*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --font-mono: ui-monospace, 'SF Mono', Menlo, Monaco, 'Cascadia Code', monospace;
  --color-bg: #fafafa;
  --color-surface: #ffffff;
  --color-text: #111111;
  --color-text-muted: #666666;
  --color-border: #cccccc;
  --color-border-light: #eeeeee;
  --color-primary: #111111;
  --color-primary-hover: #333333;
  --color-success: #006600;
  --color-success-bg: #e8f8e8;
  --color-error: #cc0000;
  --color-error-bg: #fde8e8;
  --color-info: #0066cc;
  --color-info-bg: #e8f4fd;
  --color-warning: #996600;
  --color-warning-bg: #fff8e8;
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --radius-sm: 3px;
  --radius-md: 4px;
  --radius-lg: 8px;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 2px 4px rgba(0,0,0,0.1);
  --shadow-lg: 0 4px 12px rgba(0,0,0,0.15);
}

html { font-size: 16px; -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }
body { font-family: var(--font-mono); background: var(--color-bg); color: var(--color-text); line-height: 1.5; min-height: 100vh; }

h1, h2, h3, h4 { font-weight: 600; line-height: 1.25; }
h1 { font-size: 1.5rem; }
h2 { font-size: 1.25rem; }
h3 { font-size: 1rem; }
h4 { font-size: 0.875rem; }
p { margin-bottom: var(--spacing-md); }
p:last-child { margin-bottom: 0; }
a { color: var(--color-text); text-decoration: underline; }
a:hover { color: var(--color-text-muted); }
small, .text-small { font-size: 0.75rem; }
.text-muted { color: var(--color-text-muted); }

.container { max-width: 1200px; margin: 0 auto; padding: var(--spacing-xl); }
.container-narrow { max-width: 640px; margin: 0 auto; padding: var(--spacing-xl); }

.header { display: flex; align-items: center; justify-content: space-between; padding: var(--spacing-md) var(--spacing-xl); border-bottom: 1px solid var(--color-border-light); background: var(--color-surface); }
.header-brand { font-weight: 600; text-decoration: none; color: var(--color-text); }
.header-brand span { color: var(--color-text-muted); font-weight: 400; }

.btn { display: inline-flex; align-items: center; justify-content: center; gap: var(--spacing-sm); padding: 0.75rem 1.25rem; font-family: var(--font-mono); font-size: 0.875rem; font-weight: 600; text-decoration: none; border: 1px solid transparent; border-radius: var(--radius-md); cursor: pointer; transition: all 0.15s ease; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-primary { background: var(--color-primary); color: #fff; border-color: var(--color-primary); }
.btn-primary:hover:not(:disabled) { background: var(--color-primary-hover); }
.btn-secondary { background: var(--color-surface); color: var(--color-text); border-color: var(--color-border); }
.btn-secondary:hover:not(:disabled) { background: var(--color-bg); }
.btn-ghost { background: transparent; color: var(--color-text); border-color: transparent; }
.btn-ghost:hover:not(:disabled) { background: var(--color-bg); }
.btn-sm { padding: 0.5rem 0.75rem; font-size: 0.75rem; }
.btn-lg { padding: 1rem 1.5rem; font-size: 1rem; }

label { display: block; font-size: 0.75rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em; color: var(--color-text-muted); margin-bottom: var(--spacing-sm); }
input[type="text"], input[type="email"], input[type="password"], textarea, select { width: 100%; padding: 0.75rem; font-family: var(--font-mono); font-size: 1rem; color: var(--color-text); background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-md); transition: border-color 0.15s; }
input:focus, textarea:focus, select:focus { outline: none; border-color: var(--color-primary); }
input::placeholder, textarea::placeholder { color: var(--color-text-muted); }
.form-group { margin-bottom: var(--spacing-lg); }
.form-hint { font-size: 0.75rem; color: var(--color-text-muted); margin-top: var(--spacing-xs); }
.form-error { font-size: 0.75rem; color: var(--color-error); margin-top: var(--spacing-xs); }

.dropzone { border: 2px dashed var(--color-border); border-radius: var(--radius-md); padding: var(--spacing-xl); text-align: center; cursor: pointer; transition: all 0.15s; }
.dropzone:hover, .dropzone.drag-over { border-color: var(--color-primary); background: rgba(0,0,0,0.02); }
.dropzone.has-file { border-style: solid; border-color: var(--color-primary); background: var(--color-surface); }
.dropzone-text { color: var(--color-text-muted); }
.dropzone-filename { font-weight: 600; color: var(--color-text); word-break: break-all; }

.card { background: var(--color-surface); border: 1px solid var(--color-border-light); border-radius: var(--radius-md); padding: var(--spacing-lg); }
.card-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: var(--spacing-md); }

