/* ==================== Variables CSS ==================== */
:root {
    --primary: #FF6347;
    --primary-dark: #E5533D;
    --secondary: #4ECDC4;
    --accent: #FFE66D;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --info: #3b82f6;
    
    --bg-dark: #0A0E27;
    --bg-darker: #060918;
    --bg-card: #151A36;
    --bg-card-hover: #1A1F3A;
    
    --text-primary: #F7F7FF;
    --text-secondary: #B8B8D1;
    --text-muted: #6B7280;
    
    --border-color: rgba(255, 255, 255, 0.1);
    --shadow: rgba(0, 0, 0, 0.3);
    
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

[data-theme="light"] {
    --bg-dark: #F3F4F6;
    --bg-darker: #FFFFFF;
    --bg-card: #FFFFFF;
    --bg-card-hover: #F9FAFB;
    
    --text-primary: #111827;
    --text-secondary: #4B5563;
    --text-muted: #9CA3AF;
    
    --border-color: #E5E7EB;
    --shadow: rgba(0, 0, 0, 0.1);
}

/* ==================== Reset y Base ==================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-primary);
    background: var(--bg-dark);
    color: var(--text-primary);
    min-height: 100vh;
    transition: background 0.3s ease, color 0.3s ease;
}

/* ==================== Container ==================== */
.app-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
}

/* ==================== Header ==================== */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.header-left {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.logo {
    font-size: 2rem;
}

.header-title h1 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.header-title p {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.header-right {
    display: flex;
    gap: 1rem;
    align-items: center;
}

/* ==================== Navigation Buttons ==================== */
.nav-buttons {
    display: flex;
    gap: 0.5rem;
    background: var(--bg-card);
    padding: 0.5rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.nav-btn {
    padding: 0.5rem 1.25rem;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.nav-btn:hover {
    color: var(--text-primary);
    background: var(--bg-card-hover);
}

.nav-btn.active {
    background: var(--primary);
    color: white;
}

.theme-toggle {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 0.65rem 1rem;
    border-radius: 10px;
    color: var(--text-primary);
    font-size: 0.875rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.theme-toggle:hover {
    background: var(--bg-card-hover);
    transform: translateY(-2px);
}

/* ==================== View Container ==================== */
.view-container {
    display: none;
}

.view-container.active {
    display: block;
}

/* ==================== Stats Tabs ==================== */
.stats-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    background: var(--bg-card);
    padding: 0.5rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    overflow-x: auto;
}

.tab-btn {
    padding: 0.5rem 1.5rem;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    white-space: nowrap;
}

.tab-btn:hover {
    color: var(--text-primary);
    background: var(--bg-card-hover);
}

.tab-btn.active {
    background: var(--primary);
    color: white;
}

/* ==================== Stats Grid ==================== */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 1.5rem;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 100px;
    height: 100px;
    background: radial-gradient(circle, var(--primary) 0%, transparent 70%);
    opacity: 0.1;
}

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px var(--shadow);
    border-color: var(--primary);
}

.stat-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 0.75rem;
}

.stat-title {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.stat-icon {
    font-size: 2rem;
    opacity: 0.3;
}

.stat-value {
    font-size: 2.25rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.stat-change {
    font-size: 0.875rem;
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.stat-change.positive {
    color: var(--success);
}

.stat-change.negative {
    color: var(--danger);
}

.stat-change.neutral {
    color: var(--warning);
}

/* ==================== Charts Grid ==================== */
.charts-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.chart-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 1.5rem;
}

.chart-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.chart-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
}

.chart-menu {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.25rem;
    border-radius: 6px;
    transition: all 0.3s ease;
}

.chart-menu:hover {
    background: var(--bg-card-hover);
    color: var(--text-primary);
}

.chart-container {
    position: relative;
    height: 300px;
}

.chart-container canvas {
    max-height: 100%;
}

/* ==================== Sessions Table ==================== */
.sessions-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 1.5rem;
}

.sessions-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.sessions-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
}

.view-all-link {
    color: var(--primary);
    font-size: 0.875rem;
    text-decoration: none;
    font-weight: 500;
    transition: opacity 0.3s ease;
}

