/* CALCULATOR PAGE - DAWHOLE STYLE */
*{
    box-sizing:border-box;
    margin:0;
    padding:0;
    font-family:system-ui,-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif
}
body{
    background:var(--bg);
    color:var(--text-color);
    min-height:100vh;
     padding: 20px;
}
.math-header {
    width: 100%;
    max-width: 2000px;
    background-color: var(--header-bg);
    border-radius: 12px;
    padding: 15px 25px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0px;

    box-shadow: var(--card-shadow);
}
.brand .logo-text {
    font-size: 32px;
    font-weight: 700;
    color: inherit;
    text-decoration: none;
}

.brand .tagline {
    font-size: 15px;
    opacity: .7;
    margin-top: 2px;
}

.page-title h2 {
    font-size: 36px;
    font-weight: 500;
    margin: 0;
}
.main-container{
    width:80%;
    max-width:2500px;
    margin:30px auto;
    padding:0 30px;
    display:grid;
    grid-template-columns:minmax(0,1fr) 320px;
    gap:60px;
    align-items:start
}
.calculator-card{
    width:100%
}
.display-row{
    display:flex;
    gap:12px;
    align-items:center;
    margin-bottom:20px
}
#calcInput{
flex:1;
min-width:0;
background:var(--card-bg);
color:var(--text-color);
border:1px solid var(--card-border);
border-radius:12px;
padding:14px 20px;
font-size:19px;
outline:none;
transition:border-color .2s,box-shadow .2s,background-color .2s
}
#calcInput::placeholder{
color:var(--text-color);
opacity:.45
}
#calcInput:focus{
border-color:#7da2f7;
box-shadow:0 0 0 3px rgba(92,141,246,.12)
}
.result-box{
    background:var(--card-bg);
    color:var(--text-color);
    border:1px solid var(--card-border);
    border-radius:12px;
    padding:14px 20px;
    font-size:20px;
    font-weight:600;
    min-width:160px;
    text-align:right;
    white-space:nowrap;
    box-shadow:var(--card-shadow)
}
.btn-ac{
    background:var(--card-bg);
    color:var(--text-color);
    border:1px solid var(--card-border);
    border-radius:12px;
    padding:14px 24px;
    font-size:16px;
    font-weight:700;
    cursor:pointer;
    transition:background-color .2s,border-color .2s,transform .15s
}
.btn-ac:hover{
    background:var(--panel-btn-hover);
    transform:translateY(-1px)
}
.keypad-grid{
    display:grid;
    grid-template-columns:repeat(7,minmax(0,1fr));
    gap:10px
}
.btn{
    background:var(--card-bg);
    color:var(--text-color);
    border:1px solid var(--card-border);
    border-radius:12px;
    padding:15px 8px;
    font-size:21px;
    font-weight:500;
    cursor:pointer;
    user-select:none;
    box-shadow:var(--card-shadow);
    transition:background-color .15s,border-color .15s,transform .15s,box-shadow .15s
}
.btn:hover{
    background:var(--panel-btn-hover);
    border-color:#8da9ed;
    transform:translateY(-2px);
    box-shadow:var(--card-shadow-hover)
}
.btn:active{
    transform:translateY(0)
}
.btn-op{
    font-weight:700
}
.btn-action{
    background:var(--header-bg);
    font-weight:600
}
.sidebar-right{
    position:relative;
    height:100%
}
.sticky-wrapper{
    position:sticky;
    top:20px;
    background:var(--header-bg);
    border:1px solid var(--card-border);
    border-radius:20px;
    padding:16px;
    display:flex;
    flex-direction:column;
    gap:16px;
    box-shadow:var(--card-shadow)
}
.ad-box,.extra-box{
    background:var(--card-bg);
    color:var(--text-color);
    border:1px solid var(--card-border);
    border-radius:14px;
    padding:20px;
    text-align:center;
    font-size:16px;
    display:flex;
    align-items:center;
    justify-content:center;
    box-shadow:var(--card-shadow)
}
.ad-box{
    min-height:120px
}
.extra-box{
    min-height:200px
}
@media(max-width:1000px){
    .main-container{
        width:10%;
        grid-template-columns:1fr;
        gap:30px
    }
    .sidebar-right{
        display:none
    }
}

