:root {
  --teal:#00D4BE; --teal-dim:rgba(0,212,190,0.13); --teal-glow:rgba(0,212,190,0.28);
  --coral:#FF6B6B; --gold:#F7C948; --success:#3DDB85;
}
[data-theme="dark"] {
  --bg:#070B14; --surface:#0E1525; --surface2:#141C30; --surface3:#1A2440;
  --border:rgba(0,212,190,0.12); --border2:rgba(255,255,255,0.07);
  --text:#E8EDF5; --text2:#B0BCCF; --muted:#6B7A99;
  --shadow:rgba(0,0,0,0.5);
  --scanline:rgba(0,212,190,0.018);
}
[data-theme="light"] {
  --bg:#F0F4FA; --surface:#FFFFFF; --surface2:#F5F8FF; --surface3:#EBF0FA;
  --border:rgba(0,160,145,0.18); --border2:rgba(0,0,0,0.07);
  --text:#0D1526; --text2:#3A4560; --muted:#8A97B0;
  --shadow:rgba(0,0,0,0.1);
  --scanline:transparent;
}

*{margin:0;padding:0;box-sizing:border-box;}
body{background:var(--bg);color:var(--text);font-family:'DM Sans',sans-serif;min-height:100vh;overflow-x:hidden;transition:background 0.3s,color 0.3s;}
body::before{content:'';position:fixed;inset:0;background:repeating-linear-gradient(0deg,transparent,transparent 2px,var(--scanline) 2px,var(--scanline) 4px);pointer-events:none;z-index:9999;}

/* NAV */
nav{background:var(--surface);border-bottom:1px solid var(--border);padding:0 28px;display:flex;align-items:center;height:60px;position:sticky;top:0;z-index:100;backdrop-filter:blur(12px);box-shadow:0 2px 12px var(--shadow);gap:8px;}
.logo{font-family:'Syne',sans-serif;font-weight:800;font-size:19px;color:var(--teal);letter-spacing:-0.5px;margin-right:36px;display:flex;align-items:center;gap:8px;flex-shrink:0;}
.logo-icon{width:26px;height:26px;border:2px solid var(--teal);border-radius:6px;display:flex;align-items:center;justify-content:center;font-size:12px;}
.nav-tabs{display:flex;gap:3px;}
.nav-tab{font-family:'DM Mono',monospace;font-size:11.5px;font-weight:500;padding:7px 18px;border-radius:6px;border:1px solid transparent;color:var(--muted);cursor:pointer;transition:all 0.2s;letter-spacing:0.4px;background:none;}
.nav-tab:hover{color:var(--text);border-color:var(--border);}
.nav-tab.active{color:var(--teal);background:var(--teal-dim);border-color:rgba(0,212,190,0.3);}
.nav-right{margin-left:auto;display:flex;align-items:center;gap:14px;}
.live-badge{display:flex;align-items:center;gap:6px;font-family:'DM Mono',monospace;font-size:11px;color:var(--success);}
.live-dot{width:7px;height:7px;border-radius:50%;background:var(--success);animation:pulse 1.5s infinite;}
@keyframes pulse{0%,100%{opacity:1;transform:scale(1)}50%{opacity:0.5;transform:scale(0.8)}}

/* THEME TOGGLE */
.theme-toggle{width:44px;height:24px;border-radius:12px;border:1px solid var(--border);background:var(--surface2);cursor:pointer;position:relative;transition:all 0.3s;flex-shrink:0;}
.theme-toggle::after{content:'';position:absolute;top:3px;left:3px;width:16px;height:16px;border-radius:50%;background:var(--teal);transition:transform 0.3s;}
[data-theme="light"] .theme-toggle::after{transform:translateX(20px);}
.theme-icon{font-size:12px;position:absolute;top:50%;transform:translateY(-50%);transition:opacity 0.3s;}
.icon-moon{left:6px;}
.icon-sun{right:5px;opacity:0;}
[data-theme="light"] .icon-moon{opacity:0;}
[data-theme="light"] .icon-sun{opacity:1;}

/* PAGES */
.page{display:none;padding:28px;max-width:1160px;margin:0 auto;}
.page.active{display:block;animation:fadeIn 0.3s ease;}
@keyframes fadeIn{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:translateY(0)}}

/* HEADERS */
.page-title{font-family:'Syne',sans-serif;font-weight:800;font-size:30px;line-height:1;}
.page-title span{color:var(--teal);}
.page-sub{font-size:13px;color:var(--muted);margin-top:6px;}

