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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

.header {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: 20px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
}

.logo {
    color: white;
    font-size: 1.8rem;
    font-weight: 700;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.nav-menu {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.nav-btn {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 600;
    font-size: 0.9rem;
    backdrop-filter: blur(5px);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.nav-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.nav-btn.active {
    background: rgba(255, 255, 255, 0.9);
    color: #667eea;
    font-weight: 700;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 30px 20px;
}

.tool-section {
    display: none;
    animation: fadeIn 0.5s ease;
}

.tool-section.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.welcome-section {
    text-align: center;
    color: white;
    padding: 60px 20px;
}

.welcome-title {
    font-size: 3rem;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.welcome-subtitle {
    font-size: 1.3rem;
    margin-bottom: 40px;
    opacity: 0.9;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
    margin-top: 40px;
}

.feature-card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 30px;
    text-align: center;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.2);
    transition: transform 0.3s ease;
    cursor: pointer;
}

.feature-card:hover {
    transform: translateY(-10px);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 15px;
}

.feature-title {
    color: #2d3748;
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 10px;
}

.feature-desc {
    color: #4a5568;
    line-height: 1.6;
}

/* Tool-specific styles */
.calculator-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 25px;
    margin-bottom: 30px;
}

.calculator-card,
.tool-card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.2);
    transition: transform 0.3s ease;
}

.calculator-card:hover,
.tool-card:hover {
    transform: translateY(-5px);
}

.card-title {
    color: #2d3748;
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 20px;
    text-align: center;
    padding-bottom: 15px;
    border-bottom: 3px solid #667eea;
}

.input-group {
    margin-bottom: 20px;
}

label {
    display: block;
    color: #2d3748;
    font-weight: 600;
    margin-bottom: 8px;
    font-size: 1rem;
}

input,
select {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #e2e8f0;
    border-radius: 10px;
    font-size: 1rem;
    transition: all 0.3s ease;
    background: white;
}

input:focus,
select:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.calculate-btn,
.action-btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 15px 30px;
    border-radius: 12px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    width: 100%;
    margin-bottom: 20px;
}

.calculate-btn:hover,
.action-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.3);
}

.result {
    background: #f0f8ff;
    border-left: 5px solid #667eea;
    padding: 20px;
    border-radius: 10px;
    margin-top: 20px;
    display: none;
}

.result.show {
    display: block;
    animation: slideIn 0.5s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes spin {
    from {
        transform: rotate(0deg);
    }

    to {
        transform: rotate(360deg);
    }
}

@keyframes bounce {

    0%,
    20%,
    50%,
    80%,
    100% {
        transform: translateY(0);
    }

    40% {
        transform: translateY(-20px);
    }

    60% {
        transform: translateY(-10px);
    }
}

@keyframes pulse {
    0% {
        transform: scale(1);
    }

    50% {
        transform: scale(1.1);
    }

    100% {
        transform: scale(1);
    }
}

@keyframes rainbow {
    0% {
        color: #ff6b6b;
    }

    16% {
        color: #4ecdc4;
    }

    32% {
        color: #45b7d1;
    }

    48% {
        color: #96ceb4;
    }

    64% {
        color: #feca57;
    }

    80% {
        color: #ff9ff3;
    }

    100% {
        color: #ff6b6b;
    }
}

@keyframes progressBar {
    0% {
        width: 0%;
    }

    50% {
        width: 70%;
    }

    100% {
        width: 100%;
    }
}

.result-animation {
    animation: bounce 1s ease, pulse 2s infinite;
}

.rainbow-text {
    animation: rainbow 3s linear infinite;
}

.result-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 0;
    border-bottom: 1px solid #e2e8f0;
}

.result-item:last-child {
    border-bottom: none;
    font-weight: bold;
    font-size: 1.1rem;
    color: #667eea;
}

