/* -------------------------------
   Bulk Mailer — Modern UI Styles
   Author: you :)
   Version: 2.0 - Optimized & Enhanced
---------------------------------*/

/* ========== CSS Variables ========== */
:root{
  --bg: #f7f8fa;
  --card: #ffffff;
  --text: #101828;
  --muted: #667085;
  --border: #e4e7ec;
  --ring: #84caff;
  --accent: #3b82f6;
  --accent-600: #2563eb;
  --accent-700: #1d4ed8;
  --accent-hover: #60a5fa;
  --shadow: 0 1px 2px rgba(16,24,40,.04), 0 8px 24px rgba(16,24,40,.08);
  --shadow-lg: 0 4px 6px rgba(16,24,40,.06), 0 12px 32px rgba(16,24,40,.12);

  --radius: 16px;
  --radius-sm: 12px;
  --radius-xs: 8px;
  --space-1: .5rem;
  --space-2: .75rem;
  --space-3: 1rem;
  --space-4: 1.25rem;
  --space-5: 1.5rem;
  --space-6: 2rem;

  --code-bg: #f1f4f9;
  --code-text: #0b1220;
  --progress-bg: #e6eefc;
  --progress-fg: #3b82f6;
  
  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

@media (prefers-color-scheme: dark){
  :root{
    --bg: #0b1220;
    --card: #0f172a;
    --text: #e6eaf2;
    --muted: #9aa4b2;
    --border: #1f2937;
    --ring: #294bff;
    --accent: #60a5fa;
    --accent-600: #3b82f6;
    --accent-700: #2563eb;
    --accent-hover: #93c5fd;
    --shadow: 0 1px 2px rgba(0,0,0,.25), 0 8px 24px rgba(0,0,0,.35);
    --shadow-lg: 0 4px 6px rgba(0,0,0,.3), 0 12px 32px rgba(0,0,0,.4);

    --code-bg: #0d162b;
    --code-text: #e6eaf2;
    --progress-bg: #1c2a4a;
    --progress-fg: #60a5fa;
  }
}

/* ========== Base Reset ========== */
*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  font: 500 15px/1.65 system-ui, -apple-system, Segoe UI, Roboto, "Helvetica Neue", Arial, "Noto Sans", "Apple Color Emoji","Segoe UI Emoji";
  color:var(--text);
  background: radial-gradient(1200px 600px at 10% -10%, rgba(59,130,246,.1), transparent 40%),
              radial-gradient(1000px 500px at 110% -20%, rgba(99,102,241,.08), transparent 40%),
              var(--bg);
  padding: clamp(16px, 2vw, 32px);
  min-height: 100vh;
}

h2{
  margin: 0 0 var(--space-5);
  font-size: clamp(24px, 2.8vw, 32px);
  font-weight: 700;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, var(--accent), var(--accent-600));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
h3{
  margin: var(--space-5) 0 var(--space-4);
  font-size: clamp(18px, 2.2vw, 22px);
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--text);
}

.hidden{display:none !important}

/* ========== Card / Box ========== */
.box{
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: clamp(20px, 2.5vw, 28px);
  margin: 0 auto var(--space-6);
  max-width: 1200px;
  box-shadow: var(--shadow);
  backdrop-filter: saturate(1.1) blur(2px);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}
.box::before{
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent-600), var(--accent));
  opacity: 0;
  transition: var(--transition);
}
.box:hover::before{
  opacity: 1;
}
.box:hover{
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

/* ========== Grid Layout ========== */
.row{
  display: grid;
  gap: var(--space-4);
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}
.col{display:flex; flex-direction:column; gap:8px}

/* ========== Labels & Hints ========== */
label{font-weight:600; font-size:.96rem}
.hint{
  color: var(--muted);
  font-size: .9rem;
  display: flex;
  align-items: flex-start;
  gap: var(--space-2);
}
.hint i{
  color: var(--accent);
  margin-top: 2px;
  flex-shrink: 0;
  font-size: 14px;
}
code, .box code{
  background: var(--code-bg);
  color: var(--code-text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 2px 6px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
}

/* ========== Form Controls ========== */
.form-input, .form-textarea{
  width:100%;
  padding: 14px 16px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: color-mix(in oklab, var(--card), transparent 2%);
  color: var(--text);
  transition: var(--transition);
  outline: none;
  font-size: 15px;
}
.form-input::placeholder,
.form-textarea::placeholder{
  color: color-mix(in oklab, var(--muted), transparent 30%);
  font-weight: 400;
}

