:root {
  color-scheme: light;
  --bg: #edf1f5;
  --ink: #14212b;
  --muted: #66717c;
  --line: #cdd6df;
  --panel: #ffffff;
  --accent: #176b87;
  --accent-strong: #0f5369;
  --mark: #f3b23c;
  --paper: #fffdf8;
  --shadow: 0 18px 50px rgba(26, 43, 56, 0.14);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--ink);
  font-family: "Noto Sans TC", "Microsoft JhengHei", system-ui, sans-serif;
}

button,
input,
textarea,
select {
  font: inherit;
}

button {
  min-height: 42px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
  cursor: pointer;
  font-weight: 700;
}

.button-link {
  align-items: center;
  border: 1px solid var(--line);
  border-radius: 8px;
  cursor: pointer;
  display: inline-flex;
  font-weight: 700;
  justify-content: center;
  min-height: 42px;
  padding: 0 14px;
  text-align: center;
  text-decoration: none;
}

button:hover {
  border-color: var(--accent);
}

.primary {
  border-color: var(--accent);
  background: var(--accent);
  color: #fff;
}

.primary:hover {
  background: var(--accent-strong);
}

.primary:disabled,
button:disabled {
  cursor: not-allowed;
  opacity: 0.55;
}

.full {
  width: 100%;
  margin-bottom: 10px;
}

.monitor-form {
  margin: 0;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  border: 0;
  white-space: nowrap;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: clamp(24px, 4vw, 52px) clamp(18px, 5vw, 56px);
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.97), rgba(241, 248, 251, 0.9)),
    #ffffff;
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
  position: sticky;
  top: 0;
  z-index: 5;
}

body[data-page="teacher"] .topbar {
  justify-content: center;
  text-align: center;
}

body[data-page="teacher"] .topbar > div {
  display: grid;
  justify-items: center;
  width: min(100%, 960px);
  margin: 0 auto;
}

body[data-page="teacher"] .topbar .eyebrow,
body[data-page="teacher"] .topbar h1 {
  width: 100%;
  margin-left: auto;
  margin-right: auto;
  text-align: center !important;
}

.eyebrow {
  display: inline-block;
  max-width: 100%;
  margin: 0 0 10px;
  color: var(--accent);
  font-size: clamp(1.75rem, 4.2vw, 3.5rem);
  font-weight: 900;
  letter-spacing: 0;
  line-height: 1.08;
  overflow-wrap: anywhere;
  text-shadow: 0 8px 18px rgba(23, 107, 135, 0.12);
  text-transform: none;
}

h1,
h2,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 0;
  font-size: clamp(1.8rem, 3.2vw, 3rem);
  line-height: 1.08;
}

h2 {
  margin-bottom: 0;
  font-size: 1rem;
}

.tabs {
  display: flex;
  gap: 8px;
  padding: 4px;
  background: #e3eaf0;
  border-radius: 10px;
}

.tab {
  min-width: 92px;
  border: 0;
  background: transparent;
}

.tab.active {
  background: #fff;
  box-shadow: 0 4px 16px rgba(23, 43, 56, 0.12);
}

main {
  padding: 22px clamp(16px, 4vw, 44px) 44px;
}

.workspace {
  display: none;
  grid-template-columns: minmax(300px, 380px) minmax(0, 1fr);
  gap: 22px;
  align-items: start;
}

.workspace.active {
  display: grid;
}

.teacher-flow {
  display: none;
  gap: 22px;
  max-width: 980px;
  margin: 0 auto;
}

.teacher-flow.active {
  display: grid;
}

.flow-panel {
  position: static;
}

.teacher-preview-block {
  display: grid;
  gap: 12px;
}

.teacher-preview-block .hint {
  margin-bottom: 0;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
  padding: 18px;
  position: sticky;
  top: 112px;
}

.compact {
  max-width: 420px;
}

.section-title {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 8px 0 12px;
}

.section-title span {
  display: grid;
  width: 28px;
  height: 28px;
  place-items: center;
  border-radius: 50%;
  background: #dbeef3;
  color: var(--accent-strong);
  font-weight: 900;
}

.field {
  display: grid;
  gap: 7px;
  margin-bottom: 14px;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 700;
}

input,
textarea,
select {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
  padding: 10px 12px;
  resize: vertical;
}

textarea {
  line-height: 1.55;
}

.upload {
  display: grid;
  gap: 4px;
  padding: 14px;
  border: 1px dashed #9eb0bd;
  border-radius: 8px;
  background: #f8fafc;
  color: var(--ink);
  cursor: pointer;
}

.upload input {
  display: none;
}

.upload small,
.hint,
.status {
  color: var(--muted);
  line-height: 1.5;
}

.paste-zone {
  margin: 0 0 14px;
  padding: 14px;
  border: 1px dashed #9eb0bd;
  border-radius: 8px;
  background: #fff;
  color: var(--muted);
  text-align: center;
  font-weight: 700;
}

.paste-zone-large {
  display: grid;
  min-height: 96px;
  place-items: center;
  background: #f8fafc;
  color: var(--accent-strong);
  font-size: 1rem;
}

