/* ================================================================
   设备管理系统 — v4 redesign
   遵循 taste-skill / redesign-skill 设计审计
   Stack: vanilla CSS · Flask · 响应式
   Palette: Slate neutral + Teal accent · tinted shadows
   ================================================================ */

/* ── CSS Variables ── */
:root {
  --font-sans: "SF Pro Display","PingFang SC","Microsoft YaHei","Helvetica Neue",Arial,sans-serif;
  --font-mono: "SF Mono","Fira Code","Cascadia Code",Consolas,monospace;
  --bg:        #f7f8fa;
  --card-bg:   #ffffff;
  --text:      #1e293b;
  --text-2:    #475569;
  --text-3:    #94a3b8;
  --accent:    #0d9488;
  --accent-h:  #0f766e;
  --accent-l:  #f0fdfa;
  --accent-bg: #ccfbf1;
  --border:    #e2e8f0;
  --border-l:  #f1f5f9;
  --shadow-sm: 0 1px 2px rgba(15,23,42,.04);
  --shadow-md: 0 4px 12px rgba(15,23,42,.06);
  --shadow-lg: 0 8px 24px rgba(15,23,42,.08);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --green:  #16a34a;
  --amber:  #d97706;
  --red:    #dc2626;
  --purple: #7c3aed;
  --blue:   #2563eb;
}

/* ── Reset ── */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{font-size:16px;-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{
  font-family:var(--font-sans);
  background:var(--bg);
  color:var(--text);
  line-height:1.6;
  min-height:100vh;
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
}

/* ── Skip link (a11y) ── */
.skip-link{
  position:absolute;top:-100px;left:12px;z-index:200;
  background:var(--accent);color:#fff;padding:8px 16px;
  border-radius:var(--radius-sm);font-size:13px;font-weight:600;
  transition:top .2s;
}
.skip-link:focus{top:8px}

/* ── Grain texture overlay ── */
body::after{
  content:"";position:fixed;inset:0;z-index:9999;pointer-events:none;
  opacity:.015;
  background-image:url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* ── Animations ── */
@keyframes fadeInUp{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:translateY(0)}}
@keyframes slideUp{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}
@keyframes toastBounce{0%{opacity:0;transform:translateX(-50%) translateY(-20px) scale(.9)}60%{transform:translateX(-50%) translateY(4px) scale(1.02)}100%{opacity:1;transform:translateX(-50%) translateY(0) scale(1)}}
@keyframes toastOut{to{opacity:0;transform:translateX(-50%) translateY(-12px)}}
@keyframes modalIn{from{opacity:0;transform:translateY(16px) scale(.98)}to{opacity:1;transform:translateY(0) scale(1)}}
@keyframes overlayIn{from{opacity:0}to{opacity:1}}
@keyframes shimmer{0%{background-position:-200px 0}100%{background-position:calc(200px + 100%) 0}}
@keyframes dotPulse{0%,100%{opacity:.4}50%{opacity:1}}

/* ── Entry stagger ── */
.content>*{animation:fadeInUp .35s ease both}
.stats .stat-item:nth-child(1){animation-delay:0s}
.stats .stat-item:nth-child(2){animation-delay:.04s}
.stats .stat-item:nth-child(3){animation-delay:.08s}
.stats .stat-item:nth-child(4){animation-delay:.12s}
.stats .stat-item:nth-child(5){animation-delay:.16s}
.stats .stat-item:nth-child(6){animation-delay:.20s}
.stats .stat-item:nth-child(7){animation-delay:.24s}
.card{animation:fadeInUp .35s ease both;animation-delay:.04s}
.tab-bar{animation:fadeInUp .3s ease both;animation-delay:.02s}

