/* CSS Variables for Themes */
:root {
    --bg-primary: #f8f9fa;
    --bg-secondary: #ffffff;
    --text-primary: #333333;
    --text-secondary: #666666;
    --accent-color: #ff6347;
    --accent-hover: #ff4500;
    --border-color: #e1e4e8;
    --shadow-color: rgba(0, 0, 0, 0.05);
    --card-bg: #ffffff;
    --input-bg: #f0f2f5;
    --progress-bg: #f0f2f5;
    --transition: all 0.3s ease;
}

.dark-mode {
    --bg-primary: #1a1a1a;
    --bg-secondary: #252525;
    --text-primary: #f8f9fa;
    --text-secondary: #b0b0b0;
    --accent-color: #ff6347;
    --accent-hover: #ff4500;
    --border-color: #444444;
    --shadow-color: rgba(0, 0, 0, 0.2);
    --card-bg: #2d2d2d;
    --input-bg: #333333;
    --progress-bg: #333333;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: var(--transition);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

button {
    cursor: pointer;
    border: none;
    background: none;
    transition: var(--transition);
}

button:focus, input:focus {
    outline: none;
}

.hidden {
    display: none !important;
}

/* Header Styles */
header {
    background-color: var(--bg-secondary);
    padding: 1rem 2rem;
    box-shadow: 0 2px 5px var(--shadow-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

header h1 {
    font-size: 1.5rem;
    color: var(--accent-color);
    font-weight: 600;
}

.theme-toggle button {
    display: flex;
    align-items: center;
    background-color: var(--input-bg);
    padding: 0.5rem 1rem;
    border-radius: 30px;
    color: var(--text-primary);
    font-size: 0.9rem;
}

.theme-toggle button i {
    margin-right: 0.5rem;
}

.theme-toggle button:hover {
    background-color: var(--accent-color);
    color: white;
}

/* Settings Button Styles */
.settings-toggle button {
    display: flex;
    align-items: center;
    background-color: var(--input-bg);
    padding: 0.5rem 1rem;
    border-radius: 30px;
    color: var(--text-primary);
    font-size: 0.9rem;
}

.settings-toggle button i {
    margin-right: 0.5rem;
}

.settings-toggle button:hover {
    background-color: var(--accent-color);
    color: white;
}

/* Header Navigation */
.header-nav {
    display: flex;
    gap: 1rem;
    align-items: center;
    flex: 1;
    justify-content: flex-end;
}

/* Hamburger menu and responsive nav */
.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-primary);
}
@media (max-width: 768px) {
    header { position: relative; padding: 1rem 0; flex-wrap: wrap; flex-direction: column; align-items: center; justify-content: flex-start; }
    /* Show hamburger, hide nav by default */
    .menu-toggle { display: block; align-self: center; margin: 0 auto 1rem; }
    .header-nav {
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        padding: 0;
        margin: 0;
        background-color: var(--bg-secondary);
        box-shadow: 0 2px 5px var(--shadow-color);
        z-index: 1000;
        display: none;
        flex-direction: column;
        align-items: center;
        gap: 0;
    }
    .header-nav.open { display: flex; }
    /* Simplify mobile nav buttons */
    .header-nav button {
        display: block;
        width: auto;
        padding: 1rem 2rem;
        margin: 0.5rem auto;
        border: none;
        border-radius: 5px;
        background-color: var(--input-bg);
        color: var(--text-primary);
        text-align: center;
    }
    .header-nav button + button {
        border-top: 1px solid var(--border-color);
    }
    .header-nav button i {
        margin-right: 0.5rem;
    }
}

/* Main Layout */
main {
    flex: 1;
    padding: 2rem;
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

@media (min-width: 900px) {
    main {
        grid-template-columns: 1fr 1fr;
    }
    
    .stats-section {
        grid-column: 1 / 3;
    }
}

/* Section Styles */
section {
    background-color: var(--bg-secondary);
    border-radius: 10px;
    box-shadow: 0 4px 10px var(--shadow-color);
    padding: 1.5rem;
    transition: var(--transition);
}

section h2 {
    margin-bottom: 1rem;
    color: var(--accent-color);
    font-weight: 600;
}

/* Timer Styles */
.timer-container {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.timer-display {
    text-align: center;
    margin-bottom: 1.5rem;
    width: 100%;
}

#timer-label {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
}

#time-left {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.timer-progress {
    width: 100%;
    height: 8px;
    background-color: var(--progress-bg);
    border-radius: 4px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    width: 0;
    background-color: var(--accent-color);
    transition: width 1s linear;
}

