/* ===================================
   Design System & CSS Variables
   =================================== */

:root {
    /* Header Styles */
    --header-bg: var(--primary-500);
    --header-text: white;
    --header-height: 60px;

    /* Color Palette - Zalo Blue Theme */
    --primary-hue: 212;
    --primary-sat: 100%;
    --primary-light: 51%;

    --primary-50: hsl(212, 100%, 95%);
    --primary-100: hsl(212, 100%, 85%);
    --primary-200: hsl(212, 100%, 75%);
    --primary-500: hsl(212, 100%, 51%);
    /* Zalo Blue #0068FF */
    --primary-600: hsl(212, 100%, 45%);
    --primary-700: hsl(212, 100%, 35%);
    --primary-900: hsl(212, 100%, 15%);

    --accent-hue: 200;
    --accent-500: hsl(200, 100%, 50%);
    /* Light Blue */
    --accent-600: hsl(200, 100%, 45%);

    --success: hsl(142, 71%, 45%);
    --warning: hsl(38, 92%, 50%);
    --error: hsl(0, 84%, 60%);

    /* Neutral Colors */
    --white: #ffffff;
    --gray-100: #F0F5FA;
    /* Xanh nhat (thay cho xam nhat) */
    --gray-200: #D6E4F0;
    /* Xanh nhat hon (thay cho xam) */
    --gray-300: #BCCCDC;
    /* Xanh ghi (thay cho xam ghi) */
    --gray-400: #9AA6B8;
    --gray-500: #6B7A90;
    --gray-600: #465A75;
    /* Xanh than vua (chu phu) */
    --gray-700: #2C3E50;
    /* Xanh than dam */
    --gray-800: #1A3B5D;
    /* Xanh than dam hon (chu chinh) */
    --gray-900: #0E2A47;
    /* Xanh den (tieu de) */
    --black: #051525;
    /* Xanh gan nhu den */

    /* Gradients - Zalo Style */
    --gradient-primary: linear-gradient(135deg, #0068FF 0%, #00A3FF 100%);
    --gradient-dark: linear-gradient(135deg, var(--gray-800) 0%, var(--gray-900) 100%);
    --gradient-glass: linear-gradient(135deg, rgba(255, 255, 255, 0.1) 0%, rgba(255, 255, 255, 0.05) 100%);

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 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 */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --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);
    --shadow-glow: 0 0 20px rgba(var(--primary-hue), var(--primary-sat), var(--primary-light), 0.3);

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);

    /* Banner */
    --banner-height: 200px;

    /* Z-index */
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal-backdrop: 1040;
    --z-modal: 1050;
    --z-popover: 1060;
    --z-tooltip: 1070;
}

/* ===================================
   Base Styles & Reset
   =================================== */

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

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

h1,
h2,
h3,
h4,
h5,
h6 {
    color: #0E2A47;
    /* Tieu de Xanh Den cho noi bat */
    font-weight: 600;
    margin-bottom: 0.5rem;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--gray-800);

    /* Hybrid Background: Xanh Top-Left -> Hinh Bottom-Right */
    background-color: #D6EBFF;
    background-image:
        linear-gradient(135deg, #D6EBFF 30%, rgba(214, 235, 255, 0.9) 70%, transparent 100%),
        url('C:/Users/letro/.gemini/antigravity/brain/ac43984f-8c0b-4fa1-85e9-e67d83f4d0d2/ultra_wide_tea_3_1769833392501.png');
    background-repeat: no-repeat;
    background-position: center bottom;
    background-attachment: fixed;
    background-size: cover;
    /* Dam bao nen phu ra sat vien, khong bi cat boi padding */

    min-height: 100vh;
    overflow-x: hidden;
    margin: 0;
    padding: 0;

    /* Better touch scrolling */
    -webkit-overflow-scrolling: touch;
}

@media (max-width: 480px) {
    body {
        background-attachment: scroll;
        /* Performance boost on mobile */
        background-position: center 20%;
    }
}


/* ===================================
   Custom Scrollbar
   =================================== */

/* Scrollbar track */
::-webkit-scrollbar {
    width: 14px;
}

::-webkit-scrollbar-track {
    background: var(--gray-100);
    border-left: 2px solid var(--gray-300);
    border-right: 2px solid var(--gray-300);
    margin-top: 0;
    /* No gap after top button */
    margin-bottom: 0;
    /* No gap before bottom button */
}

/* Scrollbar thumb */
::-webkit-scrollbar-thumb {
    background: linear-gradient(180deg, var(--primary-500) 0%, var(--primary-600) 100%);
    border-radius: 10px;
    border: 2px solid var(--gray-300);
    min-height: 40px;
    /* Ensure thumb is visible and starts from top */
}

::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(180deg, var(--primary-600) 0%, var(--primary-700) 100%);
}

/* Scrollbar buttons (arrows) */
::-webkit-scrollbar-button {
    height: 16px;
    background: var(--gray-200);
    border: 2px solid var(--gray-300);
}