.view-all-link:hover {
    opacity: 0.8;
}

.sessions-table {
    width: 100%;
    border-collapse: collapse;
}

.sessions-table thead {
    border-bottom: 1px solid var(--border-color);
}

.sessions-table th {
    padding: 0.75rem 1rem;
    text-align: left;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.sessions-table td {
    padding: 1rem;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.875rem;
}

.sessions-table tr:last-child td {
    border-bottom: none;
}

.sessions-table tr:hover {
    background: var(--bg-card-hover);
}

/* ==================== Timer View ==================== */
.timer-view {
    max-width: 800px;
    margin: 0 auto;
}

.timer-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    padding: 3rem 2rem;
    text-align: center;
    box-shadow: 0 10px 40px var(--shadow);
    position: relative;
}

.mode-selector {
    display: flex;
    gap: 0.5rem;
    justify-content: center;
    margin-bottom: 3rem;
    background: var(--bg-darker);
    padding: 0.5rem;
    border-radius: 12px;
}

.mode-btn {
    padding: 0.75rem 2rem;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 600;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.mode-btn:hover {
    color: var(--text-primary);
}

.mode-btn.active {
    background: var(--primary);
    color: white;
}

/* 🌀 Anillo de Progreso SVG (Nuevo) */
.timer-display-container {
    position: relative;
    width: 300px;
    height: 300px;
    margin: 0 auto 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.timer-svg {
    position: absolute;
    top: 0;
    left: 0;
    transform: rotate(-90deg);
}

.timer-circle-bg {
    fill: none;
    stroke: var(--bg-darker);
    stroke-width: 8;
}

.timer-circle-progress {
    fill: none;
    stroke: var(--primary);
    stroke-width: 8;
    stroke-linecap: round;
    transition: stroke-dashoffset 1s linear, stroke 0.3s ease;
}

.timer-display {
    font-size: 6rem;
    font-weight: 700;
    color: var(--text-primary);
    font-variant-numeric: tabular-nums;
    letter-spacing: -0.05em;
    z-index: 10;
}

/* 🎯 Campo de Tarea de Enfoque (Nuevo) */
.focus-task-container {
    margin-bottom: 2rem;
}

.focus-input {
    width: 100%;
    max-width: 400px;
    padding: 0.75rem 1.5rem;
    background: var(--bg-darker);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    color: var(--text-primary);
    font-size: 1rem;
    text-align: center;
    transition: all 0.3s ease;
}

.focus-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 15px rgba(255, 99, 71, 0.2);
}

.timer-controls {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 1rem;
}

.control-btn {
    padding: 1rem 3rem;
    border: none;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.control-btn.primary {
    background: var(--primary);
    color: white;
}

.control-btn.primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 8px 16px rgba(255, 99, 71, 0.3);
}

.control-btn.secondary {
    background: var(--bg-darker);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.control-btn.secondary:hover {
    background: var(--bg-card-hover);
}

/* 🗑️ Botón de Limpieza (Nuevo) */
.btn-danger {
    padding: 0.5rem 1rem;
    background: transparent;
    border: 1px solid var(--danger);
    color: var(--danger);
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-left: auto; /* Alineado a la derecha */
}

.btn-danger:hover {
    background: var(--danger);
    color: white;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(239, 68, 68, 0.2);
}

.btn-danger:active {
    transform: scale(0.95);
}

/* ==================== Footer ==================== */
.footer {
    margin-top: 4rem;
    padding: 2.5rem 1.5rem 2rem;
    border-top: 1px solid var(--border-color);
    text-align: center;
}

/* Animation */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.stat-card, .chart-card, .sessions-card {
    animation: fadeIn 0.5s ease;
}

/* Botón Volver */
.back-button {
    position: fixed;
    bottom: 30px;
    left: 30px;
    background: rgba(255, 99, 71, 0.9);
    backdrop-filter: blur(10px);
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 12px;
    padding: 0.75rem 1.25rem;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
    transition: all 0.3s ease;
    z-index: 9999;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}