/* ==========================================================================
   StudyAI - Design Inspirador & Motivador
   Foco: Energia, Progresso, Conquistas
   ========================================================================== */

:root {
  /* Paleta de Cores Vibrantes & Motivadoras */
  --bg-color: #0a0a0f;
  --bg-gradient: 
    radial-gradient(ellipse 80% 50% at 20% 0%, rgba(99, 102, 241, 0.15) 0%, transparent 50%),
    radial-gradient(ellipse 60% 40% at 80% 100%, rgba(6, 182, 212, 0.12) 0%, transparent 50%),
    radial-gradient(ellipse 50% 30% at 50% 50%, rgba(236, 72, 153, 0.08) 0%, transparent 50%),
    linear-gradient(180deg, #0f0f1a 0%, #0a0a0f 100%);
  
  /* Glassmorfismo Premium */
  --s1: rgba(255, 255, 255, 0.03);
  --s2: rgba(255, 255, 255, 0.06);
  --s3: rgba(255, 255, 255, 0.1);
  --s4: rgba(255, 255, 255, 0.15);
  
  --border: rgba(255, 255, 255, 0.1);
  --border-glow: rgba(99, 102, 241, 0.5);
  
  --text: #ffffff;
  --text-muted: #a1a1aa;
  
  /* Cores de Acento Vibrantes */
  --accent: #8b5cf6; /* Violeta vibrante */
  --accent-hover: #a78bfa;
  --accent-neon: #c4b5fd;
  --accent-gradient: linear-gradient(135deg, #8b5cf6 0%, #6366f1 100%);
  
  --cyan: #06b6d4;
  --cyan-glow: #22d3ee;
  --cyan-gradient: linear-gradient(135deg, #06b6d4 0%, #0891b2 100%);
  
  --pink: #ec4899;
  --pink-glow: #f472b6;
  --pink-gradient: linear-gradient(135deg, #ec4899 0%, #f43f5e 100%);
  
  --green: #10b981;
  --green-glow: #34d399;
  --green-gradient: linear-gradient(135deg, #10b981 0%, #059669 100%);
  
  --amber: #f59e0b;
  --amber-glow: #fbbf24;
  --amber-gradient: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
  
  --rose: #f43f5e;
  --rose-glow: #fb7185;
  
  /* Estrutura */
  --sidebar: 280px;
  --r-xl: 28px;
  --r-lg: 20px;
  --r-md: 14px;
  --r-sm: 10px;
  --ease: 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --ease-bounce: 0.5s cubic-bezier(0.68, -0.55, 0.265, 1.55);
  
  --shadow-sm: 0 4px 6px -1px rgba(0,0,0,0.3), 0 2px 4px -1px rgba(0,0,0,0.2);
  --shadow-md: 0 8px 12px -2px rgba(0,0,0,0.4), 0 4px 6px -2px rgba(0,0,0,0.3);
  --shadow-lg: 0 20px 25px -5px rgba(0,0,0,0.5), 0 10px 10px -5px rgba(0,0,0,0.4);
  --shadow-neon: 0 0 30px rgba(139, 92, 246, 0.4);
  --shadow-glow: 0 0 40px rgba(99, 102, 241, 0.3);
  
  /* Tipografia */
  --font-sans: 'Geist', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'Geist Mono', ui-monospace, SFMono-Regular, Consolas, monospace;
}

/* ── Reset & Body ── */
* { margin:0; padding:0; box-sizing:border-box; -webkit-font-smoothing: antialiased; }
body {
  font-family: var(--font-sans);
  background: var(--bg-color);
  background-image: var(--bg-gradient);
  background-attachment: fixed;
  color: var(--text);
  min-height: 100vh;
  overflow-x: hidden;
  line-height: 1.6;
}

