/* ============================================================
   小学生个人学习系统 - 样式
   风格：清新、简洁、温暖，蓝绿色系
   ============================================================ */

:root {
  --c-bg: #f4f8f9;
  --c-surface: #ffffff;
  --c-surface-2: #f0f6f7;
  --c-primary: #2fb4a6;      /* 主色：清新绿松石 */
  --c-primary-dark: #1f9488;
  --c-primary-soft: #d8f0ed;
  --c-accent: #4a9ad4;       /* 辅助：柔和蓝 */
  --c-accent-soft: #dcecf8;
  --c-warm: #f4a261;         /* 温暖点缀：橙 */
  --c-warm-soft: #fdebd8;
  --c-danger: #e76f6f;
  --c-text: #2c3e46;
  --c-text-soft: #6b7c85;
  --c-text-mute: #9aa8ae;
  --c-border: #e4edef;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 4px 18px rgba(47, 180, 166, 0.10);
  --shadow-hover: 0 8px 26px rgba(47, 180, 166, 0.18);
  --sidebar-w: 232px;
  --font: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, -apple-system, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; }
body {
  font-family: var(--font);
  background: var(--c-bg);
  color: var(--c-text);
  font-size: 15px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }
img { max-width: 100%; }

#app { display: flex; min-height: 100vh; }

/* ---------------- 侧边栏 ---------------- */
.sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  background: var(--c-surface);
  border-right: 1px solid var(--c-border);
  display: flex;
  flex-direction: column;
  padding: 20px 14px;
  position: sticky;
  top: 0;
  height: 100vh;
}
.brand { display: flex; align-items: center; gap: 10px; padding: 6px 8px 20px; }
.brand-logo { font-size: 30px; }
.brand-text strong { display: block; font-size: 16px; }
.brand-text small { color: var(--c-text-mute); font-size: 12px; }

.nav { display: flex; flex-direction: column; gap: 4px; flex: 1; }
.nav-item {
  display: flex; align-items: center; gap: 12px;
  padding: 11px 14px; border-radius: var(--radius-sm);
  color: var(--c-text-soft); font-weight: 500;
  transition: background .18s, color .18s, transform .1s;
}
.nav-item .ico { font-size: 18px; width: 22px; text-align: center; }
.nav-item:hover { background: var(--c-surface-2); color: var(--c-text); }
.nav-item.active { background: var(--c-primary-soft); color: var(--c-primary-dark); font-weight: 600; }
.sidebar-foot { padding: 10px 8px 0; }
.mini-stat {
  background: var(--c-warm-soft); color: #b9701f;
  border-radius: 999px; padding: 8px 14px; font-size: 12.5px;
  text-align: center; font-weight: 600;
}

/* ---------------- 主区域 ---------------- */
.main { flex: 1; display: flex; flex-direction: column; min-width: 0; }
.topbar {
  display: flex; align-items: center; gap: 14px;
  padding: 16px 26px; background: var(--c-surface);
  border-bottom: 1px solid var(--c-border); position: sticky; top: 0; z-index: 20;
}
.topbar h1 { font-size: 19px; font-weight: 700; }
.topbar-right { margin-left: auto; }
.date-chip {
  background: var(--c-accent-soft); color: var(--c-accent);
  padding: 6px 14px; border-radius: 999px; font-size: 13px; font-weight: 600;
}
.menu-btn { display: none; font-size: 22px; color: var(--c-text); }

.content { padding: 24px 26px 48px; max-width: 1100px; width: 100%; }

/* ---------------- 通用组件 ---------------- */
.card {
  background: var(--c-surface); border-radius: var(--radius);
  box-shadow: var(--shadow); padding: 20px; border: 1px solid var(--c-border);
}
.grid { display: grid; gap: 18px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-auto { grid-template-columns: repeat(auto-fill, minmax(210px, 1fr)); }

.section-title { font-size: 16px; font-weight: 700; margin: 26px 0 14px; display: flex; align-items: center; gap: 8px; }
.section-title:first-child { margin-top: 0; }

.btn {
  display: inline-flex; align-items: center; gap: 7px; justify-content: center;
  background: var(--c-primary); color: #fff; padding: 10px 18px;
  border-radius: var(--radius-sm); font-weight: 600; font-size: 14px;
  transition: background .18s, transform .1s, box-shadow .18s;
}
.btn:hover { background: var(--c-primary-dark); box-shadow: var(--shadow); }
.btn:active { transform: translateY(1px); }
.btn:disabled { background: var(--c-text-mute); cursor: not-allowed; box-shadow: none; }
.btn-ghost { background: var(--c-surface-2); color: var(--c-text); }
.btn-ghost:hover { background: var(--c-primary-soft); color: var(--c-primary-dark); }
.btn-accent { background: var(--c-accent); }
.btn-accent:hover { background: #3a83bb; }
.btn-warm { background: var(--c-warm); }
.btn-warm:hover { background: #e08c47; }
.btn-danger { background: var(--c-danger); }
.btn-danger:hover { background: #d45555; }
.btn-sm { padding: 6px 12px; font-size: 13px; }
.btn-block { width: 100%; }

