/* ===== CSS VARIABLES ===== */
:root {
    --primary-color: #3b82f6;
    --primary-hover: #2563eb;
    --success-color: #10b981;
    --success-hover: #059669;
    --danger-color: #ef4444;
    --danger-hover: #dc2626;
    
    --bg-primary: #f9fafb;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f3f4f6;
    
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --text-tertiary: #9ca3af;
    
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    
    --transition: all 0.3s ease;
}

body.dark-mode {
    --bg-primary: #111827;
    --bg-secondary: #1f2937;
    --bg-tertiary: #374151;
    
    --text-primary: #f9fafb;
    --text-secondary: #d1d5db;
    --text-tertiary: #9ca3af;
    
    --border-color: #374151;
}

/* ===== RESET & BASE STYLES ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: var(--transition);
}

/* ===== CONTAINER ===== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* ===== NAVIGATION ===== */
.navbar {
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
}

.logo-icon {
    color: var(--primary-color);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.back-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-primary);
    text-decoration: none;
    transition: var(--transition);
}

.back-link:hover {
    color: var(--primary-color);
}

/* ===== BUTTONS ===== */
.btn-primary, .btn-secondary, .btn-success, .btn-danger {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.625rem 1.25rem;
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
}

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

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

.btn-secondary {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
}

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

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

.btn-success:hover {
    background-color: var(--success-hover);
}

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

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

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

.btn-block {
    width: 100%;
    justify-content: center;
}

.icon-btn {
    background: none;
    border: none;
    padding: 0.5rem;
    border-radius: var(--radius-md);
    cursor: pointer;
    color: var(--text-primary);
    transition: var(--transition);
}

.icon-btn:hover {
    background-color: var(--bg-tertiary);
}

/* ===== HERO SECTION ===== */
.hero {
    text-align: center;
    padding: 5rem 1rem;
}

.hero-title {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 42rem;
    margin: 0 auto 2rem;
}

/* ===== FEATURES SECTION ===== */
.features {
    padding: 5rem 1rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.feature-card {
    background-color: var(--bg-secondary);
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
}

.feature-icon {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.feature-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.feature-description {
    color: var(--text-secondary);
}

/* ===== CARDS ===== */
.card {
    background-color: var(--bg-secondary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    padding: 2rem;
}

/* ===== FORMS ===== */
.form-container {
    max-width: 42rem;
    margin: 3rem auto;
}

.form-card {
    padding: 2.5rem;
}

.page-title {
    font-size: 2.5rem;
    font-weight: 800;
    text-align: center;
    margin-bottom: 2rem;
}