/* ── Animações Globais ── */
@keyframes slideUpFade { 
  from { transform: translateY(30px); opacity: 0; } 
  to { transform: translateY(0); opacity: 1; } 
}
@keyframes pulseGlow {
  0%, 100% { box-shadow: 0 0 20px rgba(139, 92, 246, 0.4); }
  50% { box-shadow: 0 0 40px rgba(139, 92, 246, 0.6); }
}
@keyframes float {
  0%, 100% { transform: translateY(0px); }
  50% { transform: translateY(-10px); }
}
@keyframes shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}
@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}
@keyframes bounceIn {
  0% { transform: scale(0.8); opacity: 0; }
  50% { transform: scale(1.05); }
  100% { transform: scale(1); opacity: 1; }
}

/* ── Botões Universais ── */
.btn {
  border: none; border-radius: var(--r-md); padding: 14px 28px; 
  font-size: 15px; font-weight: 600; cursor: pointer; 
  font-family: var(--font-sans); transition: all var(--ease);
  display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  position: relative; overflow: hidden;
  text-transform: none; letter-spacing: 0.3px;
}
.btn::before {
  content: ''; position: absolute; top: 0; left: -100%; width: 100%; height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  transition: left 0.6s ease;
}
.btn:hover::before { left: 100%; }

.btn-primary { 
  background: var(--accent-gradient); 
  color: #fff; box-shadow: var(--shadow-md), 0 0 30px rgba(139, 92, 246, 0.3); 
}
.btn-primary:hover { 
  transform: translateY(-3px) scale(1.02); 
  box-shadow: var(--shadow-lg), 0 0 50px rgba(139, 92, 246, 0.5); 
}

.btn-cyan { 
  background: var(--cyan-gradient); 
  color: #fff; font-weight: 700; box-shadow: var(--shadow-md), 0 0 30px rgba(6, 182, 212, 0.3);
}
.btn-cyan:hover { 
  box-shadow: var(--shadow-lg), 0 0 50px rgba(6, 182, 212, 0.5); 
  transform: translateY(-3px) scale(1.02); 
}

.btn-pink {
  background: var(--pink-gradient);
  color: #fff; font-weight: 700; box-shadow: var(--shadow-md), 0 0 30px rgba(236, 72, 153, 0.3);
}
.btn-pink:hover {
  box-shadow: var(--shadow-lg), 0 0 50px rgba(236, 72, 153, 0.5);
  transform: translateY(-3px) scale(1.02);
}

.btn-green {
  background: var(--green-gradient);
  color: #fff; font-weight: 700; box-shadow: var(--shadow-md), 0 0 30px rgba(16, 185, 129, 0.3);
}
.btn-green:hover {
  box-shadow: var(--shadow-lg), 0 0 50px rgba(16, 185, 129, 0.5);
  transform: translateY(-3px) scale(1.02);
}

.btn-amber {
  background: var(--amber-gradient);
  color: #fff; font-weight: 700; box-shadow: var(--shadow-md), 0 0 30px rgba(245, 158, 11, 0.3);
}
.btn-amber:hover {
  box-shadow: var(--shadow-lg), 0 0 50px rgba(245, 158, 11, 0.5);
  transform: translateY(-3px) scale(1.02);
}

.btn-secondary { 
  background: var(--s2); color: var(--text); border: 1px solid var(--border); 
  box-shadow: var(--shadow-sm);
}
.btn-secondary:hover { 
  background: var(--s3); border-color: var(--accent-neon); 
  transform: translateY(-2px);
}

/* ── Formulários e Inputs ── */
.input-field, select {
  width: 100%; background: var(--s2); border: 1px solid var(--border); 
  border-radius: var(--r-md); padding: 16px 18px; color: var(--text); 
  font-family: var(--font-sans); font-size: 15px; outline: none;
  transition: all var(--ease);
}
.input-field:focus, select:focus { 
  border-color: var(--accent); background: var(--s3); 
  box-shadow: 0 0 0 4px rgba(139, 92, 246, 0.15), 0 0 20px rgba(139, 92, 246, 0.2); 
  transform: translateY(-1px);
}
.form-label { 
  display: block; font-size: 12px; font-weight: 700; 
  text-transform: uppercase; letter-spacing: 1.5px; color: var(--cyan-glow); 
  margin-bottom: 10px; 
}

