:root {
  --bg-start: #12060a;
  --bg-mid: #1b0b11;
  --bg-end: #241018;
  --panel-start: #1a0a10;
  --panel-end: #2a1119;
  --text: #f6eef1;
  --muted: #c7a4b1;
  --line: #5a3340;
  --active: #f6eef1;
  --accent-soft: #ddd2d7;
  --btn-bg: #17171a;
  --btn-bg-hover: #1f2024;
  --btn-bg-active: #2a2b31;
  --btn-border: #74414f;
  --btn-border-hover: #84505f;
  --btn-border-active: #956272;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: linear-gradient(
    135deg,
    #050505 0%,
    #050505 25%,
    #050505 50%,
    #050505 75%,
    var(--bg-end) 100%
  );
  color: var(--text);
  font-family: Arial, sans-serif;
}

.app {
  min-height: 100vh;
}

.left-tab {
  position: fixed;
  left: 0;
  top: 0;
  width: 220px;
  height: 100vh;
  border-right: 1px solid var(--line);
  background: linear-gradient(
    180deg,
    #4a1f2a 0%,
    #0a0a0a 15%,
    #050505 85%,
    #4a1f2a 100%
  );
  padding: 40px 20px;
  box-shadow: 0 0 30px rgba(0, 0, 0, 0.45);
}

.tab-nav {
  display: grid;
  gap: 12px;
}

.tab-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  text-decoration: none;
  font-size: 18px;
  padding: 10px 12px;
  border-radius: 10px;
  background: var(--btn-bg);
  border: 1px solid var(--btn-border);
  transition: color 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}

.tab-link:hover {
  color: var(--accent-soft);
  background: var(--btn-bg-hover);
  border-color: var(--btn-border-hover);
}

.tab-link.active {
  color: var(--active);
  font-weight: 700;
  background: var(--btn-bg-active);
  border-color: var(--btn-border-active);
  text-shadow: none;
}

.center-content {
  margin-left: 220px;
  min-height: 100vh;
  display: flex;
  justify-content: flex-start;
  align-items: flex-start;
  padding: 56px 56px 24px;
}

.content-head {
  width: min(720px, 100%);
  text-align: left;
  margin-top: 0;
}

#tab-title {
  margin: 0;
  font-size: clamp(2rem, 8vw, 4rem);
  font-weight: 700;
  text-shadow: none;
}

#tab-subtitle {
  margin: 0.7rem 0 0;
  color: var(--muted);
  font-size: clamp(1rem, 2.6vw, 1.2rem);
}

@media (max-width: 700px) {
  .left-tab {
    position: static;
    width: 100%;
    height: auto;
    border-right: 0;
    border-bottom: 1px solid var(--line);
    padding: 16px;
  }

  .center-content {
    margin-left: 0;
    min-height: calc(100vh - 80px);
    padding: 28px 20px 20px;
  }
}