/* CARDS */
.card{background:var(--surface);border:1px solid var(--border);border-radius:14px;padding:24px;transition:background 0.3s,border 0.3s;}
.card-label{font-family:'DM Mono',monospace;font-size:10.5px;color:var(--teal);letter-spacing:1.5px;text-transform:uppercase;margin-bottom:18px;}
.form-label{font-size:11px;color:var(--muted);margin-bottom:7px;display:block;font-family:'DM Mono',monospace;letter-spacing:0.5px;}
.form-input{width:100%;background:var(--surface2);border:1px solid var(--border);border-radius:8px;padding:11px 14px;color:var(--text);font-family:'DM Sans',sans-serif;font-size:14px;outline:none;transition:border-color 0.2s,background 0.3s;}
.form-input:focus{border-color:var(--teal);box-shadow:0 0 0 3px var(--teal-dim);}
.form-input::placeholder{color:var(--muted);}

/* PHOTO INPUT — DUAL MODE */
.photo-input-wrap{margin-bottom:20px;}
.photo-mode-tabs{display:flex;gap:6px;margin-bottom:10px;}
.pmode-btn{flex:1;padding:8px;border-radius:7px;border:1px solid var(--border);background:var(--surface2);color:var(--muted);font-family:'DM Mono',monospace;font-size:11px;cursor:pointer;transition:all 0.2s;display:flex;align-items:center;justify-content:center;gap:6px;}
.pmode-btn.active{background:var(--teal-dim);border-color:rgba(0,212,190,0.3);color:var(--teal);}
.photo-panel{display:none;}
.photo-panel.active{display:block;}

/* UPLOAD ZONE */
.photo-zone{border:2px dashed rgba(0,212,190,0.25);border-radius:10px;padding:28px;text-align:center;cursor:pointer;transition:all 0.2s;position:relative;background:var(--surface2);}
.photo-zone:hover{border-color:var(--teal);background:var(--teal-dim);}
.photo-zone input{position:absolute;inset:0;opacity:0;cursor:pointer;width:100%;height:100%;}
.photo-icon{font-size:36px;margin-bottom:10px;opacity:0.45;}
.photo-hint{font-size:12.5px;color:var(--muted);}
.photo-hint strong{color:var(--teal);}
.photo-preview{width:100px;height:100px;border-radius:10px;object-fit:cover;border:2px solid var(--teal);}

/* LIVE CAPTURE */
.cam-capture-wrap{border-radius:10px;overflow:hidden;background:#000;position:relative;aspect-ratio:4/3;display:flex;align-items:center;justify-content:center;}
#regVideo{width:100%;height:100%;object-fit:cover;}
.reg-cam-placeholder{text-align:center;color:var(--muted);}
.reg-cam-overlay{position:absolute;inset:0;pointer-events:none;}
.reg-corner{position:absolute;width:20px;height:20px;border-color:var(--teal);border-style:solid;}
.reg-corner.tl{top:12px;left:12px;border-width:2px 0 0 2px;}
.reg-corner.tr{top:12px;right:12px;border-width:2px 2px 0 0;}
.reg-corner.bl{bottom:12px;left:12px;border-width:0 0 2px 2px;}
.reg-corner.br{bottom:12px;right:12px;border-width:0 2px 2px 0;}
.cam-capture-controls{display:flex;gap:8px;margin-top:10px;}
.btn-sm{flex:1;padding:9px 12px;border-radius:7px;border:1px solid var(--border);background:var(--surface2);color:var(--text);font-family:'Syne',sans-serif;font-weight:600;font-size:12px;cursor:pointer;transition:all 0.2s;}
.btn-sm:hover{border-color:var(--teal);color:var(--teal);}
.btn-sm.primary{background:var(--teal);color:#000;border-color:var(--teal);}
.btn-sm.primary:hover{background:#00f0d8;box-shadow:0 0 16px var(--teal-glow);}
.btn-sm:disabled{opacity:0.4;cursor:not-allowed;}

/* CAPTURED PREVIEW BAR */
.captured-bar{display:flex;align-items:center;gap:10px;padding:10px 12px;background:rgba(61,219,133,0.08);border:1px solid rgba(61,219,133,0.2);border-radius:8px;margin-top:8px;font-size:12.5px;color:var(--success);}
.captured-bar img{width:36px;height:36px;border-radius:6px;object-fit:cover;}
.captured-bar.hidden{display:none;}
.remove-photo{margin-left:auto;cursor:pointer;color:var(--muted);font-size:16px;}
.remove-photo:hover{color:var(--coral);}

