:root {
  --bg: #f5f7fb;
  --surface: #ffffff;
  --surface-soft: #eef3ff;
  --text: #172033;
  --muted: #667085;
  --line: #d8dfec;
  --primary: #3157d5;
  --primary-dark: #243fa0;
  --hero-start: #18264c;
  --hero-end: #3157d5;
  --hero-text: #ffffff;
  --hero-muted: rgba(255, 255, 255, 0.78);
  --hero-eyebrow: #b8c6ff;
  --hero-control-bg: rgba(255, 255, 255, 0.12);
  --hero-control-border: rgba(255, 255, 255, 0.22);
  --success: #138a52;
  --warning: #b7791f;
  --danger: #c2413d;
  --shadow: 0 18px 45px rgba(31, 42, 68, 0.12);
  --radius-xl: 28px;
  --radius-lg: 20px;
  --radius-md: 14px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background:
    radial-gradient(circle at top left, rgba(49, 87, 213, 0.16), transparent 34rem),
    var(--bg);
  color: var(--text);
  font-family:
    "Pretendard",
    "Noto Sans KR",
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
  line-height: 1.5;
}

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

button {
  border: 0;
  cursor: pointer;
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.52;
}

.app-shell {
  margin: 0 auto;
  max-width: 1380px;
  padding: 18px 28px 28px;
}

.hero {
  background: linear-gradient(135deg, var(--hero-start), var(--hero-end));
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow);
  color: var(--hero-text);
  overflow: hidden;
  padding: 28px;
}

.auth-panel {
  background: #ffffff;
  border-bottom: 1px solid var(--line);
  box-shadow: 0 2px 12px rgba(31, 42, 68, 0.08);
  padding: 9px 28px;
  position: sticky;
  top: 0;
  width: 100%;
  z-index: 100;
}

.auth-bar {
  align-items: center;
  display: flex;
  gap: 12px;
  margin: 0 auto;
  max-width: 1380px;
}

.auth-bar-right {
  align-items: center;
  display: flex;
  gap: 10px;
  margin-left: auto;
}

.auth-eyebrow {
  margin: 0;
  white-space: nowrap;
}

.topbar,
.hero-grid,
.section-heading,
.file-title-row,
.toolbar,
.request-actions,
.student-row,
.meta-row,
.login-actions {
  align-items: center;
  display: flex;
  gap: 16px;
}

.topbar,
.section-heading,
.file-title-row,
.student-row,
.login-actions {
  justify-content: space-between;
}

.hero h1,
.hero h2,
.section-heading h2,
.file-detail h2,
.teacher-panel h3 {
  margin: 0;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 4.25rem);
  letter-spacing: -0.06em;
}

.class-code {
  font-size: 0.42em;
  letter-spacing: -0.02em;
  opacity: 0.82;
  vertical-align: middle;
}

.hero h2 {
  font-size: clamp(1.75rem, 4vw, 3.1rem);
  letter-spacing: -0.055em;
  line-height: 1.08;
  max-width: 760px;
}

.hero p {
  color: var(--hero-muted);
  margin: 14px 0 0;
  max-width: 700px;
}

.eyebrow {
  color: inherit;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  margin: 0 0 6px;
  text-transform: uppercase;
}

.hero .eyebrow {
  color: var(--hero-eyebrow);
}

.account-actions {
  background: var(--hero-control-bg);
  border: 1px solid var(--hero-control-border);
  border-radius: 999px;
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 5px;
}

.role-button {
  background: transparent;
  border-radius: 999px;
  color: var(--hero-muted);
  font-weight: 800;
  padding: 10px 16px;
}

.role-button.active {
  background: #ffffff;
  color: var(--primary);
}

.account-actions .status-badge {
  background: var(--hero-control-bg);
  color: var(--hero-text);
}

.hero-grid {
  align-items: flex-end;
  justify-content: space-between;
  margin-top: 54px;
}

.status-card {
  background: var(--hero-control-bg);
  border: 1px solid var(--hero-control-border);
  border-radius: var(--radius-lg);
  min-width: 280px;
  padding: 22px;
}

.status-dot {
  background: #77f2b1;
  border-radius: 50%;
  display: inline-block;
  height: 10px;
  margin-right: 8px;
  width: 10px;
}

.main-layout {
  display: grid;
  gap: 22px;
  grid-template-columns: 340px minmax(0, 1fr);
  margin-top: 22px;
}

