:root{
  --green:#1D9E75;--green-light:#E1F5EE;--green-mid:#5DCAA5;--green-dark:#0F6E56;
  --purple-light:#EEF2FF;--purple-mid:#AFA9EC;--purple-text:#534AB7;
  --gray-50:#F9FAFB;--gray-100:#F3F4F6;--gray-200:#E5E7EB;
  --gray-400:#9CA3AF;--gray-600:#4B5563;--gray-800:#1F2937;
  --danger:#DC2626;--radius:10px;--radius-sm:6px;
  --shadow:0 1px 3px rgba(0,0,0,0.08);--shadow-md:0 4px 16px rgba(0,0,0,0.10);
}
*{box-sizing:border-box;margin:0;padding:0}
body{font-family:'DM Sans',sans-serif;background:#F0F4F8;color:var(--gray-800);min-height:100vh;font-size:15px}
.topbar{background:white;border-bottom:1px solid var(--gray-200);padding:0 24px;height:56px;display:flex;align-items:center;justify-content:space-between;position:sticky;top:0;z-index:100;box-shadow:var(--shadow)}
.brand{display:flex;align-items:center;gap:10px}
.brand-icon{width:32px;height:32px;background:var(--green);border-radius:var(--radius-sm);display:flex;align-items:center;justify-content:center;color:white;font-size:13px;font-weight:700;letter-spacing:-0.5px}
.brand-title{font-size:15px;font-weight:600}
.brand-sub{font-size:11px;color:var(--gray-400)}
.topbar-right{display:flex;align-items:center;gap:8px}
.badge-admin{font-size:11px;font-weight:600;background:var(--green-light);color:#fff;padding:3px 10px;border-radius:20px}
.btn{padding:7px 14px;border-radius:var(--radius-sm);border:1px solid var(--gray-200);background:white;font-size:14px;font-weight:500;color:var(--gray-600);cursor:pointer;font-family:'DM Sans',sans-serif;transition:all 0.15s}
.btn:hover{background:var(--gray-50);border-color:var(--gray-400)}
.btn-primary{background:var(--green);color:white;border-color:var(--green)}
.btn-primary:hover{background:var(--green-dark);border-color:var(--green-dark)}
.btn-sm{padding:5px 11px;font-size:12px}
.btn:disabled{opacity:0.5;cursor:not-allowed}
.btn-theme{background:none;border:none;cursor:pointer;font-size:18px;padding:4px 6px;border-radius:var(--radius-sm);line-height:1;transition:background 0.15s;font-family:'DM Sans',sans-serif}
.btn-theme:hover{background:var(--gray-100)}
.container{max-width:980px;margin:0 auto;padding:24px 20px}
.card{background:white;border-radius:var(--radius);border:1px solid var(--gray-200);box-shadow:var(--shadow);padding:20px 24px;margin-bottom:16px}
#auth-screen{min-height:calc(100vh - 56px);display:flex;align-items:center;justify-content:center}
.auth-card{background:white;border-radius:16px;border:1px solid var(--gray-200);box-shadow:var(--shadow-md);padding:40px;width:360px;text-align:center}
.auth-icon{width:56px;height:56px;background:var(--green-light);border-radius:14px;display:flex;align-items:center;justify-content:center;margin:0 auto 20px;font-size:26px}
.auth-card h2{font-size:20px;font-weight:600;margin-bottom:8px}
.auth-card p{font-size:14px;color:var(--gray-400);margin-bottom:24px;line-height:1.6}
.auth-note{font-size:12px;color:var(--gray-400);margin-top:16px;line-height:1.5}
#pin-screen{min-height:calc(100vh - 56px);display:flex;align-items:center;justify-content:center}
.pin-card{background:white;border-radius:16px;border:1px solid var(--gray-200);box-shadow:var(--shadow-md);padding:36px 32px;width:300px;text-align:center}