.form-group {
    margin-bottom:1.5rem;
}
.form-label {
display: block;
font-weight: 600;
margin-bottom: 0.5rem;
color: var(--text-primary);
}
.form-input, .form-textarea {
width: 100%;
padding: 0.75rem;
border: 1px solid var(--border-color);
border-radius: var(--radius-md);
background-color: var(--bg-secondary);
color: var(--text-primary);
font-size: 1rem;
transition: var(--transition);
}
.form-input:focus, .form-textarea:focus {
outline: none;
border-color: var(--primary-color);
box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}
.form-row {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 1.5rem;
}
/* ===== TRIPS PAGE ===== */
.trips-container {
padding: 3rem 1rem;
}
.trips-grid {
display: grid;
grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
gap: 2rem;
}
.trip-card {
background-color: var(--bg-secondary);
border-radius: var(--radius-lg);
box-shadow: var(--shadow-lg);
padding: 1.5rem;
transition: var(--transition);
}
.trip-card:hover {
transform: translateY(-4px);
box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
}
.trip-title {
font-size: 1.5rem;
font-weight: 700;
margin-bottom: 1rem;
}
.trip-details {
display: flex;
flex-direction: column;
gap: 0.5rem;
margin-bottom: 1.5rem;
color: var(--text-secondary);
}
.trip-detail {
display: flex;
align-items: center;
gap: 0.5rem;
}
.trip-actions {
display: flex;
gap: 0.5rem;
}
/* ===== BUILDER PAGE ===== */
.builder-container {
padding: 2rem 1rem;
}
.trip-info-card {
margin-bottom: 2rem;
}
.trip-info-title {
font-size: 2rem;
font-weight: 700;
margin-bottom: 0.75rem;
}
.trip-info-details {
display: flex;
flex-wrap: wrap;
gap: 1.5rem;
color: var(--text-secondary);
}
.trip-info-item {
display: flex;
align-items: center;
gap: 0.5rem;
}
.actions-bar {
margin-bottom: 1.5rem;
}
.days-container {
display: flex;
flex-direction: column;
gap: 1.5rem;
}
.day-card {
background-color: var(--bg-secondary);
border-radius: var(--radius-lg);
box-shadow: var(--shadow-lg);
padding: 1.5rem;
}
.day-header {
display: flex;
justify-content: space-between;
align-items: center;
margin-bottom: 1.5rem;
}
.day-title {
font-size: 1.75rem;
font-weight: 700;
}
.day-actions {
display: flex;
gap: 0.5rem;
}
.activities-list {
display: flex;
flex-direction: column;
gap: 0.75rem;
}
.activity-card {
background-color: var(--bg-tertiary);
border-radius: var(--radius-md);
padding: 1rem;
}
.activity-header {
display: flex;
justify-content: space-between;
align-items: flex-start;
}
.activity-main {
flex: 1;
}
.activity-time-title {
display: flex;
align-items: center;
gap: 0.5rem;
margin-bottom: 0.25rem;
}
.activity-time {
font-weight: 600;
color: var(--primary-color);
}
.activity-title {
font-weight: 700;
}
.activity-notes {
color: var(--text-secondary);
margin-top: 0.5rem;
}
.activity-actions {
display: flex;
gap: 0.5rem;
}
.activity-btn {
background: none;
border: none;
padding: 0.25rem;
cursor: pointer;
color: var(--text-secondary);
transition: var(--transition);
}
.activity-btn:hover {
color: var(--primary-color);
}
.activity-btn.delete:hover {
color: var(--danger-color);
}
.empty-activities {
color: var(--text-tertiary);
font-style: italic;
text-align: center;
padding: 2rem 0;
}
/* ===== MODAL ===== */
.modal {
position: fixed;
top: 0;
left: 0;
width: 100%;
height: 100%;
background-color: rgba(0, 0, 0, 0.5);
display: flex;
align-items: center;
justify-content: center;
z-index: 1000;
padding: 1rem;
}
.modal.hidden {
display: none;
}
.modal-content {
background-color: var(--bg-secondary);
border-radius: var(--radius-lg);
padding: 2rem;
max-width: 500px;
width: 100%;
max-height: 90vh;
overflow-y: auto;
}
.modal-title {
font-size: 1.75rem;
font-weight: 700;
margin-bottom: 1.5rem;
}
.modal-actions {
display: flex;
gap: 0.75rem;
margin-top: 1.5rem;
}
/* ===== EMPTY STATE ===== */
.empty-state {
text-align: center;
padding: 5rem 1rem;
}
.empty-state.hidden {
display: none;
}
.empty-icon {
color: var(--text-tertiary);
margin: 0 auto 1.5rem;
}
.empty-title {
font-size: 1.75rem;
font-weight: 700;
margin-bottom: 0.75rem;
}
.empty-description {
color: var(--text-secondary);
margin-bottom: 1.5rem;
}
/* ===== FOOTER ===== */
.footer {
background-color: var(--bg-tertiary);
padding: 2rem 0;
margin-top: 5rem;
text-align: center;
color: var(--text-secondary);
}
/* ===== UTILITIES ===== */
.hidden {
display: none !important;
}
/* ===== DARK MODE ICONS ===== */
body:not(.dark-mode) .moon-icon {
display: none;
}
body.dark-mode .sun-icon {
display: none;
}
body.dark-mode .moon-icon {
display: block;
}
/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
.hero-title {
font-size: 2rem;
}
.hero-subtitle {
    font-size: 1rem;
}

.form-row {
    grid-template-columns: 1fr;
}

.nav-links {
    gap: 0.5rem;
}

.page-title {
    font-size: 2rem;
}

.trip-info-details {
    flex-direction: column;
    gap: 0.75rem;
}}
@media (max-width: 480px) {
.hero {
padding: 3rem 1rem;
}}