.form-input:hover, .form-textarea:hover{
  border-color: color-mix(in oklab, var(--accent), transparent 60%);
}

.form-input:focus, .form-textarea:focus{
  border-color: var(--accent);
  box-shadow: 0 0 0 4px color-mix(in oklab, var(--ring), transparent 75%);
  background: var(--card);
  transform: translateY(-1px);
}

input[type="file"].form-input{
  padding: 10px;
}

/* ========== Buttons ========== */
.btn{
  appearance: none;
  border: none;
  background: linear-gradient(135deg, var(--accent), var(--accent-600));
  color: #fff;
  font-weight: 600;
  font-size: 15px;
  padding: 14px 24px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  box-shadow: 0 4px 12px rgba(59,130,246,.3), inset 0 1px 0 rgba(255,255,255,.2);
  position: relative;
  overflow: hidden;
}
.btn::before{
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,.2), transparent);
  transition: left 0.5s ease;
}
.btn:hover::before{
  left: 100%;
}
.btn:hover{
  filter: brightness(1.08);
  box-shadow: 0 6px 20px rgba(59,130,246,.4), inset 0 1px 0 rgba(255,255,255,.25);
  transform: translateY(-2px);
}
.btn:active{ 
  transform: translateY(0px);
  box-shadow: 0 2px 8px rgba(59,130,246,.3);
}
.btn:disabled{
  opacity:.55; 
  cursor:not-allowed;
  filter: grayscale(.3);
  transform: none !important;
}

/* ========== Email List Container ========== */
.list-email-container{
  position: sticky; 
  top: -8px;
  z-index: 10;
  padding: var(--space-3) var(--space-4);
  margin: -8px 0 var(--space-4);
  background: color-mix(in oklab, var(--card), transparent 5%);
  border: 2px dashed var(--border);
  border-radius: var(--radius-sm);
  backdrop-filter: blur(8px);
  transition: var(--transition);
}
.list-email-container:hover{
  border-color: color-mix(in oklab, var(--accent), transparent 50%);
  background: color-mix(in oklab, var(--card), transparent 0%);
}
.list-email-container label{
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  user-select: none;
}
.list-email-container input[type="checkbox"]{
  width: 20px;
  height: 20px;
  cursor: pointer;
  accent-color: var(--accent);
}

/* ========== Email List Grid ========== */
.email-list{
  max-height: 480px;
  overflow-y: auto;
  overflow-x: hidden;
  padding: var(--space-4);
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 10px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: color-mix(in oklab, var(--card), transparent 2%);
  transition: var(--transition);
}
.email-list:hover{
  border-color: color-mix(in oklab, var(--accent), transparent 40%);
}
.email-list > .list-email-item{
  display:flex; 
  align-items:center; 
  gap:12px;
  padding: 14px 16px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-xs);
  background: color-mix(in oklab, var(--card), transparent 2%);
  transition: var(--transition);
  margin-bottom: 0;
}
.email-list > .list-email-item:hover{
  border-color: color-mix(in oklab, var(--accent), transparent 50%);
  background: color-mix(in oklab, var(--card), transparent 0%);
  transform: translateX(4px);
  box-shadow: 0 2px 8px rgba(59,130,246,.1);
}
.email-list > .list-email-item input[type="checkbox"].emailChk{
  width:20px; 
  height:20px; 
  accent-color: var(--accent-700);
  cursor: pointer;
  flex-shrink: 0;
}
.email-list > .list-email-item .emailText{
  flex: 1;
  min-width: 0;
  font-weight: 500;
  color: var(--text);
  display: inline-block;
}
.email-list > .list-email-item .nameInput{
  flex: 0 0 auto;
  max-width: 240px;
  padding: 10px 12px;
  font-size: 14px;
}
.email-list .meta{
  display:flex; flex-direction:column; gap:2px;
  font-size:.93rem;
}
.email-list .meta .name{font-weight:600}
.email-list .meta .address{color:var(--muted); font-feature-settings:"tnum" 1}