.pin-card h2{font-size:18px;font-weight:600;margin-bottom:6px}
.pin-card p{font-size:13px;color:var(--gray-400);margin-bottom:24px}
.pin-dots{display:flex;gap:14px;justify-content:center;margin-bottom:28px}
.pin-dot{width:14px;height:14px;border-radius:50%;border:2px solid var(--gray-200);background:white;transition:all 0.15s}
.pin-dot.filled{background:var(--green);border-color:var(--green)}
.pin-dot.error{background:var(--danger);border-color:var(--danger)}
.pin-keypad{display:grid;grid-template-columns:repeat(3,1fr);gap:8px}
.pin-key{height:50px;border-radius:var(--radius-sm);border:1px solid var(--gray-200);background:white;font-size:18px;font-weight:500;cursor:pointer;font-family:'DM Mono',monospace;color:var(--gray-800);transition:all 0.1s}
.pin-key:hover{background:var(--gray-50)}
.pin-key:active{transform:scale(0.96)}
.pin-key.del{font-size:14px;font-family:'DM Sans',sans-serif;color:var(--gray-400)}
.pin-key.empty{visibility:hidden}
.pin-error{font-size:12px;color:var(--danger);margin-top:14px;height:16px}
@keyframes shake{0%,100%{transform:translateX(0)}20%{transform:translateX(-8px)}40%{transform:translateX(8px)}60%{transform:translateX(-5px)}80%{transform:translateX(5px)}}
.shake{animation:shake 0.4s ease}
.status-bar{padding:9px 14px;border-radius:var(--radius-sm);font-size:13px;font-weight:500;display:flex;align-items:center;gap:8px;margin-bottom:14px}
.status-ok{background:var(--green-light);border:1px solid #9FE1CB;color:var(--green-dark)}
.status-err{background:#FEE2E2;border:1px solid #FCA5A5;color:#991B1B}
.week-nav{display:flex;align-items:center;gap:12px;margin-bottom:16px}
.week-label{flex:1;text-align:center;font-size:16px;font-weight:600}
.btn-today{background:var(--green);color:white;border:none;border-radius:var(--radius-sm);padding:6px 16px;font-size:12px;font-weight:600;cursor:pointer;font-family:'DM Sans',sans-serif;transition:all 0.15s;white-space:nowrap}
.btn-today:hover{background:var(--green-dark)}
.btn-today:active{transform:scale(0.97)}
.btn-today.at-today{background:var(--gray-200);color:var(--gray-400);cursor:default}
.btn-today.at-today:hover{background:var(--gray-200)}
.grid-wrap{overflow-x:auto}
.grid{display:grid;grid-template-columns:70px repeat(5,minmax(0,1fr));gap:3px;min-width:520px}
.col-head{font-size:14px;font-weight:600;text-align:center;padding:6px 4px 10px;color:var(--gray-400)}
.col-head.today{color:var(--green)}
.col-head.holiday{color:var(--danger)}
.col-date{font-size:11px;font-weight:400;margin-top:2px}
.p-label{font-size:12px;color:var(--gray-400);display:flex;flex-direction:column;align-items:flex-end;justify-content:center;padding-right:8px;height:52px;line-height:1.4}
.p-label .ptime{font-size:10px;opacity:0.7}
.r-label{height:18px;display:flex;align-items:center;justify-content:flex-end;padding-right:8px;font-size:9px;color:var(--gray-400);opacity:0.5}
.slot{height:52px;border-radius:var(--radius-sm);border:1px solid var(--gray-200);display:flex;flex-direction:column;align-items:center;justify-content:center;overflow:hidden;transition:all 0.12s}
.slot-recess{height:18px;border:none;background:transparent}
.slot-free{background:white}
.slot-free.admin{cursor:pointer}
.slot-free.admin:hover{background:var(--green-light);border-color:var(--green)}
