:root {
  --md-primary: #1a73e8;
  --md-primary-light: #4285f4;
  --md-primary-container: #d3e3fd;
  --md-on-primary: #ffffff;
  --md-on-primary-container: #001d36;
  --md-secondary: #5f6368;
  --md-error: #d93025;
  --md-surface: #ffffff;
  --md-surface-dim: #f8f9fa;
  --md-surface-container: #f1f3f4;
  --md-surface-container-high: #e8eaed;
  --md-on-surface: #1f1f1f;
  --md-on-surface-variant: #5f6368;
  --md-outline: #dadce0;
  --md-outline-variant: #e8eaed;
  --md-shadow-1: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.08);
  --md-shadow-2: 0 3px 6px rgba(0,0,0,0.15), 0 2px 4px rgba(0,0,0,0.10);
  --md-radius-sm: 8px;
  --md-radius-md: 12px;
  --md-radius-lg: 16px;
  --md-transition: 200ms cubic-bezier(0.2, 0, 0, 1);
}

[data-theme="dark"] {
  color-scheme: dark;
  --md-primary: #8ab4f8;
  --md-primary-light: #a8c7fa;
  --md-primary-container: #004a77;
  --md-on-primary: #003258;
  --md-on-primary-container: #d3e3fd;
  --md-secondary: #9aa0a6;
  --md-error: #f28b82;
  --md-surface: #1f1f1f;
  --md-surface-dim: #141414;
  --md-surface-container: #2d2d2d;
  --md-surface-container-high: #383838;
  --md-on-surface: #e8eaed;
  --md-on-surface-variant: #9aa0a6;
  --md-outline: #5f6368;
  --md-outline-variant: #3c4043;
  --md-shadow-1: 0 1px 3px rgba(0,0,0,0.4);
  --md-shadow-2: 0 3px 6px rgba(0,0,0,0.5);
}

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

body {
  font-family: 'Google Sans', 'Segoe UI', Roboto, sans-serif;
  background: var(--md-surface-dim);
  color: var(--md-on-surface);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.header {
  width: 100%;
  padding: 20px 40px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--md-surface);
  border-bottom: 1px solid var(--md-outline-variant);
  box-shadow: var(--md-shadow-1);
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 18px;
  color: var(--md-on-surface);
}

.logo .material-icons-round {
  color: var(--md-primary);
}

.theme-switch {
  cursor: pointer;
  padding: 8px;
  border-radius: 50%;
  transition: background 0.2s;
}
.theme-switch:hover {
  background: var(--md-surface-container);
}

.container {
  max-width: 600px;
  width: 100%;
  padding: 40px 20px;
}

.card {
  background: var(--md-surface);
  border-radius: var(--md-radius-lg);
  box-shadow: var(--md-shadow-1);
}

.hidden { display: none !important; }

/* ─── Shared Components ───────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  font-family: inherit;
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--md-radius-sm);
  cursor: pointer;
  border: none;
  transition: all var(--md-transition);
}

.btn-primary {
  background: var(--md-primary);
  color: var(--md-on-primary);
}
.btn-primary:hover:not(:disabled) {
  background: var(--md-primary-light);
  box-shadow: var(--md-shadow-1);
}
.btn-secondary {
  background: transparent;
  color: var(--md-primary);
  border: 1px solid var(--md-outline);
}
.btn-secondary:hover {
  background: var(--md-surface-container);
}
.btn-success {
  background: #22c55e !important;
  color: white !important;
}
.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ─── Donation Panel specifics ────────────────────────────── */
.donation-panel {
  padding: 0 !important;
  overflow: hidden;
  border: 1px solid var(--md-primary);
  box-shadow: 0 0 0 1px var(--md-primary-container), var(--md-shadow-2);
}

.donation-header {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 20px 24px;
  background: linear-gradient(135deg, var(--md-primary), var(--md-primary-light));
  color: var(--md-on-primary);
  position: relative;
  overflow: hidden;
}

.donation-header-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(10px);
}
.donation-header-icon .material-icons-round { color: var(--md-on-primary); font-size: 24px; }
.donation-title { font-size: 18px; font-weight: 700; z-index: 1; position: relative; }
.donation-subtitle { font-size: 12px; opacity: 0.85; margin-top: 2px; z-index: 1; position: relative;}
.donation-badge {
  margin-left: auto;
  background: rgba(255, 255, 255, 0.2);
  padding: 4px 12px;
  border-radius: 100px;
  font-size: 11px;
  font-weight: 700;
  border: 1px solid rgba(255, 255, 255, 0.3);
  z-index: 1;
}