/* PRIMARY BTN */
.btn-primary{background:var(--teal);color:#000;font-family:'Syne',sans-serif;font-weight:700;font-size:13.5px;padding:13px 28px;border-radius:8px;border:none;cursor:pointer;width:100%;transition:all 0.2s;}
.btn-primary:hover{background:#00f0d8;box-shadow:0 0 20px var(--teal-glow);transform:translateY(-1px);}
.btn-primary:disabled{opacity:0.4;cursor:not-allowed;transform:none;}

/* STUDENTS LIST */
.reg-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px;}
.students-list{display:flex;flex-direction:column;gap:8px;max-height:430px;overflow-y:auto;}
.students-list::-webkit-scrollbar{width:4px;}
.students-list::-webkit-scrollbar-thumb{background:var(--border);border-radius:4px;}
.student-item{display:flex;align-items:center;gap:11px;padding:11px;background:var(--surface2);border-radius:9px;border:1px solid var(--border2);}
.student-avatar{width:42px;height:42px;border-radius:7px;object-fit:cover;border:1.5px solid var(--border);background:var(--surface);display:flex;align-items:center;justify-content:center;font-size:18px;flex-shrink:0;overflow:hidden;}
.student-avatar img{width:100%;height:100%;object-fit:cover;}
.student-name{font-family:'Syne',sans-serif;font-weight:600;font-size:13.5px;}
.student-meta{font-family:'DM Mono',monospace;font-size:10.5px;color:var(--muted);margin-top:2px;}
.student-class{font-family:'DM Mono',monospace;font-size:10.5px;padding:3px 8px;background:var(--teal-dim);color:var(--teal);border-radius:4px;flex-shrink:0;}
.empty-state{text-align:center;padding:36px;color:var(--muted);}
.empty-state .icon{font-size:36px;opacity:0.25;margin-bottom:10px;}

/* TOAST */
.toast{position:fixed;bottom:22px;right:22px;background:var(--surface);border:1px solid var(--teal);border-radius:10px;padding:13px 18px;font-size:12.5px;color:var(--text);z-index:9998;display:flex;align-items:center;gap:10px;animation:toastIn 0.3s ease;box-shadow:0 8px 28px var(--shadow);}
.toast.hidden{display:none;}
.toast.error{border-color:var(--coral);}
.toast.info{border-color:var(--gold);}
@keyframes toastIn{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}

/* ====== SCAN PAGE ====== */
.scan-layout{display:grid;grid-template-columns:1fr 360px;gap:20px;}
.camera-card{background:var(--surface);border:1px solid var(--border);border-radius:14px;overflow:hidden;}
.camera-header{padding:14px 18px;border-bottom:1px solid var(--border);display:flex;align-items:center;justify-content:space-between;}
.cam-status{display:flex;align-items:center;gap:7px;font-family:'DM Mono',monospace;font-size:11.5px;}
.camera-viewport{position:relative;background:#000;aspect-ratio:4/3;display:flex;align-items:center;justify-content:center;}
video#camVideo{width:100%;height:100%;object-fit:cover;display:none;}
canvas#snapCanvas{display:none;}
.cam-placeholder{width:100%;aspect-ratio:4/3;background:var(--surface2);display:flex;flex-direction:column;align-items:center;justify-content:center;gap:10px;}
.scan-overlay{position:absolute;inset:0;pointer-events:none;}
.scan-corner{position:absolute;width:22px;height:22px;border-color:var(--teal);border-style:solid;}
.scan-corner.tl{top:18px;left:18px;border-width:2px 0 0 2px;}
.scan-corner.tr{top:18px;right:18px;border-width:2px 2px 0 0;}
.scan-corner.bl{bottom:18px;left:18px;border-width:0 0 2px 2px;}
.scan-corner.br{bottom:18px;right:18px;border-width:0 2px 2px 0;}
.scan-line{position:absolute;left:18px;right:18px;height:2px;background:linear-gradient(90deg,transparent,var(--teal),transparent);opacity:0;animation:scanMove 2.5s ease-in-out infinite;}
.scan-line.active{opacity:1;}
@keyframes scanMove{0%{top:18px}100%{top:calc(100% - 20px)}}
.face-box{position:absolute;border:2px solid var(--teal);border-radius:4px;box-shadow:0 0 14px var(--teal-glow);display:none;top:18%;left:24%;width:52%;height:58%;}
.face-box.show{display:block;animation:boxPop 0.4s ease;}
.face-box.matched{border-color:var(--success);box-shadow:0 0 14px rgba(61,219,133,0.4);}
.face-box.unknown{border-color:var(--coral);box-shadow:0 0 14px rgba(255,107,107,0.4);}
@keyframes boxPop{from{opacity:0;transform:scale(0.92)}to{opacity:1;transform:scale(1)}}
.face-label{position:absolute;bottom:-32px;left:50%;transform:translateX(-50%);background:var(--teal);color:#000;font-family:'DM Mono',monospace;font-size:10px;font-weight:500;padding:3px 10px;border-radius:4px;white-space:nowrap;}
.face-label.unknown{background:var(--coral);color:#fff;}
.camera-controls{padding:14px 18px;display:flex;gap:10px;border-top:1px solid var(--border);}
.btn-cam{flex:1;padding:11px;border-radius:7px;border:1px solid var(--border);background:var(--surface2);color:var(--text);font-family:'Syne',sans-serif;font-weight:600;font-size:12.5px;cursor:pointer;transition:all 0.2s;}
.btn-cam:hover{border-color:var(--teal);color:var(--teal);}
.btn-cam.primary{background:var(--teal);color:#000;border-color:var(--teal);}
.btn-cam.primary:hover{background:#00f0d8;box-shadow:0 0 18px var(--teal-glow);}
.btn-cam:disabled{opacity:0.35;cursor:not-allowed;}

