:root {
  --bg-color: var(--tg-theme-bg-color, #0f172a);
  --secondary-bg-color: var(--tg-theme-secondary-bg-color, #1e293b);
  --text-color: var(--tg-theme-text-color, #f8fafc);
  --hint-color: var(--tg-theme-hint-color, #94a3b8);
  --link-color: var(--tg-theme-link-color, #38bdf8);
  --button-color: var(--tg-theme-button-color, #2563eb);
  --button-text-color: var(--tg-theme-button-text-color, #ffffff);
  --accent-color: #3b82f6;
  --accent-gradient: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --card-border: rgba(255, 255, 255, 0.08);
  --radius-lg: 16px;
  --radius-md: 12px;
  --radius-sm: 8px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-tap-highlight-color: transparent;
}

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  min-height: 100vh;
  padding-bottom: 80px;
  overflow-x: hidden;
}

/* Header */
.app-header {
  padding: 18px 16px 12px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--secondary-bg-color);
  border-bottom: 1px solid var(--card-border);
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(12px);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand-icon {
  font-size: 26px;
}

.brand-title {
  font-size: 19px;
  font-weight: 700;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.user-badge {
  display: flex;
  align-items: center;
  gap: 6px;
  background: rgba(255, 255, 255, 0.06);
  padding: 6px 12px;
  border-radius: 20px;
  font-size: 13px;
  font-weight: 500;
  border: 1px solid var(--card-border);
}

/* Navigation Tabs */
.tabs-nav {
  display: flex;
  background: var(--secondary-bg-color);
  margin: 12px 16px;
  padding: 4px;
  border-radius: var(--radius-md);
  border: 1px solid var(--card-border);
}

.tab-btn {
  flex: 1;
  padding: 10px 4px;
  border: none;
  background: transparent;
  color: var(--hint-color);
  font-size: 12.5px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.2s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 5px;
  white-space: nowrap;
}

.tab-btn.active {
  background: var(--accent-gradient);
  color: #ffffff;
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.35);
}

/* Container */
.container {
  padding: 0 16px;
}

.tab-content {
  display: none;
  animation: fadeIn 0.25s ease-in-out;
}

.tab-content.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Cards */
.card {
  background: var(--secondary-bg-color);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 16px;
  margin-bottom: 14px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
  position: relative;
  overflow: hidden;
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 10px;
}

.card-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--text-color);
  line-height: 1.3;
}

.badge {
  font-size: 11px;
  font-weight: 700;
  padding: 4px 8px;
  border-radius: 12px;
  text-transform: uppercase;
}

.badge-active {
  background: rgba(16, 185, 129, 0.15);
  color: var(--success-color);
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.badge-finished {
  background: rgba(148, 163, 184, 0.15);
  color: var(--hint-color);
}

.card-desc {
  font-size: 13px;
  color: var(--hint-color);
  margin-bottom: 12px;
  line-height: 1.4;
}

.card-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 12px;
  color: var(--hint-color);
  margin-bottom: 14px;
  padding: 8px 12px;
  background: rgba(0, 0, 0, 0.15);
  border-radius: var(--radius-sm);
}

.meta-item {
  display: flex;
  align-items: center;
  gap: 4px;
}

/* Prizes list */
.prizes-box {
  background: rgba(255, 255, 255, 0.03);
  border-radius: var(--radius-sm);
  padding: 10px;
  margin-bottom: 14px;
}

.prizes-title {
  font-size: 12px;
  font-weight: 600;
  color: var(--hint-color);
  margin-bottom: 6px;
  text-transform: uppercase;
}

.prize-item {
  font-size: 13px;
  color: var(--text-color);
  padding: 4px 0;
  display: flex;
  align-items: center;
  gap: 6px;
}

/* Action Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  padding: 12px 16px;
  border-radius: var(--radius-md);
  border: none;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
  gap: 8px;
}

.btn-primary {
  background: var(--accent-gradient);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.3);
}

.btn-primary:active {
  transform: scale(0.98);
}

.btn-joined {
  background: rgba(16, 185, 129, 0.15);
  color: var(--success-color);
  border: 1px solid rgba(16, 185, 129, 0.4);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-color);
  border: 1px solid var(--card-border);
}

.btn-sm {
  padding: 8px 12px;
  font-size: 13px;
  width: auto;
}

/* Form inputs */
.form-group {
  margin-bottom: 16px;
}

.form-label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--text-color);
}

.form-input, .form-textarea, .form-select {
  width: 100%;
  padding: 12px 14px;
  background: rgba(0, 0, 0, 0.2);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  color: var(--text-color);
  font-size: 14px;
  outline: none;
  transition: border-color 0.2s;
}

.form-input:focus, .form-textarea:focus {
  border-color: var(--accent-color);
}

.form-textarea {
  min-height: 80px;
  resize: vertical;
}

.duration-pills {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.pill-btn {
  padding: 8px 14px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--card-border);
  border-radius: 20px;
  color: var(--hint-color);
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
}

.pill-btn.active {
  background: var(--accent-color);
  color: #ffffff;
  border-color: var(--accent-color);
}

/* Referral link block */
.ref-block {
  background: rgba(59, 130, 246, 0.08);
  border: 1px dashed rgba(59, 130, 246, 0.3);
  padding: 12px;
  border-radius: var(--radius-md);
  margin-top: 10px;
}

.ref-header {
  font-size: 12px;
  font-weight: 700;
  color: var(--link-color);
  margin-bottom: 6px;
}

.ref-input-group {
  display: flex;
  gap: 8px;
}

.ref-input {
  flex: 1;
  padding: 8px 10px;
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-sm);
  color: var(--text-color);
  font-size: 12px;
  font-family: monospace;
}

/* Modal */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  display: none;
  align-items: center;
  justify-content: center;
  padding: 16px;
  z-index: 100;
  backdrop-filter: blur(4px);
}

.modal-overlay.open {
  display: flex;
}

.modal-content {
  background: var(--secondary-bg-color);
  border-radius: var(--radius-lg);
  border: 1px solid var(--card-border);
  padding: 22px;
  width: 100%;
  max-width: 440px;
  max-height: 90vh;
  overflow-y: auto;
}

/* Toast */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: #1e293b;
  color: #ffffff;
  padding: 10px 20px;
  border-radius: 30px;
  font-size: 13px;
  font-weight: 600;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
  border: 1px solid var(--card-border);
  z-index: 200;
  opacity: 0;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  pointer-events: none;
}

.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}