.input, .select, .textarea {
  width: 100%; padding: 10px 14px; border: 1.5px solid var(--c-border);
  border-radius: var(--radius-sm); font-family: inherit; font-size: 14px;
  color: var(--c-text); background: var(--c-surface); transition: border-color .18s;
}
.input:focus, .select:focus, .textarea:focus { outline: none; border-color: var(--c-primary); }
.textarea { resize: vertical; min-height: 120px; }
.field { margin-bottom: 16px; }
.field label { display: block; font-weight: 600; font-size: 13.5px; margin-bottom: 7px; color: var(--c-text-soft); }
.field .hint { color: var(--c-text-mute); font-size: 12px; margin-top: 5px; }

.badge {
  display: inline-block; padding: 3px 10px; border-radius: 999px;
  font-size: 12px; font-weight: 600; background: var(--c-surface-2); color: var(--c-text-soft);
}
.badge-ok { background: var(--c-primary-soft); color: var(--c-primary-dark); }
.badge-warm { background: var(--c-warm-soft); color: #b9701f; }
.badge-accent { background: var(--c-accent-soft); color: var(--c-accent); }

.empty {
  text-align: center; color: var(--c-text-mute); padding: 48px 20px;
}
.empty .emoji { font-size: 46px; display: block; margin-bottom: 12px; }

.row { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.row-between { justify-content: space-between; }
.spacer { flex: 1; }
.muted { color: var(--c-text-mute); }
.text-soft { color: var(--c-text-soft); }

/* ---------------- 仪表盘 ---------------- */
.hero {
  background: linear-gradient(120deg, var(--c-primary) 0%, var(--c-accent) 100%);
  color: #fff; border-radius: var(--radius); padding: 26px 28px; box-shadow: var(--shadow);
  display: flex; align-items: center; justify-content: space-between; gap: 20px; flex-wrap: wrap;
}
.hero h2 { font-size: 22px; margin-bottom: 6px; }
.hero p { opacity: .92; font-size: 14px; }
.hero .hero-cta { display: flex; gap: 10px; flex-wrap: wrap; }
.hero .btn-ghost { background: rgba(255,255,255,.22); color: #fff; }
.hero .btn-ghost:hover { background: rgba(255,255,255,.34); color: #fff; }

.stat-card { text-align: center; }
.stat-card .num { font-size: 30px; font-weight: 800; color: var(--c-primary-dark); line-height: 1.1; }
.stat-card .label { color: var(--c-text-soft); font-size: 13px; margin-top: 4px; }
.stat-card .ico-top { font-size: 26px; margin-bottom: 6px; }

.progress-bar { height: 12px; background: var(--c-surface-2); border-radius: 999px; overflow: hidden; }
.progress-bar > span { display: block; height: 100%; background: linear-gradient(90deg, var(--c-primary), var(--c-accent)); border-radius: 999px; transition: width .5s; }

.quick-links { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.quick-link {
  background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius);
  padding: 20px; text-align: center; transition: transform .12s, box-shadow .18s, border-color .18s;
}
.quick-link:hover { transform: translateY(-3px); box-shadow: var(--shadow-hover); border-color: var(--c-primary-soft); }
.quick-link .qico { font-size: 32px; display: block; margin-bottom: 8px; }
.quick-link strong { display: block; font-size: 15px; }
.quick-link small { color: var(--c-text-mute); }

/* ---------------- 单词卡片 ---------------- */
.word-deck { display: flex; flex-direction: column; align-items: center; gap: 18px; }
.flashcard {
  width: 100%; max-width: 460px; min-height: 240px; perspective: 1200px; cursor: pointer;
}
.flashcard-inner { position: relative; width: 100%; height: 240px; transition: transform .5s; transform-style: preserve-3d; }
.flashcard.flipped .flashcard-inner { transform: rotateY(180deg); }
.flashcard-face {
  position: absolute; inset: 0; backface-visibility: hidden; border-radius: var(--radius);
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  padding: 24px; box-shadow: var(--shadow); text-align: center;
}
.flashcard-front { background: linear-gradient(135deg, #fff, var(--c-primary-soft)); }
.flashcard-back { background: linear-gradient(135deg, #fff, var(--c-accent-soft)); transform: rotateY(180deg); }
.flashcard .word-text { font-size: 40px; font-weight: 800; color: var(--c-primary-dark); }
.flashcard .phonetic { color: var(--c-text-soft); margin-top: 8px; font-size: 16px; }
.flashcard .meaning { font-size: 26px; font-weight: 700; color: var(--c-accent); }
.flashcard .flip-hint { position: absolute; bottom: 12px; font-size: 12px; color: var(--c-text-mute); }
.deck-progress { color: var(--c-text-soft); font-weight: 600; }
.deck-nav { display: flex; gap: 12px; align-items: center; }

