation: drift3 38s ease-in-out infinite alternate; }
@keyframes drift1 { to { transform: translate(70px, 50px); } }
@keyframes drift2 { to { transform: translate(-80px, -60px); } }
@keyframes drift3 { to { transform: translate(60px, -40px); } }

/* ---- 侧栏 ---- */
.sidebar {
  position: fixed; top: 0; left: 0; bottom: 0; width: 252px; z-index: 5;
  display: flex; flex-direction: column; gap: 20px;
  padding: 26px 16px 20px;
  background: rgba(255, 255, 255, 0.03);
  border-right: 1px solid rgba(255, 255, 255, 0.07);
  backdrop-filter: blur(20px);
}
.logo { display: flex; gap: 10px; align-items: center; padding: 0 8px; }
.logo-mark { font-size: 26px; }
.logo-name { font-size: 17px; font-weight: 800; letter-spacing: 0.3px; }
.logo-sub { font-size: 11px; color: var(--text-2); }

.lang-seg {
  display: flex; gap: 4px; margin: 0 8px; padding: 3px;
  border-radius: 999px;
  background: var(--glass); border: 1px solid var(--glass-line);
}
.lang-btn {
  flex: 1; appearance: none; border: none; cursor: pointer;
  font-family: var(--font); font-size: 12px; font-weight: 700;
  color: var(--text-2); background: transparent;
  border-radius: 999px; padding: 6px 0;
  transition: background 0.18s, color 0.18s;
}
.lang-btn:hover { color: var(--text-1); }
.lang-btn.on {
  background: var(--grad); color: #fff;
  box-shadow: 0 4px 14px rgba(140, 92, 246, 0.4);
}

.stops { display: flex; flex-direction: column; gap: 6px; }
.stop {
  display: flex; align-items: center; gap: 10px;
  padding: 10px 10px; border-radius: 12px; cursor: pointer;
  border: 1px solid transparent; transition: background 0.15s, border-color 0.15s;
  user-select: none;
}
.stop:hover { background: rgba(255, 255, 255, 0.05); }
.stop.active { background: rgba(140, 92, 246, 0.16); border-color: rgba(140, 92, 246, 0.35); }
.stop-num {
  width: 24px; height: 24px; border-radius: 50%; flex: none;
  display: grid; place-items: center;
  font-size: 12px; font-weight: 700;
  background: rgba(255, 255, 255, 0.08); color: var(--text-2);
}
.stop.active .stop-num { background: var(--grad); color: #fff; }
.stop.done .stop-num { background: rgba(77, 223, 174, 0.2); color: var(--mint); }
.stop-name { font-size: 13.5px; font-weight: 600; line-height: 1.35; }
.stop-desc { font-size: 11px; color: var(--text-2); line-height: 1.4; margin-top: 2px; }

.side-foot { margin-top: auto; display: flex; flex-direction: column; gap: 12px; }
.progress-card {
  padding: 12px; border-radius: 14px;
  background: var(--glass); border: 1px solid var(--glass-line);
}
.progress-label { font-size: 11px; color: var(--text-2); margin-bottom: 8px; }
.progress-track { height: 5px; border-radius: 3px; background: rgba(255, 255, 255, 0.09); overflow: hidden; }
.progress-fill { height: 100%; width: 0; border-radius: 3px; background: var(--grad); transition: width 0.5s cubic-bezier(0.3, 1.3, 0.4, 1); }
.progress-num { font-size: 11px; color: var(--text-2); margin-top: 7px; text-align: right; }
.side-note { font-size: 10.5px; color: rgba(255, 255, 255, 0.3); padding: 0 6px; }

/* ---- 主区 ---- */
.main { position: relative; z-index: 1; margin-left: 252px; padding: 44px 40px 80px; }
.wrap { max-width: 900px; margin: 0 auto; }