/* Scrollbar đẹp cho email-list */
.email-list::-webkit-scrollbar{ width: 10px }
.email-list::-webkit-scrollbar-track{ background: transparent }
.email-list::-webkit-scrollbar-thumb{
  background: color-mix(in oklab, var(--progress-fg), transparent 40%);
  border: 2px solid transparent;
  background-clip: padding-box;
  border-radius: 999px;
}
.email-list{
  scrollbar-width: thin;
  scrollbar-color: color-mix(in oklab, var(--progress-fg), transparent 40%) transparent;
}

/* ========== Preview ========== */
.preview-box{
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-5);
  background: conic-gradient(from 180deg at 0% 0%, rgba(59,130,246,.08), transparent 30%) no-repeat,
              color-mix(in oklab, var(--card), transparent 1%);
  min-height: 160px;
  overflow: auto;
  box-shadow: inset 0 2px 4px rgba(0,0,0,.02);
  transition: var(--transition);
  position: relative;
}
.preview-box:hover{
  border-color: color-mix(in oklab, var(--accent), transparent 40%);
  box-shadow: inset 0 2px 4px rgba(0,0,0,.04), 0 0 0 4px color-mix(in oklab, var(--ring), transparent 80%);
}
.preview-box::-webkit-scrollbar{ width: 8px }
.preview-box::-webkit-scrollbar-track{ background: transparent }
.preview-box::-webkit-scrollbar-thumb{
  background: color-mix(in oklab, var(--muted), transparent 60%);
  border-radius: 999px;
}
.preview-box::-webkit-scrollbar-thumb:hover{
  background: color-mix(in oklab, var(--accent), transparent 50%);
}

/* ========== Progress ========== */
.progress-container{
  width:100%;
  height: 14px;
  border-radius: 999px;
  background: var(--progress-bg);
  border: 1px solid var(--border);
  overflow:hidden;
  box-shadow: inset 0 1px 2px rgba(0,0,0,.05);
}
.progress-bar{
  height:100%;
  width:0%;
  background: linear-gradient(90deg, var(--progress-fg), color-mix(in oklab, var(--progress-fg), white 20%), var(--progress-fg));
  background-size: 200% 100%;
  color:#fff;
  font-weight:700;
  font-size:.75rem;
  line-height: 14px;
  text-align:center;
  transition: width .4s cubic-bezier(0.4, 0, 0.2, 1), background-position 1.5s ease;
  position: relative;
  overflow: hidden;
}
.progress-bar::after{
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,.3), transparent);
  animation: shimmer 2s infinite;
}
@keyframes shimmer{
  0%{ left: -100%; }
  100%{ left: 100%; }
}

/* ========== Log Box ========== */
#logBox,
.log-box{
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  padding: var(--space-4);
  background: color-mix(in oklab, var(--card), transparent 3%);
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono";
  white-space: pre-wrap;
  font-size: 14px;
  line-height: 1.6;
  max-height: 300px;
  overflow-y: auto;
  margin: var(--space-5) 0;
  min-height: 60px;
}
#logBox:empty,
.log-box:empty{
  display: none;
}
#logBox::-webkit-scrollbar,
.log-box::-webkit-scrollbar{ width: 8px }
#logBox::-webkit-scrollbar-track,
.log-box::-webkit-scrollbar-track{ background: transparent }
#logBox::-webkit-scrollbar-thumb,
.log-box::-webkit-scrollbar-thumb{
  background: color-mix(in oklab, var(--muted), transparent 60%);
  border-radius: 999px;
}
#logBox::-webkit-scrollbar-thumb:hover,
.log-box::-webkit-scrollbar-thumb:hover{
  background: color-mix(in oklab, var(--accent), transparent 50%);
}

/* ========== Utility ========== */
hr{
  border: none;
  border-top: 1px solid var(--border);
  margin: var(--space-5) 0;
  opacity:.8;
}

/* ========== Small screen tweaks ========== */
@media (max-width: 768px){
  body{
    padding: 16px;
  }
  .box{
    padding: 18px;
    margin-bottom: var(--space-4);
  }
  h2{
    font-size: 22px;
    margin-bottom: var(--space-4);
  }
  .row{
    grid-template-columns: 1fr;
    gap: var(--space-3);
  }
  .btn{ 
    width:100%;
    padding: 14px 20px;
  }
  .list-email-container{ 
    position: static;
    margin-top: 0;
  }
  .email-list{
    max-height: 360px;
    padding: var(--space-3);
    grid-template-columns: 1fr;
  }
  .email-list .list-email-item{
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }
  .email-list .list-email-item .nameInput{
    max-width: 100%;
    width: 100%;
  }
  .preview-box{
    padding: var(--space-4);
    min-height: 140px;
  }
}

