/* ============ DESIGN TOKENS ============ */
:root {
  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1rem + 0.75vw, 1.5rem);
  --text-xl: clamp(1.5rem, 1.2rem + 1.25vw, 2.25rem);
  --text-2xl: clamp(2rem, 1.2rem + 2.5vw, 3.25rem);

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Surfaces — warm parchment */
  --color-bg: #f6f3ec;
  --color-surface: #ffffff;
  --color-surface-2: #fbf9f4;
  --color-surface-offset: #eee9dd;
  --color-border: #ddd5c3;
  --color-divider: #e6e0d1;

  /* Text — deep navy ink */
  --color-text: #1c2536;
  --color-text-muted: #5a6478;
  --color-text-faint: #8b93a3;
  --color-text-inverse: #f6f3ec;

  /* Primary — Trinity Navy */
  --color-primary: #1c3358;
  --color-primary-hover: #14263f;
  --color-primary-active: #0e1c30;
  --color-primary-highlight: #d9e0ea;

  /* Accent — Academic Gold */
  --color-accent: #a8722f;
  --color-accent-hover: #8c5d24;
  --color-accent-highlight: #ecdcc2;

  --color-error: #a4293e;
  --color-error-highlight: #f0d7db;
  --color-success: #2f6b3f;
  --color-success-highlight: #d9e8db;

  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  --shadow-sm: 0 1px 2px rgba(28, 37, 54, 0.06);
  --shadow-md: 0 4px 16px rgba(28, 37, 54, 0.1);
  --shadow-lg: 0 16px 40px rgba(28, 37, 54, 0.16);

  --font-display: 'Source Serif 4', Georgia, serif;
  --font-body: 'General Sans', 'Helvetica Neue', sans-serif;
  --font-mono: 'IBM Plex Mono', 'Courier New', monospace;
}

/* ============ APP SHELL ============ */

body {
  background:
    radial-gradient(circle at 12% -10%, rgba(28, 51, 88, 0.06), transparent 45%),
    var(--color-bg);
}

.app-shell {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

/* ---- header ---- */
.app-header {
  background: var(--color-primary);
  color: var(--color-text-inverse);
  box-shadow: var(--shadow-sm);
}
.app-header__inner {
  max-width: 1180px;
  margin: 0 auto;
  padding: var(--space-4) var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}
.brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}
.brand__mark {
  flex-shrink: 0;
}
.brand__mark img {
  display: block;
  width: 32px;
  height: 32px;
  object-fit: contain;
}
.brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.25;
}
.brand__name {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--text-base);
  letter-spacing: 0.01em;
}
.brand__tagline {
  font-size: var(--text-xs);
  color: rgba(246, 243, 236, 0.65);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}
.header-actions__email {
  font-size: var(--text-xs);
  color: rgba(246, 243, 236, 0.75);
}

/* ---- buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 600;
  white-space: nowrap;
  border: 1px solid transparent;
}
.btn-primary {
  background: var(--color-accent);
  color: #fff;
}
.btn-primary:hover {
  background: var(--color-accent-hover);
}
.btn-primary:disabled {
  background: var(--color-text-faint);
  cursor: not-allowed;
}
.btn-outline {
  background: transparent;
  border-color: var(--color-border);
  color: var(--color-text);
}
.btn-outline:hover {
  background: var(--color-surface-offset);
}
.btn-ghost {
  background: rgba(246, 243, 236, 0.1);
  color: var(--color-text-inverse);
  border-color: rgba(246, 243, 236, 0.25);
}
.btn-ghost:hover {
  background: rgba(246, 243, 236, 0.18);
}
.btn-block {
  width: 100%;
}
.btn-sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-xs);
}

/* ---- main / centering ---- */
.app-main {
  flex: 1;
  display: flex;
  flex-direction: column;
}
.center-screen {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-8) var(--space-4);
}