/* ═══════════════════════ LOGIN ═══════════════════════ */
.login-page{
  display:flex;align-items:center;justify-content:center;
  min-height:100dvh;padding:16px;
  background:var(--bg);
}
.login-box{
  width:100%;max-width:380px;
  background:var(--card-bg);
  border-radius:var(--radius-lg);
  padding:36px 28px 32px;
  box-shadow:var(--shadow-md);
  animation:fadeInUp .45s ease;
  border:1px solid var(--border-l);
}
.login-box .icon{
  text-align:center;font-size:36px;margin-bottom:8px;
}
.login-box h1{
  text-align:center;font-size:22px;font-weight:700;color:var(--text);
  margin-bottom:4px;letter-spacing:-.01em;text-wrap:balance;
}
.login-box .sub{
  text-align:center;font-size:13px;color:var(--text-3);margin-bottom:28px;
  text-wrap:balance;
}
.login-tabs{
  display:flex;background:var(--border-l);border-radius:var(--radius-md);
  padding:4px;margin-bottom:22px;
}
.login-tabs span{
  flex:1;text-align:center;padding:10px 0;border-radius:8px;
  font-size:14px;font-weight:500;color:var(--text-3);
  cursor:pointer;transition:all .2s cubic-bezier(.4,0,.2,1);user-select:none;
}
.login-tabs span.on{
  background:var(--card-bg);color:var(--accent);font-weight:600;
  box-shadow:var(--shadow-sm);
}
.fg{margin-bottom:14px}
.fg input,.fg select{
  width:100%;padding:12px 14px;
  border:1.5px solid var(--border);border-radius:var(--radius-md);
  font-size:14px;color:var(--text);outline:none;
  background:var(--card-bg);
  transition:border-color .2s ease,box-shadow .2s ease,transform .15s ease;
}
.fg input:focus,.fg select:focus{
  border-color:var(--accent);
  box-shadow:0 0 0 3px rgba(13,148,136,.12);
  outline:none;
}
.fg-row{display:flex;gap:8px}
.fg-row input{flex:1}
.fg-row button{
  width:auto;white-space:nowrap;font-size:13px;
  padding:12px 16px;
  background:var(--card-bg);color:var(--accent);
  border:1.5px solid var(--border);border-radius:var(--radius-md);
  font-weight:600;cursor:pointer;
  transition:all .2s ease;
}
.fg-row button:hover:not(:disabled){background:var(--accent-l);border-color:var(--accent)}
.fg-row button:disabled{opacity:.5;cursor:not-allowed}

.btn-submit{
  width:100%;padding:13px;border:none;
  border-radius:var(--radius-md);font-size:15px;font-weight:600;
  color:#fff;background:var(--accent);
  cursor:pointer;transition:all .2s ease;
}
.btn-submit:hover{background:var(--accent-h);transform:translateY(-1px);
  box-shadow:0 4px 14px rgba(13,148,136,.3)}
.btn-submit:active{transform:scale(.98)}

.msg{margin-top:12px;text-align:center;font-size:13px;min-height:20px}
.msg.err{color:var(--red)}.msg.ok{color:var(--green)}

.code-block{
  background:var(--accent-l);border:2px dashed #99f6e4;
  border-radius:var(--radius-md);padding:20px 12px;text-align:center;margin-top:8px;
}
.code-block .big{font-size:32px;font-weight:700;letter-spacing:6px;color:var(--accent)}
.code-block .tip{font-size:11px;color:var(--text-3);margin-bottom:8px}

/* ═══════════════════════ TOPBAR ═══════════════════════ */
.topbar{
  background:var(--card-bg);border-bottom:1px solid var(--border);
  padding:0 20px;height:56px;
  display:flex;align-items:center;justify-content:space-between;
  position:sticky;top:0;z-index:50;
  box-shadow:var(--shadow-sm);
}
.topbar .brand{
  font-size:16px;font-weight:700;color:var(--text);
  display:flex;align-items:center;gap:8px;
  letter-spacing:-.01em;
  text-decoration:none;
}
.topbar .brand .ico{font-size:22px}
.topbar .actions{display:flex;align-items:center;gap:10px}

