:root {
  --font-size-display-lg: 32px;
  --font-size-display-md: 24px;
  --font-size-title-lg: 20px;
  --font-size-title-md: 18px;
  --font-size-title-sm: 16px;
  --font-size-body-md: 14px;
  --font-size-body-sm: 13px;
  --font-size-caption: 12px;
  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --text-strong: #5a5a5a;
  --text-primary: #666666;
  --text-secondary: #767676;
  --surface-page: #f7f7f7;
  --surface-card: #ffffff;
  --surface-warm: #f4f0e8;
  --border-strong: #c8c8c8;
  --border-default: #d9d9d9;
  --divider: #e5e5e5;
  --brand: #9a7337;
  --brand-soft: #e9dcc1;
  --success-surface: #eef1eb;
  --radius: 8px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  color: var(--text-primary);
  background: var(--surface-page);
}

* {
  box-sizing: border-box;
}

body {
  min-width: 320px;
  margin: 0;
  background: var(--surface-page);
  color: var(--text-primary);
}

a {
  color: inherit;
  text-decoration: none;
}

button,
input,
select,
textarea {
  font: inherit;
}

.support-header {
  display: flex;
  min-height: 76px;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 12px clamp(18px, 4vw, 64px);
  border-bottom: 1px solid var(--divider);
  background: rgba(255, 255, 255, 0.96);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
}

.brand-logo {
  display: block;
  width: 146px;
  height: 46px;
  object-fit: contain;
  object-position: left center;
}

.back-link {
  min-height: 44px;
  padding: 11px 16px;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-size: var(--font-size-body-md);
  font-weight: var(--font-weight-medium);
}

.support-main {
  display: grid;
  grid-template-columns: minmax(300px, 0.82fr) minmax(540px, 1.18fr);
  gap: clamp(32px, 5vw, 72px);
  width: min(1320px, 100%);
  margin: 0 auto;
  padding: clamp(44px, 6vw, 84px) clamp(18px, 4vw, 64px);
}

.support-intro {
  align-self: start;
}

.intro-copy {
  padding-bottom: 32px;
  border-bottom: 1px solid var(--border-default);
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--text-secondary);
  font-size: var(--font-size-body-sm);
  font-weight: var(--font-weight-medium);
}

h1,
h2,
p {
  margin-top: 0;
}

h1 {
  max-width: 580px;
  margin-bottom: 18px;
  color: var(--text-strong);
  font-size: clamp(32px, 4vw, 52px);
  font-weight: var(--font-weight-semibold);
  line-height: 1.2;
}

h2 {
  margin-bottom: 10px;
  color: var(--text-strong);
  font-size: var(--font-size-title-lg);
  font-weight: var(--font-weight-semibold);
  line-height: 1.35;
}

.intro-copy > p:last-child,
.form-heading > p:last-child {
  margin-bottom: 0;
  font-size: var(--font-size-body-md);
  line-height: 1.7;
}

.contact-block {
  margin-top: 30px;
}

.block-heading {
  margin-bottom: 18px;
}

.block-heading > span {
  display: block;
  margin-bottom: 8px;
  color: var(--text-secondary);
  font-size: var(--font-size-body-sm);
  font-weight: var(--font-weight-semibold);
}

.contact-list {
  margin: 0;
  border-top: 1px solid var(--border-default);
}

.contact-list > div {
  display: grid;
  grid-template-columns: 88px minmax(0, 1fr);
  gap: 18px;
  padding: 16px 0;
  border-bottom: 1px solid var(--divider);
}

.contact-list dt {
  color: var(--text-secondary);
  font-size: var(--font-size-body-sm);
}

.contact-list dd {
  min-width: 0;
  margin: 0;
  overflow-wrap: anywhere;
  color: var(--text-strong);
  font-size: var(--font-size-body-md);
  font-weight: var(--font-weight-medium);
  line-height: 1.55;
}

.contact-list a {
  text-decoration: underline;
  text-decoration-color: var(--brand-soft);
  text-underline-offset: 4px;
}

.feedback-panel {
  min-height: 720px;
  align-self: start;
  padding: clamp(24px, 4vw, 44px);
  border: 1px solid var(--border-default);
  border-top: 4px solid var(--brand);
  border-radius: var(--radius);
  background: var(--surface-card);
  box-shadow: 0 20px 60px rgba(90, 90, 90, 0.1);
}

.form-heading {
  margin-bottom: 28px;
}

.support-form {
  display: grid;
  gap: 20px;
}

.support-form fieldset {
  min-width: 0;
  margin: 0;
  padding: 0;
  border: 0;
}

.support-form legend,
.support-form label > span {
  display: block;
  margin-bottom: 8px;
  color: var(--text-primary);
  font-size: var(--font-size-body-md);
  font-weight: var(--font-weight-medium);
}

.segment-control {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  overflow: hidden;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
}

.segment-control label {
  position: relative;
  min-width: 0;
  border-right: 1px solid var(--border-default);
}

.segment-control label:last-child {
  border-right: 0;
}

.segment-control input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.segment-control span {
  display: grid;
  min-height: 46px;
  margin: 0 !important;
  padding: 8px;
  place-items: center;
  text-align: center;
  cursor: pointer;
}

