body {
  background-color: #0f172a; /* Dark Navy */
  color: #f8fafc;
  font-family: 'Segoe UI', sans-serif;
  margin: 0;
  display: flex;
}

.sidebar {
  width: 240px;
  background-color: #1e293b; /* Sidebar Dark */
  color: white;
  height: 100vh;
  padding: 20px;
}

main.content {
  padding: 30px;
  flex-grow: 1;
  background-color: #0f172a;
}


:root {
  --primary-color: #3b82f6;
  --primary-hover: #2563eb;
  --bg-dark: #0f172a;
  --bg-light: #ffffff;
  --text-dark: #0f172a;
  --text-light: #f8fafc;
  --card-bg-dark: #1e293b;
  --card-bg-light: #f1f5f9;
  --sidebar-width: 240px;
}

body {
  margin: 0;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: var(--bg-dark);
  color: var(--text-light);
  display: flex;
  min-height: 100vh;
  transition: background 0.3s, color 0.3s;
}

body.light {
  background-color: var(--bg-light);
  color: var(--text-dark);
}

/* Sidebar */
.sidebar {
  width: var(--sidebar-width);
  background-color: var(--card-bg-dark);
  display: flex;
  flex-direction: column;
  padding: 20px 0;
  position: fixed;
  height: 100vh;
  transition: background 0.3s;
}

body.light .sidebar {
  background-color: var(--card-bg-light);
}

.sidebar .logo {
  text-align: center;
  margin-bottom: 30px;
}

.sidebar .logo img {
  height: 40px;
}

.sidebar nav a {
  padding: 14px 24px;
  text-decoration: none;
  color: var(--text-light);
  display: block;
  font-size: 16px;
  transition: background 0.2s, color 0.2s;
  border-left: 4px solid transparent;
}

body.light .sidebar nav a {
  color: var(--text-dark);
}

.sidebar nav a.active,
.sidebar nav a:hover {
  background-color: var(--primary-hover);
  border-left: 4px solid var(--primary-color);
  color: white;
}

/* Main content */
main.content {
  margin-left: var(--sidebar-width);
  padding: 30px;
  flex-grow: 1;
  background-color: inherit;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 30px;
}

.toggle-theme {
  background-color: var(--primary-color);
  color: white;
  padding: 8px 14px;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.3s;
}

.toggle-theme:hover {
  background-color: var(--primary-hover);
}

/* Section and Cards */
.tab-content h2 {
  margin-top: 0;
  font-size: 24px;
  margin-bottom: 20px;
}

.project-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.project-list li {
  background-color: var(--card-bg-dark);
  border-radius: 12px;
  padding: 16px;
  margin-bottom: 16px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  transition: background 0.3s, box-shadow 0.3s;
}

body.light .project-list li {
  background-color: var(--card-bg-light);
}

.project-list li strong {
  font-size: 18px;
}

.project-list a {
  color: var(--primary-color);
  text-decoration: none;
  font-weight: 500;
  margin-right: 10px;
}

.project-list a:hover {
  text-decoration: underline;
}

/* Modal */
#addModal {
  position: fixed;
  top: 0;
  left: 0;
  background-color: rgba(0, 0, 0, 0.5);
  width: 100%;
  height: 100%;
  display: none;
  z-index: 999;
}

#addModal form {
  background-color: white;
  padding: 24px;
  width: 400px;
  margin: 10% auto;
  border-radius: 12px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
}

#addModal input,
#addModal select {
  width: 100%;
  padding: 10px;
  margin-bottom: 15px;
  border-radius: 6px;
  border: 1px solid #ccc;
}

#addModal button {
  padding: 10px 16px;
  margin-right: 10px;
  background-color: var(--primary-color);
  color: white;
  border: none;
  border-radius: 6px;
  cursor: pointer;
}

#addModal button:hover {
  background-color: var(--primary-hover);
}

/* Embedded Sheets */
iframe.sheet-frame {
  width: 100%;
  height: 360px;
  border: none;
  border-radius: 8px;
  margin-top: 10px;
}

.sheet-wrapper {
  height: 400px;
  overflow: hidden; /* prevent double scroll */
  border-radius: 8px;
  margin-top: 10px;
  background: #fff;
  display: flex;
}

.sheet-frame {
  width: 100%;
  height: 100%;
  border: none;
  pointer-events: auto;
}