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

/* CSS Custom Properties */
:root {
    /* Color Palette */
    --color-primary: #00ADB5;
    --color-secondary: #FFD369;
    --color-dark: #222831;
    --color-gray: #393E46;
    --color-light: #EEEEEE;
    --color-white: #FFFFFF;
    --color-success: #4CAF50;
    --color-warning: #FF9800;
    --color-error: #F44336;
    --color-info: #2196F3;
    
    /* Typography */
    --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    
    /* Border Radius */
    --border-radius-sm: 0.25rem;
    --border-radius-md: 0.5rem;
    --border-radius-lg: 0.75rem;
    --border-radius-xl: 1rem;
    --border-radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 300ms ease-in-out;
    --transition-slow: 500ms ease-in-out;
    
    /* Z-index */
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal-backdrop: 1040;
    --z-modal: 1050;
    --z-popover: 1060;
    --z-tooltip: 1070;
    --z-toast: 1080;
}

/* Dark Theme Variables */
[data-theme="dark"] {
    --color-light: #393E46;
    --color-white: #222831;
    --color-dark: #EEEEEE;
    --color-gray: #EEEEEE;
}

/* Base Styles */
html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-dark);
    background-color: var(--color-white);
    transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Header */
.header {
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    color: var(--color-white);
    padding: var(--spacing-xl) 0;
    position: relative;
    overflow: hidden;
}

.header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="10" height="10" patternUnits="userSpaceOnUse"><path d="M 10 0 L 0 0 0 10" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="1"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
}

.header__content {
    position: relative;
    z-index: 1;
    text-align: center;
}

.header__title {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
}

.header__icon {
    font-size: var(--font-size-3xl);
    animation: pulse 2s infinite;
}

.header__subtitle {
    font-size: var(--font-size-lg);
    opacity: 0.9;
    font-weight: 300;
}

/* Theme Toggle */
.theme-toggle {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    background: rgba(255, 255, 255, 0.2);
    border: none;
    border-radius: var(--border-radius-full);
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-normal);
    backdrop-filter: blur(10px);
}

.theme-toggle:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1);
}

.theme-toggle__icon {
    font-size: var(--font-size-xl);
    transition: transform var(--transition-normal);
}

/* Main Content */
.main {
    padding: var(--spacing-2xl) 0;
    min-height: calc(100vh - 200px);
}

/* Quick Mode */
.quick-mode {
    margin-bottom: var(--spacing-2xl);
    text-align: center;
}

.quick-mode__toggle {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-md);
    background: var(--color-light);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--border-radius-full);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

.quick-mode__toggle:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.quick-mode__label {
    font-weight: 600;
    color: var(--color-dark);
}

/* Switch Component */
.switch {
    position: relative;
    display: inline-block;
    width: 60px;
    height: 34px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--color-gray);
    transition: var(--transition-normal);
    border-radius: 34px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 26px;
    width: 26px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    transition: var(--transition-normal);
    border-radius: 50%;
}

input:checked + .slider {
    background-color: var(--color-primary);
}

input:checked + .slider:before {
    transform: translateX(26px);
}

/* Calculator Section */
.calculator {
    margin-bottom: var(--spacing-3xl);
}

.calculator__grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
    align-items: start;
}

.calculator__form-container {
    background: var(--color-white);
    border-radius: var(--border-radius-xl);
    padding: var(--spacing-2xl);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--color-light);
    transition: all var(--transition-normal);
}

.calculator__form-container:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.calculator__results {
    background: var(--color-white);
    border-radius: var(--border-radius-xl);
    padding: var(--spacing-2xl);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--color-light);
    min-height: 400px;
    transition: all var(--transition-normal);
}

/* Form Styles */
.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group--hidden {
    display: none;
}

.form-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
    color: var(--color-dark);
    font-size: var(--font-size-sm);
}

.form-label__icon {
    font-size: var(--font-size-lg);
}

.form-input {
    width: 100%;
    padding: var(--spacing-md);
    border: 2px solid var(--color-light);
    border-radius: var(--border-radius-md);
    font-size: var(--font-size-base);
    transition: all var(--transition-normal);
    background: var(--color-white);
    color: var(--color-dark);
}

.form-input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(0, 173, 181, 0.1);
}

.form-input:invalid {
    border-color: var(--color-error);
}

/* Quick Duration Buttons */
.quick-duration {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-sm);
}