/* ── Layout Base da App (Sidebar + Main) ── */
.app-container { display: flex; min-height: 100vh; }

.sidebar {
  position: fixed; left: 0; top: 0; bottom: 0; width: var(--sidebar);
  background: rgba(10, 11, 16, 0.6); backdrop-filter: blur(30px); -webkit-backdrop-filter: blur(30px);
  border-right: 1px solid var(--border);
  display: flex; flex-direction: column; z-index: 300;
  transition: transform 0.3s ease, width 0.3s ease;
}
.logo { 
  padding: 36px 28px; display: flex; align-items: center; gap: 14px; 
  border-bottom: 1px solid var(--border); 
}
.logomark { 
  width: 44px; height: 44px; border-radius: var(--r-md); 
  background: var(--accent-gradient); 
  display: flex; align-items: center; justify-content: center; 
  box-shadow: 0 0 30px rgba(139, 92, 246, 0.5); 
  animation: pulseGlow 3s ease-in-out infinite;
}
.logotext { font-size: 26px; font-weight: 800; letter-spacing: -0.5px; }
.logotext span { color: var(--cyan-glow); }

.nav-scroll { flex: 1; overflow-y: auto; padding: 28px 20px; }
.nav-scroll::-webkit-scrollbar { width: 4px; }
.nav-scroll::-webkit-scrollbar-thumb { background: var(--s3); border-radius: 4px; }

.nav-label { 
  font-size: 11px; text-transform: uppercase; letter-spacing: 2.5px; 
  color: var(--text-muted); padding: 0 16px 16px; display: block; font-weight: 700; 
}
.nav-btn {
  display: flex; align-items: center; gap: 14px; width: 100%; padding: 14px 16px; 
  border: none; background: transparent; color: var(--text-muted); 
  font-family: var(--font-sans); font-size: 15px; font-weight: 500; 
  border-radius: var(--r-md); cursor: pointer; transition: all var(--ease); 
  text-align: left; margin-bottom: 8px; text-decoration: none;
}
.nav-btn:hover { 
  background: rgba(255,255,255,0.05); 
  color: var(--text); 
  transform: translateX(4px);
}
.nav-btn.active { 
  background: linear-gradient(90deg, rgba(139, 92, 246, 0.2), transparent); 
  color: var(--text); border-left: 3px solid var(--accent); font-weight: 600; 
  box-shadow: 0 0 20px rgba(139, 92, 246, 0.1);
}

.sidebar-footer { 
  padding: 24px; border-top: 1px solid var(--border); background: rgba(0,0,0,0.3); 
}
.user-card { 
  background: var(--s2); border: 1px solid var(--border); 
  border-radius: var(--r-lg); padding: 18px; transition: all var(--ease);
}
.user-card:hover { 
  border-color: var(--accent-neon); 
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}
.user-top { display: flex; align-items: center; gap: 14px; }
.user-avatar { 
  width: 46px; height: 46px; border-radius: 50%; 
  background: var(--pink-gradient); 
  display: flex; align-items: center; justify-content: center; 
  font-weight: 700; font-size: 18px; box-shadow: 0 0 20px rgba(236, 72, 153, 0.5); 
}
.user-name { font-size: 15px; font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.user-meta { font-size: 12px; color: var(--cyan-glow); margin-top: 3px; font-weight: 500; }

/* ── Main Area & Topbar ── */
.main { 
  margin-left: var(--sidebar); flex: 1; min-height: 100vh; 
  display: flex; flex-direction: column; 
}
.topbar {
  position: sticky; top: 0; z-index: 200; 
  background: rgba(10, 10, 15, 0.8); backdrop-filter: blur(30px); -webkit-backdrop-filter: blur(30px);
  border-bottom: 1px solid var(--border); padding: 24px 48px; 
  display: flex; align-items: center; justify-content: space-between;
}
.topbar-title { font-size: 22px; font-weight: 700; letter-spacing: -0.5px; }
.topbar-title span { color: var(--pink-glow); }

.page-content { 
  padding: 48px; flex: 1; animation: slideUpFade 0.6s cubic-bezier(0.16, 1, 0.3, 1) forwards; 
}

