/* 音乐转换工具官网 · QQ音乐黄绿色主题 */
:root {
  --green: #31c27c;
  --green-light: #8bc34a;
  --green-dark: #1fa568;
  --grad: linear-gradient(135deg, #31c27c 0%, #8bc34a 100%);
  --bg: #f7faf8;
  --card: #ffffff;
  --text: #1a1b1c;
  --text-2: #6b7280;
  --border: #e6f0ea;
  --radius: 14px;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}
a { color: var(--green-dark); text-decoration: none; }
img { max-width: 100%; }

/* ===== 顶部导航 ===== */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.92); backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 1100px; margin: 0 auto; padding: 12px 20px;
  display: flex; align-items: center; gap: 18px;
}
.nav-logo {
  display: flex; align-items: center; gap: 8px; font-weight: 700; font-size: 17px;
  color: var(--green-dark);
}
.nav-logo .logo-dot {
  width: 26px; height: 26px; border-radius: 8px; background: var(--grad);
  display: inline-flex; align-items: center; justify-content: center;
  color: #fff; font-size: 14px;
}
.nav-links { display: flex; gap: 4px; margin-left: auto; flex-wrap: wrap; }
.nav-links a {
  padding: 6px 12px; border-radius: 8px; color: var(--text); font-size: 14px;
}
.nav-links a:hover { background: #eafaf1; color: var(--green-dark); }
.nav-admin { font-size: 13px; color: var(--text-2); }

/* ===== 首屏 Hero ===== */
.hero {
  background: linear-gradient(160deg, #e8fbf0 0%, #f4fbea 55%, #ffffff 100%);
  padding: 72px 20px 56px; text-align: center;
}
.hero-badge {
  display: inline-block; padding: 5px 16px; border-radius: 999px;
  background: var(--grad); color: #fff; font-size: 13px; font-weight: 600;
  box-shadow: 0 4px 14px rgba(49,194,124,.35);
}
.hero h1 { font-size: 44px; margin: 18px 0 8px; letter-spacing: 1px; }
.hero h1 span { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero .subtitle { color: var(--text-2); font-size: 18px; margin-bottom: 26px; }
.hero-points { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; margin-bottom: 30px; }
.hero-points .pt {
  display: flex; align-items: center; gap: 6px; background: #fff; padding: 8px 16px;
  border-radius: 999px; font-size: 14px; box-shadow: 0 2px 10px rgba(0,0,0,.05);
  border: 1px solid var(--border);
}
.pt::before { content: "✓"; color: var(--green); font-weight: 700; }
.btn-download {
  display: inline-block; padding: 14px 44px; border-radius: 999px;
  background: var(--grad); color: #fff; font-size: 18px; font-weight: 700;
  box-shadow: 0 8px 24px rgba(49,194,124,.4); transition: transform .15s, box-shadow .15s;
}
.btn-download:hover { transform: translateY(-2px); box-shadow: 0 12px 30px rgba(49,194,124,.5); color: #fff; }
.hero-meta { margin-top: 22px; color: var(--text-2); font-size: 14px; }
.hero-meta .sep { margin: 0 10px; color: #cbd5cf; }
.hero-tags { margin-top: 14px; display: flex; gap: 10px; justify-content: center; }
.hero-tags span {
  padding: 4px 14px; border-radius: 999px; border: 1px solid var(--green);
  color: var(--green-dark); font-size: 13px; background: #fff;
}
.hero-alt { margin-top: 14px; font-size: 14px; }

/* ===== 板块容器 ===== */
.section { max-width: 1100px; margin: 0 auto; padding: 56px 20px; }
.section-head { text-align: center; margin-bottom: 36px; }
.section-head h2 { font-size: 30px; }
.section-head h2 em { font-style: normal; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.section-head p { color: var(--text-2); margin-top: 8px; }

/* ===== 功能卡片 ===== */
.feature-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 18px; }
.feature-card {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 26px 22px; transition: transform .15s, box-shadow .15s;
}
.feature-card:hover { transform: translateY(-4px); box-shadow: 0 10px 30px rgba(49,194,124,.12); }
.feature-card .f-icon {
  width: 52px; height: 52px; border-radius: 14px; background: #eafaf1;
  display: flex; align-items: center; justify-content: center; font-size: 26px; margin-bottom: 14px;
}
.feature-card h3 { font-size: 17px; margin-bottom: 6px; }
.feature-card p { color: var(--text-2); font-size: 14px; margin-bottom: 12px; }
.feature-card .f-tags { display: flex; gap: 6px; flex-wrap: wrap; }
.feature-card .f-tags span {
  font-size: 12px; color: var(--green-dark); background: #eefbf3;
  padding: 3px 10px; border-radius: 999px;
}

/* ===== 格式支持 ===== */
.format-box {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 28px; margin-bottom: 18px;
}
.format-box h3 { font-size: 18px; margin-bottom: 14px; display: flex; align-items: center; gap: 8px; }
.format-chips { display: flex; flex-wrap: wrap; gap: 8px; }
.format-chips span {
  padding: 6px 14px; border-radius: 8px; font-size: 13px; font-weight: 600;
  background: #f0faf4; color: #2c9a64; border: 1px solid #d9f0e3;
}
.format-chips span.special { background: var(--grad); color: #fff; border: none; }
.format-note { margin-top: 14px; font-size: 13px; color: var(--text-2); }

