/* =========================
   GOOGLE FONT
========================= */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&display=swap');


/* =========================
   RESET
========================= */

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



/* =========================
   BODY
========================= */

body {
    font-family: 'Inter', sans-serif;
    background: #171717;
    color: white;
}



/* =========================
   MAIN WRAPPER
========================= */

.problem-wrapper {
    width: 92%;
    max-width: 1300px;
    margin: 0 auto;
    padding-top: 110px;
    padding-bottom: 100px;
    box-sizing: border-box;
}



/* Old .navbar styles removed — page now uses .cbt-navbar from styles.css */




/* =========================
   LOGO AREA
========================= */

.logo-area {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.logo-area a {
    text-decoration: none;
}


/* TOP LOGO */

.top-logo {
    display: flex;
    align-items: center;
    gap: 14px;
}


/* MAIN LOGO */

.main-logo {
    font-size: 44px;
    font-weight: 900;
    letter-spacing: 1px;
    cursor: pointer;
    transition: 0.4s ease;
}


/* LOGO HOVER */

.main-logo:hover {
    transform: scale(1.02);
    filter: drop-shadow(0 0 12px rgba(245, 166, 35, 0.35));
}


/* WHITE TEXT */

.white-text {
    color: white;
}


/* GOLD TEXT */

.gold-text {
    color: #f5a623;
    text-shadow: 0 0 18px rgba(245, 166, 35, 0.35);
}


/* BOTTOM LOGO */

.bottom-logo {
    display: flex;
    align-items: center;
    gap: 12px;
}


/* SUB LOGO */

.sub-logo {
    font-size: 18px;
    font-weight: 700;
    letter-spacing: 4px;
    color: #9f9f9f;
}


/* SUB LOGO SPAN */

.sub-logo span {
    color: #f5a623;
}


/* UNLOCK ICON */

.unlock-icon {
    width: 28px;
    height: 28px;
    object-fit: contain;
    transition: 0.4s ease;
}


/* ICON HOVER */

.unlock-icon:hover {
    transform: rotate(-8deg) scale(1.12);
    filter: drop-shadow(0 0 12px rgba(245, 166, 35, 0.45));
}



/* =========================
   NAVIGATION MENU
========================= */

nav ul {
    display: flex;
    align-items: center;
    gap: 18px;
    list-style: none;
}


/* NAV LINKS */

nav ul li a {
    position: relative;
    color: rgba(255, 255, 255, 0.88);
    text-decoration: none;
    font-size: 17px;
    font-weight: 500;
    padding: 14px 22px;
    border-radius: 14px;
    transition: all 0.35s ease;
    overflow: hidden;
}


/* HOVER EFFECT */

nav ul li a:hover {
    color: #ffffff;
    background: rgba(255, 255, 255, 0.06);
    transform: translateY(-2px) scale(1.03);
    box-shadow:
        0 4px 18px rgba(245, 166, 35, 0.15),
        inset 0 1px 0 rgba(255, 255, 255, 0.04);
}


/* ACTIVE LINK */

nav ul li a.active {
    color: #f5a623 !important;
    background: rgba(245, 166, 35, 0.10);
    box-shadow: 0 0 18px rgba(245, 166, 35, 0.12);
}


/* ANIMATED UNDERLINE */

nav ul li a::after {
    content: "";
    position: absolute;
    left: 50%;
    bottom: 6px;
    width: 0%;
    height: 2px;
    background: #f5a623;
    border-radius: 20px;
    transform: translateX(-50%);
    transition: 0.35s ease;
}

nav ul li a:hover::after {
    width: 60%;
}



/* =========================
   BACK BUTTON
========================= */

.back-btn.sol-specific {
    margin-bottom: 28px;
}



/* =========================
   PROBLEM HEADER META
========================= */

.problem-meta {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 18px;
    flex-wrap: wrap;
}



/* DIFFICULTY BADGES */

.badge-easy {
    display: inline-block;
    background: rgba(40, 200, 64, 0.12);
    color: #28c840;
    border: 1px solid rgba(40, 200, 64, 0.3);
    padding: 5px 14px;
    border-radius: 50px;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 1px;
}