.quick-duration__btn {
    padding: var(--spacing-md);
    border: 2px solid var(--color-light);
    border-radius: var(--border-radius-md);
    background: var(--color-white);
    color: var(--color-dark);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
}

.quick-duration__btn:hover {
    border-color: var(--color-primary);
    background: var(--color-primary);
    color: var(--color-white);
    transform: translateY(-2px);
}

.quick-duration__btn.active {
    border-color: var(--color-primary);
    background: var(--color-primary);
    color: var(--color-white);
}

/* Button Styles */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-lg);
    border: none;
    border-radius: var(--border-radius-md);
    font-size: var(--font-size-base);
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: all var(--transition-normal);
    min-height: 48px;
}

.btn--primary {
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    color: var(--color-white);
    box-shadow: var(--shadow-md);
}

.btn--primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn--secondary {
    background: var(--color-light);
    color: var(--color-dark);
    border: 2px solid var(--color-light);
}

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

.btn__icon {
    font-size: var(--font-size-lg);
}

/* Results Placeholder */
.results-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    height: 100%;
    min-height: 300px;
    color: var(--color-gray);
}

.results-placeholder__icon {
    font-size: var(--font-size-4xl);
    margin-bottom: var(--spacing-lg);
    opacity: 0.7;
}

.results-placeholder__title {
    font-size: var(--font-size-xl);
    margin-bottom: var(--spacing-md);
    color: var(--color-dark);
}

.results-placeholder__text {
    font-size: var(--font-size-base);
    opacity: 0.8;
}

/* Results Display */
.results {
    animation: slideInUp var(--transition-normal);
}

.results__main {
    text-align: center;
    margin-bottom: var(--spacing-xl);
    padding: var(--spacing-xl);
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    border-radius: var(--border-radius-lg);
    color: var(--color-white);
    position: relative;
    overflow: hidden;
}

.results__main::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="2" fill="rgba(255,255,255,0.1)"/></svg>') repeat;
    opacity: 0.3;
}

.results__calories {
    position: relative;
    z-index: 1;
}

.results__number {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    display: block;
}

.results__label {
    font-size: var(--font-size-lg);
    opacity: 0.9;
}

.results__activity {
    position: relative;
    z-index: 1;
    margin-top: var(--spacing-md);
    font-size: var(--font-size-base);
    opacity: 0.8;
}

.results__details {
    display: grid;
    gap: var(--spacing-md);
}

.results__card {
    background: var(--color-light);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius-md);
    transition: all var(--transition-normal);
}

.results__card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.results__card-title {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--color-gray);
    margin-bottom: var(--spacing-sm);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.results__card-content {
    font-size: var(--font-size-base);
    color: var(--color-dark);
    font-weight: 500;
}

.results__actions {
    margin-top: var(--spacing-xl);
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
}

/* Section Styles */
.section-title {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    font-size: var(--font-size-2xl);
    font-weight: 700;
    margin-bottom: var(--spacing-xl);
    color: var(--color-dark);
}

.section-title__icon {
    font-size: var(--font-size-2xl);
}

/* Goals Section */
.goals {
    margin-bottom: var(--spacing-3xl);
}

.goals__header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xl);
}

.goals__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.goal-card {
    background: var(--color-white);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-light);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.goal-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.goal-card__header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-lg);
}

.goal-card__title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-dark);
}

.goal-card__type {
    background: var(--color-primary);
    color: var(--color-white);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--border-radius-full);
    font-size: var(--font-size-xs);
    font-weight: 600;
    text-transform: uppercase;
}

.goal-card__progress {
    margin-bottom: var(--spacing-lg);
}

.goal-card__progress-text {
    display: flex;
    justify-content: space-between;
    margin-bottom: var(--spacing-sm);
    font-size: var(--font-size-sm);
    color: var(--color-gray);
}

.goal-card__progress-bar {
    width: 100%;
    height: 8px;
    background: var(--color-light);
    border-radius: var(--border-radius-full);
    overflow: hidden;
}

.goal-card__progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
    border-radius: var(--border-radius-full);
    transition: width var(--transition-slow);
}

.goal-card__actions {
    display: flex;
    gap: var(--spacing-sm);
}

.goal-card__btn {
    flex: 1;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--color-light);
    background: var(--color-white);
    color: var(--color-dark);
    border-radius: var(--border-radius-sm);
    font-size: var(--font-size-sm);
    cursor: pointer;
    transition: all var(--transition-normal);
}