.segment-control input:checked + span {
  background: var(--surface-warm);
  color: var(--text-strong);
  box-shadow: inset 0 -3px 0 var(--brand);
}

.segment-control input:focus-visible + span {
  outline: 3px solid var(--brand-soft);
  outline-offset: -3px;
}

.form-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.support-form label {
  min-width: 0;
}

.support-form input,
.support-form select,
.support-form textarea {
  width: 100%;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  background: var(--surface-card);
  color: var(--text-primary);
  font-size: var(--font-size-title-sm);
  font-weight: var(--font-weight-regular);
}

.support-form input,
.support-form select {
  min-height: 48px;
  padding: 0 13px;
}

.support-form textarea {
  min-height: 112px;
  padding: 13px;
  resize: vertical;
  line-height: 1.55;
}

.support-form input:focus,
.support-form select:focus,
.support-form textarea:focus {
  border-color: var(--brand);
  outline: 3px solid var(--brand-soft);
}

.support-form [aria-invalid="true"] {
  border-style: dashed;
  border-color: var(--text-strong);
}

.support-form small {
  display: block;
  min-height: 18px;
  margin-top: 5px;
  color: var(--text-secondary);
  font-size: var(--font-size-caption);
  line-height: 1.4;
}

.field-meta {
  display: flex;
  justify-content: space-between;
  gap: 16px;
}

.field-meta > span {
  flex: 0 0 auto;
  margin-top: 5px;
  color: var(--text-secondary);
  font-size: var(--font-size-caption);
}

.field-meta b {
  font-weight: var(--font-weight-regular);
}

.submit-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding-top: 4px;
}

.submit-row p {
  max-width: 420px;
  margin-bottom: 0;
  color: var(--text-secondary);
  font-size: var(--font-size-body-sm);
  line-height: 1.55;
}

.submit-row button,
.success-actions button,
.success-actions a {
  display: inline-grid;
  min-width: 148px;
  min-height: 48px;
  padding: 10px 18px;
  place-items: center;
  border: 1px solid var(--text-strong);
  border-radius: var(--radius);
  background: var(--text-strong);
  color: var(--surface-card);
  font-size: var(--font-size-body-md);
  font-weight: var(--font-weight-semibold);
  cursor: pointer;
}

.form-status {
  min-height: 20px;
  margin: 0;
  color: var(--text-strong);
  font-size: var(--font-size-body-sm);
}

.success-view {
  display: grid;
  min-height: 630px;
  align-content: center;
  justify-items: start;
  padding: clamp(16px, 4vw, 48px);
  background: var(--success-surface);
}

.success-view[hidden] {
  display: none;
}

.success-mark {
  display: grid;
  width: 64px;
  height: 64px;
  margin-bottom: 28px;
  place-items: center;
  border: 2px solid var(--text-strong);
  border-radius: 50%;
  color: var(--text-strong);
  font-size: var(--font-size-display-md);
  font-weight: var(--font-weight-semibold);
}

.success-view h2 {
  margin-bottom: 12px;
  font-size: var(--font-size-display-lg);
}

.success-view > p:not(.eyebrow) {
  margin-bottom: 28px;
  line-height: 1.65;
}

.success-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.success-actions a {
  background: transparent;
  color: var(--text-strong);
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 28px;
  padding: 28px clamp(18px, 4vw, 64px);
  border-top: 1px solid var(--divider);
  background: var(--surface-card);
  color: var(--text-secondary);
  font-size: var(--font-size-body-sm);
}

.site-footer strong,
.site-footer span {
  display: block;
  margin-bottom: 7px;
  font-weight: var(--font-weight-regular);
}

.records {
  text-align: right;
}

.records a {
  color: var(--text-primary);
  text-decoration: underline;
  text-underline-offset: 4px;
}

a:focus-visible,
button:focus-visible {
  outline: 3px solid var(--brand-soft);
  outline-offset: 3px;
}

@media (max-width: 960px) {
  .support-main {
    grid-template-columns: 1fr;
  }

  .support-intro {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }

  .intro-copy {
    padding: 0;
    border: 0;
  }

  .contact-block {
    margin-top: 0;
  }
}

@media (max-width: 680px) {

  .support-main {
    padding-top: 36px;
  }

  .support-intro,
  .form-grid {
    grid-template-columns: 1fr;
  }

  .intro-copy {
    padding-bottom: 28px;
    border-bottom: 1px solid var(--border-default);
  }

  .segment-control {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .segment-control label:nth-child(2) {
    border-right: 0;
  }

  .segment-control label:nth-child(-n + 2) {
    border-bottom: 1px solid var(--border-default);
  }

  .submit-row,
  .site-footer {
    align-items: stretch;
    flex-direction: column;
  }

  .submit-row button {
    width: 100%;
  }

  .records {
    text-align: left;
  }
}

@media (max-width: 420px) {
  .brand-logo {
    width: 124px;
    height: 40px;
  }

  .back-link {
    padding-inline: 12px;
  }

  h1 {
    font-size: var(--font-size-display-lg);
  }

  .feedback-panel {
    padding: 22px 16px;
  }

  .contact-list > div {
    grid-template-columns: 1fr;
    gap: 6px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
  }
}