@media(max-width:600px){
    .math-header{
        padding:16px 20px
    }
    .brand .logo-text{
        font-size:26px
    }
    .brand .tagline{
        font-size:13px
    }
    .page-title h2{
        font-size:28px
    }
    .main-container{
        width:100%;
        padding:0 16px;
        margin:20px auto
    }
    .display-row{
        gap:8px;
        flex-wrap:wrap
    }
    #calcInput{
    flex:1 1 100%;
    width:100%;
    padding:13px 14px;
    font-size:16px
    }
    .result-box{
        flex:1;
        min-width:0;
        padding:13px 14px;
        font-size:16px
    }
    .btn-ac{
        padding:13px 16px
    }
    .keypad-grid{
        grid-template-columns:repeat(4,minmax(0,1fr));
        gap:7px
    }
    .keypad-grid .btn{
        padding:13px 4px;
        border-radius:10px;
        font-size:14px
    }
    .keypad-grid .mobile-order-1{
        order:1
    }
    .keypad-grid .mobile-order-2{
        order:2
    }
    .keypad-grid .mobile-order-3{
        order:3
    }
    .keypad-grid .mobile-order-4{
        order:4
    }
    .keypad-grid .mobile-order-5{
        order:5
    }
    .keypad-grid .mobile-order-6{
        order:6
    }
    .keypad-grid .mobile-order-7{
        order:7
    }
    .keypad-grid .mobile-order-10{
        order:10
    }
    .keypad-grid .mobile-order-11{
        order:11
    }
    .keypad-grid .mobile-order-12{
        order:12
    }
    .keypad-grid .mobile-order-13{
        order:13
    }
    .keypad-grid .mobile-order-14{
        order:14
    }
    .keypad-grid .mobile-order-15{
        order:15
    }
    .keypad-grid .mobile-order-16{
        order:16
    }
    .keypad-grid .mobile-order-17{
        order:17
    }
    .keypad-grid .mobile-order-18{
        order:18
    }
    .keypad-grid .mobile-order-19{
        order:19
    }
    .keypad-grid .mobile-order-20{
        order:20
    }
    .keypad-grid .mobile-order-21{
        order:21
    }
    .keypad-grid .mobile-order-22{
        order:22
    }
    .keypad-grid .mobile-order-23{
        order:23
    }
    .keypad-grid .mobile-order-24{
        order:24
    }
    .keypad-grid .mobile-order-26{
        order:26
    }
    .keypad-grid .mobile-order-27{
        order:27
    }
    .keypad-grid .mobile-order-30{
        order:30
    }
    .keypad-grid .mobile-order-31{
        order:31
    }
    .keypad-grid .mobile-order-32{
        order:32
    }
    .keypad-grid .mobile-order-34{
        order:34
    }
    .keypad-grid .mobile-order-35{
        order:35
    }
    .keypad-grid .mobile-order-36{
        order:36
    }
    .keypad-grid .mobile-order-38{
        order:38
    }
    .keypad-grid .mobile-order-39{
        order:39
    }
    .keypad-grid .mobile-order-40{
        order:40
    }
    .keypad-grid .mobile-order-42{
        order:42
    }
    .keypad-grid .mobile-order-43{
        order:43
    }
    .keypad-grid .mobile-order-44{
        order:44
    }
    .keypad-grid .mobile-order-50{
        order:50
    }
    .keypad-grid .mobile-order-51{
        order:51
    }
    .keypad-grid .mobile-order-52{
        order:52
    }
    .keypad-grid .mobile-order-53{
        order:53
    }
    .keypad-grid .mobile-order-54{
        order:54
    }
    .keypad-grid .mobile-order-55{
        order:55
    }
}
@media(max-width:480px){

    .page-title h2{
        font-size:24px
    }
    .keypad-grid {
        grid-template-columns: repeat(4, minmax(0, 1fr));
        gap: 7px;
    }

    .keypad-grid .btn {
        order: var(--mobile-order);
        padding: 13px 4px;
        border-radius: 10px;
        font-size: 18px;
    }
}