.status { padding: var(--spacing-md); border-radius: var(--radius-md); font-size: 0.875rem; }
.status-info { background: var(--color-info-bg); color: var(--color-info); }
.status-success { background: var(--color-success-bg); color: var(--color-success); }
.status-error { background: var(--color-error-bg); color: var(--color-error); }
.status-warning { background: var(--color-warning-bg); color: var(--color-warning); }

.loading { display: flex; align-items: center; justify-content: center; padding: var(--spacing-xl); }
.spinner { width: 24px; height: 24px; border: 2px solid var(--color-border); border-top-color: var(--color-primary); border-radius: 50%; animation: spin 0.8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

.app-layout { display: grid; grid-template-columns: 200px 1fr; grid-template-rows: auto 1fr auto; height: 100vh; }
.app-header { grid-column: 1 / -1; }
.app-sidebar { background: var(--color-surface); border-right: 1px solid var(--color-border-light); overflow-y: auto; padding: var(--spacing-md); }
.app-main { overflow: auto; background: var(--color-bg); position: relative; }
.app-toolbar { grid-column: 1 / -1; background: var(--color-surface); border-top: 1px solid var(--color-border-light); padding: var(--spacing-md) var(--spacing-xl); display: flex; align-items: center; gap: var(--spacing-md); }

.page-thumbs { display: flex; flex-direction: column; gap: var(--spacing-sm); }
.page-thumb { position: relative; border: 2px solid var(--color-border-light); border-radius: var(--radius-sm); cursor: pointer; transition: border-color 0.15s; overflow: hidden; }
.page-thumb:hover { border-color: var(--color-border); }
.page-thumb.active { border-color: var(--color-primary); }
.page-thumb canvas { display: block; width: 100%; height: auto; }
.page-thumb-number { position: absolute; bottom: 4px; right: 4px; font-size: 0.625rem; background: rgba(0,0,0,0.6); color: #fff; padding: 2px 6px; border-radius: 2px; }
.page-thumb-badge { position: absolute; top: 4px; right: 4px; width: 8px; height: 8px; border-radius: 50%; background: var(--color-primary); }

.pdf-viewer { display: flex; justify-content: center; padding: var(--spacing-xl); min-height: 100%; }
.pdf-page-container { position: relative; box-shadow: var(--shadow-lg); background: white; }
.pdf-page-container canvas { display: block; }

.field-overlay { position: absolute; border: 2px solid; border-radius: var(--radius-sm); cursor: pointer; transition: all 0.15s; display: flex; align-items: center; justify-content: center; font-size: 0.625rem; text-transform: uppercase; font-weight: 600; background: rgba(255,255,255,0.9); }
.field-overlay:hover { box-shadow: var(--shadow-md); }
.field-overlay.selected { box-shadow: 0 0 0 2px var(--color-primary); }
.field-overlay.filled { background: rgba(255,255,255,0.95); }
.field-overlay.filled img { max-width: 100%; max-height: 100%; object-fit: contain; }
.field-overlay .field-label { color: inherit; opacity: 0.8; }

.resize-handle { position: absolute; width: 10px; height: 10px; background: var(--color-primary); border-radius: 2px; }
.resize-handle-se { right: -5px; bottom: -5px; cursor: se-resize; }
.resize-handle-sw { left: -5px; bottom: -5px; cursor: sw-resize; }

.field-delete { position: absolute; top: -8px; right: -8px; width: 18px; height: 18px; background: var(--color-error); color: #fff; border: none; border-radius: 50%; font-size: 12px; line-height: 1; cursor: pointer; display: none; }
.field-overlay.selected .field-delete { display: flex; align-items: center; justify-content: center; }

.signer-tag { display: inline-flex; align-items: center; gap: var(--spacing-xs); padding: var(--spacing-xs) var(--spacing-sm); border-radius: var(--radius-sm); font-size: 0.75rem; font-weight: 600; }
.signer-dot { width: 8px; height: 8px; border-radius: 50%; }

.signer-card { border: 1px solid var(--color-border-light); border-radius: var(--radius-md); padding: var(--spacing-md); margin-bottom: var(--spacing-sm); }
.signer-card-header { display: flex; align-items: center; gap: var(--spacing-sm); margin-bottom: var(--spacing-xs); }
.signer-card-name { font-weight: 600; font-size: 0.875rem; }
.signer-card-email { font-size: 0.75rem; color: var(--color-text-muted); }
.signer-card-status { font-size: 0.75rem; margin-top: var(--spacing-sm); }

.tool-btn { display: inline-flex; align-items: center; gap: var(--spacing-xs); padding: var(--spacing-sm) var(--spacing-md); font-family: var(--font-mono); font-size: 0.75rem; font-weight: 600; background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-md); cursor: pointer; transition: all 0.15s; }
.tool-btn:hover { background: var(--color-bg); }
.tool-btn.active { background: var(--color-primary); color: #fff; border-color: var(--color-primary); }