.timer-controls {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.control-btn {
    background-color: var(--accent-color);
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 30px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

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

.timer-info {
    display: flex;
    justify-content: space-between;
    width: 100%;
    padding: 1rem;
    background-color: var(--input-bg);
    border-radius: 8px;
    margin-top: 1rem;
}

.session-count, .current-task-display {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.session-count span:first-child, .current-task-display span:first-child {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

/* Task Styles */
.task-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

#exit-focus-mode {
    background-color: var(--input-bg);
    color: var(--text-primary);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
}

#exit-focus-mode:hover {
    background-color: var(--accent-color);
    color: white;
}

.task-form {
    display: flex;
    margin-bottom: 1.5rem;
}

#task-input {
    flex: 1;
    padding: 0.75rem 1rem;
    border: none;
    background-color: var(--input-bg);
    border-radius: 8px 0 0 8px;
    color: var(--text-primary);
}

#add-task-btn {
    background-color: var(--accent-color);
    color: white;
    padding: 0.75rem 1rem;
    border-radius: 0 8px 8px 0;
}

#add-task-btn:hover {
    background-color: var(--accent-hover);
}

.task-list-container {
    max-height: 300px;
    overflow-y: auto;
}

#task-list {
    list-style: none;
}

.task-item {
    display: flex;
    align-items: center;
    padding: 1rem;
    border-bottom: 1px solid var(--border-color);
    animation: fadeIn 0.3s ease;
}

.task-item:last-child {
    border-bottom: none;
}

.task-checkbox {
    margin-right: 1rem;
    width: 20px;
    height: 20px;
    border: 2px solid var(--accent-color);
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
}

.task-checkbox.completed {
    background-color: var(--accent-color);
}

.task-checkbox.completed i {
    display: block;
    color: white;
    font-size: 0.8rem;
}

.task-checkbox i {
    display: none;
}

.task-content {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.task-content.completed {
    text-decoration: line-through;
    color: var(--text-secondary);
}

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

.task-action-btn {
    color: var(--text-secondary);
    font-size: 0.9rem;
    padding: 0.3rem;
}

.task-action-btn:hover {
    color: var(--accent-color);
}

.focus-btn {
    color: var(--accent-color);
}

/* Stats Styles */
.stats-container {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

@media (min-width: 600px) {
    .stats-container {
        grid-template-columns: 1fr 2fr;
    }
}

.stats-card {
    background-color: var(--card-bg);
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 2px 5px var(--shadow-color);
}

.stats-card h3 {
    margin-bottom: 1rem;
    color: var(--text-primary);
    font-size: 1.1rem;
}

.stats-item {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--border-color);
}

.stats-item:last-child {
    border-bottom: none;
}

/* Notification Styles */
.notification {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    width: 300px;
    background-color: var(--card-bg);
    border-left: 5px solid var(--accent-color);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    border-radius: 8px;
    overflow: hidden;
    transform: translateX(120%);
    transition: transform 0.3s ease;
}

.notification.show {
    transform: translateX(0);
}

.notification-content {
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

#notification-close {
    color: var(--text-secondary);
}

#notification-close:hover {
    color: var(--accent-color);
}

/* Footer Styles */
footer {
    text-align: center;
    padding: 1rem;
    background-color: var(--bg-secondary);
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: auto;
}

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

.task-item.hidden {
    display: none;
}

.task-item.focus-mode {
    background-color: var(--accent-color);
    color: white;
    border-radius: 8px;
}

.task-item.focus-mode .task-checkbox {
    border-color: white;
}

.task-item.focus-mode .task-action-btn {
    color: white;
}

/* For better scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--accent-color);
    border-radius: 10px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-hover);
}

/* Settings Modal Styles */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 2000;
}

.modal.show {
    display: flex;
}

.modal-content {
    background-color: var(--bg-secondary);
    padding: 2rem;
    border-radius: 10px;
    width: 90%;
    max-width: 400px;
    box-shadow: 0 4px 10px var(--shadow-color);
}

.modal-content h2 {
    margin-top: 0;
    color: var(--accent-color);
    font-size: 1.3rem;
    margin-bottom: 1rem;
}

.modal-content label {
    display: block;
    margin-bottom: 1rem;
    font-size: 0.9rem;
    color: var(--text-primary);
}

.modal-content input {
    width: 100%;
    padding: 0.5rem;
    margin-top: 0.25rem;
    border: 1px solid var(--border-color);
    border-radius: 5px;
    background-color: var(--input-bg);
    color: var(--text-primary);
}

.modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: 1rem;
    margin-top: 1.5rem;
}