/* ---- auth card ---- */
.auth-card {
  width: 100%;
  max-width: 420px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  padding: var(--space-10) var(--space-8);
}
.auth-card__logo {
  display: flex;
  justify-content: center;
  margin-bottom: var(--space-4);
}
.auth-card__logo img {
  display: block;
  width: 88px;
  height: 88px;
  object-fit: contain;
}
.auth-card__brand-name {
  text-align: center;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-lg);
  letter-spacing: 0.06em;
  color: var(--color-accent);
  line-height: 1.4;
  margin-bottom: var(--space-6);
}
.auth-card__brand-name span {
  display: block;
  font-family: var(--font-body);
  font-weight: 500;
  font-size: var(--text-xs);
  letter-spacing: 0.03em;
  color: var(--color-text-muted);
  text-transform: uppercase;
  margin-top: 2px;
}
.auth-card__title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 600;
  text-align: center;
  margin-bottom: var(--space-2);
}
.auth-card__subtitle {
  text-align: center;
  color: var(--color-text-muted);
  font-size: var(--text-sm);
  margin-bottom: var(--space-8);
}
.field {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-bottom: var(--space-5);
}
.field label {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}
.field input,
.field select {
  padding: var(--space-3) var(--space-4);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface-2);
  font-size: var(--text-sm);
}
.field input:focus,
.field select:focus {
  border-color: var(--color-primary);
  background: #fff;
}
.field input.invalid {
  border-color: var(--color-error);
}
.auth-toggle {
  text-align: center;
  margin-top: var(--space-6);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}
.auth-toggle button {
  color: var(--color-primary);
  font-weight: 600;
  text-decoration: underline;
}
.auth-message {
  font-size: var(--text-sm);
  border-radius: var(--radius-md);
  padding: var(--space-3) var(--space-4);
  margin-bottom: var(--space-5);
}
.auth-message--error {
  background: var(--color-error-highlight);
  color: var(--color-error);
}
.auth-message--success {
  background: var(--color-success-highlight);
  color: var(--color-success);
}
.auth-message[hidden] {
  display: none;
}

/* ---- paywall ---- */
.paywall-card {
  width: 100%;
  max-width: 460px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  padding: var(--space-10) var(--space-8);
  text-align: center;
}
.paywall-card__badge {
  display: inline-block;
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-accent);
  background: var(--color-accent-highlight);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  margin-bottom: var(--space-5);
}
.paywall-card__title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 600;
  margin-bottom: var(--space-3);
}
.paywall-card__price {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--space-1);
}
.paywall-card__price span {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-muted);
}
.paywall-card__desc {
  color: var(--color-text-muted);
  font-size: var(--text-sm);
  margin-bottom: var(--space-8);
}
.paywall-card__list {
  text-align: left;
  list-style: none;
  margin-bottom: var(--space-8);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}
.paywall-card__list li {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  font-size: var(--text-sm);
  color: var(--color-text);
}
.paywall-card__check {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  border-radius: var(--radius-full);
  background: var(--color-success-highlight);
  color: var(--color-success);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 700;
  margin-top: 1px;
}
.paywall-footnote {
  margin-top: var(--space-6);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}
.spinner {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  border: 2px solid rgba(255, 255, 255, 0.4);
  border-top-color: #fff;
  animation: spin 0.7s linear infinite;
}
.spinner-dark {
  border: 2px solid rgba(28, 37, 54, 0.15);
  border-top-color: var(--color-primary);
}
@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* ---- generic loading screen ---- */
.loading-screen {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-4);
  color: var(--color-text-muted);
  font-size: var(--text-sm);
}

/* ============ INVOICE APP ============ */
.workspace {
  max-width: 1180px;
  margin: 0 auto;
  width: 100%;
  padding: var(--space-8) var(--space-6);
  display: grid;
  grid-template-columns: minmax(320px, 420px) 1fr;
  gap: var(--space-8);
  align-items: start;
}

