/* 数字情书生成器 - 紧凑布局 + 上传区排版修复 + 预览卡片居中 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

/* 页面从顶部开始，避免初始“被拉长” */
body {
  background: linear-gradient(135deg, #ff9ec5 0%, #ff6b9c 100%);
  color: #fff;
  display: block;               /* 不再用 flex 居中 */
  padding: 20px 16px;
  overflow-x: hidden;
  min-height: 100vh;
}

/* ===== 布局 ===== */
.container {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;               /* 居中 */
  display: grid;
  grid-template-columns: 1fr 1fr; /* 左表单 + 右预览（编辑页保持双栏） */
  gap: 20px;
  z-index: 20;
}

/* 顶部标题更紧凑，并粘顶（滚动时保持可见） */
.header {
  grid-column: 1 / -1;
  position: sticky;
  top: 6px;
  z-index: 5;
  padding: 10px 8px;
  margin-bottom: 8px;
  border-radius: 12px;
  background: rgba(255,255,255,.12);
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
  border: 1px solid rgba(255,255,255,.18);
  box-shadow: 0 8px 18px rgba(0,0,0,.18);
  text-align: center;
}
.header h1 {
  font-size: 2.2rem;
  font-weight: 700;
  text-shadow: 0 6px 16px rgba(0,0,0,.22);
}
.header p {
  margin-top: 4px;
  font-size: .95rem;
  opacity: .9;
  color: #ffe6f2;
}

/* ===== 卡片统一外观（表单 / 预览） ===== */
.form-container,
.preview-container {
  background: rgba(255,255,255,.2);
  border: 1px solid rgba(255,255,255,.24);
  border-radius: 18px;
  box-shadow: 0 10px 26px rgba(0,0,0,.22);
  padding: 20px;
  position: relative;
  /* 桌面端给卡片设置“上限高度”，避免整页过长 */
  max-height: calc(100vh - 150px);
  overflow: auto;
  scroll-behavior: smooth;
}
.preview-container { background: rgba(255,255,255,.16); }

/* ===== 表单 ===== */
.form-group { margin-bottom: 14px; }

.form-group label {
  display: block;
  margin-bottom: 6px;
  font-size: 1rem;
  color: #ffe6f2;
  text-shadow: 0 1px 3px rgba(0,0,0,.18);
  font-weight: 600;
}

.form-input {
  width: 100%;
  padding: 10px 14px;
  border: none;
  border-radius: 10px;
  background: rgba(255,255,255,.95);
  font-size: 1rem;
  color: #333;
  transition: all .2s ease;
  border: 2px solid transparent;
}
.form-input:focus {
  outline: none;
  border-color: #ff9ec5;
  box-shadow: 0 0 0 3px rgba(255,158,197,.28);
}

textarea.form-input {
  min-height: 140px;            /* 更紧凑 */
  resize: vertical;
  line-height: 1.7;
}
.char-count {
  text-align: right;
  font-size: .85rem;
  color: rgba(255,255,255,.85);
  margin-top: 4px;
}

/* ===== 上传文件区域（排版修复） ===== */
.file-upload {
  display: flex;
  align-items: center;
  gap: 10px;
}
#bg-image { display: none; }     /* 隐藏原始 input，改用 label 触发 */

.upload-btn {
  background: rgba(255,158,197,.35);
  color: #fff;
  padding: 8px 14px;
  border-radius: 8px;
  cursor: pointer;
  transition: all .2s ease;
  font-size: .9rem;
  border: 1px solid transparent;
  white-space: nowrap;
}
.upload-btn:hover {
  background: rgba(255,158,197,.55);
  transform: translateY(-1px);
}
.file-name {
  font-size: .9rem;
  color: #fff;
  opacity: .9;
  max-width: 320px;             /* ⭐ 文件名过长省略 */
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

#preview {
  display: none;
  margin-top: 10px;
  border-radius: 10px;
  max-height: 160px;
  object-fit: cover;
  box-shadow: 0 6px 14px rgba(0,0,0,.22);
}

/* 主要按钮 */
.submit-btn {
  width: 100%;
  padding: 12px;
  background: linear-gradient(135deg, #ff9ec5, #ff6b9c);
  border: none;
  border-radius: 12px;
  font-size: 1.05rem;
  font-weight: 700;
  color: white;
  cursor: pointer;
  transition: all .2s ease;
  box-shadow: 0 10px 20px rgba(255,107,156,.32);
  margin-top: 14px;
}
.submit-btn:hover { transform: translateY(-1px); box-shadow: 0 14px 24px rgba(255,107,156,.42); }
.submit-btn:active { transform: scale(.98); }