/* ── Dashboard Cartões ── */
.welcome-banner {
  background: linear-gradient(135deg, rgba(139, 92, 246, 0.15) 0%, rgba(6, 182, 212, 0.08) 100%);
  border: 1px solid rgba(139, 92, 246, 0.3); border-radius: var(--r-xl); 
  padding: 40px 48px; margin-bottom: 40px; position: relative; overflow: hidden;
  box-shadow: var(--shadow-md), 0 0 40px rgba(139, 92, 246, 0.15);
}
.welcome-banner::before {
  content: ''; position: absolute; top: -50%; left: -50%; width: 200%; height: 200%;
  background: radial-gradient(circle, rgba(139, 92, 246, 0.1) 0%, transparent 50%);
  pointer-events: none;
  animation: gradientShift 8s ease infinite;
}
.welcome-msg { 
  font-size: 16px; color: var(--text-muted); margin-top: 16px; font-style: italic; 
  background: rgba(0,0,0,0.4); padding: 16px 20px; border-radius: var(--r-md); 
  border-left: 4px solid var(--cyan); display: inline-block;
}

.stat-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 28px; margin-bottom: 44px; }
.stat-card { 
  background: var(--s1); border: 1px solid var(--border); border-radius: var(--r-xl); 
  padding: 32px 24px; text-align: center; position: relative; overflow: hidden;
  transition: all var(--ease); backdrop-filter: blur(15px);
}
.stat-card:hover { 
  transform: translateY(-6px); 
  box-shadow: var(--shadow-lg), 0 0 30px rgba(139, 92, 246, 0.2); 
  border-color: rgba(255,255,255,0.15);
}
.stat-card::before { 
  content: ''; position: absolute; top: 0; left: 0; width: 100%; height: 4px; 
  background: var(--accent-gradient); 
}
.stat-card.cyan::before { background: var(--cyan-gradient); box-shadow: 0 0 20px var(--cyan); }
.stat-card.pink::before { background: var(--pink-gradient); box-shadow: 0 0 20px var(--pink); }
.stat-card.amber::before { background: var(--amber-gradient); box-shadow: 0 0 20px var(--amber); }
.stat-card.green::before { background: var(--green-gradient); box-shadow: 0 0 20px var(--green); }

.stat-val { font-size: 52px; font-weight: 800; font-family: var(--font-mono); line-height: 1; margin: 16px 0; }
.stat-lbl { font-size: 13px; font-weight: 700; color: var(--text-muted); text-transform: uppercase; letter-spacing: 1.5px; }

.subjects-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 24px; }
.subject-card {
  background: var(--s1); border: 1px solid var(--border); border-radius: var(--r-xl); 
  padding: 28px; display: flex; justify-content: space-between; align-items: center; 
  transition: all var(--ease); backdrop-filter: blur(15px);
}
.subject-card:hover { 
  border-color: var(--cyan); transform: scale(1.03) translateY(-4px); 
  background: rgba(30, 34, 51, 0.95); 
  box-shadow: var(--shadow-lg), 0 0 30px rgba(6, 182, 212, 0.2); 
}
.sub-info-title { font-weight: 700; font-size: 18px; letter-spacing: -0.3px; }
.sub-info-year { font-size: 14px; color: var(--text-muted); margin-top: 6px; }
.sub-badge-grade { 
  font-family: var(--font-mono); font-size: 20px; font-weight: 800; 
  background: rgba(16, 185, 129, 0.15); color: var(--green-glow); 
  padding: 10px 18px; border-radius: var(--r-md); border: 1px solid rgba(16, 185, 129, 0.4); 
  box-shadow: 0 0 20px rgba(16, 185, 129, 0.2);
}