/* ── topbar buttons ── */
.topbar .btn-sm{
  padding:7px 16px;font-size:13px;border-radius:var(--radius-md);
  border:1.5px solid var(--border);background:var(--card-bg);
  color:var(--text-2);cursor:pointer;font-weight:500;
  white-space:nowrap;transition:all .18s ease;
  text-decoration:none;display:inline-flex;align-items:center;
}
.topbar .btn-sm:hover{background:var(--accent-l);border-color:var(--accent);color:var(--accent)}
.topbar .btn-sm:active{transform:scale(.96)}

/* ═══════════════════════ CONTENT ═══════════════════════ */
.content{max-width:1120px;margin:0 auto;padding:16px 16px 40px}

/* ═══════════════════════ STATS ═══════════════════════ */
.stats{
  display:grid;grid-template-columns:repeat(2,1fr);gap:10px;margin-bottom:20px;
}
@media(min-width:500px){.stats{grid-template-columns:repeat(3,1fr)}}
@media(min-width:768px){.stats{grid-template-columns:repeat(4,1fr);gap:14px}}
@media(min-width:1024px){.stats{grid-template-columns:repeat(7,1fr)}}

.stat-item{
  background:var(--card-bg);border-radius:var(--radius-md);
  padding:16px 14px 14px;text-align:left;
  border:1px solid var(--border-l);border-top:3px solid var(--border-l);
  transition:all .25s cubic-bezier(.4,0,.2,1);cursor:default;
  position:relative;overflow:hidden;
}
.stat-item::before{
  content:'';position:absolute;top:0;left:0;right:0;height:3px;
  opacity:0;transition:opacity .3s;
}
.stat-item:hover{
  transform:translateY(-3px);
  box-shadow:0 6px 20px rgba(15,23,42,.08);
}
.stat-item .v{font-size:28px;font-weight:800;font-variant-numeric:tabular-nums;transition:all .3s ease;line-height:1.1;margin-bottom:2px}
.stat-item:hover .v{transform:scale(1.05)}
.stat-item .l{font-size:11px;color:var(--text-3);margin-top:2px;font-weight:600;text-transform:uppercase;letter-spacing:.04em}

/* color-coded top borders */
.stat-item:nth-child(1){border-top-color:var(--text-2)}.stat-item:nth-child(1) .v{color:var(--text-2)}
.stat-item:nth-child(2){border-top-color:var(--green)}.stat-item:nth-child(2) .v{color:var(--green)}
.stat-item:nth-child(3){border-top-color:var(--blue)}.stat-item:nth-child(3) .v{color:var(--blue)}
.stat-item:nth-child(4){border-top-color:var(--red)}.stat-item:nth-child(4) .v{color:var(--red)}
.stat-item:nth-child(5){border-top-color:var(--green)}.stat-item:nth-child(5) .v{color:var(--green)}
.stat-item:nth-child(6){border-top-color:var(--purple)}.stat-item:nth-child(6) .v{color:var(--purple)}
.stat-item:nth-child(7){border-top-color:var(--amber)}.stat-item:nth-child(7) .v{color:var(--amber)}

/* ═══════════════════════ TAB BAR ═══════════════════════ */
.tab-bar{
  display:flex;flex-wrap:wrap;gap:0;
  border-bottom:2px solid var(--border-l);margin-bottom:0;
}
.tab-bar a{
  flex:1 1 auto;text-align:center;padding:14px 8px;font-size:13px;
  color:var(--text-3);text-decoration:none;font-weight:500;
  border-bottom:3px solid transparent;margin-bottom:-2px;
  cursor:pointer;user-select:none;white-space:nowrap;min-width:0;
  transition:all .2s ease;
}
.tab-bar a:hover{color:var(--accent);background:var(--accent-l)}
.tab-bar a.on{color:var(--accent);border-bottom-color:var(--accent);font-weight:700;background:var(--accent-l)}
@media(min-width:500px){.tab-bar a{flex:0 0 auto;padding:14px 20px;font-size:14px}}

