/* Base Styles & Variables */
:root {
    --primary: #4f46e5;
    --primary-hover: #4338ca;
    --bg-light: #f9fafb;
    --bg-dark: #111827;
    --card-light: #ffffff;
    --card-dark: #1f2937;
    --text-light: #111827;
    --text-dark: #f9fafb;
    --text-muted-light: #6b7280;
    --text-muted-dark: #9ca3af;
    --border-light: #e5e7eb;
    --border-dark: #374151;
    --danger: #ef4444;
    --success: #10b981;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    transition: var(--transition);
}

body.light-mode {
    background-color: var(--bg-light);
    color: var(--text-light);
}

body.dark-mode {
    background-color: var(--bg-dark);
    color: var(--text-dark);
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Header & Nav */
header {
    background-color: var(--card-light);
    border-bottom: 1px solid var(--border-light);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.dark-mode header {
    background-color: var(--card-dark);
    border-bottom: 1px solid var(--border-dark);
}

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

.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
}

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

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

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 1.2rem;
    border-radius: 0.5rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    font-size: 0.9rem;
}

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

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
}

.btn-secondary {
    background-color: transparent;
    border: 1px solid var(--border-light);
    color: inherit;
}

.dark-mode .btn-secondary {
    border-color: var(--border-dark);
}

.btn-icon {
    background: none;
    border: none;
    cursor: pointer;
    color: inherit;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0.5rem;
    border-radius: 50%;
    transition: var(--transition);
}

.btn-icon:hover {
    background-color: rgba(0,0,0,0.05);
}

.dark-mode .btn-icon:hover {
    background-color: rgba(255,255,255,0.05);
}

/* Sections */
.section {
    margin-top: 3rem;
}

.section-title {
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
    font-weight: 700;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    gap: 1rem;
}

/* Search & Filter Controls */
.controls {
    display: flex;
    gap: 1rem;
    align-items: center;
    flex-wrap: wrap;
}

.search-box {
    position: relative;
}

.search-box input {
    padding: 0.6rem 1rem 0.6rem 2.5rem;
    border-radius: 0.5rem;
    border: 1px solid var(--border-light);
    background-color: var(--card-light);
    color: inherit;
    width: 250px;
    transition: var(--transition);
}

.dark-mode .search-box input {
    border-color: var(--border-dark);
    background-color: var(--card-dark);
}

.search-icon {
    position: absolute;
    left: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted-light);
}

.filter-box {
    display: flex;
    background-color: var(--card-light);
    border: 1px solid var(--border-light);
    border-radius: 0.5rem;
    padding: 0.25rem;
}

.dark-mode .filter-box {
    background-color: var(--card-dark);
    border-color: var(--border-dark);
}

.filter-btn {
    padding: 0.4rem 1rem;
    border-radius: 0.35rem;
    border: none;
    background: none;
    cursor: pointer;
    font-weight: 500;
    color: var(--text-muted-light);
    transition: var(--transition);
}

.dark-mode .filter-btn {
    color: var(--text-muted-dark);
}

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

/* Upcoming Dashboard Grid */
.upcoming-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
}

.upcoming-card {
    background: linear-gradient(135deg, var(--primary), #818cf8);
    color: white;
    padding: 1.5rem;
    border-radius: 1rem;
    box-shadow: var(--shadow);
    position: relative;
    overflow: hidden;
}

.upcoming-card::before {
    content: '';
    position: absolute;
    top: -20px;
    right: -20px;
    width: 100px;
    height: 100px;
    background: rgba(255,255,255,0.1);
    border-radius: 50%;
}

.upcoming-card .card-date {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.05rem;
    opacity: 0.9;
}

.upcoming-card .card-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin: 0.5rem 0;
}

.upcoming-card .card-time {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 500;
}

/* Reminder List & Cards */
.reminder-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.reminder-item {
    background-color: var(--card-light);
    border: 1px solid var(--border-light);
    padding: 1.25rem;
    border-radius: 0.75rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
    animation: slideIn 0.3s ease-out;
}

.dark-mode .reminder-item {
    background-color: var(--card-dark);
    border-color: var(--border-dark);
}

.reminder-item:hover {
    box-shadow: var(--shadow);
    transform: translateX(5px);
}

.reminder-info {
    display: flex;
    gap: 1.25rem;
    align-items: center;
}

.checkbox {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    border: 2px solid var(--primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.checkbox.checked {
    background-color: var(--primary);
}

.checkbox svg {
    color: white;
    width: 16px;
    height: 16px;
    display: none;
}

.checkbox.checked svg {
    display: block;
}

.reminder-details h3 {
    font-size: 1.05rem;
    margin-bottom: 0.25rem;
}

.reminder-item.completed .reminder-details h3 {
    text-decoration: line-through;
    color: var(--text-muted-light);
}

.reminder-meta {
    font-size: 0.85rem;
    color: var(--text-muted-light);
    display: flex;
    gap: 1rem;
}

.dark-mode .reminder-meta {
    color: var(--text-muted-dark);
}

.reminder-actions {
    display: flex;
    gap: 0.5rem;
}

.action-btn {
    padding: 0.5rem;
    border-radius: 0.5rem;
    border: none;
    background: none;
    cursor: pointer;
    transition: var(--transition);
}

.action-btn-edit:hover {
    color: var(--primary);
    background-color: rgba(79, 70, 229, 0.1);
}

.action-btn-delete:hover {
    color: var(--danger);
    background-color: rgba(239, 68, 68, 0.1);
}

/* Modals */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.5);
    display: none;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    backdrop-filter: blur(4px);
}

.modal.active {
    display: flex;
}

.modal-content {
    background-color: var(--card-light);
    width: 90%;
    max-width: 500px;
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    animation: modalScale 0.3s ease-out;
}

.dark-mode .modal-content {
    background-color: var(--card-dark);
}

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

.close-modal {
    font-size: 1.5rem;
    cursor: pointer;
    background: none;
    border: none;
    color: inherit;
}

.form-group {
    margin-bottom: 1.25rem;
}

.form-group label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.form-group input {
    width: 100%;
    padding: 0.75rem;
    border-radius: 0.5rem;
    border: 1px solid var(--border-light);
    background-color: var(--bg-light);
    color: inherit;
    font-family: inherit;
}

.dark-mode .form-group input {
    border-color: var(--border-dark);
    background-color: var(--bg-dark);
}

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

.modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: 1rem;
    margin-top: 2rem;
}

/* Banner */
.banner {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--card-light);
    padding: 1rem 1.5rem;
    border-radius: 0.75rem;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    display: flex;
    align-items: center;
    gap: 1.5rem;
    z-index: 500;
    border: 1px solid var(--border-light);
}

.dark-mode .banner {
    background-color: var(--card-dark);
    border-color: var(--border-dark);
}

.hidden {
    display: none !important;
}

/* Animations */
@keyframes slideIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes modalScale {
    from { opacity: 0; transform: scale(0.95); }
    to { opacity: 1; transform: scale(1); }
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 3rem 0;
    color: var(--text-muted-light);
}

/* Responsive */
@media (max-width: 768px) {
    .section-header {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .search-box input {
        width: 100%;
    }
    
    .controls {
        width: 100%;
    }
    
    .filter-box {
        width: 100%;
        justify-content: space-between;
    }
    
    .filter-btn {
        flex: 1;
        text-align: center;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .nav-container {
        padding: 0 1rem;
    }
}