/* ===== 预览卡片（垂直居中 + 上下留白） ===== */
.preview-card {
  background: rgba(255,255,255,.05);
  border-radius: 16px;
  padding: 40px 28px;            /* 加大上下内边距 */
  min-height: 320px;
  display: flex;
  flex-direction: column;        /* 垂直布局 */
  justify-content: center;       /* 垂直居中内容 */
  text-align: left;
  font-size: 1.1rem;
  line-height: 1.85;
  color: #fff;
  position: relative;
  overflow: hidden;
  box-shadow: inset 0 0 22px rgba(0,0,0,.14);
}
/* 有本地预览背景时的暗层，保证文字可读 */
.preview-card.has-bg::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 16px;
  background: rgba(0,0,0,.26);
  backdrop-filter: blur(1.8px);
  -webkit-backdrop-filter: blur(1.8px);
  z-index: 1;
}
.preview-content { position: relative; z-index: 2; }
.preview-text   { text-shadow: 0 2px 10px rgba(0,0,0,.45); }

/* ===== 分享区域 ===== */
.share-container { display: flex; flex-direction: column; gap: 12px; }
.link-input-group { display: flex; gap: 8px; }
#generated-link {
  flex: 1;
  padding: 9px 10px;
  border-radius: 8px;
  border: 1px solid rgba(255,255,255,.3);
  background: rgba(255,255,255,.15);
  color: white;
  font-size: .9rem;
}
.copy-btn {
  padding: 9px 14px;
  border-radius: 8px;
  background: rgba(255,255,255,.25);
  border: 1px solid rgba(255,255,255,.3);
  color: #fff;
  cursor: pointer;
}
.copy-btn:hover { background: rgba(255,255,255,.35); }

.share-buttons { display: flex; flex-wrap: wrap; gap: 10px; }
.share-btn {
  flex: 1; min-width: 120px; padding: 10px 12px;
  background: rgba(255,255,255,.18);
  border: 1px solid rgba(255,255,255,.28);
  border-radius: 10px; color: white; cursor: pointer;
  transition: all .2s ease; font-size: .95rem;
}
.share-btn:hover { background: rgba(255,255,255,.28); transform: translateY(-1px); }
.share-btn:active { transform: scale(.98); }

/* ===== toast ===== */
.toast {
  position: fixed;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(0,0,0,.72);
  color: white;
  padding: 12px 18px;
  border-radius: 10px;
  box-shadow: 0 8px 20px rgba(0,0,0,.22);
  opacity: 0;
  visibility: hidden;
  transition: all .25s ease;
  z-index: 9999;
}
.toast.show { opacity: 1; visibility: visible; transform: translate(-50%, -6px); }

/* ===== 爱心动画 ===== */
.heart {
  position: fixed;
  pointer-events: none;
  z-index: 999;
  animation: floatUp 6s ease-in-out forwards;
  font-size: 24px;
  color: #ff9ec5;
  text-shadow: 0 0 12px rgba(255,158,197,.7);
}
@keyframes floatUp {
  0% { transform: translateY(0) scale(1); opacity: 1; }
  50% { opacity: .8; }
  100% { transform: translateY(-150vh) scale(0.5); opacity: 0; }
}

/* ===== 音乐按钮 ===== */
.hidden { display: none; }
.music-btn {
  position: fixed;
  bottom: 16px;
  right: 16px;
  width: 46px;
  height: 46px;
  background: rgba(255,255,255,.25);
  border: 2px solid rgba(255,255,255,.3);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  cursor: pointer;
  z-index: 1000;
  backdrop-filter: blur(8px);
  box-shadow: 0 6px 15px rgba(0,0,0,.22);
  transition: all .2s ease;
}
.music-btn:hover { background: rgba(255,255,255,.35); transform: scale(1.05); }

/* ===== 查看页：全屏背景 + 暗层（URL 打开时用） ===== */
#bg-fullscreen {
  position: fixed;
  inset: 0;
  background-size: cover;
  background-position: center;
  z-index: -1;
}
#bg-fullscreen::after {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,.25);
  backdrop-filter: blur(2px);
  -webkit-backdrop-filter: blur(2px);
}