/* ═══════════════════════ CARDS (reduced border, spacing-first) ═══════════════════════ */
.card{
  background:var(--card-bg);border-radius:var(--radius-lg);
  padding:20px;margin-top:14px;
  border:1px solid var(--border-l);
  transition:box-shadow .25s ease,border-color .25s ease;
}
@media(min-width:640px){.card{padding:24px}}
.card:hover{box-shadow:var(--shadow-md);border-color:var(--border)}
.card h2{font-size:16px;font-weight:700;color:var(--text);margin-bottom:14px;letter-spacing:-.01em}
.card-head{
  display:flex;justify-content:space-between;align-items:center;
  margin-bottom:14px;flex-wrap:wrap;gap:10px;
}

/* ═══════════════════════ DEVICE CARDS (mobile) ═══════════════════════ */
.device-cards{display:block}
@media(min-width:768px){.device-cards{display:none}}

.dev-card{
  background:var(--card-bg);border:1px solid var(--border-l);
  border-radius:var(--radius-md);padding:16px;margin-bottom:12px;
  transition:all .25s cubic-bezier(.4,0,.2,1);animation:slideUp .35s ease both;
  box-shadow:0 1px 2px rgba(15,23,42,.02);
}
.dev-card:nth-child(1){animation-delay:.05s}
.dev-card:nth-child(2){animation-delay:.1s}
.dev-card:nth-child(3){animation-delay:.15s}
.dev-card:nth-child(4){animation-delay:.2s}
.dev-card:nth-child(5){animation-delay:.25s}
.dev-card:hover{
  transform:translateY(-3px);
  box-shadow:0 8px 24px rgba(15,23,42,.1);border-color:var(--accent);
}
.dev-card .dc-row{
  display:flex;justify-content:space-between;align-items:center;
  padding:4px 0;font-size:13px;
}
.dev-card .dc-row .lbl{color:var(--text-3);font-size:12px;min-width:60px}
.dev-card .dc-row .val{color:var(--text);text-align:right;word-break:break-all}
.dev-card .dc-actions{
  margin-top:10px;padding-top:10px;border-top:1px solid var(--border-l);
  display:flex;flex-wrap:wrap;gap:6px;
}
.dev-card .dc-id{font-size:12px;color:var(--text-2);font-family:var(--font-mono);word-break:break-all}

/* ═══════════════════════ TABLE ═══════════════════════ */
.device-table{display:none}
@media(min-width:768px){.device-table{display:block}}

table{width:100%;border-collapse:collapse;font-size:13px}
th{
  text-align:left;font-size:11px;font-weight:700;color:var(--text-2);
  padding:12px 14px;background:var(--border-l);
  white-space:nowrap;text-transform:uppercase;letter-spacing:.03em;
}
td{
  padding:13px 14px;border-bottom:1px solid var(--border-l);
  vertical-align:middle;font-variant-numeric:tabular-nums;
  transition:background .15s ease;
}
tbody tr{transition:all .15s ease}
tbody tr:nth-child(even) td{background:rgba(241,245,249,.6)}
tbody tr:hover td{background:var(--accent-l)}

/* ── Empty state ── */
.empty-state{
  text-align:center;padding:40px 20px;color:var(--text-3);
}
.empty-state .empty-icon{font-size:40px;margin-bottom:12px;opacity:.6}
.empty-state .empty-title{font-size:16px;font-weight:600;color:var(--text-2);margin-bottom:6px}
.empty-state .empty-hint{font-size:13px;color:var(--text-3);max-width:320px;margin:0 auto 18px;line-height:1.6;text-wrap:balance}
.empty-state .empty-action{display:inline-flex}