/* ===== 文章卡片 ===== */
.article-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 18px; }
.article-card {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  overflow: hidden; cursor: pointer; transition: transform .15s, box-shadow .15s;
}
.article-card:hover { transform: translateY(-4px); box-shadow: 0 10px 30px rgba(49,194,124,.12); }
.article-card .a-cover { height: 150px; background: var(--grad); display: flex; align-items: center; justify-content: center; color: #fff; font-size: 34px; }
.article-card .a-cover img { width: 100%; height: 100%; object-fit: cover; }
.article-card .a-body { padding: 16px 18px; }
.article-card .a-cat { font-size: 12px; color: var(--green-dark); background: #eefbf3; padding: 2px 10px; border-radius: 999px; }
.article-card h3 { font-size: 16px; margin: 8px 0 6px; }
.article-card p { color: var(--text-2); font-size: 13px; }
.article-card .a-date { font-size: 12px; color: #9aa8a0; margin-top: 10px; }

/* ===== 文章详情弹窗 ===== */
.modal-mask {
  position: fixed; inset: 0; background: rgba(0,0,0,.45); z-index: 200;
  display: flex; align-items: flex-start; justify-content: center; padding: 40px 16px; overflow-y: auto;
}
.modal-box {
  background: #fff; border-radius: 16px; max-width: 760px; width: 100%;
  padding: 30px 34px; position: relative;
}
.modal-box h2 { font-size: 24px; margin-bottom: 10px; }
.modal-box .m-meta { color: var(--text-2); font-size: 13px; margin-bottom: 18px; }
.modal-box .m-close {
  position: absolute; top: 14px; right: 16px; border: none; background: #f2f5f3;
  width: 32px; height: 32px; border-radius: 50%; cursor: pointer; font-size: 16px; color: #666;
}
.modal-box .m-content { font-size: 15px; line-height: 1.8; word-break: break-word; }
.modal-box .m-content img { border-radius: 10px; margin: 8px 0; }
.modal-box .m-content h1, .modal-box .m-content h2, .modal-box .m-content h3 { margin: 18px 0 8px; }
.modal-box .m-content p { margin: 8px 0; }
.modal-box .m-content ul, .modal-box .m-content ol { padding-left: 22px; margin: 8px 0; }
.modal-box .m-content blockquote { border-left: 3px solid var(--green); padding-left: 12px; color: var(--text-2); margin: 8px 0; }

/* ===== AI 动态 ===== */
.ai-news {
  background: linear-gradient(160deg, #e8fbf0, #f6fcec);
  border: 1px solid #d9f0e3; border-radius: var(--radius); padding: 26px 28px;
}
.ai-news .an-date { font-size: 13px; color: var(--green-dark); font-weight: 600; }
.ai-news .an-overview { font-size: 15px; margin: 10px 0 16px; }
.ai-news ul { list-style: none; }
.ai-news li {
  padding: 10px 0; border-top: 1px dashed #cde8d8; display: flex; gap: 10px; align-items: baseline;
}
.ai-news li .an-src {
  flex-shrink: 0; font-size: 12px; color: var(--green-dark); background: #eafaf1;
  padding: 1px 8px; border-radius: 6px;
}
.ai-news li a { font-size: 14px; color: var(--text); }
.ai-news li a:hover { color: var(--green-dark); }

/* ===== FAQ ===== */
.faq-item { background: var(--card); border: 1px solid var(--border); border-radius: 12px; margin-bottom: 10px; overflow: hidden; }
.faq-q {
  padding: 14px 18px; cursor: pointer; font-weight: 600; font-size: 15px;
  display: flex; justify-content: space-between; align-items: center; user-select: none;
}
.faq-q::after { content: "+"; color: var(--green); font-size: 20px; transition: transform .2s; }
.faq-item.open .faq-q::after { transform: rotate(45deg); }
.faq-a { display: none; padding: 0 18px 16px; color: var(--text-2); font-size: 14px; }
.faq-item.open .faq-a { display: block; }

/* ===== 联系方式 ===== */
.contact-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 16px; }
.contact-card {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 22px; text-align: center;
}
.contact-card .c-icon { font-size: 28px; margin-bottom: 8px; }
.contact-card .c-label { font-size: 13px; color: var(--text-2); }
.contact-card .c-value { font-size: 16px; font-weight: 600; margin-top: 4px; word-break: break-all; }
.contact-note { text-align: center; color: var(--text-2); margin-top: 20px; font-size: 14px; }

/* ===== 自定义板块富文本 ===== */
.custom-block {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 28px 30px; line-height: 1.8; font-size: 15px;
}
.custom-block h1, .custom-block h2, .custom-block h3 { margin: 14px 0 8px; }
.custom-block p { margin: 8px 0; }
.custom-block ul, .custom-block ol { padding-left: 22px; }
.custom-block img { border-radius: 10px; }
.custom-block blockquote { border-left: 3px solid var(--green); padding-left: 12px; color: var(--text-2); }

/* ===== 页脚 ===== */
.footer {
  border-top: 1px solid var(--border); padding: 26px 20px; text-align: center;
  color: var(--text-2); font-size: 13px; background: #fff;
}
.footer .foot-links { margin-bottom: 8px; display: flex; gap: 16px; justify-content: center; }

/* ===== 空态与通用 ===== */
.empty { text-align: center; color: var(--text-2); padding: 30px 0; }
.hidden { display: none !important; }
.loading { text-align: center; padding: 40px; color: var(--text-2); }

/* 响应式 */
@media (max-width: 640px) {
  .hero h1 { font-size: 32px; }
  .nav-links { display: none; }
  .modal-box { padding: 22px 18px; }
}