.premium-features-list {
  display: flex;
  gap: 8px;
  padding: 16px 24px;
  background: var(--md-surface-dim);
}
.premium-feature-item {
  display: flex;
  align-items: center;
  gap: 6px;
  flex: 1;
  font-size: 11px;
  font-weight: 500;
  color: var(--md-on-surface-variant);
  padding: 8px 12px;
  background: var(--md-surface);
  border-radius: var(--md-radius-sm);
  border: 1px solid var(--md-outline-variant);
}
.premium-feature-item .material-icons-round { font-size: 16px; color: var(--md-primary); }

.donation-step { padding: 20px 24px; transition: opacity var(--md-transition); }
.donation-step-disabled { opacity: 0.45; pointer-events: none; }
.donation-step-header { display: flex; align-items: center; gap: 12px; margin-bottom: 16px; }
.donation-step-number { width: 28px; height: 28px; border-radius: 50%; background: var(--md-primary); color: var(--md-on-primary); display: flex; align-items: center; justify-content: center; font-size: 13px; font-weight: 700;}
.donation-step-label { font-size: 14px; font-weight: 600; color: var(--md-on-surface); }
.donation-divider { height: 1px; background: var(--md-outline-variant); margin: 0; }

.donation-email-wrap { position: relative; display: flex; align-items: center; }
.donation-email-icon { position: absolute; left: 14px; font-size: 20px; color: var(--md-on-surface-variant); }
.donation-email-input {
  width: 100%;
  padding: 14px 16px 14px 46px;
  border: 2px solid var(--md-outline);
  border-radius: var(--md-radius-md);
  background: var(--md-surface);
  color: var(--md-on-surface);
  font-family: inherit;
  font-size: 14px;
  outline: none;
  transition: all var(--md-transition);
}
.donation-email-input:focus {
  border-color: var(--md-primary);
  box-shadow: 0 0 0 3px var(--md-primary-container);
}
.donation-email-hint { font-size: 11px; color: var(--md-on-surface-variant); margin-top: 8px; padding-left: 2px; }

/* Radio Buttons */
.payment-radio-group { display: flex; flex-direction: column; gap: 10px; }
.payment-radio {
  display: flex; align-items: center; gap: 14px; padding: 14px 16px; border: 2px solid var(--md-outline-variant); border-radius: var(--md-radius-md); cursor: pointer; transition: all var(--md-transition);
}
.payment-radio:hover { border-color: var(--md-primary); background: var(--md-surface-dim); }
.payment-radio:has(input:checked) { border-color: var(--md-primary); background: var(--md-primary-container); }
.payment-radio input { display: none; }
.payment-radio-control { width: 20px; height: 20px; border: 2px solid var(--md-outline); border-radius: 50%; position: relative;}
.payment-radio-control::after { content: ''; position: absolute; top: 50%; left: 50%; width: 0; height: 0; border-radius: 50%; background: var(--md-primary); transform: translate(-50%, -50%); transition: all var(--md-transition); }
.payment-radio:has(input:checked) .payment-radio-control { border-color: var(--md-primary); }
.payment-radio:has(input:checked) .payment-radio-control::after { width: 10px; height: 10px; }
.payment-radio-content { flex: 1; display: flex; align-items: center; }
.payment-radio-label-row { display: flex; align-items: center; gap: 10px; font-size: 14px; font-weight: 500; }
.payment-radio-label-row .material-icons-round { color: var(--md-primary); font-size: 22px; }

.donation-field { margin-top: 24px; }
.donation-field:first-child { margin-top: 0; }
.donation-field-label { display: block; font-size: 12px; font-weight: 600; color: var(--md-on-surface-variant); text-transform: uppercase; margin-bottom: 12px; }

.donation-tier-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 8px; }
.donation-tier {
  display: flex; flex-direction: column; align-items: center; padding: 16px 12px; border: 2px solid var(--md-outline-variant); border-radius: var(--md-radius-md); background: var(--md-surface); cursor: pointer; transition: all var(--md-transition); position: relative;
}
.donation-tier:hover { border-color: var(--md-primary); background: var(--md-surface-dim); transform: translateY(-2px); }
.donation-tier.active { border-color: var(--md-primary); background: var(--md-primary-container); }
.tier-popular-badge { position: absolute; top: -2px; right: -2px; background: var(--md-primary); color: white; font-size: 9px; font-weight: 700; text-transform: uppercase; padding: 3px 8px; border-top-right-radius: var(--md-radius-md); border-bottom-left-radius: 6px; }
.tier-amount { font-size: 22px; font-weight: 700; color: var(--md-on-surface); }
.tier-eth { font-size: 11px; color: var(--md-on-surface-variant); font-family: monospace; }
.tier-label { font-size: 10px; font-weight: 600; text-transform: uppercase; color: var(--md-primary); margin-top: 4px; }