/* ===== 响应式（编辑页与通用） ===== */
@media (max-width: 900px) {
  .container { grid-template-columns: 1fr; gap: 16px; }
  /* 移动端不限制卡片高度，避免嵌套滚动 */
  .form-container, .preview-container { max-height: none; overflow: visible; }
  .header { position: static; margin-bottom: 10px; }
  .header h1 { font-size: 1.8rem; }
}

/* ===== 预览页排版优化 ===== */

/* 顶部标题条：收窄宽度、半透明磨砂、靠中 */
.view-header {
  grid-column: 1 / -1;
  max-width: 980px;
  margin: 12px auto 8px;
  padding: 12px 18px;
  border-radius: 14px;
  background: rgba(255,255,255,.12);
  border: 1px solid rgba(255,255,255,.18);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  box-shadow: 0 10px 24px rgba(0,0,0,.18);
  text-align: center;
}
.view-header h1 {
  font-size: 2.2rem;
  margin: 0;
}
.view-header p {
  margin-top: 4px;
  opacity: .9;
}

/* “信纸面板”：限制正文宽度、统一左对齐、适度留白与对比度 */
.letter-panel {
  max-width: 960px;
  margin: 22px auto;
  padding: 28px 26px;
  border-radius: 16px;
  background: rgba(0,0,0,.18);      /* 让文字和背景有足够对比 */
  border: 1px solid rgba(255,255,255,.12);
  backdrop-filter: blur(2px);
  -webkit-backdrop-filter: blur(2px);
  box-shadow: 0 12px 30px rgba(0,0,0,.24);
  /* ✨ 预览页进入时淡入上浮 */
  opacity: 0;
  transform: translateY(20px);
  animation: fadeUp 1.2s ease forwards;
}

/* 面板内文字层级与版式 */
.letter-panel .preview-header h2 {
  margin-bottom: 14px;
  line-height: 1.35;
}
.letter-panel .preview-text {
  text-align: left;
  font-size: 1.15rem;
  line-height: 1.95;
  text-shadow: 0 2px 10px rgba(0,0,0,.45);
}
/* ✨ 轻微闪光的小星星 */
.letter-panel .preview-text p {
  position: relative;
}
.letter-panel .preview-text p::after {
  content: "✨";
  position: absolute;
  top: -10px;
  right: -14px;
  opacity: 0;
  animation: twinkle 4s infinite;
}

.letter-panel .preview-text p { margin: 10px 0; }
.letter-panel .preview-signature {
  margin-top: 22px;
  opacity: .95;
}

/* 让卡片始终在视觉中心区域，不会贴太上/太下 */
#view-card {
  background: transparent;           /* 背景交给面板处理 */
  box-shadow: none;
  padding: 0;
  display: block;                    /* 取消居中 flex，避免内容被挤 */
}

/* ⭐ 仅在“预览页”宽屏时单列，编辑页不受影响 */
@media (min-width: 900px) {
  .view-mode .container {            /* 只有 body 上有 .view-mode 才生效 */
    grid-template-columns: 1fr;
  }
}

/* ======= 浪漫增强：仅在预览页生效的背景呼吸动画 ======= */
body.view-mode {
  background: linear-gradient(135deg, #ff9ec5, #ff6b9c, #ffc3d6);
  background-size: 300% 300%;
  animation: bgflow 12s ease-in-out infinite;
}

/* 流星视觉元素 */
.meteor {
  position: fixed;
  top: -40px;
  width: 2px;
  height: 80px;
  background: linear-gradient(45deg, #fff, transparent);
  opacity: 0.8;
  transform: rotate(45deg);
  animation: fall 3s linear forwards;
  z-index: 2000;
  pointer-events: none;
}

/* ======= 关键帧 ======= */
@keyframes fadeUp {
  to { opacity: 1; transform: translateY(0); }
}
@keyframes twinkle {
  0%, 90%, 100% { opacity: 0; transform: scale(0.5) rotate(0deg); }
  50% { opacity: 1; transform: scale(1.2) rotate(15deg); }
}
@keyframes bgflow {
  0%   { background-position: 0% 50%; }
  50%  { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}
@keyframes fall {
  0% { transform: translate(0,0) rotate(45deg); opacity: 1; }
  100% { transform: translate(-200px, 400px) rotate(45deg); opacity: 0; }
}