.sidebar,
.panel {
  background: rgba(255, 255, 255, 0.88);
  border: 1px solid rgba(216, 223, 236, 0.86);
  border-radius: var(--radius-xl);
  box-shadow: 0 16px 36px rgba(31, 42, 68, 0.08);
  padding: 22px;
}

.workspace {
  display: grid;
  gap: 22px;
}

.teacher-panel {
  grid-column: 1 / -1;
}

.teacher-grid {
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.file-list,
.folder-list,
.request-list,
.student-list,
.credential-list,
.palette-grid {
  display: grid;
  gap: 12px;
  margin-top: 18px;
}

.file-card,
.folder-card,
.request-card,
.student-row,
.credential-card,
.notice,
.empty-state {
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 15px;
}

.file-card,
.folder-card {
  text-align: left;
  transition:
    border-color 0.2s ease,
    box-shadow 0.2s ease,
    transform 0.2s ease;
  width: 100%;
}

.file-card:hover,
.file-card.active,
.folder-card:hover,
.folder-card.active {
  border-color: rgba(49, 87, 213, 0.5);
  box-shadow: 0 12px 26px rgba(49, 87, 213, 0.12);
  transform: translateY(-1px);
}

.file-card strong {
  display: block;
  font-size: 1rem;
  margin: 9px 0 4px;
}

.file-card p,
.folder-card p,
.request-card p,
.empty-state p,
.student-row p,
.credential-card p,
.helper-text {
  color: var(--muted);
  margin: 4px 0 0;
}

.badge,
.status-badge {
  border-radius: 999px;
  display: inline-flex;
  font-size: 0.78rem;
  font-weight: 800;
  padding: 5px 10px;
}

.badge-normal {
  background: #e8f7ef;
  color: var(--success);
}

.badge-important {
  background: #fff3db;
  color: var(--warning);
}

.badge-critical {
  background: #fde9e7;
  color: var(--danger);
}

.status-pending {
  background: #fff3db;
  color: var(--warning);
}

.status-approved {
  background: #e8f7ef;
  color: var(--success);
}

.status-rejected,
.status-banned {
  background: #fde9e7;
  color: var(--danger);
}

.status-open {
  background: var(--surface-soft);
  color: var(--primary);
}

.secondary-button,
.primary-button,
.danger-button,
.ghost-button {
  border-radius: 12px;
  font-weight: 800;
  padding: 10px 13px;
}

.primary-button {
  background: var(--primary);
  color: #ffffff;
}

.primary-button:hover {
  background: var(--primary-dark);
}

.secondary-button {
  background: var(--surface-soft);
  color: var(--primary);
}

.danger-button {
  background: #fde9e7;
  color: var(--danger);
}

.ghost-button {
  background: transparent;
  color: var(--primary);
}

.compact-heading {
  margin-top: 22px;
}

.login-form {
  display: grid;
  gap: 12px;
}

.mail-result {
  background: var(--surface-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  margin-top: 16px;
  padding: 16px 18px;
}

.mail-result.hidden {
  display: none;
}

.mail-result h4 {
  color: var(--muted);
  font-size: 0.85rem;
  letter-spacing: 0.05em;
  margin: 0 0 10px;
  text-transform: uppercase;
}

.mail-credential-row {
  align-items: center;
  display: flex;
  gap: 10px;
  justify-content: space-between;
  margin-bottom: 8px;
}

.mail-credential-row:last-child {
  margin-bottom: 0;
}

.mail-credential-label {
  color: var(--muted);
  font-size: 0.88rem;
  white-space: nowrap;
}

.mail-credential-value {
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: 8px;
  font-family: monospace;
  font-size: 0.95rem;
  font-weight: 700;
  padding: 4px 10px;
}

.mail-open-link {
  display: block;
  margin-top: 14px;
  text-align: center;
}

.login-subtitle-row {
  align-items: center;
  display: flex;
  gap: 10px;
  margin-top: 8px;
}

.login-subtitle-row .helper-text {
  margin: 0;
}

.login-error {
  align-items: center;
  background: #fff1f1;
  border: 1px solid #f5c2c2;
  border-radius: 10px;
  color: var(--danger);
  display: flex;
  font-size: 0.92rem;
  font-weight: 600;
  gap: 8px;
  padding: 10px 14px;
}

.login-error::before {
  content: "⚠";
  font-size: 1rem;
}

.login-error.hidden {
  display: none;
}

.input-example {
  color: #a8b0bf;
  display: block;
  font-size: 0.75em;
  font-weight: 700;
  margin: 3px 0 7px;
}