.donate-send-btn { width: 100%; justify-content: center; margin-top: 20px; padding: 16px 24px; font-size: 15px; }

/* Manual Transfer */
.wallet-display { display: flex; gap: 20px; margin-bottom: 8px; align-items: center; }
.qr-code-container { width: 120px; height: 120px; border: 2px solid var(--md-outline-variant); border-radius: var(--md-radius-md); padding: 4px; background: #fff; }
.qr-code-img { width: 100%; height: 100%; }
.wallet-address-section { flex: 1; }
.wallet-address-box { display: flex; align-items: center; gap: 8px; padding: 10px 12px; background: var(--md-surface-container); border: 1px solid var(--md-outline-variant); border-radius: var(--md-radius-sm); }
.wallet-address-text { font-size: 11px; font-family: monospace; word-break: break-all; flex: 1; }
.wallet-copy-btn { width: 32px; height: 32px; border: none; background: transparent; cursor: pointer; color: var(--md-on-surface-variant); border-radius: 4px;}
.wallet-copy-btn:hover { background: var(--md-primary-container); color: var(--md-primary); }

.txid-input-wrap { position: relative; display: flex; align-items: center; }
.txid-icon { position: absolute; left: 14px; font-size: 20px; color: var(--md-on-surface-variant); }
.donation-txid-input { width: 100%; padding: 12px 16px 12px 46px; border: 2px solid var(--md-outline); border-radius: var(--md-radius-md); background: var(--md-surface); font-family: monospace; font-size: 13px; outline: none;}
.donation-txid-input:focus { border-color: var(--md-primary); }

.manual-donation-notice { display: flex; gap: 10px; padding: 12px 16px; background: var(--md-surface-dim); border: 1px solid var(--md-outline-variant); border-radius: 8px; font-size: 12px; color: var(--md-on-surface-variant); }

/* Legal Limits */
.legal-links { margin-top: 20px; text-align: center; font-size: 13px; color: var(--md-on-surface-variant); }
.legal-links a { color: var(--md-primary); text-decoration: none; }
.legal-links a:hover { text-decoration: underline; }
.legal-content { margin-top: 20px; padding: 20px; }
.legal-content h2 { font-size: 18px; margin-bottom: 12px; }
.legal-content p { font-size: 14px; margin-bottom: 8px; color: var(--md-on-surface-variant); line-height: 1.5; }

/* Toast */
.toast { position: fixed; bottom: 20px; left: 50%; transform: translateX(-50%); background: var(--md-on-surface); color: var(--md-surface); padding: 12px 24px; border-radius: 8px; font-size: 14px; z-index: 1000; transition: opacity 0.3s; box-shadow: var(--md-shadow-2); display: flex; align-items: center; gap: 8px; }
.toast.toast-error { background: var(--md-error); color: white; }
.toast.toast-success { background: #22c55e; color: white; }

/* Modal Overlay */
.modal-overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.5); display: flex; align-items: center; justify-content: center; z-index: 2000; backdrop-filter: blur(4px); animation: fadeIn 0.2s ease; }
.modal-card { background: var(--md-surface); border-radius: var(--md-radius-lg); box-shadow: var(--md-shadow-2); padding: 32px; max-width: 420px; width: 90%; text-align: center; animation: scaleIn 0.25s ease; }
.modal-icon-wrap { width: 80px; height: 80px; border-radius: 50%; background: rgba(34,197,94,0.1); display: flex; align-items: center; justify-content: center; margin: 0 auto 20px auto; }
.modal-badge { display: inline-flex; align-items: center; gap: 6px; padding: 6px 16px; border-radius: 100px; font-size: 12px; font-weight: 700; text-transform: uppercase; background: var(--md-primary-container); color: var(--md-primary); margin-bottom: 20px; }
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
@keyframes scaleIn { from { transform: scale(0.9); opacity: 0; } to { transform: scale(1); opacity: 1; } }