.badge-medium {
    display: inline-block;
    background: rgba(255, 189, 46, 0.12);
    color: #ffbd2e;
    border: 1px solid rgba(255, 189, 46, 0.3);
    padding: 5px 14px;
    border-radius: 50px;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 1px;
}

.badge-hard {
    display: inline-block;
    background: rgba(255, 95, 87, 0.12);
    color: #ff5f57;
    border: 1px solid rgba(255, 95, 87, 0.3);
    padding: 5px 14px;
    border-radius: 50px;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 1px;
}

/* DATE LABEL */

.problem-date {
    color: #666;
    font-size: 13px;
    font-weight: 500;
}



/* =========================
   PROBLEM SECTION — Desktop 2-col grid
========================= */

.problem-section {
    display: grid;
    grid-template-columns: 1fr 320px;
    gap: 32px;
    margin-top: 20px;
    align-items: start;
}


/* =========================
   LEFT SIDE
========================= */

.left-content {
    min-width: 0;
    width: 100%;
}


/* HEADING */

.left-content h1 {
    font-size: clamp(26px, 4vw, 52px);
    line-height: 1.12;
    margin-bottom: 28px;
    font-weight: 800;
    word-break: break-word;
}



/* =========================
   PROBLEM DESCRIPTION
========================= */

.problem-description {
    background: #1e1e1e;
    border: 1px solid #2e2e2e;
    border-radius: 20px;
    padding: 32px;
    margin-bottom: 30px;
    line-height: 1.9;
    color: #c8c8c8;
    font-size: 15px;
}

.problem-description h2 {
    font-size: 17px;
    font-weight: 700;
    color: #f5a623;
    margin-bottom: 16px;
    letter-spacing: 0.5px;
}

.problem-description p {
    margin-bottom: 14px;
}

.problem-description code {
    background: rgba(245, 166, 35, 0.1);
    color: #ffd54f;
    padding: 2px 8px;
    border-radius: 6px;
    font-size: 13px;
    font-family: 'Courier New', monospace;
}



/* =========================
   CODE BOX
========================= */

.code-box {
    background: #050505;
    border-radius: 20px;
    overflow: hidden;
    border: 1px solid #262626;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
}



/* =========================
   CODE TOPBAR
========================= */

.code-topbar {
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    padding: 18px 25px;
    border-bottom: 1px solid #1f1f1f;
}

.code-topbar p {
    color: #7d8fb3;
    font-size: 13px;
}


/* DOTS */

.dots {
    position: absolute;
    left: 20px;
    display: flex;
    gap: 8px;
}

.dots span {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.dot-red    { background: #ff5f57; }
.dot-yellow { background: #ffbd2e; }
.dot-green  { background: #28c840; }

/* Legacy class names (keep for backwards compat with any old refs) */
.red    { background: #ff5f57; }
.yellow { background: #ffbd2e; }
.green  { background: #28c840; }



/* =========================
   CODE TABS
========================= */

.code-tabs {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 18px 25px;
    border-bottom: 1px solid #1c1c1c;
}


/* LEFT SIDE */

.languages {
    display: flex;
    align-items: center;
    gap: 35px;
    flex-wrap: wrap;
}


/* TAB BUTTON */

.tab-btn {
    background: transparent;
    border: none;
    color: #7d7d7d;
    font-size: 15px;
    font-family: 'Inter', sans-serif;
    cursor: pointer;
    transition: 0.3s;
    padding-bottom: 8px;
}


/* ACTIVE TAB */

.active-tab {
    color: #ffd54f !important;
    border-bottom: 2px solid #ffd54f;
}