.word-list-item {
  display: flex; align-items: center; gap: 14px; padding: 12px 14px;
  border-radius: var(--radius-sm); background: var(--c-surface-2); margin-bottom: 8px;
}
.word-list-item .w { font-weight: 700; font-size: 16px; min-width: 120px; }
.word-list-item .p { color: var(--c-text-mute); font-size: 13px; min-width: 110px; }
.word-list-item .m { color: var(--c-accent); font-weight: 600; }
.word-list-item .chk { margin-left: auto; }

/* 测试题选项 */
.opt-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; max-width: 460px; margin: 0 auto; }
.opt-btn {
  padding: 16px 14px; border-radius: var(--radius-sm); border: 2px solid var(--c-border);
  background: var(--c-surface); font-size: 16px; font-weight: 600; color: var(--c-text);
  transition: border-color .15s, background .15s, transform .1s;
}
.opt-btn:hover { border-color: var(--c-primary); background: var(--c-primary-soft); }
.opt-btn:active { transform: translateY(1px); }
.opt-btn.correct { border-color: var(--c-primary); background: var(--c-primary-soft); color: var(--c-primary-dark); }
.opt-btn.wrong { border-color: var(--c-danger); background: #fbe6e6; color: var(--c-danger); }
@media (max-width: 520px) { .opt-grid { grid-template-columns: 1fr; } }

/* ---------------- 资料 ---------------- */
.material-card { display: flex; flex-direction: column; gap: 10px; }
.material-thumb {
  height: 130px; border-radius: var(--radius-sm); background: var(--c-surface-2);
  display: flex; align-items: center; justify-content: center; overflow: hidden; font-size: 46px;
}
.material-thumb img { width: 100%; height: 100%; object-fit: cover; }
.material-card h4 { font-size: 15px; }
.material-meta { display: flex; gap: 8px; align-items: center; font-size: 12px; color: var(--c-text-mute); flex-wrap: wrap; }
.material-actions { display: flex; gap: 8px; margin-top: auto; }

.dropzone {
  border: 2px dashed var(--c-primary-soft); border-radius: var(--radius);
  padding: 30px; text-align: center; color: var(--c-text-soft); background: var(--c-surface-2);
  transition: border-color .18s, background .18s; cursor: pointer;
}
.dropzone.drag { border-color: var(--c-primary); background: var(--c-primary-soft); }
.dropzone .dz-ico { font-size: 40px; display: block; margin-bottom: 8px; }
.upload-bar { height: 8px; background: var(--c-surface-2); border-radius: 999px; overflow: hidden; margin-top: 10px; }
.upload-bar > span { display: block; height: 100%; background: var(--c-primary); width: 0; transition: width .2s; }

/* ---------------- 日记 ---------------- */
.diary-item {
  border-left: 4px solid var(--c-primary); padding: 14px 18px; margin-bottom: 14px;
  background: var(--c-surface); border-radius: var(--radius-sm); box-shadow: var(--shadow);
  border: 1px solid var(--c-border); border-left: 4px solid var(--c-primary);
}
.diary-item h4 { font-size: 16px; margin-bottom: 4px; }
.diary-item .di-date { color: var(--c-text-mute); font-size: 12.5px; margin-bottom: 8px; }
.diary-item .di-body { color: var(--c-text-soft); font-size: 14px; max-height: 96px; overflow: hidden; position: relative; }
.diary-item .di-body img { max-height: 120px; border-radius: 8px; }
.diary-actions { display: flex; gap: 8px; margin-top: 12px; }

.rte-toolbar { display: flex; gap: 4px; flex-wrap: wrap; padding: 8px; background: var(--c-surface-2); border-radius: var(--radius-sm) var(--radius-sm) 0 0; border: 1.5px solid var(--c-border); border-bottom: none; }
.rte-toolbar button { padding: 6px 11px; border-radius: 6px; font-weight: 700; color: var(--c-text-soft); font-size: 14px; }
.rte-toolbar button:hover { background: var(--c-primary-soft); color: var(--c-primary-dark); }
.rte {
  min-height: 220px; padding: 14px; border: 1.5px solid var(--c-border); border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  background: #fff; font-size: 15px; line-height: 1.7; overflow-y: auto;
}
.rte:focus { outline: none; border-color: var(--c-primary); }
.rte img { border-radius: 8px; margin: 6px 0; }

