/*
 * Schola — 设计系统 CSS 变量
 * 品牌色：Clean White + Teal + Neutral Gray
 * 字体：Segoe UI / Avenir Next / Helvetica Neue（全站统一系统字体栈）
 * 深色模式通过 [data-theme="dark"] 切换
 */

/* ============================================================
   Google Fonts 在 base.html 中通过 <link> 引入
   ============================================================ */

/* ============================================================
   浅色模式（默认）
   ============================================================ */
:root {
  /* --- 背景层次 --- */
  --color-bg:           #FFFFFF;   /* 页面底色，纯白 */
  --color-surface:      #FAFAFA;   /* 卡片/内容块 */
  --color-surface-alt:  #F5F5F5;   /* 次级表面，输入框背景 */

  /* --- 文字层次 --- */
  --color-text-primary:   #111111; /* 主文字，近纯黑 */
  --color-text-secondary: #555555; /* 说明文字、标签 */
  --color-text-muted:     #999999; /* 提示文字、占位符 */

  /* --- 品牌色 --- */
  --color-brand:          #16a37f; /* 主品牌色，活泼青绿 */
  --color-brand-hover:    #128a6a; /* 按钮 hover */
  --color-brand-light:    #f0faf6; /* 标签底色、浅色高亮块 */
  --color-brand-mid:      #b2e8d4; /* 边框高亮、标签 */
  --color-accent:         #52c9a0; /* 装饰性元素 */

  /* --- 边框与分隔线 --- */
  --color-border:         #e5e5e5; /* 卡片边框 */
  --color-divider:        #f0f0f0; /* 信息块分隔线 */

  /* --- 状态色 --- */
  --color-error:          #C0392B;
  --color-warning:        #D68910;
  --color-success:        #1E8449;
  --color-info:           #1A6B8A;

  /* --- 公告横幅 --- */
  --color-announce-info:    #EBF5FB;
  --color-announce-warning: #FEF9E7;
  --color-announce-urgent:  #FDEDEC;

  /* --- 字体 --- */
  --font-display: 'Segoe UI', 'Avenir Next', 'Helvetica Neue', Arial, sans-serif;
  --font-body:    'Segoe UI', 'Avenir Next', 'Helvetica Neue', Arial, sans-serif;

  /* --- 字号（clamp 响应式）--- */
  --text-hero:    clamp(1.8rem, 0.8rem + 2.8vw, 3.2rem);
  --text-h1:      clamp(2rem, 1.2rem + 2.5vw, 3.5rem);
  --text-h2:      clamp(1.5rem, 1rem + 1.5vw, 2.25rem);
  --text-h3:      clamp(1.125rem, 1rem + 0.75vw, 1.5rem);
  --text-body:    clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --text-sm:      clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
  --text-xs:      clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);

  /* --- 间距 --- */
  --section-gap:  clamp(3rem, 8vw, 6rem);
  --content-gap:  clamp(1.5rem, 4vw, 3rem);

  /* --- 内容宽度 --- */
  --width-narrow:  640px;
  --width-default: 960px;
  --width-wide:    1200px;

  /* --- 圆角 --- */
  --radius-pill:   9999px;
  --radius-card:   0.75rem;
  --radius-input:  0.5rem;
  --radius-lg:     1rem;

  /* --- 阴影（带颜色倾向，非纯黑）--- */
  --shadow-sm:  0 1px 3px rgba(15, 107, 104, 0.06), 0 1px 2px rgba(31, 42, 40, 0.04);
  --shadow-md:  0 4px 12px rgba(15, 107, 104, 0.08), 0 2px 4px rgba(31, 42, 40, 0.06);
  --shadow-lg:  0 8px 32px rgba(15, 107, 104, 0.10), 0 4px 8px rgba(31, 42, 40, 0.08);

  /* --- 动效 --- */
  --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
  --transition-btn: 180ms var(--ease-out-expo);
  --transition-theme: background-color 300ms ease, color 300ms ease, border-color 300ms ease;
}

/* ============================================================
   深色模式
   ============================================================ */
[data-theme="dark"] {
  --color-bg:           #0f0f0f;
  --color-surface:      #1a1a1a;
  --color-surface-alt:  #222222;

  --color-text-primary:   #eeeeee;
  --color-text-secondary: #aaaaaa;
  --color-text-muted:     #666666;

  --color-brand:          #1fcc9f;
  --color-brand-hover:    #27e0b0;
  --color-brand-light:    #0d2620;
  --color-brand-mid:      #1a4035;
  --color-accent:         #3db88a;

  --color-border:         #2a2a2a;
  --color-divider:        #1f1f1f;

  --color-announce-info:    #0D2233;
  --color-announce-warning: #2C2005;
  --color-announce-urgent:  #2C0A08;

  --shadow-sm:  0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md:  0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg:  0 8px 32px rgba(0, 0, 0, 0.5);
}

/* ============================================================
   全局基础样式
   ============================================================ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%; /* 防止 iOS 自动缩放 */
}

body {
  font-family: var(--font-body);
  font-size: var(--text-body);
  color: var(--color-text-primary);
  background-color: var(--color-bg);
  line-height: 1.65;
  transition: var(--transition-theme);
  -webkit-font-smoothing: antialiased;
}

/* --- 标题字体 --- */
h1, h2, .font-display {
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.15;
}

h3, h4, h5, h6 {
  font-family: var(--font-body);
  line-height: 1.3;
  font-weight: 600;
}

/* --- 链接 --- */
a {
  color: var(--color-brand);
  text-decoration: none;
  transition: color var(--transition-btn);
}
a:hover { color: var(--color-brand-hover); }
a:focus-visible {
  outline: 2px solid var(--color-brand);
  outline-offset: 2px;
  border-radius: 2px;
}