/* ═══════════════════════ BADGES (square, not pill) ═══════════════════════ */
.badge{
  display:inline-block;padding:3px 10px;border-radius:var(--radius-sm);
  font-size:11px;font-weight:600;white-space:nowrap;
  transition:transform .15s ease;
}
.badge:hover{transform:scale(1.06)}
.badge-idle{background:var(--border-l);color:var(--text-3)}
.badge-trial{background:#dbeafe;color:var(--blue)}
.badge-expired{background:#fee2e2;color:var(--red)}
.badge-permanent{background:#dcfce7;color:var(--green)}
.badge-locked{background:#ede9fe;color:var(--purple)}

/* ═══════════════════════ BUTTONS ═══════════════════════ */
.btn-xs{
  padding:5px 12px;font-size:12px;border-radius:var(--radius-sm);
  border:none;cursor:pointer;font-weight:600;white-space:nowrap;
  transition:all .18s ease;position:relative;overflow:hidden;
}
.btn-xs::after{
  content:'';position:absolute;inset:0;background:rgba(255,255,255,.25);
  opacity:0;transition:opacity .2s;
}
.btn-xs:active::after{opacity:1}
.btn-xs.primary{background:var(--accent);color:#fff}
.btn-xs.primary:hover{background:var(--accent-h);transform:translateY(-1px);box-shadow:0 3px 10px rgba(13,148,136,.25)}
.btn-xs.outline{background:var(--card-bg);color:var(--accent);border:1.5px solid var(--border)}
.btn-xs.outline:hover{background:var(--accent-l);border-color:var(--accent)}
.btn-xs.warn{background:var(--card-bg);color:var(--amber);border:1.5px solid #fde68a}
.btn-xs.warn:hover{background:#fffbeb}
.btn-xs.danger{background:var(--card-bg);color:var(--red);border:1.5px solid #fecaca}
.btn-xs.danger:hover{background:#fef2f2}
.btn-xs:active{transform:scale(.94)}

.btn-act{
  padding:9px 20px;font-size:13px;border-radius:var(--radius-md);
  border:none;background:var(--accent);color:#fff;
  font-weight:600;cursor:pointer;white-space:nowrap;
  transition:all .2s ease;
}
.btn-act:hover{background:var(--accent-h);transform:translateY(-1px);box-shadow:0 4px 14px rgba(13,148,136,.3)}
.btn-act:active{transform:scale(.97)}

/* ═══════════════════════ MODAL ═══════════════════════ */
.modal-overlay{
  position:fixed;inset:0;background:rgba(15,23,42,.45);z-index:100;
  display:flex;align-items:flex-end;justify-content:center;
  animation:overlayIn .2s ease;
  backdrop-filter:blur(2px);
}
@media(min-width:640px){.modal-overlay{align-items:center}}
.modal-box{
  background:var(--card-bg);width:100%;max-width:440px;
  border-radius:var(--radius-lg) var(--radius-lg) 0 0;padding:28px 24px;
  animation:modalIn .25s cubic-bezier(.4,0,.2,1);
  box-shadow:var(--shadow-lg);
}
@media(min-width:640px){.modal-box{border-radius:var(--radius-lg)}}
.modal-box h3{font-size:17px;font-weight:700;color:var(--text);margin-bottom:18px;letter-spacing:-.01em}
.modal-box .fg{margin-bottom:12px}
.modal-box .fg input{
  padding:10px 12px;border:1.5px solid var(--border);border-radius:var(--radius-md);
  font-size:14px;outline:none;width:100%;
  background:var(--card-bg);color:var(--text);
  transition:border-color .2s ease,box-shadow .2s ease;
}
.modal-box .fg input:focus{border-color:var(--accent);box-shadow:0 0 0 3px rgba(13,148,136,.12)}
.modal-actions{display:flex;gap:10px;margin-top:20px}
.modal-actions button{flex:1;padding:11px;border-radius:var(--radius-md);font-size:14px;font-weight:600;cursor:pointer;transition:all .2s ease}
.modal-actions .primary{background:var(--accent);color:#fff;border:none}
.modal-actions .primary:hover{background:var(--accent-h)}
.modal-actions .cancel{background:var(--card-bg);color:var(--text-2);border:1.5px solid var(--border)}
.modal-actions .cancel:hover{background:var(--border-l)}