/* ==========================================
 *  DESKTOP: GIỮ NGUYÊN THỨ TỰ HTML
 *  ========================================== */
/* ==========================================
 *  DESKTOP ORDER
 *  ========================================== */

@media (min-width: 601px) {

    /* Row 1: INV - DEG - x! - ( - ) - DEL - ÷ */
    .mobile-order-1  { order: 1; }
    .mobile-order-2  { order: 2; }
    .mobile-order-33 { order: 3; }
    .mobile-order-7  { order: 4; }
    .mobile-order-8  { order: 5; }
    .mobile-order-4  { order: 6; }
    .mobile-order-12 { order: 7; }

    /* Row 2: sin - cos - tan - 7 - 8 - 9 - × */
    .mobile-order-29 { order: 8; }
    .mobile-order-30 { order: 9; }
    .mobile-order-31 { order: 10; }
    .mobile-order-9  { order: 11; }
    .mobile-order-10 { order: 12; }
    .mobile-order-11 { order: 13; }
    .mobile-order-16 { order: 14; }

    /* Row 3: log - ln - e - 4 - 5 - 6 - − */
    .mobile-order-34 { order: 15; }
    .mobile-order-35 { order: 16; }
    .mobile-order-36 { order: 17; }
    .mobile-order-13 { order: 18; }
    .mobile-order-14 { order: 19; }
    .mobile-order-15 { order: 20; }
    .mobile-order-20 { order: 21; }

    /* Row 4: x^y - sqrt - π - 1 - 2 - 3 - + */
    .mobile-order-32 { order: 22; }
    .mobile-order-37 { order: 23; }
    .mobile-order-3  { order: 24; }
    .mobile-order-17 { order: 25; }
    .mobile-order-18 { order: 26; }
    .mobile-order-19 { order: 27; }
    .mobile-order-24 { order: 28; }

    /* Row 5: nPr - nCr - EXP - % - 0 - . - Undo */
    .mobile-order-5  { order: 29; }
    .mobile-order-6  { order: 30; }
    .mobile-order-38 { order: 31; }
    .mobile-order-23 { order: 32; }
    .mobile-order-22 { order: 33; }
    .mobile-order-21 { order: 34; }
    .mobile-order-27 { order: 35; }

    /* Row 6: sinh - cosh - tanh - abs - Ans - 00 - Redo */
    .mobile-order-39 { order: 36; }
    .mobile-order-40 { order: 37; }
    .mobile-order-41 { order: 38; }
    .mobile-order-42 { order: 39; }
    .mobile-order-26 { order: 40; }
    .mobile-order-25 { order: 41; }
    .mobile-order-28 { order: 42; }
}

@media (max-width: 600px) {

    .mobile-settings-toggle {
        position: fixed;
        right: 16px;
        bottom: 16px;

        width: 48px;
        height: 48px;

        display: flex;
        align-items: center;
        justify-content: center;

        border: 1px solid var(--card-border);
        border-radius: 14px;

        background: var(--card-bg);
        color: var(--text-color);

        box-shadow: var(--card-shadow);

        font-size: 28px;
        cursor: pointer;

        z-index: 9998;

        transition:
        transform 0.2s ease,
        background-color 0.2s ease;
    }

    .mobile-settings-toggle:hover {
        transform: translateY(-2px);
    }

    .mobile-settings-toggle:active {
        transform: scale(0.92);
    }
}
.mobile-settings-toggle {
    display: none;
}
/* ==========================================
 * MOBILE FLOATING PANEL
 * ========================================== */

@media (max-width: 600px) {

    .floating-panel {
        position: fixed !important;

        right: 16px !important;
        bottom: 76px !important;

        top: auto !important;
        left: auto !important;

        z-index: 9997 !important;

        opacity: 0;
        visibility: hidden;
        pointer-events: none;

        transform: translateY(10px);

        transition:
        opacity 0.2s ease,
        transform 0.2s ease,
        visibility 0.2s ease;
    }

    .floating-panel.mobile-open {
        opacity: 1;
        visibility: visible;
        pointer-events: auto;

        transform: translateY(0);
    }
}