:root {
  --bg: #f6f7fb;
  --card: #ffffff;
  --text: #14213d;
  --muted: #667085;
  --line: #e4e7ec;
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --success: #16a34a;
  --warning: #f59e0b;
  --soft-blue: #eff6ff;
  --soft-green: #f0fdf4;
  --soft-amber: #fffbeb;
  --radius: 18px;
  --shadow: 0 12px 34px rgba(20,33,61,.08);
}
* { box-sizing: border-box; }
html { font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; color: var(--text); }
body { margin: 0; line-height: 1.55; }
a { color: inherit; }
.site-bg { background: var(--bg); min-height: 100vh; }
.container { width: min(1120px, calc(100% - 32px)); margin: 0 auto; }
.narrow { max-width: 820px; }
.course-header, .lesson-header { background: rgba(255,255,255,.96); border-bottom: 1px solid var(--line); position: sticky; top: 0; z-index: 20; backdrop-filter: blur(10px); }
.header-row, .lesson-header-row { min-height: 74px; display: flex; align-items: center; justify-content: space-between; gap: 18px; }
.brand { font-size: 1.2rem; font-weight: 800; text-decoration: none; letter-spacing: -.02em; }
.header-subtitle { margin: 2px 0 0; color: var(--muted); font-size: .88rem; }
.user-menu { display: flex; align-items: center; gap: 10px; color: var(--muted); font-size: .88rem; }
.main-space { padding: 34px 0 60px; }
.progress-hero { background: linear-gradient(135deg,#172554,#1d4ed8); color: white; border-radius: 24px; padding: 30px; display: grid; grid-template-columns: 1fr auto; gap: 18px 28px; box-shadow: var(--shadow); }
.progress-hero h1 { margin: 5px 0 8px; font-size: clamp(1.7rem,3vw,2.45rem); line-height: 1.08; }
.progress-hero p { margin: 0; color: #dbeafe; max-width: 760px; }
.eyebrow { margin: 0 0 7px; font-size: .73rem; font-weight: 800; letter-spacing: .13em; text-transform: uppercase; color: #2563eb; }
.progress-hero .eyebrow { color: #bfdbfe; }
.global-progress { display: flex; flex-direction: column; text-align: right; justify-content: center; }
.global-progress strong { font-size: 2rem; }
.global-progress span { color: #bfdbfe; font-size: .8rem; }
.progress-track { height: 9px; background: rgba(255,255,255,.22); border-radius: 999px; overflow: hidden; grid-column: 1 / -1; }
.progress-track.compact { background: #edf0f4; margin-top: 18px; height: 7px; }
.progress-fill { height: 100%; background: #60a5fa; border-radius: inherit; transition: width .3s ease; }
.compact .progress-fill { background: var(--success); }
.module-list { display: grid; gap: 18px; margin-top: 22px; }
.module-card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; box-shadow: 0 8px 24px rgba(20,33,61,.04); }
.module-card h1, .module-card h2 { margin-top: 0; }
.module-head { display: flex; justify-content: space-between; gap: 28px; }
.module-head h2 { margin: 10px 0 6px; font-size: 1.15rem; }
.module-head p { margin: 0; color: var(--muted); max-width: 770px; }
.module-progress { min-width: 110px; display: flex; flex-direction: column; text-align: right; }
.module-progress strong { font-size: 1.35rem; }
.module-progress span { font-size: .78rem; color: var(--muted); }
.status-pill { display: inline-flex; padding: 4px 9px; border-radius: 999px; background: #f2f4f7; color: #667085; font-size: .7rem; font-weight: 700; text-transform: uppercase; letter-spacing: .05em; }
.status-pill.status-open { background: var(--soft-amber); color: #a16207; }
.status-pill.status-done { background: var(--soft-green); color: #15803d; }
.lesson-list { border: 1px solid var(--line); border-radius: 13px; overflow: hidden; margin-top: 17px; }
.lesson-row { display: grid; grid-template-columns: 12px 1fr auto auto; align-items: center; gap: 12px; padding: 13px 15px; text-decoration: none; border-top: 1px solid var(--line); transition: background .15s ease; }
.lesson-row:first-child { border-top: 0; }
.lesson-row:hover { background: #f8fafc; }
.lesson-state { width: 9px; height: 9px; border-radius: 50%; background: #d0d5dd; }
.lesson-state.lesson-open { background: var(--warning); }
.lesson-state.lesson-done { background: var(--success); }
.lesson-title { font-weight: 600; font-size: .91rem; }
.lesson-percent { color: var(--muted); font-size: .79rem; }
.lesson-action { border: 1px solid var(--line); border-radius: 8px; padding: 5px 9px; font-size: .78rem; background: white; }
.btn { display: inline-flex; align-items: center; justify-content: center; border-radius: 10px; padding: 10px 14px; font-weight: 700; font-size: .87rem; text-decoration: none; border: 1px solid transparent; cursor: pointer; }