@media (max-width: 520px){
  .box{
    padding: 16px;
  }
  .form-input, .form-textarea{
    padding: 12px 14px;
    font-size: 14px;
  }
  .email-list .list-email-item{
    padding: 12px;
  }
}

/* ========== CKEditor Integration ========== */
.cke_chrome{
  border-radius: var(--radius-sm) !important;
  border: 1.5px solid var(--border) !important;
  box-shadow: var(--shadow) !important;
  background: var(--card) !important;
  transition: var(--transition) !important;
  overflow: hidden;
}
.cke_chrome:hover{
  border-color: color-mix(in oklab, var(--accent), transparent 50%) !important;
  box-shadow: var(--shadow-lg) !important;
}
.cke_top{
  border-bottom: 1.5px solid var(--border) !important;
  background: color-mix(in oklab, var(--card), transparent 2%) !important;
  padding: 8px 12px !important;
}
.cke_toolbar{
  border-radius: var(--radius-xs) !important;
}
.cke_button{
  border-radius: 6px !important;
  transition: var(--transition) !important;
}
.cke_button:hover{
  background: color-mix(in oklab, var(--accent), transparent 90%) !important;
}
.cke_editable{
  background: var(--card) !important;
  color: var(--text) !important;
  padding: 16px !important;
  min-height: 250px !important;
  font-size: 15px !important;
  line-height: 1.65 !important;
}
.cke_focus .cke_chrome{
  border-color: var(--accent) !important;
  box-shadow: 0 0 0 4px color-mix(in oklab, var(--ring), transparent 75%) !important;
}
/* Đảm bảo CKEditor hiển thị đúng trong dark mode */
@media (prefers-color-scheme: dark) {
  .cke_chrome {
    background: var(--card) !important;
    border-color: var(--border) !important;
  }
  .cke_top {
    background: color-mix(in oklab, var(--card), transparent 2%) !important;
    border-bottom-color: var(--border) !important;
  }
  .cke_editable {
    background: var(--card) !important;
    color: var(--text) !important;
  }
  .cke_button_off:hover{
    background: color-mix(in oklab, var(--accent), transparent 85%) !important;
  }
}

/* ========== Header ========== */
.header-container{
  text-align: center;
  margin: 0 auto var(--space-6);
  max-width: 1200px;
  padding: var(--space-6) 0;
  position: relative;
  overflow: hidden;
}
.header-container::before{
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 200px;
  height: 200px;
  background: radial-gradient(circle, rgba(59,130,246,.15), transparent 70%);
  border-radius: 50%;
  filter: blur(40px);
}
.header-content{
  position: relative;
  z-index: 1;
}
.header-icon{
  font-size: 64px;
  margin-bottom: var(--space-3);
  animation: float 3s ease-in-out infinite;
  display: inline-block;
}
.header-icon i{
  background: linear-gradient(135deg, var(--accent), var(--accent-600));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: inline-block;
}
@keyframes float{
  0%, 100%{ transform: translateY(0px); }
  50%{ transform: translateY(-10px); }
}
.header-container h1{
  margin: 0 0 var(--space-2);
  font-size: clamp(32px, 4vw, 48px);
  font-weight: 800;
  letter-spacing: -0.04em;
  background: linear-gradient(135deg, var(--accent), var(--accent-600), #8b5cf6);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  background-size: 200% auto;
  animation: gradient-shift 3s ease infinite;
}
@keyframes gradient-shift{
  0%, 100%{ background-position: 0% 50%; }
  50%{ background-position: 100% 50%; }
}
.header-subtitle{
  color: var(--muted);
  font-size: clamp(16px, 1.8vw, 20px);
  font-weight: 500;
  margin: 0;
}

/* ========== Box Header ========== */
.box-header{
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-5);
  padding-bottom: var(--space-3);
  border-bottom: 2px solid var(--border);
}
.box-header i{
  font-size: 20px;
  color: var(--accent);
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: color-mix(in oklab, var(--accent), transparent 90%);
  border-radius: var(--radius-xs);
}
.box-header h3{
  margin: 0;
  font-size: clamp(18px, 2vw, 22px);
  font-weight: 700;
  color: var(--text);
}

