/* ═══════════════════════════════════════════
   Split Now — Design System
   ═══════════════════════════════════════════ */

:root {
  --green: #5bc5a7;
  --green-dark: #3a9d82;
  --green-glow: rgba(91, 197, 167, 0.25);
  --red: #ff6b6b;
  --bg: #0a0a0f;
  --bg-card: rgba(255, 255, 255, 0.05);
  --bg-card-hover: rgba(255, 255, 255, 0.08);
  --bg-input: rgba(255, 255, 255, 0.07);
  --text: #f0f0f5;
  --text-dim: #8a8a9a;
  --text-hint: #5a5a6a;
  --border: rgba(255, 255, 255, 0.08);
  --border-focus: rgba(91, 197, 167, 0.5);
  --radius: 14px;
  --radius-sm: 10px;
  --shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
  --font: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --safe-bottom: env(safe-area-inset-bottom, 0px);
}

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

html, body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  height: 100%;
  width: 100%;
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body::before {
  content: '';
  position: fixed;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(ellipse at 30% 20%, rgba(91, 197, 167, 0.06) 0%, transparent 50%),
              radial-gradient(ellipse at 70% 80%, rgba(91, 197, 167, 0.03) 0%, transparent 50%);
  pointer-events: none;
  z-index: 0;
}

#app {
  position: relative;
  z-index: 1;
  height: 100%;
  width: 100%;
}

/* ─── Screens ─── */

.screen {
  display: none;
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  height: 100%;
  width: 100%;
  overflow-y: auto;
}

.screen.active {
  display: flex;
  flex-direction: column;
  animation: fadeIn 0.4s ease;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* ─── Setup Screen ─── */

.setup-container {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 32px 20px;
  max-width: 420px;
  margin: 0 auto;
  width: 100%;
}

.logo-section {
  text-align: center;
  margin-bottom: 40px;
}

.logo-icon {
  width: 72px;
  height: 72px;
  margin: 0 auto 20px;
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-6px); }
}

.logo-section h1 {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.5px;
  background: linear-gradient(135deg, var(--green), #8de8cc);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.subtitle {
  color: var(--text-dim);
  font-size: 15px;
  margin-top: 6px;
  font-weight: 400;
}

/* ─── Cards ─── */

.card {
  width: 100%;
  padding: 28px 24px;
  border-radius: var(--radius);
  background: var(--bg-card);
  border: 1px solid var(--border);
}

.glass {
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: var(--shadow);
}

/* ─── Inputs ─── */

.input-label {
  display: block;
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--text-dim);
  margin-bottom: 8px;
}

.optional {
  font-weight: 400;
  text-transform: none;
  letter-spacing: 0;
  color: var(--text-hint);
}

.input {
  width: 100%;
  height: 54px;
  padding: 0 18px;
  font-size: 15px;
  font-family: var(--font);
  color: var(--text);
  background: var(--bg-input);
  border: 1.5px solid var(--border);
  border-radius: 12px;
  outline: none;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  -webkit-appearance: none;
  appearance: none;
}

.input:focus {
  border-color: var(--green);
  box-shadow: 0 0 0 4px rgba(91, 197, 167, 0.15);
  background: rgba(255, 255, 255, 0.05);
}

.input::placeholder {
  color: var(--text-hint);
}

.input-amount {
  font-size: 26px;
  font-weight: 700;
  letter-spacing: -0.5px;
  color: #fff;
}

.select {
  cursor: pointer;
  background-image: url("data:image/svg+xml,%3Csvg width='12' height='8' viewBox='0 0 12 8' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1.5L6 6.5L11 1.5' stroke='%238a8a9a' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 16px center;
  padding-right: 40px;
}

.select option {
  background: #1a1a24;
  color: var(--text);
}

.textarea {
  resize: vertical;
  min-height: 64px;
  height: auto;
  padding: 14px 18px; /* Restore vertical padding for textarea since it can't rely on height */
  line-height: 1.5;
}

.hint {
  font-size: 12px;
  color: var(--text-hint);
  margin-top: 10px;
  line-height: 1.5;
}