.result-label {
    color: #4a5568;
    font-weight: 600;
}

.result-value {
    color: #2d3748;
    font-weight: 700;
}

/* BMI specific styles */
.bmi-container {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 25px;
    padding: 40px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2);
    max-width: 500px;
    margin: 0 auto;
    text-align: center;
}

.unit-toggle {
    display: flex;
    background: #f7fafc;
    border-radius: 12px;
    padding: 5px;
    margin-bottom: 30px;
    border: 2px solid #e2e8f0;
}

.unit-btn {
    flex: 1;
    padding: 12px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    background: transparent;
    color: #4a5568;
}

.unit-btn.active {
    background: #667eea;
    color: white;
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.3);
}

.bmi-value {
    font-size: 3rem;
    font-weight: 900;
    color: #2d3748;
    margin-bottom: 10px;
}

.bmi-category {
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: 15px;
    padding: 10px 20px;
    border-radius: 25px;
    display: inline-block;
}

/* Todo specific styles */
.todo-main {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 25px;
}

.todo-section {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.2);
}

.stats-section {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 25px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.2);
    height: fit-content;
}

.add-todo-form {
    background: #f7fafc;
    border-radius: 15px;
    padding: 25px;
    margin-bottom: 25px;
    border: 2px solid #e2e8f0;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr auto auto;
    gap: 15px;
    margin-bottom: 15px;
}

.todo-list {
    max-height: 600px;
    overflow-y: auto;
    padding-right: 10px;
}

.todo-item {
    background: white;
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 15px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    border-left: 5px solid #667eea;
    transition: all 0.3s ease;
}

.todo-item:hover {
    transform: translateX(5px);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.15);
}

.todo-item.completed {
    opacity: 0.7;
    border-left-color: #48bb78;
}

.todo-item.completed .todo-text {
    text-decoration: line-through;
    color: #718096;
}

.todo-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.todo-text {
    font-size: 1.1rem;
    font-weight: 600;
    color: #2d3748;
    flex: 1;
    margin-right: 15px;
}

.todo-actions {
    display: flex;
    gap: 10px;
}

.todo-btn {
    padding: 8px 12px;
    border: none;
    border-radius: 6px;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 600;
}

.complete-btn {
    background: #48bb78;
    color: white;
}

.edit-btn {
    background: #4299e1;
    color: white;
}

.delete-btn {
    background: #f56565;
    color: white;
}

.stats-card {
    background: linear-gradient(135deg, #f0f8ff 0%, #e6f3ff 100%);
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 20px;
    text-align: center;
    border: 2px solid #667eea;
}

.stats-number {
    font-size: 2.5rem;
    font-weight: 900;
    color: #667eea;
    margin-bottom: 5px;
}

.stats-label {
    color: #4a5568;
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.9rem;
}

@media (max-width: 768px) {
    .nav-menu {
        justify-content: center;
    }

    .nav-btn {
        padding: 10px 15px;
        font-size: 0.8rem;
    }

    .calculator-grid {
        grid-template-columns: 1fr;
    }

    .todo-main {
        grid-template-columns: 1fr;
    }

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

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

    .features-grid {
        grid-template-columns: 1fr;
    }
    /* -----------------------------------------------------------------------------------------------------*/
    /* Read Text*/
    /* Progress bar với animation mượt mà hơn */
    #progressBar {
        transition: width 0.3s ease;
    }

    /* Loading spinner */
    .loading-spinner {
        display: inline-block;
        width: 20px;
        height: 20px;
        border: 3px solid #f3f3f3;
        border-top: 3px solid #667eea;
        border-radius: 50%;
        animation: spin 1s linear infinite;
    }

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

        100% {
            transform: rotate(360deg);
        }
    }

    /* OCR stats styling */
    .ocr-stats {
        animation: fadeIn 0.5s ease-in;
    }

    @keyframes fadeIn {
        from {
            opacity: 0;
            transform: translateY(10px);
        }

        to {
            opacity: 1;
            transform: translateY(0);
        }
    }
}