.goal-card__btn:hover {
    background: var(--color-primary);
    color: var(--color-white);
    border-color: var(--color-primary);
}

.goal-card__btn--danger:hover {
    background: var(--color-error);
    border-color: var(--color-error);
}

/* History Section */
.history {
    margin-bottom: var(--spacing-3xl);
}

.history__header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xl);
}

.history__controls {
    display: flex;
    gap: var(--spacing-sm);
}

.history__content {
    background: var(--color-white);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-light);
    overflow: hidden;
}

.history__empty {
    padding: var(--spacing-2xl);
    text-align: center;
    color: var(--color-gray);
}

.history__empty-icon {
    font-size: var(--font-size-4xl);
    margin-bottom: var(--spacing-lg);
    opacity: 0.5;
}

.history__list {
    max-height: 400px;
    overflow-y: auto;
}

.history__item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--color-light);
    transition: background-color var(--transition-normal);
}

.history__item:hover {
    background: var(--color-light);
}

.history__item:last-child {
    border-bottom: none;
}

.history__item-info {
    flex: 1;
}

.history__item-activity {
    font-weight: 600;
    color: var(--color-dark);
    margin-bottom: var(--spacing-xs);
}

.history__item-details {
    font-size: var(--font-size-sm);
    color: var(--color-gray);
}

.history__item-calories {
    font-size: var(--font-size-lg);
    font-weight: 700;
    color: var(--color-primary);
}

.history__item-date {
    font-size: var(--font-size-xs);
    color: var(--color-gray);
    text-align: right;
}

/* Statistics Section */
.statistics {
    margin-bottom: var(--spacing-3xl);
}

.statistics__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

.stat-card {
    background: var(--color-white);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-light);
    text-align: center;
    transition: all var(--transition-normal);
}

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.stat-card__icon {
    font-size: var(--font-size-3xl);
    margin-bottom: var(--spacing-md);
}

.stat-card__value {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.stat-card__label {
    font-size: var(--font-size-sm);
    color: var(--color-gray);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* FAQ Section */
.faq {
    margin-bottom: var(--spacing-3xl);
}

.faq__grid {
    display: grid;
    gap: var(--spacing-md);
}

.faq__item {
    background: var(--color-white);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-light);
    overflow: hidden;
}

.faq__question {
    width: 100%;
    padding: var(--spacing-lg);
    background: none;
    border: none;
    text-align: left;
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--color-dark);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all var(--transition-normal);
}

.faq__question:hover {
    background: var(--color-light);
}

.faq__icon {
    font-size: var(--font-size-lg);
    transition: transform var(--transition-normal);
}

.faq__item.active .faq__icon {
    transform: rotate(45deg);
}

.faq__answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-normal);
}

.faq__item.active .faq__answer {
    max-height: 200px;
}

.faq__answer p {
    padding: 0 var(--spacing-lg) var(--spacing-lg);
    color: var(--color-gray);
    line-height: 1.6;
}

/* Modal Styles */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: var(--z-modal);
    display: none;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md);
}

.modal.active {
    display: flex;
}

.modal__overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
}

.modal__content {
    background: var(--color-white);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-xl);
    max-width: 500px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    z-index: 1;
    animation: modalSlideIn var(--transition-normal);
}

.modal__header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--color-light);
}

.modal__title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--color-dark);
}

.modal__close {
    background: none;
    border: none;
    font-size: var(--font-size-2xl);
    color: var(--color-gray);
    cursor: pointer;
    padding: var(--spacing-sm);
    border-radius: var(--border-radius-sm);
    transition: all var(--transition-normal);
}

.modal__close:hover {
    background: var(--color-light);
    color: var(--color-dark);
}

.modal__form {
    padding: var(--spacing-lg);
}

.modal__body {
    padding: var(--spacing-lg);
}

.modal__actions {
    display: flex;
    gap: var(--spacing-md);
    justify-content: flex-end;
    margin-top: var(--spacing-lg);
}

/* Share Content */
.share-content {
    background: var(--color-light);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius-md);
    margin-bottom: var(--spacing-lg);
    font-family: monospace;
    font-size: var(--font-size-sm);
    color: var(--color-dark);
    white-space: pre-wrap;
}