/* ---------------- 日历 ---------------- */
.calendar { }
.cal-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 14px; }
.cal-head h3 { font-size: 16px; }
.cal-grid { display: grid; grid-template-columns: repeat(7, 1fr); gap: 6px; }
.cal-cell {
  aspect-ratio: 1; display: flex; align-items: center; justify-content: center;
  border-radius: 10px; font-size: 13px; color: var(--c-text-soft); background: var(--c-surface-2);
  position: relative;
}
.cal-cell.dow { background: none; color: var(--c-text-mute); font-weight: 600; aspect-ratio: auto; }
.cal-cell.empty { background: none; }
.cal-cell.done { background: var(--c-primary); color: #fff; font-weight: 700; }
.cal-cell.today { box-shadow: 0 0 0 2px var(--c-warm); }
.cal-cell.miss { background: var(--c-warm-soft); }

/* ---------------- 弹窗 & 提示 ---------------- */
.modal-backdrop {
  position: fixed; inset: 0; background: rgba(30,50,55,.42); backdrop-filter: blur(2px);
  display: flex; align-items: center; justify-content: center; z-index: 100; padding: 20px;
}
.modal-backdrop[hidden] { display: none; }
.modal {
  background: var(--c-surface); border-radius: var(--radius); box-shadow: 0 20px 60px rgba(0,0,0,.25);
  width: 100%; max-width: 560px; max-height: 88vh; overflow-y: auto; padding: 24px;
  animation: pop .2s ease;
}
@keyframes pop { from { transform: scale(.94); opacity: 0; } to { transform: scale(1); opacity: 1; } }
.modal h3 { margin-bottom: 16px; font-size: 18px; }
.modal-actions { display: flex; gap: 10px; justify-content: flex-end; margin-top: 20px; }

.toast-wrap { position: fixed; bottom: 24px; left: 50%; transform: translateX(-50%); z-index: 200; display: flex; flex-direction: column; gap: 8px; align-items: center; }
.toast {
  background: var(--c-text); color: #fff; padding: 11px 20px; border-radius: 999px;
  font-size: 14px; box-shadow: 0 6px 20px rgba(0,0,0,.2); animation: toastIn .25s ease;
}
.toast.ok { background: var(--c-primary-dark); }
.toast.warn { background: var(--c-warm); }
.toast.err { background: var(--c-danger); }
@keyframes toastIn { from { transform: translateY(12px); opacity: 0; } to { transform: translateY(0); opacity: 1; } }

.notif-banner {
  position: fixed; top: 16px; right: 16px; z-index: 150; max-width: 320px;
  background: var(--c-surface); border-radius: var(--radius); box-shadow: var(--shadow-hover);
  padding: 16px 18px; border-left: 4px solid var(--c-warm); animation: toastIn .3s ease;
}
.notif-banner strong { display: block; margin-bottom: 4px; }
.notif-banner .nb-close { position: absolute; top: 8px; right: 10px; color: var(--c-text-mute); font-size: 18px; }

/* ---------------- 响应式 ---------------- */
.bottom-nav { display: none; }

@media (max-width: 860px) {
  .sidebar {
    position: fixed; z-index: 60; left: 0; top: 0; transform: translateX(-100%);
    transition: transform .25s; box-shadow: 6px 0 24px rgba(0,0,0,.12);
  }
  .sidebar.open { transform: translateX(0); }
  .menu-btn { display: block; }
  .content { padding: 18px 16px 90px; }
  .grid-3, .quick-links { grid-template-columns: 1fr 1fr; }
  .bottom-nav {
    display: flex; position: fixed; bottom: 0; left: 0; right: 0; background: var(--c-surface);
    border-top: 1px solid var(--c-border); z-index: 50; padding: 6px 4px calc(6px + env(safe-area-inset-bottom));
  }
  .bn-item {
    flex: 1; display: flex; flex-direction: column; align-items: center; gap: 2px;
    padding: 6px 0; font-size: 11px; color: var(--c-text-mute);
  }
  .bn-item .ico { font-size: 20px; }
  .bn-item.active { color: var(--c-primary-dark); font-weight: 600; }
  .sidebar-backdrop { position: fixed; inset: 0; background: rgba(0,0,0,.3); z-index: 55; }
}
@media (max-width: 520px) {
  .grid-3, .grid-2, .quick-links { grid-template-columns: 1fr; }
  .hero { flex-direction: column; align-items: flex-start; }
  .topbar { padding: 14px 16px; }
  .flashcard .word-text { font-size: 32px; }
}