/* ========== 全局样式 ========== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --primary: #059669;
  --primary-light: #10b981;
  --primary-dark: #047857;
  --bg: #f1f5f9;
  --white: #ffffff;
  --border: #e2e8f0;
  --text: #1e293b;
  --text-muted: #64748b;
  --shadow: 0 2px 12px rgba(0,0,0,.08);
  --radius: 12px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.6;
  display: flex;
  flex-direction: column;
}

/* ========== HEADER ========== */
header {
  background: var(--white);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
}

.header-inner {
  max-width: 1600px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  padding: 0 48px;
  height: 68px;
  gap: 40px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 22px;
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
  flex-shrink: 0;
}

.logo svg { width: 36px; height: 36px; }

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

.back-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--white);
  font-size: 14px;
  color: var(--text-muted);
  cursor: pointer;
  text-decoration: none;
  transition: all .2s;
}

.back-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: #f0fdf4;
}

/* ========== TOOL HEADER ========== */
.tool-header {
  max-width: 1600px;
  margin: 40px auto 28px;
  padding: 0 48px;
}

.tool-header h2 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 8px;
}

.tool-header p {
  font-size: 15px;
  color: var(--text-muted);
}

/* ========== TOOL MAIN ========== */
.tool-main {
  max-width: 1600px;
  min-width: 80%;
  margin: 0 auto 64px;
  padding: 0 48px;
  flex: 1;
}

.tool-main.two-panel {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

@media (max-width: 768px) {
  .tool-main.two-panel { grid-template-columns: 1fr; }
}

/* ========== FORM CONTROLS ========== */
.form-control {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  outline: none;
  transition: border-color .2s, box-shadow .2s;
  color: var(--text);
  background: #fff;
  font-family: inherit;
}

.form-control:focus {
  border-color: var(--primary-light);
  box-shadow: 0 0 0 3px rgba(5, 150, 105, .12);
}

.form-group { margin-bottom: 18px; }
.form-group label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  color: var(--text);
  margin-bottom: 6px;
}
.form-group label .required { color: #ef4444; margin-left: 2px; }

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

@media (max-width: 600px) {
  .form-row { grid-template-columns: 1fr; }
}

.char-count { font-size: 12px; color: var(--text-muted); text-align: right; margin-top: 4px; }

/* ========== PANEL ========== */
.panel-col {
  background: var(--white);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  overflow: hidden;
}

.panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 16px;
  background: #f8fafc;
  border-bottom: 1px solid var(--border);
  font-size: 14px;
  font-weight: 500;
}

.panel-actions {
  display: flex;
  gap: 8px;
}

.action-btn {
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--white);
  font-size: 13px;
  cursor: pointer;
  transition: all .2s;
}

.action-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.action-btn.small {
  padding: 4px 10px;
  font-size: 12px;
}

.code-input, .code-output {
  width: 100%;
  min-height: 420px;
  padding: 20px;
  border: none;
  font-family: 'Monaco', 'Menlo', 'Consolas', monospace;
  font-size: 13px;
  line-height: 1.7;
  resize: vertical;
  background: #fafafa;
}

.code-output {
  background: #f1f5f9;
  color: var(--text);
}

.code-input:focus, .code-output:focus {
  outline: none;
}

.code-input.big {
  min-height: 200px;
}

/* ========== TYPE TABS ========== */
.type-tabs, .encode-type-tabs, .time-tabs, .loan-type-tabs {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--border);
  overflow-x: auto;
  background: #fafafa;
  border-radius: var(--radius) var(--radius) 0 0;
  padding: 0 8px;
}

.tab-btn {
  padding: 14px 18px;
  border: none;
  background: transparent;
  cursor: pointer;
  font-size: 14px;
  color: var(--text-muted);
  white-space: nowrap;
  position: relative;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: color .2s;
  border-bottom: 3px solid transparent;
  margin-bottom: -1px;
}

.tab-btn:hover { color: var(--primary); }
.tab-btn.active { color: var(--primary); border-bottom-color: var(--primary); font-weight: 600; background: var(--white); }

/* ========== GEN BTN ========== */
.gen-btn {
  width: 100%;
  padding: 12px;
  background: linear-gradient(135deg, var(--primary-dark), var(--primary-light));
  color: #fff;
  border: none;
  border-radius: 10px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: opacity .2s, transform .1s;
}

.gen-btn:hover { opacity: .92; }
.gen-btn:active { transform: scale(.98); }

/* ========== FOOTER ========== */
footer {
  background: #1e293b;
  color: #94a3b8;
  padding: 32px 24px;
  text-align: center;
  margin-top: auto;
}

.footer-inner { max-width: 1600px; margin: 0 auto; }
footer h4 { color: #e2e8f0; font-size: 17px; margin-bottom: 8px; }
footer p { font-size: 13px; }

/* ========== TOAST ========== */
.toast {
  position: fixed;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%) translateY(80px);
  background: #1e293b;
  color: #fff;
  padding: 12px 28px;
  border-radius: 99px;
  font-size: 14px;
  z-index: 999;
  transition: transform .3s ease;
  pointer-events: none;
}

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

/* ========== RESPONSIVE ========== */
@media (max-width: 1024px) {
  .header-inner { padding: 0 32px; }
  .tool-header { padding: 0 32px; margin-top: 32px; }
  .tool-main { padding: 0 32px; }
}

@media (max-width: 768px) {
  .header-inner {
    flex-wrap: wrap;
    height: auto;
    padding: 12px 16px;
    gap: 12px;
  }

  .tool-header { padding: 0 16px; margin-top: 24px; }
  .tool-header h2 { font-size: 22px; }
  .tool-main { padding: 0 16px; }
}