/* ============================================================
 * study-v2.css —— 全新课程模块（多邻国风格）
 * 设计语言：大圆角立体卡、明快分级色、粗进度条、白色空间
 * ============================================================ */

/* ---------- 宿主容器 ---------- */
#study-root { padding: 4px 2px calc(40px + env(safe-area-inset-bottom)); min-height: 100%; }
#study-root * { box-sizing: border-box; }

/* ---------- 头部问候 ---------- */
.sv-hero { margin: 6px 2px 14px; }
.sv-hero h2 { margin: 0; font-size: 22px; color: #3f3730; }
.sv-hero p { margin: 4px 0 0; font-size: 13px; color: #8a8073; }

/* ---------- 进度摘要 ---------- */
.sv-stats { display: flex; gap: 8px; margin: 0 2px 16px; }
.sv-stat {
  flex: 1; background: #fff; border-radius: 16px; padding: 12px 10px; text-align: center;
  border: 1px solid rgba(107,87,64,.08); box-shadow: 0 2px 8px rgba(78,60,48,.05);
}
.sv-stat b { display: block; font-size: 18px; color: #6f6cc0; }
.sv-stat span { font-size: 11px; color: #a49a8c; }

/* ---------- 级别选择（主界面） ---------- */
.sv-levels { display: flex; flex-direction: column; gap: 14px; margin: 4px 2px 0; }
.sv-level {
  display: block; width: 100%; text-align: left; border: 0 !important; padding: 0 !important;
  background: transparent !important; cursor: pointer;
}
.sv-level-card {
  border-radius: 20px; padding: 18px 18px 20px; color: #fff; position: relative; overflow: hidden;
  box-shadow: 0 5px 0 rgba(0,0,0,.18), 0 10px 24px rgba(0,0,0,.10);
}
.sv-lv-N5  { background: linear-gradient(135deg, #58cc8f 0%, #3fa96f 100%); box-shadow: 0 5px 0 #2c8a56, 0 10px 24px rgba(58,160,110,.25); }
.sv-lv-N4  { background: linear-gradient(135deg, #ffc53d 0%, #f0a428 100%); box-shadow: 0 5px 0 #cf8815, 0 10px 24px rgba(240,164,40,.25); }
.sv-lv-N3  { background: linear-gradient(135deg, #a78bfa 0%, #7c6ce0 100%); box-shadow: 0 5px 0 #5d4ec4, 0 10px 24px rgba(124,108,224,.28); }
.sv-lv-badge {
  display: inline-block; background: rgba(255,255,255,.28); border-radius: 999px;
  padding: 3px 12px; font-size: 13px; letter-spacing: .04em;
}
.sv-lv-name { display: block; font-size: 24px; margin-top: 10px; }
.sv-lv-sub { display: block; font-size: 12.5px; opacity: .92; margin-top: 3px; }
.sv-lv-meta { display: block; font-size: 11.5px; opacity: .85; margin-top: 10px; }
.sv-lv-bar { height: 10px; border-radius: 999px; background: rgba(0,0,0,.16); margin-top: 10px; overflow: hidden; }
.sv-lv-bar i { display: block; height: 100%; border-radius: 999px; background: #fff; }

/* ---------- 级别内部：单元列表 ---------- */
.sv-back {
  display: flex !important; align-items: center !important; gap: 6px; min-height: 40px;
  background: transparent !important; border: 0 !important; color: #6f6cc0 !important;
  font-size: 14px; padding: 0 2px !important; margin-bottom: 6px;
}
.sv-section-title { font-size: 17px; color: #3f3730; margin: 14px 2px 10px; }
.sv-unit {
  display: flex !important; align-items: center !important; gap: 12px; width: 100%;
  text-align: left; min-height: 76px; border-radius: 18px; border: 1px solid rgba(107,87,64,.10) !important;
  background: #fff !important; padding: 12px 14px !important; margin-bottom: 10px;
  box-shadow: 0 2px 0 rgba(107,87,64,.08);
}
.sv-unit-ico {
  width: 46px; height: 46px; border-radius: 14px; flex: none;
  display: flex; align-items: center; justify-content: center; font-size: 22px; color: #fff;
}
.sv-ico-word { background: linear-gradient(135deg, #58cc8f, #3fa96f); }
.sv-ico-gram { background: linear-gradient(135deg, #a78bfa, #7c6ce0); }
.sv-unit-main { flex: 1; min-width: 0; }
.sv-unit-name { font-size: 15.5px; color: #3f3730; }
.sv-unit-desc { font-size: 12px; color: #a49a8c; margin-top: 3px; }
.sv-unit-arrow { color: #c9c0b4; font-size: 18px; }