.hint a {
  color: var(--green);
  text-decoration: none;
  font-weight: 500;
}

.hint a:hover {
  text-decoration: underline;
}

/* ─── Buttons ─── */

.btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  padding: 14px 24px;
  font-size: 15px;
  font-weight: 600;
  font-family: var(--font);
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.2s;
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: linear-gradient(135deg, var(--green), var(--green-dark));
  color: #fff;
  margin-top: 20px;
  box-shadow: 0 4px 16px var(--green-glow);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 24px var(--green-glow);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

.btn-lg {
  padding: 18px 24px;
  font-size: 16px;
  border-radius: var(--radius);
  margin-bottom: 20px;
}

.btn-icon {
  background: none;
  border: none;
  color: var(--text-dim);
  cursor: pointer;
  padding: 8px;
  border-radius: 8px;
  transition: color 0.2s, background 0.2s;
}

.btn-icon:hover {
  color: var(--text);
  background: var(--bg-card);
}

.btn-text { display: inline; }
.btn-loader { display: none; }
.btn-loader.visible { display: inline-flex; }
.btn-text.hidden { display: none; }
.btn-loader.hidden { display: none; }

/* ─── Spinner ─── */

.spinner {
  width: 20px;
  height: 20px;
  border: 2.5px solid rgba(255, 255, 255, 0.3);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ─── Header ─── */

.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  padding-top: max(16px, env(safe-area-inset-top));
  background: rgba(10, 10, 15, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

.avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--green), var(--green-dark));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 700;
  color: #fff;
  text-transform: uppercase;
  flex-shrink: 0;
}

.header-title {
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.3px;
}

/* ─── Form ─── */

.main-content {
  flex: 1;
  min-height: 0;
  padding: 20px;
  padding-top: calc(85px + env(safe-area-inset-top));
  padding-bottom: calc(100px + env(safe-area-inset-bottom));
  max-width: 520px;
  margin: 0 auto;
  width: 100%;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none; /* Firefox */
  -ms-overflow-style: none;  /* Internet Explorer 10+ */
}

.main-content::-webkit-scrollbar {
  display: none; /* Safari and Chrome */
}

.form-group {
  margin-bottom: 20px;
}

.form-row {
  display: flex;
  gap: 12px;
}

.flex-1 { flex: 1; }
.flex-2 { flex: 2; }

/* ─── Split Toggle ─── */

.split-toggle {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  background: var(--bg-input);
  border-radius: 12px;
  padding: 4px;
  border: 1px solid var(--border);
}

.split-btn {
  flex: 1 1 auto;
  min-width: 0;
  padding: 10px 8px;
  font-size: 13px;
  font-weight: 500;
  font-family: var(--font);
  color: var(--text-dim);
  background: transparent;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
  white-space: nowrap;
}

.split-btn:hover:not(.active) {
  color: var(--text);
  background: rgba(255, 255, 255, 0.05);
}

.split-btn.active {
  color: #fff;
  background: var(--green);
  box-shadow: 0 2px 8px var(--green-glow);
}

/* ─── Friends List ─── */

.friends-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
  max-height: 240px;
  overflow-y: auto;
  padding: 4px 0;
}

.friends-list::-webkit-scrollbar {
  width: 4px;
}

.friends-list::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 4px;
}

.friend-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  border-radius: 12px;
  background: var(--bg-card);
  border: 1.5px solid var(--border);
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  user-select: none;
  -webkit-user-select: none;
}

.friend-item:hover {
  background: var(--bg-card-hover);
  transform: translateY(-1px);
  border-color: rgba(91, 197, 167, 0.4);
}

.friend-item.selected {
  border-color: var(--green);
  background: rgba(91, 197, 167, 0.08);
}

.friend-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: linear-gradient(135deg, #667eea, #764ba2);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 700;
  color: #fff;
  flex-shrink: 0;
}

.friend-avatar img {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  object-fit: cover;
}

.friend-name {
  flex: 1;
  font-size: 14px;
  font-weight: 500;
}

.friend-check {
  width: 20px;
  height: 20px;
  border-radius: 6px;
  border: 2px solid var(--border);
  transition: all 0.2s;
  display: flex;
  align-items: center;
  justify-content: center;
}

.friend-item.selected .friend-check {
  border-color: var(--green);
  background: var(--green);
}

.friend-item.selected .friend-check::after {
  content: '';
  width: 6px;
  height: 10px;
  border: solid #fff;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg) translateY(-1px);
}