.modal-backdrop { position: fixed; inset: 0; background: rgba(0,0,0,0.5); display: flex; align-items: center; justify-content: center; z-index: 1000; opacity: 0; visibility: hidden; transition: all 0.2s; }
.modal-backdrop.open { opacity: 1; visibility: visible; }
.modal { background: var(--color-surface); border-radius: var(--radius-lg); box-shadow: var(--shadow-lg); max-width: 500px; width: 90%; max-height: 90vh; overflow: auto; transform: scale(0.95); transition: transform 0.2s; }
.modal-backdrop.open .modal { transform: scale(1); }
.modal-header { display: flex; align-items: center; justify-content: space-between; padding: var(--spacing-lg); border-bottom: 1px solid var(--color-border-light); }
.modal-title { font-size: 1rem; font-weight: 600; }
.modal-close { background: none; border: none; font-size: 1.5rem; cursor: pointer; color: var(--color-text-muted); line-height: 1; }
.modal-close:hover { color: var(--color-text); }
.modal-body { padding: var(--spacing-lg); }
.modal-footer { display: flex; justify-content: flex-end; gap: var(--spacing-sm); padding: var(--spacing-lg); border-top: 1px solid var(--color-border-light); }

.signature-pad-container { border: 1px solid var(--color-border); border-radius: var(--radius-md); margin-bottom: var(--spacing-md); }
.signature-pad-canvas { display: block; width: 100%; height: 150px; cursor: crosshair; }
.signature-pad-actions { display: flex; justify-content: flex-end; padding: var(--spacing-sm); border-top: 1px solid var(--color-border-light); }

.tabs { display: flex; border-bottom: 1px solid var(--color-border-light); margin-bottom: var(--spacing-lg); }
.tab { padding: var(--spacing-sm) var(--spacing-md); font-size: 0.875rem; font-weight: 600; color: var(--color-text-muted); background: none; border: none; border-bottom: 2px solid transparent; cursor: pointer; transition: all 0.15s; }
.tab:hover { color: var(--color-text); }
.tab.active { color: var(--color-text); border-bottom-color: var(--color-primary); }

.password-strength { height: 4px; background: var(--color-border-light); border-radius: 2px; margin-top: var(--spacing-xs); overflow: hidden; }
.password-strength-bar { height: 100%; transition: width 0.3s, background 0.3s; }
.password-strength-bar[data-score="1"] { width: 20%; background: var(--color-error); }
.password-strength-bar[data-score="2"] { width: 40%; background: #ff6b35; }
.password-strength-bar[data-score="3"] { width: 60%; background: var(--color-warning); }
.password-strength-bar[data-score="4"] { width: 80%; background: #9acd32; }
.password-strength-bar[data-score="5"] { width: 100%; background: var(--color-success); }

.landing-hero { text-align: center; padding: 4rem var(--spacing-xl); }
.landing-title { font-size: 2rem; margin-bottom: var(--spacing-sm); }
.landing-tagline { color: var(--color-text-muted); margin-bottom: var(--spacing-xl); }
.landing-actions { display: flex; justify-content: center; gap: var(--spacing-md); margin-top: var(--spacing-xl); }
.landing-features { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: var(--spacing-lg); margin-top: var(--spacing-xl); padding: var(--spacing-xl); }
.feature-card { text-align: center; padding: var(--spacing-lg); }
.feature-icon { font-size: 2rem; margin-bottom: var(--spacing-md); }
.feature-title { margin-bottom: var(--spacing-sm); }
.feature-desc { font-size: 0.875rem; color: var(--color-text-muted); }

.footer { text-align: center; padding: var(--spacing-xl); font-size: 0.75rem; color: var(--color-text-muted); border-top: 1px solid var(--color-border-light); margin-top: auto; }

.verify-result { padding: var(--spacing-lg); border-radius: var(--radius-md); margin-bottom: var(--spacing-md); }
.verify-result h3 { display: flex; align-items: center; gap: var(--spacing-sm); margin-bottom: var(--spacing-sm); }
.verify-result-icon { font-size: 1.25rem; }
.verify-detail { font-size: 0.875rem; margin-bottom: var(--spacing-xs); }
.verify-detail code { display: block; background: rgba(0,0,0,0.05); padding: var(--spacing-sm); border-radius: var(--radius-sm); font-size: 0.75rem; word-break: break-all; margin-top: var(--spacing-xs); }

@media (max-width: 768px) {
  .app-layout { grid-template-columns: 1fr; }
  .app-sidebar { display: none; }
  .landing-features { grid-template-columns: 1fr; }
  .modal { width: 95%; margin: var(--spacing-md); }
}