/* ── Interface do Chat (Assistente IA Aberto) ── */
.chat-window { 
  background: var(--s1); border: 1px solid var(--border); border-radius: var(--r-xl); 
  display: flex; flex-direction: column; height: calc(100vh - 180px); 
  backdrop-filter: blur(20px); overflow: hidden;
  box-shadow: var(--shadow-lg), 0 0 40px rgba(139, 92, 246, 0.15);
}
.chat-head { 
  padding: 24px 28px; border-bottom: 1px solid var(--border); background: rgba(0,0,0,0.3);
  display: flex; align-items: center; justify-content: space-between; 
}
.chat-status { display: flex; align-items: center; gap: 12px; font-size: 15px; font-weight: 600; }
.chat-indicator { 
  width: 12px; height: 12px; border-radius: 50%; background: var(--green); 
  box-shadow: 0 0 15px var(--green); animation: pulseGlow 2s infinite;
}

.chat-container { 
  flex: 1; overflow-y: auto; padding: 28px; display: flex; flex-direction: column; gap: 28px; 
}
.chat-container::-webkit-scrollbar { width: 6px; }
.chat-container::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.15); border-radius: 6px; }

.chat-bubble { display: flex; gap: 18px; max-width: 85%; animation: slideUpFade 0.4s ease; }
.chat-bubble.user { align-self: flex-end; flex-direction: row-reverse; }

.chat-avatar { 
  width: 40px; height: 40px; border-radius: 50%; display: flex; align-items: center; 
  justify-content: center; font-size: 15px; font-weight: 700; flex-shrink: 0; 
}
.chat-avatar.ai { 
  background: var(--cyan-gradient); 
  color: #fff; border: 2px solid rgba(6,182,212,0.5); 
  box-shadow: 0 0 20px rgba(6,182,212,0.4);
}
.chat-avatar.user { 
  background: var(--pink-gradient); 
  color: #fff; border: 2px solid rgba(236,72,153,0.5); 
  box-shadow: 0 0 20px rgba(236,72,153,0.4);
}

.chat-text { 
  padding: 18px 24px; font-size: 15px; line-height: 1.7; white-space: pre-wrap; 
}
.chat-bubble.ai .chat-text { 
  background: var(--s2); border: 1px solid var(--border); 
  border-radius: 4px 24px 24px 24px; /* Canto reto em cima à esquerda */
}
.chat-bubble.user .chat-text { 
  background: var(--accent-gradient); color: #fff; 
  border-radius: 24px 4px 24px 24px; /* Canto reto em cima à direita */
  box-shadow: var(--shadow-md), 0 0 20px rgba(139, 92, 246, 0.3);
}

.chat-footer { 
  padding: 24px 28px; border-top: 1px solid var(--border); background: rgba(0,0,0,0.3); 
  display: flex; gap: 14px; align-items: center;
}
.chat-footer .input-field { 
  border-radius: 28px; padding: 16px 24px; background: var(--bg-color); 
}
.chat-footer .btn { border-radius: 28px; padding: 14px 32px; }

/* ── Markdown AI Render Styles ── */
.md-content p { margin-bottom: 14px; line-height: 1.7; }
.md-content p:last-child { margin-bottom: 0; }
.md-content h1, .md-content h2, .md-content h3 { color: #fff; margin: 24px 0 12px; font-weight: 700; }
.md-content h1 { font-size: 28px; }
.md-content h2 { font-size: 22px; }
.md-content h3 { font-size: 18px; }
.md-content ul, .md-content ol { padding-left: 28px; margin-bottom: 14px; }
.md-content li { margin-bottom: 8px; }
.md-content code { 
  background: rgba(0,0,0,0.4); padding: 3px 8px; border-radius: 6px; 
  font-family: var(--font-mono); color: var(--pink-glow); font-size: 0.9em; 
  border: 1px solid rgba(236, 72, 153, 0.2);
}
.md-content pre { 
  background: rgba(0,0,0,0.5); padding: 20px; border-radius: var(--r-lg); overflow-x: auto; 
  margin: 16px 0; border: 1px solid var(--border);
}
.md-content pre code { background: none; padding: 0; color: #e2e8f0; border: none; }