.kicker {
  display: inline-block; font-size: 12px; font-weight: 700; letter-spacing: 1px;
  color: var(--accent-a); background: rgba(140, 92, 246, 0.13);
  border: 1px solid rgba(140, 92, 246, 0.3);
  padding: 4px 12px; border-radius: 999px; margin-bottom: 14px;
}
h1.station-title { font-size: 30px; font-weight: 800; margin-bottom: 8px; }
.station-sub { font-size: 14.5px; color: var(--text-2); margin-bottom: 30px; line-height: 1.7; }

/* ---- 玻璃卡 ---- */
.card {
  background: var(--glass);
  border: 1px solid var(--glass-line);
  border-radius: var(--radius);
  padding: 26px;
  backdrop-filter: blur(14px);
}

/* ---- 第一站:场景卡 ---- */
.scene-visual {
  min-height: 170px; display: grid; place-items: center;
  border-radius: 14px; margin-bottom: 22px;
  background: rgba(0, 0, 0, 0.25);
  border: 1px solid rgba(255, 255, 255, 0.06);
  padding: 26px; text-align: center;
}
.scene-title { font-size: 21px; font-weight: 800; margin-bottom: 12px; }
.scene-body { font-size: 15px; line-height: 1.9; color: var(--text-1); }
.scene-body p + p { margin-top: 10px; }
.scene-nav { display: flex; flex-wrap: wrap; gap: 12px; justify-content: space-between; align-items: center; margin-top: 26px; }
.scene-dots { display: flex; gap: 6px; }
.dot { width: 7px; height: 7px; border-radius: 50%; background: rgba(255, 255, 255, 0.15); transition: 0.2s; }
.dot.on { background: var(--accent-a); transform: scale(1.3); }

.v-big { font-size: 34px; font-weight: 800; line-height: 1.5; }
.v-formula {
  font-family: var(--mono); font-size: 34px; font-weight: 700;
  background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent;
  filter: drop-shadow(0 0 24px rgba(140, 92, 246, 0.55));
}
.v-emoji { font-size: 56px; }
.v-caption { font-size: 13px; color: var(--text-2); margin-top: 12px; }
.v-row { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.v-chip {
  padding: 10px 18px; border-radius: 14px; font-size: 15px; font-weight: 700;
  background: rgba(255, 255, 255, 0.07); border: 1px solid var(--glass-line);
}
.v-arrow { align-self: center; color: var(--text-2); font-size: 18px; }

/* ---- 按钮 ---- */
.btn {
  appearance: none; border: none; cursor: pointer; font-family: var(--font);
  font-size: 14px; font-weight: 700; color: #fff;
  padding: 11px 24px; border-radius: 999px;
  background: var(--grad);
  box-shadow: 0 6px 22px rgba(140, 92, 246, 0.45);
  transition: transform 0.15s cubic-bezier(0.3, 1.5, 0.5, 1), box-shadow 0.2s;
}
.btn:hover { transform: scale(1.04); }
.btn:active { transform: scale(0.96); }
.btn.ghost {
  background: rgba(255, 255, 255, 0.07);
  border: 1px solid var(--glass-line);
  box-shadow: none; color: var(--text-1); font-weight: 600;
}
.btn:disabled { opacity: 0.35; cursor: default; transform: none; }

/* ---- 术语 ---- */
.term {
  color: #b79bff; cursor: pointer; border-bottom: 1px dashed rgba(183, 155, 255, 0.5);
  transition: 0.15s;
}
.term:hover { color: #d7c6ff; border-bottom-color: #d7c6ff; }