/* Up arrow (triangle pointing up) */
::-webkit-scrollbar-button:vertical:decrement {
    background: var(--gray-200);
    background-image: linear-gradient(135deg, transparent 40%, var(--primary-600) 40%, var(--primary-600) 60%, transparent 60%),
        linear-gradient(225deg, transparent 40%, var(--primary-600) 40%, var(--primary-600) 60%, transparent 60%);
    background-size: 50% 50%;
    background-position: center;
    background-repeat: no-repeat;
}

/* Down arrow (triangle pointing down) */
::-webkit-scrollbar-button:vertical:increment {
    background: var(--gray-200);
    background-image: linear-gradient(45deg, transparent 40%, var(--primary-600) 40%, var(--primary-600) 60%, transparent 60%),
        linear-gradient(-45deg, transparent 40%, var(--primary-600) 40%, var(--primary-600) 60%, transparent 60%);
    background-size: 50% 50%;
    background-position: center;
    background-repeat: no-repeat;
}

::-webkit-scrollbar-button:hover {
    background-color: var(--gray-300);
}

/* ===================================
   Utility Classes
   =================================== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-md);
    }
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: var(--font-size-base);
    font-weight: 600;
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-base);
    text-decoration: none;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.2);
    transform: translate(-50%, -50%);
    transition: width var(--transition-slow), height var(--transition-slow);
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-md);
}

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

.btn-secondary {
    background: var(--gray-100);
    color: var(--gray-800);
}

.btn-secondary:hover {
    background: var(--gray-200);
    transform: translateY(-2px);
}

.card {
    background: #EBF5FF;
    /* Trang anh xanh dam hon chut */
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

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

.glass {
    background: var(--gradient-glass);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

/* ===================================
   Animations
   =================================== */

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

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

@keyframes slideIn {
    from {
        transform: translateX(-100%);
    }

    to {
        transform: translateX(0);
    }
}

@keyframes pulse {

    0%,
    100% {
        opacity: 1;
    }

    50% {
        opacity: 0.5;
    }
}

.fade-in {
    animation: fadeIn var(--transition-slow) ease-out;
}

.slide-in {
    animation: slideIn var(--transition-slow) ease-out;
}

/* ===================================
   Responsive Design
   =================================== */

@media (max-width: 768px) {
    :root {
        --font-size-3xl: 1.5rem;
        --font-size-4xl: 1.875rem;
    }

    .container {
        padding: 0 var(--spacing-md);
    }
}

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

.form-group label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--gray-700);
}

.form-input {
    width: 100%;
    padding: 12px 16px;
    font-size: var(--font-size-base);
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-lg);
    background: white;
    transition: all var(--transition-base);
    color: var(--gray-800);
    appearance: none;
    -webkit-appearance: none;
}

.form-input:focus {
    outline: none;
    border-color: var(--primary-500);
    box-shadow: 0 0 0 4px var(--primary-50);
}

.form-input::placeholder {
    color: var(--gray-400);
}

/* ===================================
   Flatpickr Calendar Customization
   =================================== */

/* Override material_blue theme to make dates more visible */
.flatpickr-calendar {
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15) !important;
    border: 1px solid var(--gray-200) !important;
    /* Ensure calendar appears above sticky containers and other elements */
    z-index: var(--z-popover) !important;
}

/* Make date numbers clearly visible */
.flatpickr-day {
    color: var(--gray-800) !important;
    font-weight: 500 !important;
    opacity: 1 !important;
}

/* Hover state */
.flatpickr-day:hover {
    background: var(--primary-100) !important;
    color: var(--primary-700) !important;
}

/* Today's date */
.flatpickr-day.today {
    border-color: var(--primary-500) !important;
    color: var(--primary-600) !important;
    font-weight: 600 !important;
}

/* Selected date */
.flatpickr-day.selected {
    background: var(--primary-500) !important;
    color: white !important;
    font-weight: 600 !important;
}

/* Disabled dates (booked) */
.flatpickr-day.flatpickr-disabled {
    color: var(--gray-400) !important;
    opacity: 0.5 !important;
}

/* Days from other months */
.flatpickr-day.prevMonthDay,
.flatpickr-day.nextMonthDay {
    color: var(--gray-400) !important;
    opacity: 0.6 !important;
}

/* Month/year text */
.flatpickr-current-month .flatpickr-monthDropdown-months,
.flatpickr-current-month input.cur-year {
    color: var(--gray-800) !important;
    font-weight: 600 !important;
}

/* Weekday labels */
.flatpickr-weekday {
    color: var(--gray-700) !important;
    font-weight: 600 !important;
}

/* ===================================
   RESPONSIVE OVERRIDES
   =================================== */

/* Tablet */
@media (max-width: 768px) {
    :root {
        --banner-height: 140px;
    }
}

/* Mobile */
@media (max-width: 480px) {
    :root {
        --banner-height: 100px;
    }
}