/* ── Exercícios e Tarefas ── */
.exc-layout { display: grid; grid-template-columns: 1fr 340px; gap: 28px; }
.exc-setup-box, .exc-quiz-box, .exc-result-box { 
  background: var(--s1); border: 1px solid var(--border); border-radius: var(--r-xl); 
  padding: 40px; backdrop-filter: blur(15px);
  box-shadow: var(--shadow-md);
}
.exc-quiz-box, .exc-result-box { display: none; }

.timer-sidebar { 
  background: var(--s1); border: 1px solid var(--border); border-radius: var(--r-xl); 
  padding: 32px; text-align: center; height: fit-content; position: sticky; top: 100px; 
  box-shadow: var(--shadow-md), 0 0 30px rgba(236, 72, 153, 0.15);
}
.timer-display { 
  font-family: var(--font-mono); font-size: 56px; font-weight: 800; color: var(--pink-glow); 
  text-shadow: 0 0 25px rgba(236,72,153,0.5); margin: 20px 0; letter-spacing: -3px;
  animation: pulseGlow 3s ease-in-out infinite;
}

.quiz-question { font-size: 20px; font-weight: 700; margin-bottom: 24px; color: var(--cyan-glow); line-height: 1.5; }
.quiz-options { display: flex; flex-direction: column; gap: 14px; margin-bottom: 32px; border-bottom: 1px solid var(--border); padding-bottom: 28px; }
.option-btn { 
  background: var(--s2); border: 1px solid var(--border); padding: 18px 24px; 
  border-radius: var(--r-lg); color: var(--text); text-align: left; 
  font-size: 15px; cursor: pointer; transition: all var(--ease); 
}
.option-btn:hover { 
  border-color: var(--accent-neon); 
  background: var(--s3); 
  transform: translateX(6px); 
  box-shadow: var(--shadow-sm);
}
.option-btn.selected { 
  border-color: var(--cyan); 
  background: rgba(6,182,212,0.15); 
  font-weight: 600; 
  box-shadow: 0 0 20px rgba(6,182,212,0.2);
}

.correction-item { 
  background: var(--s2); border: 1px solid var(--border); border-radius: var(--r-lg); 
  padding: 24px; margin-bottom: 20px; 
}
.correction-item.correct { 
  border-left: 5px solid var(--green); 
  background: linear-gradient(90deg, rgba(16,185,129,0.1), transparent); 
  box-shadow: 0 0 20px rgba(16,185,129,0.15);
}
.correction-item.wrong { 
  border-left: 5px solid var(--rose); 
  background: linear-gradient(90deg, rgba(244,63,94,0.1), transparent); 
  box-shadow: 0 0 20px rgba(244,63,94,0.15);
}

.task-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(340px, 1fr)); gap: 28px; }
.task-card { 
  background: var(--s1); border: 1px solid var(--border); border-radius: var(--r-xl); 
  padding: 32px; display: flex; flex-direction: column; gap: 20px; 
  transition: all var(--ease);
}
.task-card:hover { 
  transform: translateY(-6px); 
  box-shadow: var(--shadow-lg), 0 0 30px rgba(139, 92, 246, 0.15); 
  border-color: rgba(255,255,255,0.15);
}
.task-header { display: flex; justify-content: space-between; align-items: flex-start; }
.task-title { font-weight: 700; font-size: 20px; }
.task-duration { 
  font-size: 14px; font-family: var(--font-mono); font-weight: 600; 
  background: rgba(6,182,212,0.15); padding: 8px 14px; border-radius: 8px; color: var(--cyan-glow); 
  border: 1px solid rgba(6,182,212,0.3);
  white-space: nowrap;
}