.popover-mask { position: fixed; inset: 0; z-index: 40; background: rgba(0, 0, 0, 0.45); display: none; }
.popover {
  position: fixed; z-index: 41; left: 50%; top: 50%;
  transform: translate(-50%, -50%) scale(0.9); opacity: 0;
  width: min(420px, 88vw);
  background: rgba(22, 17, 40, 0.92);
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 18px; padding: 24px;
  backdrop-filter: blur(24px);
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.5);
  display: none; transition: transform 0.22s cubic-bezier(0.3, 1.4, 0.5, 1), opacity 0.18s;
}
.popover.show { transform: translate(-50%, -50%) scale(1); opacity: 1; }
.pop-title { font-size: 16px; font-weight: 800; margin-bottom: 10px; }
.pop-body { font-size: 13.5px; line-height: 1.85; color: var(--text-1); }
.pop-close { margin-top: 16px; text-align: right; }

/* ---- 第二站:双栏 ---- */
.duo { display: grid; grid-template-columns: 1.15fr 0.85fr; gap: 20px; align-items: start; }
@media (max-width: 1100px) { .duo { grid-template-columns: 1fr; } }

.xcode-strip {
  display: flex; gap: 10px; align-items: flex-start;
  font-size: 13px; line-height: 1.7; color: var(--text-1);
  background: rgba(255, 184, 77, 0.08);
  border: 1px solid rgba(255, 184, 77, 0.25);
  border-radius: 12px; padding: 12px 14px; margin-bottom: 14px;
}
.narration { font-size: 14.5px; line-height: 1.9; margin-bottom: 16px; }

.codebox {
  background: rgba(0, 0, 0, 0.45);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 14px; padding: 16px 0; overflow-x: auto;
}
.cl { display: flex; font-family: var(--mono); font-size: 12.5px; line-height: 1.75; white-space: pre; }
.cl .ln { width: 34px; flex: none; text-align: right; padding-right: 12px; color: rgba(255, 255, 255, 0.22); user-select: none; }
.cl .ct { padding-right: 18px; }
.cl.added { background: rgba(77, 223, 174, 0.08); box-shadow: inset 3px 0 0 var(--mint); }
.cl.blankline .ct::after { content: " "; }
.k { color: #ff7ab2; } /* 关键字 */
.t { color: #82d8ff; } /* 类型 */
.s { color: #a8e28a; } /* 字符串 */
.a { color: #d0a8ff; } /* @属性 */
.c { color: rgba(255, 255, 255, 0.3); } /* 注释 */
.dim { opacity: 0.45; }

/* ---- Mac 模拟窗口 ---- */
.mock-side { position: sticky; top: 30px; }
.mac-win {
  border-radius: 14px; overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.14);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.45);
  background: linear-gradient(180deg, #171226, #0b0816);
}
.mac-win.light { background: #f5f5f7; }
.mac-bar { display: flex; gap: 7px; padding: 11px 12px; }
.mac-dot { width: 11px; height: 11px; border-radius: 50%; }
.mac-dot.r { background: #ff5f57; } .mac-dot.y { background: #febc2e; } .mac-dot.g { background: #28c840; }
.mac-body { padding: 18px 20px 24px; min-height: 260px; }
.mock-caption { font-size: 12px; color: var(--text-2); text-align: center; margin-top: 12px; line-height: 1.7; }