/* ═══════════════════════ LOG LINES ═══════════════════════ */
.log-line{
  display:flex;flex-wrap:wrap;gap:4px 10px;font-size:12px;
  padding:8px 8px;border-bottom:1px solid var(--border-l);
  border-radius:var(--radius-sm);
  transition:all .2s ease;
}
.log-line:hover{background:var(--accent-l);padding-left:12px}
.log-line .time{color:var(--text-3);min-width:130px;font-variant-numeric:tabular-nums}
.log-line .event{color:var(--accent);font-weight:600;min-width:60px}
.log-line .dev{color:var(--text-2);min-width:90px;font-family:var(--font-mono);font-size:11px}
.log-line .detail{color:var(--text-3);flex:1;min-width:120px}

/* ═══════════════════════ TOAST ═══════════════════════ */
.toast{
  position:fixed;top:16px;left:50%;transform:translateX(-50%);
  background:var(--text);color:#fff;padding:10px 22px;
  border-radius:var(--radius-md);font-size:13px;font-weight:500;
  z-index:200;box-shadow:var(--shadow-lg);white-space:nowrap;
  animation:toastBounce .45s cubic-bezier(.4,0,.2,1);
}
.toast.fade-out{animation:toastOut .25s ease forwards}

/* ═══════════════════════ ADMIN GRID ═══════════════════════ */
.admin-grid{display:grid;gap:24px}
@media(min-width:768px){.admin-grid{grid-template-columns:1fr 1fr}}

/* ═══════════════════════ SKELETON LOADING ═══════════════════════ */
.skeleton{
  background:linear-gradient(90deg,var(--border-l) 25%,var(--border) 50%,var(--border-l) 75%);
  background-size:200px 100%;animation:shimmer 1.5s ease-in-out infinite;
  border-radius:var(--radius-sm);height:16px;margin:8px 0;
}
.skeleton-row{display:flex;gap:12px;padding:12px 0;border-bottom:1px solid var(--border-l)}
.skeleton-row .sk-cell{flex:1;height:16px;border-radius:var(--radius-sm);background:linear-gradient(90deg,var(--border-l) 25%,var(--border) 50%,var(--border-l) 75%);background-size:200px 100%;animation:shimmer 1.5s ease-in-out infinite}

/* ═══════════════════════ FILTER BAR ═══════════════════════ */
.filter-bar{display:flex;flex-wrap:wrap;gap:8px;margin:12px 0;align-items:center}
.filter-bar>span{color:var(--text-3);font-size:13px}
.filter-bar select,.filter-bar input[type="date"],.filter-bar input[type="text"],.filter-bar input:not([type]){
  padding:8px 10px;border:1.5px solid var(--border);border-radius:var(--radius-md);
  font-size:13px;color:var(--text);background:var(--card-bg);outline:none;
  transition:border-color .2s ease,box-shadow .2s ease;
}
.filter-bar select:focus,.filter-bar input[type="date"]:focus,.filter-bar input[type="text"]:focus,.filter-bar input:not([type]):focus{
  border-color:var(--accent);box-shadow:0 0 0 3px rgba(13,148,136,.1);
}
#audit-path{width:140px}

/* ═══════════════════════ SCROLLBAR ═══════════════════════ */
::-webkit-scrollbar{width:6px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:var(--border);border-radius:3px}
::-webkit-scrollbar-thumb:hover{background:var(--text-3)}

/* ═══════════════════════ UTILITY ═══════════════════════ */
.hidden{display:none!important}
a{color:var(--accent);text-decoration:none;transition:color .15s}
a:hover{color:var(--accent-h)}
code{font-family:var(--font-mono);font-size:12px}
::selection{background:var(--accent-bg);color:var(--accent-h)}