:root {
  --bg: #eef2f7;
  --panel: #1659b7;
  --panel-dark: #0d4ca6;
  --panel-soft: #2b6dc7;
  --card: #ffffff;
  --muted: #7a8391;
  --text: #182230;
  --border: #d8e0ec;
  --success: #21b640;
  --danger: #d63b3b;
  --shadow: 0 24px 60px rgba(19, 42, 84, 0.15);
  --font-sans: "IBM Plex Sans", "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-sans);
  background:
    radial-gradient(circle at top right, rgba(22, 89, 183, 0.15), transparent 24rem),
    linear-gradient(180deg, #f5f8fc 0%, #eef2f7 100%);
  color: var(--text);
}

button,
input,
textarea {
  font: inherit;
}

.shell {
  min-height: 100vh;
}

.login-screen {
  display: grid;
  place-items: center;
  min-height: 100vh;
  padding: 24px;
}

.login-card {
  width: min(460px, 100%);
  background: rgba(255, 255, 255, 0.82);
  backdrop-filter: blur(16px);
  border: 1px solid rgba(22, 89, 183, 0.12);
  border-radius: 28px;
  box-shadow: var(--shadow);
  overflow: hidden;
}

.login-top {
  padding: 28px 28px 12px;
  background: linear-gradient(135deg, #1659b7 0%, #0d4ca6 100%);
  color: #fff;
}

.login-top h1 {
  margin: 0 0 8px;
  font-size: 2rem;
}

.login-top p {
  margin: 0;
  color: rgba(255, 255, 255, 0.8);
}

.login-form {
  padding: 28px;
  display: grid;
  gap: 14px;
}

.field {
  display: grid;
  gap: 8px;
}

.field label {
  font-size: 0.92rem;
  color: var(--muted);
}

.field input,
.field textarea {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 14px 16px;
  background: #fff;
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.field input:focus,
.field textarea:focus {
  border-color: #1f75ff;
  box-shadow: 0 0 0 4px rgba(31, 117, 255, 0.12);
}

.primary-btn,
.action-btn {
  border: 0;
  border-radius: 16px;
  cursor: pointer;
}

.primary-btn {
  padding: 15px 18px;
  background: linear-gradient(135deg, #27c943 0%, #20b13b 100%);
  color: #fff;
  font-weight: 700;
}

.login-note {
  margin-top: 6px;
  font-size: 0.88rem;
  color: var(--muted);
}

.app-layout {
  display: grid;
  grid-template-columns: 310px minmax(280px, 360px) minmax(0, 1fr);
  min-height: 100vh;
}

.sidebar {
  background: linear-gradient(180deg, var(--panel) 0%, var(--panel-dark) 100%);
  color: #fff;
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
}

.brand-mark {
  width: 54px;
  height: 54px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.18);
  display: grid;
  place-items: center;
  font-size: 1.5rem;
}

.brand h1 {
  margin: 0;
  font-size: 2rem;
  line-height: 1;
}

.brand p {
  margin: 6px 0 0;
  color: rgba(255, 255, 255, 0.72);
}

.mailbox-pill {
  width: 100%;
  border: 0;
  border-radius: 16px;
  padding: 14px 16px;
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  text-align: left;
  font-weight: 600;
}

.actions-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.action-btn {
  min-height: 140px;
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
  display: grid;
  place-items: center;
  align-content: center;
  gap: 12px;
  transition: transform 0.18s ease, background 0.18s ease;
}

.action-btn:hover {
  transform: translateY(-2px);
  background: rgba(255, 255, 255, 0.16);
}

.action-btn .glyph {
  font-size: 2rem;
}

.sidebar-footer {
  margin-top: auto;
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.ghost-btn {
  border: 1px solid rgba(255, 255, 255, 0.2);
  background: transparent;
  color: #fff;
  border-radius: 999px;
  padding: 10px 14px;
  cursor: pointer;
}

.list-panel,
.viewer-panel {
  background: rgba(255, 255, 255, 0.84);
  backdrop-filter: blur(10px);
}

.list-panel {
  border-right: 1px solid var(--border);
}

.panel-header {
  padding: 24px 22px 18px;
  border-bottom: 1px solid var(--border);
}

.panel-header h2 {
  margin: 0 0 6px;
  font-size: 1.1rem;
}

.panel-header p {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.messages {
  display: flex;
  flex-direction: column;
  max-height: calc(100vh - 106px);
  overflow: auto;
}

.message-row {
  border: 0;
  background: transparent;
  text-align: left;
  padding: 18px 22px;
  border-bottom: 1px solid #edf2f8;
  cursor: pointer;
}

.message-row.active {
  background: linear-gradient(90deg, rgba(22, 89, 183, 0.1), rgba(22, 89, 183, 0.02));
}

.message-row.unseen .message-subject {
  font-weight: 700;
}

.message-meta {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 8px;
  color: var(--muted);
  font-size: 0.85rem;
}

.message-subject {
  margin: 0 0 6px;
  font-size: 1rem;
}

.message-preview {
  margin: 0;
  color: #617084;
  font-size: 0.9rem;
}

.viewer-panel {
  display: flex;
  flex-direction: column;
}

.viewer-shell {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.viewer-empty {
  flex: 1;
  display: grid;
  place-items: center;
  padding: 48px;
  color: var(--muted);
}

.viewer-card {
  padding: 28px 30px;
  overflow: auto;
}

.viewer-card h2 {
  margin: 0 0 10px;
  font-size: 1.8rem;
}

.viewer-details {
  display: grid;
  gap: 6px;
  color: var(--muted);
  font-size: 0.95rem;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--border);
}

.viewer-body {
  padding-top: 22px;
  line-height: 1.7;
}

.viewer-body iframe {
  width: 100%;
  min-height: 60vh;
  border: 0;
  background: #fff;
}

.compose-sheet {
  position: fixed;
  inset: 0;
  background: rgba(17, 26, 39, 0.38);
  display: none;
  place-items: center;
  padding: 20px;
}

.compose-sheet.open {
  display: grid;
}

.compose-card {
  width: min(720px, 100%);
  background: #fff;
  border-radius: 28px;
  box-shadow: var(--shadow);
  padding: 24px;
}

.compose-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 18px;
}

.compose-header h3 {
  margin: 0;
  font-size: 1.35rem;
}

.danger-btn {
  background: var(--danger);
  color: #fff;
}

.toolbar {
  display: flex;
  gap: 12px;
  padding: 0 30px 20px;
}

.toolbar .ghost-btn,
.toolbar .danger-btn,
.toolbar .primary-btn {
  padding: 10px 16px;
  border-radius: 999px;
}

.status-banner {
  position: fixed;
  right: 20px;
  bottom: 20px;
  max-width: min(420px, calc(100vw - 32px));
  background: #162236;
  color: #fff;
  padding: 14px 18px;
  border-radius: 18px;
  box-shadow: var(--shadow);
  opacity: 0;
  transform: translateY(18px);
  pointer-events: none;
  transition: opacity 0.18s ease, transform 0.18s ease;
}

.status-banner.visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 1080px) {
  .app-layout {
    grid-template-columns: 280px 1fr;
  }

  .viewer-panel {
    grid-column: span 2;
    min-height: 50vh;
    border-top: 1px solid var(--border);
  }
}

@media (max-width: 760px) {
  .app-layout {
    grid-template-columns: 1fr;
  }

  .sidebar,
  .list-panel,
  .viewer-panel {
    min-height: auto;
  }

  .actions-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .messages {
    max-height: none;
  }

  .viewer-panel {
    grid-column: auto;
  }
}