.panel {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
}
.panel__head {
  padding: var(--space-6) var(--space-6) var(--space-4);
  border-bottom: 1px solid var(--color-divider);
}
.panel__title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 600;
}
.panel__subtitle {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  margin-top: var(--space-1);
}
.panel__body {
  padding: var(--space-6);
}
.panel__footer {
  padding: var(--space-5) var(--space-6);
  border-top: 1px solid var(--color-divider);
  display: flex;
  gap: var(--space-3);
}

fieldset.field-group {
  border: none;
  margin-bottom: var(--space-6);
}
fieldset.field-group legend {
  font-size: var(--text-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-primary);
  margin-bottom: var(--space-3);
  padding: 0;
}
.static-field {
  padding: var(--space-3) var(--space-4);
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface-offset);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
}

.line-item-row {
  display: grid;
  grid-template-columns: 1fr 120px auto;
  gap: var(--space-3);
  align-items: center;
  margin-bottom: var(--space-3);
}
.line-item-row .amount-input {
  position: relative;
}
.line-item-row .amount-input::before {
  content: '$';
  position: absolute;
  left: var(--space-3);
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-faint);
  font-size: var(--text-sm);
  pointer-events: none;
}
.line-item-row .amount-input input {
  padding-left: calc(var(--space-4) + 10px);
  width: 100%;
}
.icon-btn-remove {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  color: var(--color-error);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-base);
  flex-shrink: 0;
}
.icon-btn-remove:hover {
  background: var(--color-error-highlight);
}
.icon-btn-remove:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

.preview-panel__scroll {
  padding: var(--space-6);
  display: flex;
  justify-content: center;
  overflow-x: auto;
}

/* ---- invoice document sheet ---- */
.invoice-sheet {
  width: 100%;
  max-width: 720px;
  background: #ffffff;
  color: #1c2536;
  padding: 48px 44px;
  box-shadow: var(--shadow-md);
  border-radius: var(--radius-md);
}
.invoice-doc-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 24px;
  padding-bottom: 20px;
  border-bottom: 2px solid #1c3358;
  margin-bottom: 24px;
}
.invoice-doc-header__brand {
  display: flex;
  align-items: center;
  gap: 14px;
}
.invoice-doc-header__logo {
  display: block;
  width: 64px;
  height: 64px;
  object-fit: contain;
  flex-shrink: 0;
}
.invoice-doc-header__company {
  font-family: 'Source Serif 4', Georgia, serif;
  font-weight: 700;
  font-size: 19px;
  letter-spacing: 0.04em;
  color: #1c3358;
  line-height: 1.3;
}
.invoice-doc-header__company-sub {
  font-family: 'Source Serif 4', Georgia, serif;
  font-weight: 600;
  font-size: 13px;
  color: #a8722f;
  margin-bottom: 4px;
}
.invoice-doc-header__meta {
  font-size: 12px;
  color: #5a6478;
  line-height: 1.6;
}
.invoice-doc-header__title {
  text-align: right;
}
.invoice-doc-header__label {
  font-family: 'Source Serif 4', Georgia, serif;
  font-size: 22px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: #a8722f;
}
.invoice-doc-header__date {
  font-size: 12px;
  color: #5a6478;
  margin-top: 4px;
}

.invoice-doc-facts {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 24px;
}
.invoice-doc-facts__block {
  padding: 14px 16px;
  background: #fbf9f4;
  border: 1px solid #eee9dd;
  border-radius: 8px;
}
.invoice-doc-facts__label {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #a8722f;
  margin-bottom: 4px;
}
.invoice-doc-facts__value {
  font-size: 14px;
  font-weight: 600;
  color: #1c2536;
}
.invoice-doc-facts__value--muted {
  font-weight: 400;
  color: #5a6478;
  font-size: 13px;
}

.invoice-doc-service {
  padding: 12px 16px;
  border-radius: 8px;
  background: #d9e0ea;
  color: #1c3358;
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 24px;
}