.mock-hello { color: #111; font-size: 15px; padding-top: 60px; text-align: center; }
.mock-title {
  font-size: 19px; font-weight: 800; line-height: 1.35;
  background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent;
}
.mock-inputs { display: flex; gap: 8px; margin-top: 14px; }
.mock-input {
  flex: 1; font-size: 12px; color: var(--text-2);
  background: rgba(255, 255, 255, 0.06); border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 8px; padding: 8px 10px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.mock-input .typed { color: var(--text-1); }
.mock-addbtn {
  font-size: 12px; font-weight: 700; color: #fff; flex: none;
  background: var(--grad); border-radius: 8px; padding: 8px 14px;
}
.mock-addbtn.pressed { transform: scale(0.94); }
.mock-tasks { margin-top: 14px; display: flex; flex-direction: column; gap: 8px; }
.mock-task {
  display: flex; flex-wrap: wrap; align-items: center; gap: 6px 10px;
  background: rgba(255, 255, 255, 0.055); border: 1px solid rgba(255, 255, 255, 0.09);
  border-radius: 10px; padding: 9px 12px; font-size: 13px;
  animation: taskIn 0.35s cubic-bezier(0.3, 1.4, 0.5, 1);
}
@keyframes taskIn { from { opacity: 0; transform: translateY(8px) scale(0.97); } }
.mock-circle {
  width: 18px; height: 18px; border-radius: 50%; flex: none; cursor: pointer;
  border: 1.5px solid rgba(255, 255, 255, 0.3);
  display: grid; place-items: center; font-size: 10px; color: #fff;
  transition: 0.2s;
}
.mock-circle.done { background: var(--grad); border-color: transparent; }
.mock-task .tt { transition: 0.2s; }
.mock-task .tt.done { text-decoration: line-through; color: var(--text-2); }
.mock-reward {
  font-size: 11px; color: #ffc7dd; background: rgba(237, 72, 153, 0.14);
  border: 1px solid rgba(237, 72, 153, 0.3); border-radius: 999px; padding: 3px 9px;
  animation: taskIn 0.3s;
}
.mock-badges { display: flex; flex-direction: column; gap: 7px; margin-top: 16px; }
.mock-badge {
  font-family: var(--mono); font-size: 11px; color: var(--text-2);
  background: rgba(255, 255, 255, 0.05); border: 1px dashed rgba(255, 255, 255, 0.18);
  border-radius: 8px; padding: 7px 10px;
}
.mock-dock {
  display: flex; justify-content: center; gap: 12px; padding: 10px 16px; margin: 70px auto 0;
  width: fit-content; border-radius: 18px;
  background: rgba(255, 255, 255, 0.08); border: 1px solid rgba(255, 255, 255, 0.14);
  backdrop-filter: blur(8px);
}
.dock-ic { width: 44px; height: 44px; border-radius: 11px; display: grid; place-items: center; font-size: 22px; }
.dock-ic.hero { background: linear-gradient(135deg, #2a1a52, #7040c8); box-shadow: 0 6px 18px rgba(140, 92, 246, 0.5); animation: bounceIn 0.6s cubic-bezier(0.3, 1.6, 0.5, 1); }
@keyframes bounceIn { from { transform: translateY(26px) scale(0.6); opacity: 0; } }

/* ---- 步骤导航 ---- */
.step-head { display: flex; flex-wrap: wrap; align-items: baseline; gap: 6px 12px; margin-bottom: 18px; }
.step-count { font-family: var(--mono); font-size: 12px; color: var(--text-2); flex: none; }
.step-title { font-size: 19px; font-weight: 800; }
.step-nav { display: flex; flex-wrap: wrap; gap: 12px; justify-content: space-between; align-items: center; margin-top: 22px; }

/* ---- 第三站:挖空 ---- */
.lesson-card {
  background: rgba(255, 184, 77, 0.07);
  border: 1px solid rgba(255, 184, 77, 0.28);
  border-radius: 14px; padding: 18px 20px; margin-bottom: 16px;
}
.lesson-tag { font-size: 12px; font-weight: 800; color: var(--amber); margin-bottom: 8px; }
.lesson-body { font-size: 14px; line-height: 1.9; }

.blank-q { font-size: 14.5px; font-weight: 700; margin: 18px 0 12px; }
.options { display: flex; flex-wrap: wrap; gap: 10px; }
.opt {
  font-family: var(--mono); font-size: 13.5px; font-weight: 600; color: var(--text-1);
  background: rgba(255, 255, 255, 0.06); border: 1px solid var(--glass-line);
  border-radius: 12px; padding: 10px 18px; cursor: pointer;
  transition: transform 0.15s cubic-bezier(0.3, 1.5, 0.5, 1), background 0.15s, border-color 0.15s;
}
.opt:hover { transform: translateY(-2px); background: rgba(255, 255, 255, 0.1); }
.opt.right { background: rgba(77, 223, 174, 0.16); border-color: var(--mint); color: var(--mint); }
.opt.wrong { background: rgba(255, 95, 87, 0.13); border-color: rgba(255, 95, 87, 0.55); animation: shake 0.35s; }
@keyframes shake { 25% { transform: translateX(-5px); } 75% { transform: translateX(5px); } }