/* ---------- 学习卡片（单词 / 语法逐个学） ---------- */
.sv-stage { display: flex; flex-direction: column; gap: 14px; margin-top: 8px; }
.sv-prog { height: 12px; border-radius: 999px; background: #e8e3da; overflow: hidden; }
.sv-prog i { display: block; height: 100%; border-radius: 999px; background: linear-gradient(90deg,#58cc8f,#3fa96f); transition: width .25s ease; }
.sv-card {
  background: #fff; border-radius: 24px; padding: 26px 20px; text-align: center;
  border: 1px solid rgba(107,87,64,.08); box-shadow: 0 2px 0 rgba(107,87,64,.10), 0 8px 20px rgba(78,60,48,.06);
  min-height: 300px; display: flex; flex-direction: column; align-items: center; justify-content: center;
}
.sv-card .sv-pos {
  display: inline-block; font-size: 11px; color: #58a07e; background: rgba(88,204,143,.14);
  border-radius: 999px; padding: 3px 12px; margin-bottom: 14px;
}
.sv-card .sv-word { font-size: 32px; color: #3f3730; line-height: 1.3; }
.sv-card .sv-kana { font-size: 17px; color: #8a8073; margin-top: 8px; }
.sv-card .sv-zh { font-size: 17px; color: #5b5048; margin-top: 16px; }
.sv-card .sv-en { font-size: 13px; color: #a49a8c; margin-top: 5px; }
.sv-card .sv-ex {
  margin-top: 22px; padding: 12px 14px; border-radius: 14px; background: #faf7f2;
  font-size: 14.5px; color: #5b5048; line-height: 1.7; text-align: center; width: 100%;
}
.sv-card .sv-ex b { color: #6f6cc0; }

.sv-audio {
  display: flex !important; align-items: center !important; justify-content: center !important;
  gap: 8px; min-height: 48px; padding: 0 22px !important; margin: 18px auto 0;
  border-radius: 999px !important; border: 2px solid #58cc8f !important; background: #fff !important;
  color: #3fa96f !important; font-size: 15px;
}

.sv-nav { display: flex; gap: 10px; }
.sv-nav button {
  flex: 1; display: flex !important; align-items: center !important; justify-content: center !important;
  min-height: 56px; border-radius: 16px; font-size: 15.5px;
}
.sv-btn-ghost { border: 2px solid rgba(107,87,64,.16) !important; background: #fff !important; color: #8a8073 !important; }
.sv-btn-main {
  border: 0 !important; color: #fff !important; background: #58cc8f !important;
  box-shadow: 0 4px 0 #3fa96f;
}

.sv-done { text-align: center; padding: 30px 10px; }
.sv-done .sv-trophy { font-size: 64px; }
.sv-done h3 { font-size: 22px; color: #3f3730; margin: 10px 0 6px; }
.sv-done p { font-size: 13.5px; color: #8a8073; margin-bottom: 18px; }

/* ---------- 语法卡 ---------- */
.sv-gram-title { font-size: 21px; color: #6f6cc0; line-height: 1.4; margin-bottom: 4px; }
.sv-gram-usage { font-size: 13.5px; color: #5b5048; margin-top: 6px; }
.sv-gram-form {
  margin-top: 12px; font-size: 13px; color: #fff; background: #a78bfa;
  border-radius: 999px; padding: 5px 16px; display: inline-block;
}
.sv-gram-explain { margin-top: 16px; font-size: 14px; color: #5b5048; line-height: 1.75; text-align: left; width: 100%; }
.sv-gram-explain-en { font-size: 13px; color: #a49a8c; line-height: 1.65; margin-top: 8px; text-align: left; width: 100%; padding-left: 10px; border-left: 3px solid #e4dcf8; }
.sv-gram-examples { width: 100%; margin-top: 14px; text-align: left; }
.sv-gram-examples .sv-ex { margin-top: 8px; }

.sv-tag { display: inline-block; font-size: 11px; color: #7c6ce0; background: rgba(167,139,250,.15); border-radius: 999px; padding: 2px 10px; }

/* ---------- 空态 ---------- */
.sv-empty { text-align: center; padding: 40px 16px; color: #a49a8c; font-size: 14px; }

/* ---------- 深色适配 ---------- */
@media (prefers-color-scheme: dark) {
  .sv-stat, .sv-unit, .sv-card { background: #2a2622; border-color: rgba(255,255,255,.06); }
  .sv-hero h2, .sv-section-title, .sv-unit-name, .sv-card .sv-word, .sv-done h3 { color: #ece7df; }
  .sv-hero p, .sv-stat span, .sv-unit-desc, .sv-card .sv-kana, .sv-card .sv-en, .sv-done p, .sv-card .sv-zh, .sv-gram-usage, .sv-gram-explain, .sv-card .sv-ex { color: #b8ae9f; }
  .sv-card .sv-ex { background: #322d28; }
  .sv-gram-explain-en { border-left-color: #4a4070; }
  .sv-btn-ghost { background: #2a2622 !important; color: #b8ae9f !important; border-color: rgba(255,255,255,.14) !important; }
  .sv-audio { background: #2a2622 !important; }
}