/* ─── Custom Split ─── */

.custom-split {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 20px;
}

.custom-split.hidden {
  display: none;
}

.split-row {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  background: var(--bg-card);
  border-radius: var(--radius-sm);
}

.split-row .friend-name {
  flex: 1;
}

.split-input {
  width: 90px;
  padding: 8px 12px;
  font-size: 14px;
  font-family: var(--font);
  color: var(--text);
  background: var(--bg-input);
  border: 1.5px solid var(--border);
  border-radius: 8px;
  outline: none;
  text-align: right;
  transition: border-color 0.2s;
}

.split-input:focus {
  border-color: var(--border-focus);
}

.split-suffix {
  font-size: 13px;
  color: var(--text-dim);
  width: 16px;
}

.split-label-hint {
  padding: 6px 0 4px;
}

.split-hint {
  font-size: 12px;
  color: var(--text-hint);
  font-weight: 400;
}

/* ─── Toast ─── */

.toast {
  position: fixed;
  bottom: calc(24px + var(--safe-bottom));
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  padding: 14px 24px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 500;
  z-index: 1000;
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  max-width: 90%;
  text-align: center;
}

.toast.visible {
  transform: translateX(-50%) translateY(0);
}

.toast.hidden {
  display: block;
}

.toast.success {
  background: var(--green);
  color: #fff;
  box-shadow: 0 8px 24px var(--green-glow);
}

.toast.error {
  background: var(--red);
  color: #fff;
  box-shadow: 0 8px 24px rgba(255, 107, 107, 0.3);
}

.toast.update {
  background: linear-gradient(135deg, #4facfe, #00f2fe);
  color: #fff;
  box-shadow: 0 8px 24px rgba(79, 172, 254, 0.3);
  cursor: pointer;
}

/* ─── Empty State ─── */

.empty-state {
  text-align: center;
  padding: 24px;
  color: var(--text-hint);
  font-size: 13px;
}

/* ─── Bottom Nav ─── */

.bottom-nav {
  display: flex;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: rgba(10, 10, 15, 0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-top: 1px solid var(--border);
  padding: 8px 0;
  padding-bottom: calc(8px + env(safe-area-inset-bottom));
  z-index: 100;
  width: 100%;
}

.nav-tab {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 8px 0;
  font-size: 11px;
  font-weight: 500;
  font-family: var(--font);
  color: var(--text-hint);
  background: none;
  border: none;
  cursor: pointer;
  transition: color 0.2s;
}

.nav-tab.active {
  color: var(--green);
}

.nav-tab:hover {
  color: var(--text-dim);
}

.nav-tab.active:hover {
  color: var(--green);
}

/* ─── Month Selector ─── */

.month-selector {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  margin-bottom: 24px;
}

.month-arrow {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--bg-card);
  border: 1.5px solid var(--border);
  color: var(--text);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s;
}

.month-arrow:hover {
  background: var(--bg-card-hover);
  border-color: var(--green);
  color: var(--green);
}

.month-arrow:active {
  transform: scale(0.92);
}

.month-label {
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.3px;
  min-width: 160px;
  text-align: center;
}

/* ─── Usage Report Card ─── */

.usage-report {
  animation: fadeIn 0.3s ease;
}

.usage-loading {
  display: flex;
  justify-content: center;
  padding: 60px 0;
}

.report-card {
  padding: 24px;
  border-radius: var(--radius);
  background: var(--bg-card);
  border: 1px solid var(--border);
}

.report-total-section {
  text-align: center;
  padding: 8px 0 4px;
}

.report-total-label {
  display: block;
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--text-dim);
  margin-bottom: 8px;
}

.report-total-amount {
  display: block;
  font-size: 32px;
  font-weight: 700;
  letter-spacing: -1px;
  background: linear-gradient(135deg, var(--green), #8de8cc);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.report-divider {
  height: 1px;
  background: var(--border);
  margin: 20px 0;
}

.report-bars {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.report-bar-row {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.report-bar-label {
  display: flex;
  align-items: center;
  gap: 8px;
}

.report-cat-dot {
  width: 10px;
  height: 10px;
  border-radius: 3px;
  flex-shrink: 0;
}