.invoice-doc-table {
  width: 100%;
  margin-bottom: 8px;
}
.invoice-doc-table thead th {
  text-align: left;
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #5a6478;
  padding: 8px 4px;
  border-bottom: 1px solid #ddd5c3;
}
.invoice-doc-table thead th.num {
  text-align: right;
}
.invoice-doc-table tbody td {
  padding: 10px 4px;
  font-size: 14px;
  border-bottom: 1px solid #eee9dd;
}
.invoice-doc-table tbody td.num {
  text-align: right;
  font-family: 'IBM Plex Mono', monospace;
  font-weight: 500;
}
.invoice-doc-table tbody tr td:empty::before {
  content: '\2014';
  color: #8b93a3;
}

.invoice-doc-totals {
  display: flex;
  justify-content: flex-end;
  margin-top: 16px;
  margin-bottom: 28px;
}
.invoice-doc-totals__figures {
  min-width: 240px;
}
.invoice-doc-totals__figures .row {
  display: flex;
  justify-content: space-between;
  padding: 8px 0;
  font-size: 14px;
  color: #5a6478;
}
.invoice-doc-totals__figures .row.total {
  border-top: 2px solid #1c3358;
  margin-top: 4px;
  padding-top: 12px;
  font-weight: 700;
  font-size: 17px;
  color: #1c3358;
}
.invoice-doc-totals__figures .row .num {
  font-family: 'IBM Plex Mono', monospace;
}

.invoice-doc-payment {
  padding: 16px;
  border: 1px solid #eee9dd;
  border-radius: 8px;
  background: #fbf9f4;
  margin-bottom: 28px;
  font-size: 14px;
}
.invoice-doc-payment strong {
  color: #1c3358;
}
.invoice-doc-payment .card-last4 {
  font-family: 'IBM Plex Mono', monospace;
  font-weight: 600;
  letter-spacing: 0.05em;
}

.invoice-doc-footer {
  padding-top: 20px;
  border-top: 1px solid #ddd5c3;
  font-size: 11px;
  line-height: 1.7;
  color: #5a6478;
}
.invoice-doc-footer p {
  margin-bottom: 6px;
}
.invoice-doc-footer .legal-strong {
  font-weight: 700;
  color: #1c2536;
}
.invoice-doc-footer .legal-caps {
  font-weight: 700;
  color: #a4293e;
  text-transform: uppercase;
  letter-spacing: 0.01em;
}

/* ---- toast ---- */
.toast-region {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  z-index: 100;
}
.toast {
  background: var(--color-primary);
  color: #fff;
  padding: var(--space-3) var(--space-5);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  font-size: var(--text-sm);
  max-width: 320px;
}
.toast--error {
  background: var(--color-error);
}
.toast--success {
  background: var(--color-success);
}

[hidden] {
  display: none !important;
}

/* ============ RESPONSIVE ============ */
@media (max-width: 980px) {
  .workspace {
    grid-template-columns: 1fr;
  }
}
@media (max-width: 640px) {
  .app-header__inner {
    padding: var(--space-3) var(--space-4);
  }
  .header-actions__email {
    display: none;
  }
  .brand__tagline {
    font-size: 9.5px;
    letter-spacing: 0.02em;
    white-space: nowrap;
  }
  .workspace {
    padding: var(--space-5) var(--space-4);
  }
  .invoice-sheet {
    padding: 28px 20px;
  }
  .invoice-doc-header {
    flex-direction: column;
    gap: 12px;
  }
  .invoice-doc-header__title {
    text-align: left;
  }
  .invoice-doc-facts {
    grid-template-columns: 1fr;
  }
  .grid-2 {
    grid-template-columns: 1fr;
  }
  .line-item-row {
    grid-template-columns: 1fr;
  }
  .auth-card,
  .paywall-card {
    padding: var(--space-8) var(--space-5);
  }
}