/* ==========================================================================
   VPNVL — tutorial.css
   上手教程页(setup)的页面级版式:步骤卡、系统小节、示例块、核对清单。
   设计值全部取自 base.css 的 :root 令牌,组件内不写颜色字面量。
   ========================================================================== */

.tut-body {
  position: relative;
  z-index: 1;
  padding-bottom: var(--sec-y);
}

.tut-link {
  color: var(--accent-dark);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}
.tut-link:hover { color: var(--accent); }

/* ---------------------------------------------------------------
   1. 步骤堆栈
   --------------------------------------------------------------- */
.tut-steps {
  display: flex;
  flex-direction: column;
  gap: 20px;
  margin: 0;
}

.tut-step {
  position: relative;
  display: grid;
  grid-template-columns: 54px minmax(0, 1fr);
  gap: 20px;
  padding: 26px 26px 24px;
  border-radius: var(--r-xl);
  background: var(--panel-3);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-panel);
}
.tut-step::before {
  content: "";
  position: absolute;
  top: 0;
  left: 26px;
  right: 26px;
  height: 2px;
  background-image: linear-gradient(90deg, transparent 0%, var(--accent-16) 24%, var(--mint-22) 70%, transparent 100%);
}

.tut-num {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  min-width: 0;
}
.tut-num b {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  flex: 0 0 auto;
  border-radius: 15px;
  background-image: linear-gradient(180deg, var(--panel-3) 0%, var(--panel-12) 100%);
  border: 1px solid var(--accent-16);
  box-shadow: var(--shadow-chip);
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--accent-dark);
}
.tut-num i {
  display: block;
  width: 2px;
  flex: 1 1 auto;
  min-height: 18px;
  border-radius: 2px;
  background-image: linear-gradient(180deg, var(--accent-16) 0%, transparent 100%);
}

.tut-main { min-width: 0; }

.tut-main .kicker { margin-bottom: 0; }

.tut-main h2 {
  margin-top: 8px;
  font-size: clamp(20px, 2.1vw, 27px);
}

.tut-main h3 {
  margin-top: 20px;
  font-size: 16px;
  line-height: 1.4;
}

.tut-main p {
  margin-top: 10px;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--text-2);
}
.tut-main p strong { color: var(--text); font-weight: 600; }

.tut-main ul {
  margin: 12px 0 0;
  padding-left: 1.15em;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--text-2);
}
.tut-main li + li { margin-top: 7px; }
.tut-main li::marker { color: var(--accent); }

.tut-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin-top: 18px;
}

/* ---------------------------------------------------------------
   2. 订阅链接示例块
   --------------------------------------------------------------- */
.tut-sample {
  margin-top: 14px;
  padding: 12px 14px;
  border-radius: var(--r-md);
  background: var(--panel-5);
  border: 1px dashed var(--accent-24);
}
.tut-sample-label {
  display: block;
  margin-bottom: 7px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--muted);
}
.tut-sample code {
  display: inline-block;
  max-width: 100%;
  background: var(--panel-3);
  font-size: 12.5px;
}

/* ---------------------------------------------------------------
   3. 各平台小节
   --------------------------------------------------------------- */
.tut-os {
  margin-top: 16px;
  padding: 16px 18px 18px;
  border-radius: var(--r-lg);
  background: var(--panel-5);
  border: 1px solid var(--border-soft);
}
.tut-os h3 { margin-top: 0; }
.tut-os p { margin-top: 8px; font-size: 14px; line-height: 1.76; }

.tut-os-tag {
  display: inline-block;
  margin-right: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--muted);
}

/* ---------------------------------------------------------------
   4. 上手核对清单
   --------------------------------------------------------------- */
.tut-check {
  margin-top: 26px;
  padding: 26px;
  border-radius: var(--r-xl);
  background-image: var(--grad-panel-soft);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-panel);
}
.tut-check .kicker { margin-bottom: 0; }
.tut-check h2 {
  margin-top: 8px;
  font-size: clamp(20px, 2.1vw, 27px);
}
.tut-check > p {
  margin-top: 10px;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--text-2);
}

.tut-check-list {
  display: grid;
  gap: 12px;
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
}
.tut-check-list li {
  display: grid;
  grid-template-columns: 20px minmax(0, 1fr);
  gap: 10px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-2);
}
.tut-check-list svg {
  width: 18px;
  height: 18px;
  margin-top: 3px;
  color: var(--success);
}
.tut-check-list b { color: var(--text); font-weight: 600; }

.tut-check .callout { margin-bottom: 0; }

/* ---------------------------------------------------------------
   5. 断点
   --------------------------------------------------------------- */
@media (max-width: 900px) {
  .tut-step {
    grid-template-columns: 46px minmax(0, 1fr);
    gap: 14px;
    padding: 22px 20px;
  }
  .tut-num b {
    width: 40px;
    height: 40px;
    border-radius: 13px;
    font-size: 14px;
  }
  .tut-step::before { left: 20px; right: 20px; }
}

@media (max-width: 640px) {
  .tut-step {
    grid-template-columns: minmax(0, 1fr);
    gap: 10px;
    padding: 20px 18px;
  }
  .tut-num {
    flex-direction: row;
    align-items: center;
    gap: 10px;
  }
  .tut-num i { display: none; }
  .tut-main h2 { font-size: clamp(19px, 5vw, 23px); }
  .tut-check { padding: 20px 18px; }
  .tut-os { padding: 14px; }
  .tut-actions .btn { width: 100%; }
}