.btn-primary { background: var(--primary); color: white; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-secondary { background: white; color: var(--text); border-color: var(--line); }
.btn-small { padding: 7px 10px; font-size: .78rem; }
.auth-shell { min-height: 100vh; display: grid; place-items: center; padding: 24px; }
.auth-card { width: min(440px,100%); background: white; border: 1px solid var(--line); border-radius: 24px; padding: 34px; box-shadow: var(--shadow); }
.auth-card h1 { margin: 7px 0; }
.auth-foot { margin: 20px 0 0; color: var(--muted); font-size: .86rem; }
.muted { color: var(--muted); }
.form-stack { display: grid; gap: 15px; margin-top: 22px; }
.form-stack label { display: grid; gap: 6px; font-size: .84rem; font-weight: 700; }
.form-stack input, .form-stack select, .form-stack textarea { width: 100%; padding: 11px 12px; border: 1px solid #d0d5dd; border-radius: 10px; font: inherit; background: white; }
.form-stack input:focus, .form-stack select:focus, .form-stack textarea:focus { outline: 3px solid #dbeafe; border-color: #60a5fa; }
.form-error { color: #b42318; background: #fef3f2; padding: 10px 12px; border-radius: 10px; margin: 0; font-size: .83rem; }
.form-note { color: #175cd3; background: #eff8ff; padding: 10px 12px; border-radius: 10px; margin: 0; font-size: .83rem; }
.lesson-header-row { min-height: 62px; }
.back-link, .tutor-link { font-weight: 700; font-size: .84rem; text-decoration: none; }
.lesson-module { color: var(--muted); font-size: .82rem; text-align: center; }
.lesson-shell { width: min(900px,calc(100% - 32px)); margin: 32px auto 60px; }
.lesson-card { background: white; border: 1px solid var(--line); border-radius: 22px; padding: clamp(24px,4vw,46px); box-shadow: 0 8px 28px rgba(20,33,61,.05); }
.lesson-card h1 { margin: 4px 0 24px; line-height: 1.14; font-size: clamp(1.8rem,4vw,2.6rem); }
.lesson-content { color: #344054; font-size: 1.02rem; }
.lesson-content h2 { color: var(--text); margin: 30px 0 10px; }
.lesson-content p { margin: 0 0 16px; }
.lesson-content ul { margin: 0 0 20px; padding-left: 22px; }
.lesson-nav { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 20px; }
.lesson-nav > div:last-child { text-align: right; }
.ia-block { border-left: 4px solid #f59e0b; background: var(--soft-amber); padding: 18px; border-radius: 13px; margin: 24px 0; }
.ia-block__header { display: flex; align-items: center; gap: 8px; font-size: .86rem; font-weight: 800; color: #92400e; }
.ia-block__content { margin-top: 8px; font-size: .92rem; color: #475467; }
.ia-block__content p:last-child { margin-bottom: 0; }
.info-box { border: 1px solid #bfdbfe; background: var(--soft-blue); border-radius: 14px; padding: 18px; margin: 22px 0; }
.info-box strong { color: #1d4ed8; }
.thread-list { display: grid; gap: 10px; margin-top: 15px; }
.thread-row { display: flex; justify-content: space-between; gap: 16px; border: 1px solid var(--line); border-radius: 11px; padding: 12px; }
.thread-row div { display: grid; }
.thread-row span { font-size: .76rem; color: var(--muted); }
@media (max-width: 720px) {
  .header-row, .module-head { align-items: flex-start; flex-direction: column; }
  .user-menu { flex-wrap: wrap; }
  .progress-hero { grid-template-columns: 1fr; }
  .global-progress { text-align: left; }
  .lesson-row { grid-template-columns: 10px 1fr auto; }
  .lesson-percent { display: none; }
  .lesson-nav { grid-template-columns: 1fr; }
  .lesson-nav > div:last-child { text-align: left; }
  .lesson-header-row { flex-wrap: wrap; padding: 10px 0; }
  .lesson-module { order: 3; width: 100%; }
}


/* Estado de lecciones aun no publicadas */
.lesson-row.is-upcoming { cursor: default; opacity: .68; background: #fafafa; }
.lesson-row.is-upcoming:hover { background: #fafafa; }
.lesson-state.lesson-upcoming { background: #98a2b3; }
.lesson-action.is-disabled { color: #667085; background: #f2f4f7; }

/* Diagnostico */
.diagnostic-grid { display: grid; gap: 16px; }
.choice-grid { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 10px; }
.choice-card { display: block; border: 1px solid var(--line); border-radius: 12px; padding: 12px; background: white; }
.choice-card input { margin-right: 7px; }
.ai-result { margin-top: 20px; }
.ai-badge { display: inline-flex; align-items: center; gap: 6px; border-radius: 999px; background: #fff7ed; color: #9a3412; padding: 5px 9px; font-size: .73rem; font-weight: 800; }
.hidden { display: none !important; }
@media (max-width: 720px) { .choice-grid { grid-template-columns: 1fr; } }