.slot-booked{background:#C8F0DE;border-color:#5DCAA5}
.slot-booked.admin{cursor:pointer}
.slot-booked.admin:hover{border-color:var(--green)}
.slot-teaching{background:#DDD6FE;border-color:#8B7FD4;cursor:not-allowed}
.slot-blocked{background:var(--gray-100);border-color:var(--gray-200)}
.slot-blocked.admin{cursor:pointer}
.slot-blocked.admin:hover{background:var(--gray-200)}
.slot-holiday{background:var(--gray-100);opacity:0.4;cursor:not-allowed}
.slot-past{background:repeating-linear-gradient(135deg,#E5E7EB,#E5E7EB 4px,#D1D5DB 4px,#D1D5DB 5px);opacity:0.5;cursor:not-allowed}
.slot-loading{background:var(--gray-50);border-style:dashed}
.s-text{font-size:12px;font-weight:700;text-align:center;padding:0 3px;line-height:1.25;overflow:hidden;white-space:nowrap;text-overflow:ellipsis;max-width:100%}
.s-sub{font-size:10px;font-weight:400;text-align:center;padding:0 3px;line-height:1.2;overflow:hidden;white-space:nowrap;text-overflow:ellipsis;max-width:100%;margin-top:1px}
.slot-booked .s-text{color:var(--green-dark)}
.slot-booked .s-sub{color:var(--green-mid)}
.slot-teaching .s-text{color:var(--purple-text)}
.slot-blocked .s-text{color:var(--gray-400)}
.legend{display:flex;gap:14px;flex-wrap:wrap;margin-top:14px}
.leg-item{display:flex;align-items:center;gap:5px;font-size:12px;color:var(--gray-400)}
.leg-dot{width:10px;height:10px;border-radius:3px;border:1px solid var(--gray-200)}
.leg-dot-free{background:white}
.leg-dot-booked{background:#C8F0DE;border-color:#5DCAA5}
.leg-dot-teaching{background:#DDD6FE;border-color:#8B7FD4}
.admin-hint{font-size:12px;color:var(--gray-400);margin-top:10px;font-style:italic}
.view-tabs{display:flex;gap:6px;margin-bottom:14px}
.tab{padding:6px 14px;border-radius:var(--radius-sm);border:1px solid var(--gray-200);background:white;font-size:12px;font-weight:500;color:var(--gray-400);cursor:pointer;font-family:'DM Sans',sans-serif;transition:all 0.12s}
.tab.active{background:var(--gray-800);color:white;border-color:var(--gray-800)}
.modal-bg{position:fixed;inset:0;background:rgba(0,0,0,0.38);display:flex;align-items:center;justify-content:center;z-index:200;padding:16px}
.modal{background:white;border-radius:14px;box-shadow:var(--shadow-md);padding:24px;width:420px;max-width:100%;max-height:90vh;overflow-y:auto}
.modal h2{font-size:18px;font-weight:600;margin-bottom:4px}
.modal-sub{font-size:12px;color:var(--gray-400);margin-bottom:18px}
.form-row{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.form-group{margin-bottom:12px}
.form-group label{font-size:13px;color:var(--gray-600);display:block;margin-bottom:4px;font-weight:500}
.form-group input,.form-group textarea{width:100%;border:1px solid var(--gray-200);border-radius:var(--radius-sm);padding:8px 10px;font-size:14px;color:var(--gray-800);font-family:'DM Sans',sans-serif;transition:border-color 0.15s;resize:vertical}
.form-group textarea{min-height:64px}
.form-group input:focus,.form-group textarea:focus{outline:none;border-color:var(--green)}
.form-group select{width:100%;border:1px solid var(--gray-200);border-radius:var(--radius-sm);padding:8px 10px;font-size:14px;color:var(--gray-800);font-family:'DM Sans',sans-serif;transition:border-color 0.15s;background:white;appearance:auto;cursor:pointer}