/* HOVER */

.tab-btn:hover {
    color: white;
}


/* COPY BUTTON */

.copy-btn {
    background: rgba(255, 196, 0, 0.1);
    border: 1px solid rgba(255, 196, 0, 0.3);
    color: #ffc400;
    cursor: pointer;
    font-size: 13px;
    font-weight: 600;
    font-family: 'Inter', sans-serif;
    padding: 6px 14px;
    border-radius: 6px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    white-space: nowrap;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.copy-btn:hover {
    background: rgba(255, 196, 0, 0.2);
    border-color: rgba(255, 196, 0, 0.6);
    color: #fff;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(255, 196, 0, 0.15);
}

.copy-btn:active {
    transform: translateY(1px);
    box-shadow: 0 1px 4px rgba(255, 196, 0, 0.1);
}



/* =========================
   CODE CONTENT
========================= */

.code-content {
    padding: 30px;
    color: #ffffff;
    font-size: 15px;
    line-height: 2;
    overflow-x: auto;
    white-space: pre;
    font-family: 'Courier New', Consolas, 'Liberation Mono', monospace;
}



/* =========================
   UPCOMING / LOCKED MESSAGE
========================= */

.upcoming-message {
    margin: 30px;
    padding: 30px;
    background: rgba(255, 193, 7, 0.07);
    border: 1px solid rgba(255, 193, 7, 0.25);
    border-radius: 16px;
    text-align: center;
    color: #ffc107;
    font-size: 16px;
    font-weight: 600;
    line-height: 1.7;
}

.upcoming-message .lock-icon {
    font-size: 36px;
    display: block;
    margin-bottom: 14px;
}



/* =========================
   RIGHT SIDEBAR
========================= */

.right-content {
    width: 100%;           /* takes the grid column's full width */
    display: flex;
    flex-direction: column;
    gap: 20px;
    position: sticky;
    top: 100px;            /* stays visible while scrolling */
    align-self: start;
    min-width: 0;
    flex-shrink: 0;
}



/* =========================
   VIDEO CARD
========================= */

.video-card {
    border-radius: 20px;
    overflow: hidden;
    border: 1px solid #5c1f1f;
    background: #050505;
}

.video-card iframe {
    width: 100%;
    height: 200px;
    display: block;
    border: none;
}



/* =========================
   INFO CARD (Time/Space)
========================= */

.info-card {
    background: #222222;
    border: 1px solid #383838;
    border-radius: 20px;
    padding: 30px;
}

.info-card p {
    color: #8c8c8c;
    font-size: 12px;
    margin-bottom: 14px;
    font-weight: 700;
    letter-spacing: 1.5px;
    text-transform: uppercase;
}

.info-card h3 {
    color: #f5a623;
    font-size: 38px;
    font-weight: 800;
    letter-spacing: -1px;
}



/* =========================
   TAGS CARD
========================= */

.tags-card {
    background: #1e1e1e;
    border: 1px solid #2e2e2e;
    border-radius: 20px;
    padding: 24px;
}

.tags-card p {
    color: #8c8c8c;
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 1.5px;
    text-transform: uppercase;
    margin-bottom: 14px;
}

.tags-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.tag-chip {
    background: rgba(255, 255, 255, 0.06);
    color: #c0c0c0;
    border: 1px solid rgba(255, 255, 255, 0.1);
    padding: 5px 12px;
    border-radius: 8px;
    font-size: 12px;
    font-weight: 500;
}



/* =========================
   PREV / NEXT NAVIGATION
========================= */

.solution-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 50px;
    gap: 20px;
}

.nav-link {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    background: #1e1e1e;
    border: 1px solid #2e2e2e;
    border-radius: 16px;
    padding: 18px 24px;
    transition: 0.3s ease;
    max-width: 48%;
    min-width: 0;
}

.nav-link:hover {
    border-color: rgba(245, 166, 35, 0.35);
    background: rgba(245, 166, 35, 0.06);
    transform: translateY(-2px);
}

.nav-link.prev {
    flex-direction: row;
}

.nav-link.next {
    flex-direction: row-reverse;
    margin-left: auto;
}

.nav-arrow {
    font-size: 20px;
    color: #f5a623;
    flex-shrink: 0;
}

.nav-info {
    display: flex;
    flex-direction: column;
    gap: 4px;
    min-width: 0;
}

