/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #4f46e5;
    --primary-dark: #4338ca;
    --secondary-color: #6b7280;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --background-color: #f3f4f6;
    --card-background: #ffffff;
    --text-color: #1f2937;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --radius: 12px;
    --radius-sm: 8px;
    --nav-height: 64px;
    --header-height: 56px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.5;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}

#app {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: var(--card-background);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    padding: 0 16px;
}

.header-title {
    font-size: 18px;
    font-weight: 600;
}

/* Main Content */
.main-content {
    flex: 1;
    padding: calc(var(--header-height) + 16px) 16px calc(var(--nav-height) + 16px);
    max-width: 600px;
    margin: 0 auto;
    width: 100%;
}

/* Views */
.view {
    display: none;
}

.view.active {
    display: block;
}

.view-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 16px;
}

.view-header h2 {
    font-size: 24px;
    font-weight: 600;
}

/* Sections */
.section {
    margin-top: 24px;
}

.section h3 {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 12px;
}

.section h4 {
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 8px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 20px;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-secondary {
    background: var(--border-color);
    color: var(--text-color);
}

.btn-secondary:hover {
    background: #d1d5db;
}

.btn-text {
    background: transparent;
    color: var(--primary-color);
    padding: 8px 12px;
}

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

.btn-large {
    width: 100%;
    padding: 14px 24px;
    font-size: 16px;
}

.btn-small {
    padding: 6px 12px;
    font-size: 12px;
}

/* Quick Actions */
.quick-actions {
    margin-bottom: 24px;
}

/* Cards */
.card-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.card {
    background: var(--card-background);
    border-radius: var(--radius);
    padding: 16px;
    box-shadow: var(--shadow);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 8px;
}

.card-title {
    font-size: 16px;
    font-weight: 600;
}

.card-subtitle {
    font-size: 13px;
    color: var(--text-secondary);
}

.card-body {
    margin-top: 8px;
}

.card-actions {
    display: flex;
    gap: 8px;
    margin-top: 12px;
}

.badge {
    display: inline-block;
    padding: 2px 8px;
    border-radius: 12px;
    font-size: 11px;
    font-weight: 500;
    text-transform: uppercase;
}

.badge-strength {
    background: #dbeafe;
    color: #1e40af;
}

.badge-cardio {
    background: #fef3c7;
    color: #92400e;
}

/* Empty State */
.empty-state {
    text-align: center;
    color: var(--text-secondary);
    padding: 32px 16px;
}

/* Forms */
.form {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-group label {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
}

.form-group input,
.form-group select,
.form-group textarea {
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 16px;
    background: var(--card-background);
    color: var(--text-color);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.form-row {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
}

/* Tabs */
.tabs {
    display: flex;
    gap: 8px;
    margin-bottom: 16px;
    overflow-x: auto;
    padding-bottom: 4px;
}

.tab {
    padding: 8px 16px;
    border: none;
    background: var(--border-color);
    border-radius: 20px;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    white-space: nowrap;
    transition: all 0.2s;
}

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

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: flex-end;
    justify-content: center;
    z-index: 200;
}

.modal.hidden {
    display: none;
}

.modal-content {
    background: var(--card-background);
    border-radius: var(--radius) var(--radius) 0 0;
    padding: 20px;
    width: 100%;
    max-width: 600px;
    max-height: 90vh;
    overflow-y: auto;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.modal-header h3 {
    font-size: 18px;
    font-weight: 600;
}

/* Bottom Navigation */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: var(--card-background);
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-around;
    align-items: center;
    padding-bottom: env(safe-area-inset-bottom);
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    padding: 8px 16px;
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    transition: color 0.2s;
}

.nav-item.active {
    color: var(--primary-color);
}

.nav-icon {
    font-size: 20px;
}

.nav-label {
    font-size: 11px;
    font-weight: 500;
}

/* Plan Exercise Item */
.plan-exercise-item {
    display: flex;
    gap: 8px;
    align-items: flex-start;
    padding: 12px;
    background: var(--background-color);
    border-radius: var(--radius-sm);
    margin-bottom: 8px;
}

.plan-exercise-item select {
    flex: 1;
}

.plan-exercise-item input {
    width: 70px;
}

.plan-exercise-item .btn {
    padding: 8px;
}

/* Session Entry */
.session-entry {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px;
    background: var(--background-color);
    border-radius: var(--radius-sm);
}

.entry-info {
    flex: 1;
}

.entry-name {
    font-weight: 500;
}

.entry-details {
    font-size: 13px;
    color: var(--text-secondary);
}

/* Utilities */
.hidden {
    display: none !important;
}

.text-center {
    text-align: center;
}

.mt-2 {
    margin-top: 8px;
}

.mt-4 {
    margin-top: 16px;
}

/* Responsive adjustments for larger screens */
@media (min-width: 640px) {
    .modal-content {
        border-radius: var(--radius);
        margin-bottom: 20px;
    }

    .modal {
        align-items: center;
    }
}

@media (min-width: 768px) {
    :root {
        --header-height: 64px;
    }

    .header-title {
        font-size: 20px;
    }

    .main-content {
        padding: calc(var(--header-height) + 24px) 24px calc(var(--nav-height) + 24px);
    }
}