.form-group select:focus{outline:none;border-color:var(--green)}
.form-group select:disabled{background:var(--gray-50);color:var(--gray-400);cursor:not-allowed}
.req{color:var(--danger)}
.modal-actions{display:flex;gap:8px;margin-top:16px}
.booking-row{background:white;border:1px solid var(--gray-200);border-radius:var(--radius-sm);padding:12px 16px;display:flex;align-items:flex-start;justify-content:space-between;gap:12px;margin-bottom:8px}
.b-main{font-size:14px;font-weight:600;color:var(--gray-800)}
.b-meta{font-size:12px;color:var(--gray-400);margin-top:3px;line-height:1.5}
.b-badge{font-size:10px;font-weight:600;background:var(--green-light);color:var(--green-dark);padding:2px 8px;border-radius:20px;white-space:nowrap}
.b-actions{display:flex;align-items:center;gap:6px;flex-shrink:0;margin-top:2px}
.toast{position:fixed;bottom:24px;left:50%;transform:translateX(-50%);color:white;padding:10px 20px;border-radius:8px;font-size:13px;font-weight:500;box-shadow:var(--shadow-md);opacity:0;transition:opacity 0.25s;pointer-events:none;white-space:nowrap;z-index:300}
.toast.show{opacity:1}
.toast-ok{background:var(--green)}
.toast-err{background:var(--danger)}
.spinner{width:14px;height:14px;border:2px solid rgba(255,255,255,0.4);border-top-color:white;border-radius:50%;animation:spin 0.7s linear infinite;display:inline-block;vertical-align:middle}
@keyframes spin{to{transform:rotate(360deg)}}
.hidden{display:none!important}
[data-theme="dark"]{--green-light:#1a3a2e;--green-mid:#4db884;--green-dark:#5DCAA5;--purple-light:#2a2545;--purple-mid:#AFA9EC;--purple-text:#AFA9EC;--gray-50:#1A1D27;--gray-100:#252836;--gray-200:#2A2D37;--gray-600:#C9CDD5;--gray-800:#E5E7EB;--shadow:0 1px 3px rgba(0,0,0,0.3);--shadow-md:0 4px 16px rgba(0,0,0,0.4)}
[data-theme="dark"] body{background:#0F1117}
[data-theme="dark"] .topbar{background:#1A1D27;border-bottom-color:#2A2D37}
[data-theme="dark"] .card,[data-theme="dark"] .auth-card,[data-theme="dark"] .pin-card,[data-theme="dark"] .modal{background:#1A1D27}
[data-theme="dark"] .btn{background:#252836;color:var(--gray-600);border-color:var(--gray-200)}
[data-theme="dark"] .btn:hover{background:var(--gray-200);border-color:#4A4D57}
[data-theme="dark"] .slot-free{background:#252836}
[data-theme="dark"] .slot-booked{background:#1a3a2e;border-color:#2d6b50}
[data-theme="dark"] .slot-teaching{background:#2a2545;border-color:#5b4f8a}
[data-theme="dark"] .slot-past{background:repeating-linear-gradient(135deg,#181b24,#181b24 4px,#101318 4px,#101318 5px)}
[data-theme="dark"] .pin-dot{background:#252836;border-color:var(--gray-200)}
[data-theme="dark"] .pin-key{background:#252836;border-color:var(--gray-200);color:var(--gray-800)}
[data-theme="dark"] .pin-key:hover{background:var(--gray-200)}
[data-theme="dark"] .tab{background:#252836;border-color:var(--gray-200);color:var(--gray-400)}
[data-theme="dark"] .tab.active{background:var(--gray-800);color:#0F1117;border-color:var(--gray-800)}
[data-theme="dark"] .form-group input,[data-theme="dark"] .form-group textarea{background:#252836;border-color:var(--gray-200);color:var(--gray-800)}
[data-theme="dark"] .form-group select{background:#252836;border-color:var(--gray-200);color:var(--gray-800)}