/* ── Whiteboard (Quadro Digital) ── */
.whiteboard-layer { 
  position: fixed; inset: 0; background: rgba(5,6,8,0.95); z-index: 10000; 
  display: none; flex-direction: column; padding: 20px; 
}
.whiteboard-layer.show { display: flex; }
.wb-controls { 
  background: var(--s1); border: 2px solid var(--border); 
  border-radius: var(--r-xl) var(--r-xl) 0 0; padding: 16px; 
  display: flex; gap: 20px; align-items: center; flex-wrap: wrap; 
}
.wb-canvas-container { 
  flex: 1; background: #ffffff; 
  border-radius: 0 0 var(--r-xl) var(--r-xl); 
  position: relative; overflow: hidden; 
}
#wbCanvas { 
  position: absolute; top: 0; left: 0; width: 100%; height: 100%; cursor: text; 
}
.color-dot { 
  width: 24px; height: 24px; border-radius: 50%; cursor: pointer; 
  border: 2px solid transparent; transition: all var(--ease); 
}
.color-dot.active { border-color: #000; transform: scale(1.1); }
.tool-btn { 
  background: var(--s2); border: 1px solid var(--border); 
  padding: 6px 12px; border-radius: 8px; color: var(--text); 
  font-size: 12px; cursor: pointer; font-weight: 600; transition: all var(--ease); 
}
.tool-btn.active { background: var(--cyan); color: #000; }
.canvas-text-input { 
  position: absolute; background: transparent; border: 1px dashed var(--accent); 
  color: #000000; font-family: 'Geist', sans-serif; font-size: 16px; 
  font-weight: 500; outline: none; padding: 2px; z-index: 10005; 
}

/* ── Modal Onboarding & Login (Vitrine) ── */
.onboard-layer {
  position: fixed; inset: 0; background: var(--bg-gradient); z-index: 9999;
  display: flex; align-items: center; justify-content: center; padding: 20px; overflow-y: auto;
}
.onboard-layer.hide { display: none; }
.onboard-card {
  background: rgba(20, 22, 35, 0.9); backdrop-filter: blur(30px); -webkit-backdrop-filter: blur(30px);
  border: 1px solid rgba(255,255,255,0.15); border-radius: var(--r-xl);
  padding: 56px; width: 100%; max-width: 680px; 
  box-shadow: 0 40px 80px rgba(0,0,0,0.6), 0 0 60px rgba(139, 92, 246, 0.2);
  animation: bounceIn 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);
}
.onboard-header { text-align: center; margin-bottom: 44px; }
.onboard-title { 
  font-size: 40px; font-weight: 800; letter-spacing: -1.5px;
  background: linear-gradient(135deg, #fff, var(--cyan-glow), var(--accent-neon)); 
  background-size: 200% 200%;
  -webkit-background-clip: text; 
  background-clip: text;
  -webkit-text-fill-color: transparent; 
  animation: gradientShift 4s ease infinite;
}
.onboard-subtitle { font-size: 16px; color: var(--text-muted); margin-top: 12px; line-height: 1.6; }

.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.radio-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 14px; margin-bottom: 24px; }
.radio-box {
  background: var(--s2); border: 1px solid var(--border); padding: 16px; border-radius: var(--r-lg);
  text-align: center; cursor: pointer; font-size: 15px; font-weight: 600; transition: all var(--ease);
}
.radio-box:hover { 
  border-color: var(--accent-neon); 
  background: rgba(255,255,255,0.08); 
  transform: translateY(-2px);
}
.radio-box.active { 
  background: var(--accent-gradient); 
  border-color: var(--accent-neon); 
  box-shadow: 0 8px 25px rgba(139, 92, 246, 0.5); 
  transform: translateY(-2px);
}

.notes-section { display: none; margin-top: 36px; animation: slideUpFade 0.5s ease; }
.notes-section.show { display: block; }
.notes-headline { 
  font-size: 14px; font-weight: 700; color: var(--pink-glow); 
  letter-spacing: 1.5px; margin-bottom: 20px; text-transform: uppercase; 
}
.notes-grid { 
  display: grid; grid-template-columns: 1fr 110px; gap: 18px; 
  background: rgba(0,0,0,0.3); padding: 28px; border-radius: var(--r-lg); 
  border: 1px solid var(--border); max-height: 280px; overflow-y: auto; 
}
.notes-grid::-webkit-scrollbar { width: 6px; }
.notes-grid::-webkit-scrollbar-thumb { background: var(--s3); border-radius: 6px; }