.share-actions {
    display: flex;
    gap: var(--spacing-md);
}

/* Toast Notifications */
.toast-container {
    position: fixed;
    top: var(--spacing-md);
    right: var(--spacing-md);
    z-index: var(--z-toast);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.toast {
    background: var(--color-white);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-md) var(--spacing-lg);
    box-shadow: var(--shadow-lg);
    border-left: 4px solid var(--color-primary);
    min-width: 300px;
    animation: toastSlideIn var(--transition-normal);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.toast--success {
    border-left-color: var(--color-success);
}

.toast--error {
    border-left-color: var(--color-error);
}

.toast--warning {
    border-left-color: var(--color-warning);
}

.toast__icon {
    font-size: var(--font-size-lg);
}

.toast__message {
    flex: 1;
    color: var(--color-dark);
    font-size: var(--font-size-sm);
}

.toast__close {
    background: none;
    border: none;
    color: var(--color-gray);
    cursor: pointer;
    padding: var(--spacing-xs);
    border-radius: var(--border-radius-sm);
    transition: all var(--transition-normal);
}

.toast__close:hover {
    background: var(--color-light);
    color: var(--color-dark);
}

/* Loading Spinner */
.loading {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(4px);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: var(--z-modal);
    flex-direction: column;
    gap: var(--spacing-lg);
}

.loading.active {
    display: flex;
}

.loading__spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--color-light);
    border-top: 4px solid var(--color-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

.loading__text {
    color: var(--color-dark);
    font-weight: 600;
}

/* Footer */
.footer {
    background: var(--color-dark);
    color: var(--color-light);
    padding: var(--spacing-xl) 0;
    text-align: center;
    margin-top: var(--spacing-3xl);
}

.footer__text {
    font-size: var(--font-size-sm);
}

.footer__link {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-normal);
}

.footer__link:hover {
    color: var(--color-secondary);
}

/* Animations */
@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: scale(0.9) translateY(-20px);
    }
    to {
        opacity: 1;
        transform: scale(1) translateY(0);
    }
}

@keyframes toastSlideIn {
    from {
        opacity: 0;
        transform: translateX(100%);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .header__title {
        font-size: var(--font-size-3xl);
        flex-direction: column;
        gap: var(--spacing-sm);
    }
    
    .calculator__grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .calculator__form-container,
    .calculator__results {
        padding: var(--spacing-lg);
    }
    
    .goals__header,
    .history__header {
        flex-direction: column;
        gap: var(--spacing-md);
        align-items: stretch;
    }
    
    .history__controls {
        justify-content: center;
    }
    
    .quick-duration {
        grid-template-columns: 1fr;
    }
    
    .results__actions {
        flex-direction: column;
    }
    
    .modal__actions {
        flex-direction: column;
    }
    
    .share-actions {
        flex-direction: column;
    }
    
    .toast-container {
        left: var(--spacing-sm);
        right: var(--spacing-sm);
    }
    
    .toast {
        min-width: auto;
    }
    
    .theme-toggle {
        position: relative;
        top: auto;
        right: auto;
        margin-top: var(--spacing-lg);
    }
}

@media (max-width: 480px) {
    .header {
        padding: var(--spacing-lg) 0;
    }
    
    .header__title {
        font-size: var(--font-size-2xl);
    }
    
    .main {
        padding: var(--spacing-lg) 0;
    }
    
    .calculator__form-container,
    .calculator__results {
        padding: var(--spacing-md);
    }
    
    .goal-card,
    .stat-card {
        padding: var(--spacing-lg);
    }
    
    .results__main {
        padding: var(--spacing-lg);
    }
    
    .results__number {
        font-size: var(--font-size-3xl);
    }
}

/* Print Styles */
@media print {
    .header,
    .footer,
    .theme-toggle,
    .modal,
    .toast-container,
    .loading {
        display: none !important;
    }
    
    .main {
        margin: 0;
        padding: 0;
    }
    
    .calculator__grid {
        grid-template-columns: 1fr;
    }
    
    .calculator__form-container {
        display: none;
    }
    
    * {
        box-shadow: none !important;
    }
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
    :root {
        --color-primary: #0066CC;
        --color-secondary: #FF6600;
        --color-dark: #000000;
        --color-gray: #666666;
        --color-light: #F0F0F0;
        --color-white: #FFFFFF;
    }
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus Styles for Accessibility */
*:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Screen Reader Only */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}