[data-theme="dark"] .booking-row{background:#1A1D27;border-color:var(--gray-200)}
[data-theme="dark"] .status-ok{border-color:#2d6b50}
[data-theme="dark"] .status-err{background:#3a1a1a;border-color:#7a3a3a;color:#FCA5A5}
[data-theme="dark"] .btn-today.at-today{background:#252836;color:var(--gray-400)}
[data-theme="dark"] .btn-today.at-today:hover{background:#252836}
[data-theme="dark"] .leg-dot-free{background:#252836}
[data-theme="dark"] .leg-dot-booked{background:#1a3a2e;border-color:#2d6b50}
[data-theme="dark"] .leg-dot-teaching{background:#2a2545;border-color:#5b4f8a}
[data-theme="dark"] ::-webkit-scrollbar{width:8px;height:8px}
[data-theme="dark"] ::-webkit-scrollbar-track{background:#0F1117}
[data-theme="dark"] ::-webkit-scrollbar-thumb{background:var(--gray-200);border-radius:4px}
[data-theme="dark"] ::-webkit-scrollbar-thumb:hover{background:#4A4D57}
.stats-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-bottom:16px}
.stat-card{background:white;border-radius:var(--radius);border:1px solid var(--gray-200);box-shadow:var(--shadow);padding:20px 24px}
.stat-card-wide{grid-column:span 2}
.stat-number{font-size:30px;font-weight:700;color:var(--gray-800);line-height:1.1;display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-bottom:6px}
.stat-label{font-size:12px;font-weight:500;color:var(--gray-400);text-transform:uppercase;letter-spacing:0.05em}
.stat-hint{font-size:11px;color:var(--gray-400);margin-top:6px}
.stat-delta{font-size:13px;font-weight:600;padding:2px 7px;border-radius:20px}
.stat-delta.positive{background:#D1FAE5;color:#065F46}
.stat-delta.negative{background:#FEE2E2;color:#991B1B}
.stat-bar-wrap{height:6px;background:var(--gray-100);border-radius:3px;margin-top:10px;overflow:hidden}
.stat-bar{height:100%;background:var(--green);border-radius:3px;transition:width 0.4s ease}
.stat-rank{display:flex;flex-direction:column;gap:6px}
.stat-rank-row{display:flex;align-items:center;gap:8px;font-size:13px}
.stat-rank-pos{color:var(--gray-400);font-weight:600;min-width:16px}
.stat-rank-name{flex:1;color:var(--gray-800);font-weight:500}
.stat-rank-count{color:var(--gray-400);font-size:12px}
@media(max-width:720px){.stats-grid{grid-template-columns:repeat(2,1fr)}.stat-card-wide{grid-column:span 2}}
@media(max-width:480px){.stats-grid{grid-template-columns:1fr}.stat-card-wide{grid-column:span 1}}
[data-theme="dark"] .stat-card{background:#1A1D27;border-color:var(--gray-200)}
[data-theme="dark"] .stat-delta.positive{background:#064e3b;color:#6ee7b7}
[data-theme="dark"] .stat-delta.negative{background:#450a0a;color:#fca5a5}
[data-theme="dark"] .stat-bar-wrap{background:var(--gray-100)}
[data-theme="dark"] .stat-rank-name{color:var(--gray-800)}
.confirm-modal{background:white;border-radius:14px;box-shadow:var(--shadow-md);padding:24px;width:380px;max-width:100%}
.confirm-modal h2{font-size:17px;font-weight:600;margin-bottom:4px}
.btn-danger{background:var(--danger);color:white;border-color:var(--danger)}
.btn-danger:hover{background:#b91c1c;border-color:#b91c1c}
[data-theme="dark"] .confirm-modal{background:#1A1D27}
[data-theme="dark"] .btn-danger:hover{background:#c91c1c;border-color:#c91c1c}