.upload-dropzone {
  margin-bottom: 14px;
  min-height: 118px;
  place-content: center;
  text-align: center;
}

.upload-dropzone strong {
  color: var(--accent-strong);
}

.paste-zone:focus {
  outline: 3px solid rgba(23, 107, 135, 0.2);
  border-color: var(--accent);
}

.paste-zone.active {
  border-color: var(--accent);
  background: #eef8fb;
  color: var(--accent-strong);
}

.status {
  min-height: 22px;
  margin-bottom: 14px;
  font-size: 0.9rem;
}

.status.error {
  color: #a2352a;
}

.status.success {
  color: #17633a;
}

.qr-panel {
  display: grid;
  justify-items: center;
  gap: 10px;
  margin: 6px 0 14px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f8fafc;
}

.qr-panel[hidden] {
  display: none;
}

.qr-code {
  display: grid;
  width: 204px;
  height: 204px;
  place-items: center;
  padding: 10px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.qr-code canvas,
.qr-code img {
  width: 184px;
  height: 184px;
}

.share-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 10px;
}

.share-actions button {
  width: 100%;
}

.monitor-panel {
  max-width: 620px;
  margin: 0 auto;
  position: static;
}

.monitor-state {
  margin: 16px 0;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f8fafc;
  color: var(--accent-strong);
  font-size: 1.3rem;
  font-weight: 900;
}

.monitor-state[data-status="completed"] {
  background: #eef8f0;
  color: #17633a;
}

.monitor-state[data-status="missing"],
.monitor-state[data-status="expired"],
.monitor-state[data-status="offline"] {
  background: #fff4f2;
  color: #a2352a;
}

.toolbar {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin: 8px 0 12px;
}

.document-shell {
  min-width: 0;
}

.doc-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 10px;
  color: var(--muted);
  font-weight: 800;
}

.doc-actions p {
  margin-bottom: 0;
}

.document {
  width: min(100%, 860px);
  aspect-ratio: 3 / 4;
  margin: 0 auto;
  position: relative;
  overflow: hidden;
  background: var(--paper);
  border: 1px solid #d7cab4;
  box-shadow: var(--shadow);
}

.doc-canvas {
  display: block;
  width: 100%;
  height: 100%;
}

.paper-text {
  padding: 58px 64px;
  line-height: 1.85;
  white-space: pre-wrap;
}

.paper-text h2 {
  margin-bottom: 28px;
  text-align: center;
  font-size: 1.7rem;
}

.field-layer {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.signature-field {
  position: absolute;
  display: grid;
  place-items: center;
  min-width: 42px;
  min-height: 28px;
  border: 2px dashed var(--accent);
  background: rgba(23, 107, 135, 0.08);
  color: var(--accent-strong);
  font-weight: 900;
  pointer-events: auto;
  user-select: none;
  touch-action: none;
  overflow: visible;
}

.teacher-doc .signature-field {
  cursor: move;
}

.signature-field.editable {
  outline: 2px solid rgba(243, 178, 60, 0.35);
  outline-offset: 2px;
}

.signature-label {
  display: block;
  max-width: calc(100% - 18px);
  overflow: hidden;
  padding: 0 8px;
  pointer-events: none;
  text-align: center;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.resize-handle {
  position: absolute;
  right: -14px;
  bottom: -14px;
  z-index: 3;
  width: 34px;
  height: 34px;
  border: 3px solid #fff;
  border-radius: 8px;
  background: var(--mark);
  box-shadow: 0 2px 8px rgba(20, 33, 43, 0.24);
  cursor: nwse-resize;
  pointer-events: auto;
  touch-action: none;
}

.resize-handle::before {
  content: "";
  position: absolute;
  right: 8px;
  bottom: 8px;
  width: 12px;
  height: 12px;
  border-right: 3px solid rgba(20, 33, 43, 0.65);
  border-bottom: 3px solid rgba(20, 33, 43, 0.65);
}

.signature-field.selected {
  outline: 3px solid rgba(243, 178, 60, 0.65);
  outline-offset: 2px;
}

.signature-field img {
  max-width: 96%;
  max-height: 92%;
}

.signature-pad-wrap {
  background: #f7fafc;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 8px;
}

#signaturePad {
  display: block;
  width: 100%;
  height: 180px;
  background: #fff;
  border-radius: 6px;
  touch-action: none;
}

.completed-image {
  display: none;
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 8px;
  margin-top: 12px;
}

.completed-image.active {
  display: block;
}

@media (max-width: 900px) {
  .topbar {
    align-items: stretch;
    flex-direction: column;
    gap: 10px;
    padding: 20px clamp(16px, 5vw, 28px);
  }

  .eyebrow {
    margin-bottom: 8px;
    font-size: clamp(1.35rem, 7vw, 2.4rem);
  }

  h1 {
    font-size: clamp(1.7rem, 8vw, 2.6rem);
  }

  .tabs {
    width: 100%;
  }

  .tab {
    flex: 1;
  }

  .workspace,
  .workspace.active {
    display: block;
  }

  .panel {
    position: static;
    margin-bottom: 18px;
  }

  .paper-text {
    padding: 34px 26px;
  }

  .document {
    width: 100%;
  }
}