/* ========== Upload Area ========== */
.upload-box .upload-area{
  position: relative;
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: var(--space-6);
  text-align: center;
  background: color-mix(in oklab, var(--card), transparent 2%);
  transition: var(--transition);
  cursor: pointer;
  margin-bottom: var(--space-4);
}
.upload-box .upload-area:hover{
  border-color: var(--accent);
  background: color-mix(in oklab, var(--accent), transparent 95%);
  transform: translateY(-2px);
}
.upload-box .upload-area.drag-over{
  border-color: var(--accent);
  background: color-mix(in oklab, var(--accent), transparent 90%);
  box-shadow: 0 0 0 4px color-mix(in oklab, var(--ring), transparent 75%);
}
.upload-icon{
  font-size: 48px;
  color: var(--accent);
  margin-bottom: var(--space-3);
  opacity: 0.7;
}
.upload-label{
  display: block;
  cursor: pointer;
}
.upload-text{
  display: block;
  font-weight: 600;
  color: var(--text);
  margin-bottom: var(--space-2);
  font-size: 16px;
}
.upload-hint{
  display: block;
  color: var(--muted);
  font-size: 14px;
}
.file-input{
  position: absolute;
  opacity: 0;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  cursor: pointer;
}
.upload-info{
  display: flex;
  align-items: flex-start;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
  padding: var(--space-3);
  background: color-mix(in oklab, var(--accent), transparent 95%);
  border-radius: var(--radius-xs);
  border-left: 3px solid var(--accent);
}
.upload-info i{
  color: var(--accent);
  margin-top: 2px;
  flex-shrink: 0;
}

/* ========== Form Groups ========== */
.form-group{
  margin-bottom: var(--space-5);
}
.form-group label{
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-2);
  font-weight: 600;
  font-size: 15px;
}
.form-group label i{
  color: var(--accent);
  font-size: 16px;
  width: 20px;
  text-align: center;
}

/* ========== Password Toggle ========== */
.password-wrapper{
  position: relative;
  display: flex;
  align-items: center;
}
.password-wrapper .form-input{
  padding-right: 48px;
}
.password-toggle{
  position: absolute;
  right: 12px;
  background: none;
  border: none;
  color: var(--muted);
  cursor: pointer;
  padding: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-xs);
  transition: var(--transition);
  z-index: 1;
}
.password-toggle:hover{
  color: var(--accent);
  background: color-mix(in oklab, var(--accent), transparent 90%);
}
.password-toggle:active{
  transform: scale(0.95);
}

/* ========== Buttons Enhanced ========== */
.btn-primary{
  width: 100%;
  margin-top: var(--space-4);
}
.btn-primary i,
.btn-send i{
  margin-right: var(--space-2);
}
.btn-send{
  width: 100%;
  margin-top: var(--space-5);
  padding: 16px 24px;
  font-size: 16px;
  font-weight: 700;
}

/* ========== Section Divider ========== */
.section-divider{
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border), transparent);
  margin: var(--space-6) 0;
}

/* ========== Preview Placeholder ========== */
.preview-placeholder{
  text-align: center;
  padding: var(--space-6);
  color: var(--muted);
}
.preview-placeholder i{
  font-size: 48px;
  margin-bottom: var(--space-3);
  opacity: 0.5;
}
.preview-placeholder p{
  margin: 0;
  font-size: 14px;
}

/* ========== Progress Section ========== */
.progress-section{
  margin: var(--space-5) 0;
}
.progress-header{
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-3);
  font-weight: 600;
  font-size: 14px;
  color: var(--text);
}
.progress-text{
  color: var(--accent);
  font-weight: 700;
}


/* ========== Email Section Animation ========== */
.email-section{
  animation: slideUp 0.4s ease-out;
}
@keyframes slideUp{
  from{
    opacity: 0;
    transform: translateY(20px);
  }
  to{
    opacity: 1;
    transform: translateY(0);
  }
}

/* ========== Responsive Updates ========== */
@media (max-width: 768px){
  .header-container{
    padding: var(--space-4) 0;
  }
  .header-icon{
    font-size: 48px;
  }
  .upload-area{
    padding: var(--space-4) !important;
  }
  .upload-icon{
    font-size: 36px;
  }
  .box-header{
    flex-wrap: wrap;
  }
  .progress-header{
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-2);
  }
}