.report-cat-name {
  font-size: 13px;
  font-weight: 500;
  color: var(--text);
}

.report-bar-track {
  width: 100%;
  height: 8px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 4px;
  overflow: hidden;
}

.report-bar-fill {
  height: 100%;
  border-radius: 4px;
  transition: width 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.report-bar-value {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.report-bar-amount {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
}

.report-bar-pct {
  font-size: 12px;
  font-weight: 500;
  color: var(--text-dim);
}

.report-bar-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.report-subcats {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 6px;
  padding: 10px 14px;
  background: rgba(255, 255, 255, 0.03);
  border-radius: 8px;
  border-left: 3px solid rgba(255, 255, 255, 0.1);
}

.report-subcat-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
}

.report-subcat-name {
  color: var(--text-dim);
  font-weight: 500;
}

.report-subcat-amount {
  color: var(--text);
  font-weight: 600;
  opacity: 0.8;
}

.report-summary-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.report-summary-label {
  font-size: 13px;
  color: var(--text-dim);
  font-weight: 500;
}

.report-summary-count {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
}

.report-empty {
  text-align: center;
  padding: 40px 0;
  color: var(--text-hint);
}

.report-empty svg {
  margin-bottom: 12px;
  opacity: 0.5;
}

.report-empty p {
  font-size: 14px;
}

/* ─── Uncategorized Expenses ─── */

.uncat-section {
  margin-top: 4px;
}

.uncat-header {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 600;
  color: #f0a45d;
  margin-bottom: 12px;
}

.uncat-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.uncat-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  background: rgba(240, 164, 93, 0.06);
  border: 1px solid rgba(240, 164, 93, 0.15);
  border-radius: 10px;
  transition: background 0.2s;
}

.uncat-desc {
  font-size: 13px;
  font-weight: 500;
  color: var(--text);
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.uncat-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
  margin-left: 12px;
}

.uncat-date {
  font-size: 12px;
  color: var(--text-hint);
}

.uncat-amount {
  font-size: 13px;
  font-weight: 600;
  color: #f0a45d;
}

/* ─── OAuth / Auth Styles ─── */

.btn-oauth {
  background: linear-gradient(135deg, var(--green), var(--green-dark));
  color: #fff;
  box-shadow: 0 4px 16px var(--green-glow);
  font-size: 15px;
  font-weight: 600;
  gap: 10px;
}

.btn-oauth:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 24px var(--green-glow);
}

.btn-oauth:active {
  transform: translateY(0);
}

.btn-oauth.hidden {
  display: none !important;
}

.auth-divider {
  display: flex;
  align-items: center;
  gap: 16px;
  margin: 20px 0;
}

.auth-divider::before,
.auth-divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

.auth-divider span {
  font-size: 12px;
  font-weight: 500;
  color: var(--text-hint);
  text-transform: uppercase;
  letter-spacing: 0.8px;
}

.auth-divider.hidden {
  display: none !important;
}

.btn-expand {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  width: 100%;
  padding: 10px 16px;
  font-size: 13px;
  font-weight: 500;
  font-family: var(--font);
  color: var(--text-dim);
  background: none;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.2s;
}

.btn-expand:hover {
  color: var(--text);
  border-color: var(--green);
  background: rgba(91, 197, 167, 0.05);
}

.expand-chevron {
  transition: transform 0.3s ease;
}

.btn-expand.expanded .expand-chevron {
  transform: rotate(180deg);
}

.apikey-fields {
  overflow: hidden;
  transition: max-height 0.35s ease, opacity 0.3s ease, margin-top 0.3s ease;
  max-height: 300px;
  opacity: 1;
  margin-top: 16px;
}

.apikey-fields.collapsed {
  max-height: 0;
  opacity: 0;
  margin-top: 0;
}

/* ─── Utilities ─── */

.hidden {
  display: none !important;
}

/* ─── Responsive ─── */

@media (max-width: 380px) {
  .setup-container { padding: 24px 16px; }
  .card { padding: 24px 18px; }
  .main-content { padding: 16px; }
  .logo-section h1 { font-size: 24px; }
  .report-total-amount { font-size: 26px; }
}

@media (min-width: 768px) {
  .setup-container { padding: 48px 24px; }
  .main-content { padding: 32px 24px; padding-bottom: 24px; }
}