.nav-label {
    font-size: 11px;
    font-weight: 700;
    color: #666;
    letter-spacing: 1.5px;
    text-transform: uppercase;
}

.nav-title {
    font-size: 14px;
    font-weight: 600;
    color: #ddd;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.nav-placeholder {
    flex: 1;
}



/* =========================
   404 / ERROR STATE
========================= */

.not-found {
    text-align: center;
    padding: 80px 40px;
}

.not-found h1 {
    font-size: 80px;
    font-weight: 900;
    color: #2e2e2e;
    line-height: 1;
    margin-bottom: 20px;
}

.not-found p {
    color: #666;
    font-size: 18px;
    margin-bottom: 30px;
}

.not-found a {
    color: #f5a623;
    text-decoration: none;
    font-weight: 600;
    border-bottom: 1px solid rgba(245, 166, 35, 0.35);
}



/* =========================
   ADS CARD
========================= */

.ads-card {
    border: 2px dashed #3f3f3f;
    border-radius: 20px;
    padding: 40px 30px;
    text-align: center;
}

.ads-card p {
    color: #727272;
    margin-bottom: 15px;
    font-size: 14px;
    font-weight: 700;
}

.ads-card span {
    color: #b8b8b8;
    line-height: 1.8;
    font-size: 15px;
}



/* =========================
   RESPONSIVE — 1000px (tablet)
   Sidebar stacks below code
========================= */

@media (max-width: 1000px) {

    .problem-section {
        grid-template-columns: 1fr;
        gap: 28px;
    }

    /* On tablet/mobile: video + complexity cards go above code */
    .right-content {
        order: -1;
        position: static;   /* un-stick sidebar on mobile */
        top: auto;
        flex-direction: row;
        flex-wrap: wrap;
        gap: 16px;
    }

    /* Video takes full width, info cards share row */
    .video-card  { width: 100%; }
    .info-card,
    .tags-card   { flex: 1 1 calc(50% - 8px); min-width: 140px; }

    .problem-wrapper { padding-top: 100px; }
}



/* =========================
   RESPONSIVE — 768px (mobile)
========================= */

@media (max-width: 768px) {

    .problem-wrapper {
        width: 95%;
        padding-top: 92px;
        padding-bottom: 120px;  /* extra bottom room for Back to Home btn */
    }

    .left-content h1 {
        font-size: 26px;
        margin-bottom: 18px;
    }

    .code-content {
        font-size: 13px;
        line-height: 1.8;
        padding: 20px;
    }

    /* Right cards: stack vertically on small mobile */
    .right-content {
        flex-direction: column;
    }
    .info-card,
    .tags-card {
        flex: unset;
        width: 100%;
    }

    /* Problem meta badges — prevent spilling into navbar area */
    .problem-meta {
        margin-top: 4px;
        flex-wrap: wrap;
        gap: 8px;
    }

    /* Prev/Next nav: stack vertically */
    .solution-nav {
        flex-direction: column;
        gap: 12px;
        margin-top: 32px;
        margin-bottom: 40px;   /* leave room above floating Back to Home */
    }

    .nav-link {
        max-width: 100%;
        width: 100%;
    }

    .nav-link.next {
        margin-left: 0;
    }

    .info-card h3 { font-size: 28px; }

    /* Back button pill — keep readable */
    .back-btn a {
        font-size: 13px;
        padding: 9px 16px;
    }

    /* Code box: allow horizontal scroll for code only */
    .code-box { overflow: hidden; }
    .code-content { overflow-x: auto; }
}



/* =========================
   RESPONSIVE — 480px (small phones)
========================= */

@media (max-width: 480px) {
    .problem-wrapper {
        width: 96%;
        padding-top: 88px;
        padding-bottom: 130px;
    }

    .code-content { font-size: 12px; padding: 16px; }
    .info-card { padding: 20px; }
    .info-card h3 { font-size: 26px; }
    .tags-card { padding: 16px; }

    .problem-description { padding: 20px; }
}