/* =========================
   MATERIAL BASE (GLOBAL)
   ========================= */

/* RESET */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

/* COLOR SYSTEM */
:root {
  --primary: #3b82f6;
  --primary-soft: #e0edff;
  --success: #22c55e;
  --error: #ef4444;
  --bg-gradient: linear-gradient(180deg, #eaf1ff, #ffffff);

  --text-main: #1f2937;
  --text-muted: #6b7280;

  --card-radius: 24px;
  --btn-radius: 18px;
}

/* BODY */
body {
  background: var(--bg-gradient);
  color: var(--text-main);
}

/* APP WRAPPER */
.app {
  height: 100vh;
  display: flex;
  flex-direction: column;
  position: relative;
}

/* CARD */
.card {
  background: white;
  border-radius: var(--card-radius);
  box-shadow: 0 8px 24px rgba(0,0,0,0.08);
}

/* HEADER */
.exercise-header {
  padding: 16px;
}

.exercise-title {
  font-size: 1.4rem;
  font-weight: 700;
}

.exercise-progress {
  margin-top: 6px;
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* PROGRESS BAR */
.progress-bar {
  margin-top: 10px;
  height: 8px;
  background: #e5e7eb;
  border-radius: 999px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  width: 0%;
  background: var(--primary);
  transition: width 0.4s ease;
}

/* BUTTONS */
.controls {
  display: flex;
  gap: 16px;
  padding: 16px;
  background: white;
  border-top: 1px solid #e5e7eb;
}

button {
  flex: 1;
  min-height: 52px;          /* non height fissa */
  padding: 10px 18px;        /* ← MARGINE REALE */
  border-radius: var(--btn-radius);
  border: none;

  font-size: 1.05rem;
  font-weight: 600;
  line-height: 1.2;          /* evita compressione verticale */

  background: var(--primary);
  color: white;

  box-shadow: 0 6px 14px rgba(59,130,246,0.3);
}

button:disabled {
  background: #c7d2fe;
  box-shadow: none;
  opacity: 0.7;
  cursor: default;
}

/* STATES */
.hidden {
  display: none;
}

/* RESPONSIVE */
@media (max-width: 700px) {
  .exercise-title {
    font-size: 1.2rem;
  }
}