.note-lbl { display: flex; align-items: center; font-size: 16px; font-weight: 500; }
.note-in { text-align: center; font-family: var(--font-mono); font-weight: 700; color: var(--cyan-glow); font-size: 18px; }

/* ── Landing Page Específicos ── */
.auth-modal {
  background: rgba(15, 17, 26, 0.9); backdrop-filter: blur(30px); border: 1px solid rgba(255,255,255,0.15);
  padding: 48px; border-radius: var(--r-xl); width: 100%; max-width: 480px; margin: auto;
  box-shadow: 0 40px 80px rgba(0,0,0,0.7), 0 0 0 1px rgba(139, 92, 246, 0.1);
  animation: bounceIn 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}
.modal-title { font-size: 32px; font-weight: 800; letter-spacing: -0.5px; }
.modal-sub { color: var(--text-muted); font-size: 15px; margin-bottom: 28px; line-height: 1.7; }
.tabs { display: flex; background: rgba(0,0,0,0.4); border-radius: var(--r-lg); padding: 8px; margin-bottom: 32px; }
.tab { flex: 1; text-align: center; padding: 12px; font-size: 15px; font-weight: 600; color: var(--text-muted); cursor: pointer; border-radius: var(--r-md); transition: all var(--ease); }
.tab.active { background: var(--s3); color: #fff; box-shadow: var(--shadow-sm); }
.btn-ghost { background: var(--s2); border: 1px solid var(--border); transition: all var(--ease); }
.btn-ghost:focus { border-color: var(--accent); background: rgba(139, 92, 246, 0.15); }

/* ── Responsividade ── */

/* Mobile (até 768px) */
@media (max-width: 768px) {
  :root {
    --r-xl: 20px;
    --r-lg: 16px;
    --r-md: 12px;
  }
  
  .sidebar {
    width: 280px;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
  }
  .sidebar.open {
    transform: translateX(0);
  }
  
  .main {
    margin-left: 0 !important;
  }
  
  #menuToggle {
    display: inline-flex !important;
  }
  
  .topbar {
    padding: 16px 20px;
  }
  .topbar-title {
    font-size: 18px;
  }
  
  .page-content {
    padding: 24px 20px;
  }
  
  .stat-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }
  .stat-card {
    padding: 20px 16px;
  }
  .stat-val {
    font-size: 36px;
  }
  
  .subjects-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  
  .exc-layout {
    grid-template-columns: 1fr;
  }
  
  .timer-sidebar {
    position: relative;
    top: 0;
    margin-bottom: 24px;
  }
  
  .task-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  
  .chat-window {
    height: calc(100vh - 140px);
  }
  
  .onboard-card {
    padding: 32px 24px;
    max-width: 100%;
  }
  .onboard-title {
    font-size: 28px;
  }
  
  .form-row {
    grid-template-columns: 1fr;
  }
  
  .radio-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* Tablet (769px - 1024px) */
@media (min-width: 769px) and (max-width: 1024px) {
  :root {
    --sidebar: 240px;
  }
  
  .sidebar {
    width: var(--sidebar);
  }
  
  .main {
    margin-left: var(--sidebar);
  }
  
  .topbar {
    padding: 20px 32px;
  }
  
  .page-content {
    padding: 32px 32px;
  }
  
  .stat-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }
  
  .subjects-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .task-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .exc-layout {
    grid-template-columns: 1fr 280px;
  }
}

/* PC (acima de 1024px) */
@media (min-width: 1025px) {
  .stat-grid {
    grid-template-columns: repeat(4, 1fr);
  }
  
  .subjects-grid {
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  }
  
  .task-grid {
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  }
}

/* Mobile pequeno (até 480px) */
@media (max-width: 480px) {
  .stat-grid {
    grid-template-columns: 1fr;
  }
  
  .radio-grid {
    grid-template-columns: 1fr;
  }
  
  .btn {
    padding: 12px 20px;
    font-size: 14px;
  }
  
  .chat-bubble {
    max-width: 95%;
  }
  
  .hero-title {
    font-size: 36px;
  }
  
  .feat-card {
    padding: 24px 20px;
  }
}