/* --- 图片 --- */
img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* ============================================================
   布局工具类
   ============================================================ */
.container {
  width: 100%;
  max-width: var(--width-wide);
  margin-inline: auto;
  padding-inline: clamp(1rem, 4vw, 2rem);
}
.container--default { max-width: var(--width-default); }
.container--narrow  { max-width: var(--width-narrow); }

/* ============================================================
   按钮
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.625rem 1.25rem;
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 500;
  border-radius: var(--radius-pill);
  border: 1.5px solid transparent;
  cursor: pointer;
  white-space: nowrap;
  transition: all var(--transition-btn);
  min-height: 44px; /* 触摸友好 */
  text-decoration: none;
}
.btn:focus-visible {
  outline: 2px solid var(--color-brand);
  outline-offset: 2px;
}

/* 主按钮 */
.btn-primary {
  background-color: var(--color-brand);
  color: #FFFFFF;
  border-color: var(--color-brand);
}
.btn-primary:hover {
  background-color: var(--color-brand-hover);
  border-color: var(--color-brand-hover);
  color: #FFFFFF;
}

/* 次级按钮（边框） */
.btn-secondary {
  background-color: transparent;
  color: var(--color-text-primary);
  border-color: var(--color-border);
}
.btn-secondary:hover {
  border-color: var(--color-brand);
  color: var(--color-brand);
  background-color: var(--color-brand-light);
}

/* 幽灵按钮 */
.btn-ghost {
  background-color: transparent;
  color: var(--color-text-secondary);
  border-color: transparent;
}
.btn-ghost:hover {
  background-color: var(--color-brand-light);
  color: var(--color-brand);
}

/* 危险按钮 */
.btn-danger {
  background-color: transparent;
  color: var(--color-error);
  border-color: var(--color-error);
}
.btn-danger:hover {
  background-color: var(--color-error);
  color: #fff;
}

/* ============================================================
   表单元素
   ============================================================ */
.form-input,
.form-textarea,
.form-select {
  width: 100%;
  padding: 0.625rem 0.875rem;
  font-family: var(--font-body);
  font-size: var(--text-body);
  color: var(--color-text-primary);
  background-color: var(--color-surface);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-input);
  transition: border-color var(--transition-btn), box-shadow var(--transition-btn);
  min-height: 44px;
  outline: none;
}
.form-input::placeholder,
.form-textarea::placeholder {
  color: var(--color-text-muted);
}
.form-input:focus,
.form-textarea:focus,
.form-select:focus {
  border-color: var(--color-brand);
  box-shadow: 0 0 0 3px rgba(15, 107, 104, 0.12);
}
.form-textarea { min-height: 120px; resize: vertical; }

.form-label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-primary);
  margin-bottom: 0.375rem;
}

.form-error {
  font-size: var(--text-xs);
  color: var(--color-error);
  margin-top: 0.25rem;
}

.form-group { margin-bottom: 1.25rem; }

/* ============================================================
   卡片
   ============================================================ */
.card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
}

/* ============================================================
   标签/胶囊
   ============================================================ */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 0.25rem 0.75rem;
  font-size: var(--text-xs);
  font-weight: 500;
  border-radius: var(--radius-pill);
  background-color: var(--color-brand-light);
  color: var(--color-brand);
  border: 1px solid var(--color-brand-mid);
}

/* ============================================================
   分隔线
   ============================================================ */
.divider {
  border: none;
  border-top: 1px solid var(--color-divider);
  margin-block: 1.5rem;
}

/* ============================================================
   Toast / 提示
   ============================================================ */
.toast {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  padding: 0.75rem 1.25rem;
  background-color: var(--color-text-primary);
  color: var(--color-bg);
  border-radius: var(--radius-card);
  font-size: var(--text-sm);
  box-shadow: var(--shadow-lg);
  z-index: 9999;
  opacity: 0;
  transform: translateY(0.5rem);
  transition: opacity 200ms ease, transform 200ms ease;
  pointer-events: none;
}
.toast.show {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================================
   公告横幅
   ============================================================ */
.announcement-banner {
  padding: 0.625rem 1rem;
  font-size: var(--text-sm);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
.announcement-banner--info    { background-color: var(--color-announce-info);    color: var(--color-info); }
.announcement-banner--warning { background-color: var(--color-announce-warning); color: var(--color-warning); }
.announcement-banner--urgent  { background-color: var(--color-announce-urgent);  color: var(--color-error); }

/* ============================================================
   用户反馈栏（👍 👎）
   ============================================================ */
.feedback-bar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 0.75rem;
}
.feedback-label {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}
.feedback-btn {
  background: none;
  border: 1px solid var(--color-divider);
  border-radius: 6px;
  padding: 2px 10px;
  font-size: 14px;
  cursor: pointer;
  color: var(--color-text-muted);
  transition: all var(--transition-btn);
}
.feedback-btn:hover {
  border-color: var(--color-border);
  color: var(--color-text-secondary);
  background-color: var(--color-brand-light);
}

/* ============================================================
   减少动效（无障碍）
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

/* ============================================================
   响应式断点
   ============================================================ */
/* < 600px: 移动端单列 */
@media (max-width: 599px) {
  .hide-mobile { display: none !important; }
}

/* 600–900px: 平板 */
@media (min-width: 600px) and (max-width: 899px) {
  .hide-tablet { display: none !important; }
}

/* > 900px: 桌面 */
@media (min-width: 900px) {
  .hide-desktop { display: none !important; }
}