.scan-sidebar{display:flex;flex-direction:column;gap:14px;}
.result-idle{text-align:center;padding:20px 0;color:var(--muted);}
.result-idle .icon{font-size:32px;margin-bottom:7px;opacity:0.25;}
.result-matched{text-align:center;}
.result-avatar{width:68px;height:68px;border-radius:12px;object-fit:cover;border:3px solid var(--success);margin:0 auto 11px;display:block;}
.result-name{font-family:'Syne',sans-serif;font-weight:700;font-size:17px;}
.result-class{font-family:'DM Mono',monospace;font-size:11.5px;color:var(--teal);margin-top:3px;}
.result-status{display:inline-flex;align-items:center;gap:6px;padding:5px 14px;border-radius:20px;font-size:12px;font-weight:600;margin-top:10px;}
.result-status.present{background:rgba(61,219,133,0.13);color:var(--success);border:1px solid rgba(61,219,133,0.3);}
.result-status.duplicate{background:rgba(247,201,72,0.13);color:var(--gold);border:1px solid rgba(247,201,72,0.3);}
.result-status.unknown{background:rgba(255,107,107,0.13);color:var(--coral);border:1px solid rgba(255,107,107,0.3);}
.result-confidence{font-family:'DM Mono',monospace;font-size:10.5px;color:var(--muted);margin-top:7px;}
.ai-thinking{display:none;align-items:center;gap:8px;padding:11px 14px;background:var(--teal-dim);border:1px solid rgba(0,212,190,0.2);border-radius:8px;font-family:'DM Mono',monospace;font-size:11.5px;color:var(--teal);}
.ai-thinking.show{display:flex;}
.thinking-dots span{animation:blink 1s infinite;}
.thinking-dots span:nth-child(2){animation-delay:.2s;}
.thinking-dots span:nth-child(3){animation-delay:.4s;}
@keyframes blink{0%,100%{opacity:0.3}50%{opacity:1}}
.recent-scans{display:flex;flex-direction:column;gap:7px;max-height:260px;overflow-y:auto;}
.scan-entry{display:flex;align-items:center;gap:9px;padding:9px;background:var(--surface2);border-radius:7px;border:1px solid var(--border2);}
.scan-dot{width:7px;height:7px;border-radius:50%;flex-shrink:0;}
.scan-dot.present{background:var(--success);}
.scan-dot.unknown{background:var(--coral);}
.scan-dot.duplicate{background:var(--gold);}
.scan-sname{font-size:12.5px;font-weight:500;}
.scan-time{font-family:'DM Mono',monospace;font-size:10px;color:var(--muted);}
.scan-badge{font-family:'DM Mono',monospace;font-size:10px;padding:2px 7px;border-radius:4px;}
.scan-badge.present{background:rgba(61,219,133,0.13);color:var(--success);}
.scan-badge.unknown{background:rgba(255,107,107,0.13);color:var(--coral);}
.scan-badge.duplicate{background:rgba(247,201,72,0.13);color:var(--gold);}