.credential-card {
  display: grid;
  gap: 5px;
}

.credential-card code {
  background: var(--surface-soft);
  border-radius: 8px;
  color: var(--primary);
  display: inline-block;
  font-weight: 800;
  padding: 3px 7px;
}

.folder-card strong {
  display: block;
}

.palette-grid {
  grid-template-columns: repeat(auto-fill, minmax(92px, 1fr));
}

.palette-button {
  align-items: end;
  border: 2px solid transparent;
  border-radius: 16px;
  color: #172033;
  display: flex;
  font-size: 0.72rem;
  font-weight: 900;
  justify-content: center;
  min-height: 72px;
  padding: 8px;
  text-shadow: 0 1px 10px rgba(255, 255, 255, 0.8);
}

.palette-button.active {
  border-color: var(--primary);
  box-shadow: 0 10px 20px rgba(31, 42, 68, 0.16);
}

.modal {
  align-items: center;
  background: rgba(23, 32, 51, 0.58);
  display: flex;
  inset: 0;
  justify-content: center;
  padding: 22px;
  position: fixed;
  z-index: 30;
}

.modal-card {
  background: #ffffff;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow);
  max-height: min(760px, 90vh);
  max-width: 520px;
  overflow: auto;
  padding: 24px;
  width: 100%;
}

.readonly-nickname {
  background: #f8fafc;
  border: 1px dashed var(--line);
  border-radius: 10px;
  color: var(--muted);
  display: inline-block;
  font-weight: 800;
  margin-top: 6px;
  padding: 7px 10px;
}

.locked-state {
  align-items: center;
  background: #000000 !important;
  border: 0;
  border-radius: var(--radius-lg);
  color: #ffffff;
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: 280px;
  padding: 32px 20px;
  text-align: center;
}

.locked-state.compact {
  min-height: 220px;
}

.locked-icon {
  font-size: clamp(4rem, 11vw, 8rem);
  line-height: 1;
  margin-bottom: 18px;
}

.locked-title {
  color: #ffffff;
  font-size: clamp(2rem, 5vw, 4.25rem);
  font-weight: 900;
  letter-spacing: -0.06em;
  line-height: 1;
}

.file-detail {
  display: grid;
  gap: 20px;
}

.meta-row {
  flex-wrap: wrap;
}

.content-preview,
textarea,
input,
select {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  width: 100%;
}

.content-preview {
  background: #fbfcff;
  min-height: 230px;
  padding: 20px;
  white-space: pre-wrap;
}

textarea {
  min-height: 180px;
  padding: 14px;
  resize: vertical;
}

input,
select {
  padding: 12px 13px;
}

.editor-form,
.request-form {
  display: grid;
  gap: 12px;
}

.toolbar {
  background: #fbfcff;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  flex-wrap: wrap;
  padding: 12px;
}

.toolbar label {
  align-items: center;
  color: var(--muted);
  display: inline-flex;
  font-size: 0.9rem;
  font-weight: 800;
  gap: 8px;
}

.toolbar input[type="color"] {
  height: 38px;
  padding: 4px;
  width: 54px;
}

.notice {
  background: #fff8e8;
  border-color: #f1c970;
  color: #7a4d00;
  font-weight: 700;
  margin-top: 14px;
}

.empty-state {
  border-style: dashed;
  text-align: center;
}

.hidden {
  display: none !important;
}

.toast {
  background: #172033;
  border-radius: 999px;
  bottom: 26px;
  box-shadow: var(--shadow);
  color: #ffffff;
  font-weight: 800;
  left: 50%;
  padding: 13px 18px;
  position: fixed;
  transform: translateX(-50%);
  z-index: 20;
}

@media (max-width: 960px) {
  .app-shell {
    padding: 16px;
  }

  .topbar,
  .hero-grid,
  .main-layout,
  .teacher-grid,
  .auth-grid {
    display: grid;
    grid-template-columns: 1fr;
  }

.account-actions {
    width: max-content;
  }
}

@media (max-width: 640px) {
  .hero,
  .sidebar,
  .panel {
    border-radius: 20px;
    padding: 18px;
  }

  .section-heading,
  .file-title-row,
  .request-actions,
  .student-row,
  .login-actions,
  .login-subtitle-row {
    align-items: stretch;
    display: grid;
  }
}