.feedback {
  margin-top: 14px; font-size: 13.5px; line-height: 1.85;
  border-radius: 12px; padding: 13px 16px; display: none;
}
.feedback.bad { display: block; background: rgba(255, 95, 87, 0.09); border: 1px solid rgba(255, 95, 87, 0.3); }
.feedback.good { display: block; background: rgba(77, 223, 174, 0.09); border: 1px solid rgba(77, 223, 174, 0.3); }

.blank-token {
  display: inline-block; min-width: 68px; text-align: center;
  border-bottom: 2px solid var(--accent-b); color: var(--accent-b);
  font-weight: 700; animation: pulse 1.6s ease-in-out infinite;
}
@keyframes pulse { 50% { opacity: 0.45; } }
.blank-done { color: var(--mint); font-weight: 700; }
.blank-future { color: rgba(255, 255, 255, 0.3); }

.reveal-btn { margin-top: 12px; }

/* ---- 第四站:清单 ---- */
.check-list { display: flex; flex-direction: column; gap: 12px; margin: 20px 0; }
.check-item {
  display: flex; gap: 14px; align-items: flex-start;
  background: var(--glass); border: 1px solid var(--glass-line);
  border-radius: 14px; padding: 16px 18px;
}
.check-num {
  width: 26px; height: 26px; flex: none; border-radius: 50%;
  display: grid; place-items: center; font-size: 13px; font-weight: 800;
  background: var(--grad); color: #fff;
}
.check-body { font-size: 14px; line-height: 1.85; }
.check-body b { color: #fff; }
kbd {
  font-family: var(--mono); font-size: 12px;
  background: rgba(255, 255, 255, 0.1); border: 1px solid rgba(255, 255, 255, 0.2);
  border-bottom-width: 2px; border-radius: 6px; padding: 1px 7px;
}
.copy-row { display: flex; flex-wrap: wrap; gap: 12px; justify-content: space-between; align-items: center; margin: 22px 0 10px; }
.challenge {
  background: rgba(140, 92, 246, 0.08); border: 1px solid rgba(140, 92, 246, 0.3);
  border-radius: 14px; padding: 18px 20px; margin-top: 22px;
  font-size: 14px; line-height: 1.9;
}
.challenge a {
  color: var(--mint); text-decoration: none;
  border-bottom: 1px solid rgba(77, 223, 174, 0.45); transition: 0.15s;
}
.challenge a:hover { color: #8ff0cd; border-bottom-color: #8ff0cd; }

/* ---- 彩带 ---- */
#confetti { position: fixed; inset: 0; z-index: 60; pointer-events: none; }

/* ---- 完成横幅 ---- */
.done-banner {
  text-align: center; padding: 36px 20px;
}
.done-banner .big { font-size: 44px; }
.done-banner h2 { font-size: 24px; font-weight: 800; margin: 12px 0 8px; }
.done-banner p { color: var(--text-2); font-size: 14px; line-height: 1.8; }

.toast {
  position: fixed; bottom: 28px; left: 50%; transform: translateX(-50%) translateY(80px);
  z-index: 70; background: rgba(22, 17, 40, 0.95); border: 1px solid rgba(255, 255, 255, 0.16);
  color: var(--text-1); font-size: 13.5px; font-weight: 600;
  padding: 12px 22px; border-radius: 999px; backdrop-filter: blur(16px);
  transition: transform 0.35s cubic-bezier(0.3, 1.4, 0.5, 1);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.4);
}
.toast.show { transform: translateX(-50%) translateY(0); }